Open-Path FTIR Air Monitoring of Phosphine Around Large
Fumigated Structures
Thorn, T.G., Jr. (Lorillard Tobacco Company,
Danville, VA); Timothy L. Marshall (AeroSurvey, Inc., Manhattan, KS); Charles
T. Chaffin Jr.
Field Analytical Chemistry & Technology, Vol 5 No 3, p
116-120, Jul 2001
Phosphine concentrations in the air surrounding large fumigated
structures at a tobacco storage facility were measured using an open-path
Fourier transform infrared (FTIR) spectrometer system to provide comprehensive
data, more data than could be obtained with multiple single-point detection
devices. Open-path FTIR was employed to more completely characterize phosphine
concentrations over long path lengths using a single FTIR. This paper describes
the successful result of the application.
Portable Double-Focusing Mass-Spectrometer System for Field Gas
Monitoring
Diaz, Jorge A. (Univ. de Costa Rica, San Jose); Clayton F.
Giese (Univ. of Minnesota, Minneapolis); W. Ronald Gentry (Univ. of Minnesota,
Minneapolis).
Field Analytical Chemistry & Technology, Vol 5 No 3, p
156-167, Jul 2001
A portable mass-spectrometry (MS) device based on a miniature
double-focusing sector-field mass spectrometer has been developed for in situ
gas analysis and monitoring applications. Able to detect atmospheric species at
the part-per-million (ppm) level, the 18-pound device--the Portable-CDFMS--uses
a 1.1-Tesla NdFeB permanent magnet, a lithographically defined electric sector,
a molecular-flow frit inlet, a spiral filament in a closed ion source, and a
miniature channeltron detector. The high vacuum is provided with the use of a
very compact hybrid turbomolecular and diaphragm pump combination.
In-Water Field Analytical Technology: Underwater Mass
Spectrometry, Mobile Robots, and Remote Intelligence for Wide and Local Area
Chemical Profiling
Fries, D.P.; R.T. Short; L.L. Langebrake; J.T.
Patten; M.L. Kerr; G. Kibelka; D.C. Burwell; J.C. Jalbert, Univ. of South
Florida, St. Petersburg.
Field Analytical Chemistry & Technology, Vol 5
No 3, p 121-130, Jul 2001
The authors describe the operation of chemoreceptive field
underwater robots during two field trials, one using numerical models to aid in
characterization of chemical dispersion, and the other discriminating a
chemical gradient in the field.
Environmental Applications of Thermal Extraction Cone
Penetrometry and Ultrafast Gas Chromatography/Mass Spectrometry
Albert
Robbat, Albert, Jr., Center for Field Analytical Studies and Technology, Tufts
Univ., Medford, MA.
Field Analytical Chemistry & Technology, Vol 5 No
1-2, p 60-68, May 2001
Organic contaminants can be collected and analyzed at depth
without bringing soil to the surface. A thermal extraction cone penetrometer
(TECP) probe was used to extract soil-bound semivolatile organics, transferring
them to the surface for analysis by ultrafast gas chromatography/mass
spectrometry (GC/MS). When the soil-water content was <20%, PCBs, PAHs,
chlorinated pesticides, and explosives could be collected and analyzed in five
minutes, and in 15 minutes with soil-water content between 20 and 35%. When the
TECP was directly connected to the GC/MS, TNT and four of its synthetic
precursors were speciated in 20 seconds. This project is sponsored by U.S. EPA
under the NCERQA program.
Design of Continuous-Monitoring Device Based on Membrane
Extraction with Sorbent Interface and Micro-Gas Chromatograph
Ciucanu,
Ionel; Janusz Pawliszyn, Dept. of Chemistry, Univ. of Waterloo, Waterloo,
Ontario.
Field Analytical Chemistry & Technology, Vol 5 No 1-2, p
69-74, May 2001
This paper describes a device for the continuous monitoring of the
volatile and semivolatile organic compounds in air by membrane extraction,
followed by sorbent concentration and gas chromatographic separation. The
device samples headspace and makes automatic injections, followed by rapid
separation and quantification. A membrane module, microtrap, and fan mounted in
a housing form a membrane-extraction sorbent interface (MESI) sampling unit. A
heated silicosteel capillary column was used as the transfer line. The device
shows potential for monitoring aromatic hydrocarbons, chlorinated compounds,
and terpenoids in the field.
Fast GC Instrumentation and Analysis for Field Applications
Overton, E.B.; K.R. Carney; Ned Roques; H.P. Dharmasena, Inst. for
Environmental Studies, Louisiana State Univ., Baton Rouge.
Field Analytical
Chemistry & Technology, Vol 5 No 1-2, p 97-105, May 2001
This paper describes a small, fast, dual-high-resolution-column GC
instrument that is capable of analyzing both volatile and semivolatile
analytes. The device uses two narrow-bore, 100-micron ID separation columns, is
temperature programmable at rates of 5-20°C per second, and uses less than
150 W of dc power. Typical separation times for compounds with Kovatt's
retention indices of <1000 are 10-15 s, and compounds with retention indices
of up to 2500 are separated in <1min. Analytes are simultaneously analyzed
on columns with different liquid phases because of the
dual-columns-and-detectors design, thus providing added confidence in the
quality of the analytical data. This fieldable GC device can analyze a wide
variety of sample matrices, including gases, dilute gases, thermal extracts
from VOS tubes, purge-and-trap water/soil extracts, headspace samples, membrane
extracts, SPME, thermal and SCF extracts, liquid organic solvent extracts, and
direct aqueous samples.
A Cellular Biosensor to Detect Chlorocatechols
Avakian,
Maureen D., NIEHS compiler.
NIEHS Research Brief 79, 3 Jul 2001
Scientists at the University of Kentucky (UK) have developed a
cellular biosensor system to identify and quantify 3-chlorocatechol and
4-chlorocatechol, toxic breakdown products of PCBs. A biosensor is a biological
monitor that recognizes a chemical or physical change and produces a measurable
signal in response to the environmental change. Cellular biosensors can be
designed for high sensitivity and selectivity, but the greatest advantage of
cellular systems is they are capable of measuring the bioavailability of the
compound being studied. Cellular biosensor systems operate as follows: the
compound being studied passes through the cell membrane; the compound binds to
a regulatory protein; the regulatory protein activates a promoter; the promoter
activates the reporter gene; translation of the reporter gene produces a
reporter protein; and upon addition of an external substrate, the reporter
protein produces a measurable signal. To detect 3-chlorocatechol and
4-chlorocatechol, the UK researchers applied genetic engineering techniques to
design and develop a cellular biosensor system using the bacteria
Pseudomonas putida. These bacteria can use chlorocatechols as a carbon
source, biodegrading chlorocatechols via a degradative pathway regulated by the
ClcR protein. The UK researchers introduced a plasmid that contains the lacZ
gene into P. putida. The lacZ gene is also controlled by the ClcR
protein and encodes for b-galactosidase. The researchers verified that the
system is extremely specific. They exposed the biosensor system to a series of
organic compounds (catechols, chlorophenols, biphenyl) that are structurally
related to chlorocatechols and might interfere with the biosensor system. No
appreciable levels of b-galactosidase were produced. The UK scientists have
also demonstrated that the system is capable of distinguishing 3-chlorocatechol
from 4-chlorocatechol. This biosensor system is a probe tailor-made to directly
monitor the level of chlorocatechols in soil, sediment, and water samples at
Superfund sites. Because it does not require expensive equipment or extensive
pretreatment of environmental samples, the UK biosensor system is simpler and
more economical than standard methods. The UK scientists are working to develop
additional biosensor systems. By using different reporter proteins that emit
fluorescence or bioluminescence at different wavelengths, they are developing
array sensing systems for a variety of environmental pollutants. Analysis of
the color of the light generated by the bacteria will allow for identification
of the pollutant(s) present in a particular environment. This would provide
tools for in situ monitoring of multiple contaminants at Superfund sites.
Contact: Sylvia Daunert, Dept. of Chemistry, Univ of Kentucky, Lexington, (859)
257-7060, daunert@pop.uky.edu
3-D Seismic Tomography Survey at a Groundwater Contamination
Site
Azaria, A.; C.A. Zelt; A. Levander; D. Dana; I. Morozov; B.
Magnani, Rice Univ., Center for Computational Geophysics, Houston, TX.
Eos
Trans. AGU, 81 (48), Fall Meet. Suppl., Abstract S72A-04, 2000
As part of an ongoing environmental characterization project at
Hill Air Force Base near Ogden, Utah, a 3-D seismic survey was performed over a
contaminated aquifer in July and August 2000. The site contains significant
amounts of dense non-aqueous phase liquids (DNAPLs) in a shallow aquifer less
than ~15 meters deep. The aquifer is bounded below by a clay aquiclude, in
which a paleochannel acts as a trap for the contaminants. The overburden
consists of Quaternary sands, gravels and clays. Imaging the structure of the
paleochannel at depths up to 15 meters was the main target of the survey. The
experiment included 3-D reflection, 3-D refraction, checkshot surveys, and
vertical seismic profiles in wells up to 15 meters deep. Preliminary traveltime
tomography results from the 3-D tomography and reflection surveys are
presented. The results of a 2-D pilot survey conducted in 1998 show that
velocity in the near surface increases by almost an order of magnitude in the
upper 15 m at this site, from about 200 m/s to 1500 m/s. 3-D synthetic tests
were developed using the 2-D results to design the field acquisition program.
For the tomography experiment, the entire site (approximately 95 meters by 36
meters in area) was surveyed with about 600 RefTek Texan recorders deployed in
a stationary rectangular grid having an inline spacing of 2.8 m and a crossline
spacing of 2.1 m. A shot from a .223 caliber rifle was fired at each receiver
station, yielding a dataset with about 360,000 traces, and offsets up to 100 m.
The source provides a broad frequency range from 40 Hz to greater than 300Hz.
The 2-D data and the synthetic tests suggest that the 3-D wide-angle data will
provide a well-resolved 3-D velocity model of the paleochannel using
first-arrival tomography.
High Resolution 3-D Seismic Investigations at a Groundwater
Contamination Site
Dana, D.; A. Levander; I. Morozov; C. Zelt; B.
Magnani, Rice Univ., Center for Computational Geophysics, Houston, TX.
Eos
Trans. AGU, 81 (48), Fall Meet. Suppl., Abstract S72A-03, 2000
In July and August 2000, the researchers conducted 3-D reflection,
tomography, and downhole seismic studies at Operable Unit 2 (OU2) at Hill Air
Force Base in Ogden, Utah, where dense nonaqueous phase liquids (DNAPLs)
contaminate a shallow (less than 20 m) aquifer. The survey target is a
paleochannel buried beneath Quaternary sands, gravels and clays that acts as a
local trap for contaminants. The highly irregular, steep walled paleochannel
was imaged by a pilot 2-D survey conducted in 1998, demonstrating the viability
of seismic methods for investigating the upper 20m at this site. The four week
experiment included 3-D seismic reflection, 3-D tomography, six check shot
surveys in 15m boreholes for velocity estimation, and two vertical seismic
profiles. A 223 rifle was used as the seismic source in all experiments,
producing frequencies from 40Hz to greater than 300Hz. Approximately 6000 shot
records were taken in the various experiments; the experiment at times
generated 9Gbytes of data per day. The 3-D reflection and tomography
experiments both occupied an area of 95m by 36m, and utilized over 600 RefTek
Texan instruments. For the reflection experiment the instruments were deployed
in swaths of six receiver lines 2.1m apart, with geophone intervals in the
inline direction of 0.35m. The shot pattern was a rotated brick pattern with
0.35m shot intervals in the inline and crossline directions, producing a
nominal 52-fold survey. Data quality appears to be excellent, despite a high
level of cultural noise. The shot gathers show strong reflections with
conflicting dips, characteristic of steeply dipping features.
A Hybrid Hydrologic-Geophysical Inverse Technique for the
Assessment and Monitoring of Leachates in the Vadose Zone
Brainard,
J.R. (Sandia National Laboratories, Albuquerque, NM); D.L. Alumbaugh (Univ. of
Wisconsin Madison); R.J. Glass (Sandia National Laboratories, Albuquerque, NM);
D. Labrecque (Multi-Phase Technologies LLC, Sparks, NV); J. Yeh (Univ. of
Arizona, Tucson).
Eos Trans. AGU, Vol 81 No 48, Fall Meet. Suppl., Abstract
H22C-10, 2000
During cleanup or immobilization of vadose zone contamination that
has occurred through free release of wastes on the surface or by leaking
landfills and storage tanks, new and innovative long-term vadose zone
monitoring techniques are needed to track hydrologic conditions and provide
information on important flow and transport processes. The researchers have
focused on developing, implementing, and testing a new approach that
synthesizes a recently developed inverse hydrologic modeling technique with
state-of-the-art geophysical sensing technologies. The result is a robust
method for characterizing, monitoring, and predicting fluid movement in
heterogeneous vadose zones.
Effect of Mass Transfer Rate Limitations on the Use of
Partitioning Tracers for the Characterization of DNAPL Micropools in the
Subsurface.
Pirestani, K.; P.T. Imhoff, Univ. of Delaware, Civil and
Environmental Engineering Dept., Newark.
Eos Trans. AGU, Vol 81 No 48, Fall
Meet. Suppl., Abstract H71B-08, 2000
Partitioning tracer tests (PTTs) are an innovative technology used
for the detection and subsurface distribution estimation of nonaqueous phase
liquids (NAPLs). The PTT involves injecting a tracer pulse of partitioning and
nonpartitioning tracers into an aquifer with subsequent measurement of the
tracer concentrations in extraction wells. The partitioning tracer is retarded
or slowed when it partitions into the NAPL. The amount of retardation is
proportional to the saturation of NAPL in the porous media. Column experiments
were performed to determine the minimum contact time between tracer solutions
and rectangular micropools of trichloroethylene (TCE) for detection of all TCE.
Different contact times were achieved by flushing tracer solutions of different
volumes with different flushing velocities. The TCE micropools were centimeters
in size and reflect the small volumes that may be trapped by textural
heterogeneities in some subsurface systems. The length and thickness of the TCE
micropools were varied to create different required equilibration times. The
results from these experiments were put in dimensionless form and used to
explore relationships between the size of NAPL micropool and the necessary
contact time between tracer solution and micropool for NAPL detection.
List of Leak Detection Evaluations for UST Systems, 8th Edition
National Work Group on Leak Detection Evaluations (NWGLDE). 311 pp, Mar
2001
This reference manual is for State and EPA regulators, especially
inspectors of USTs, knowledgeable UST owners and operators wanting to compare
specifications for various leak detection devices, and vendors of UST leak
detection systems. This reference manual contains a summary of specifications,
based on third-party evaluations, for over 275 systems that detect leaks from
USTs and their piping. Each summary provides information on such items as
certified detectable leak rate/threshold, test period duration, product
applicability, calibration requirements, restrictions on the use of the device,
and so on. Although maintained by a work group consisting of State and EPA
members, the "List Of Leak Detection Evaluations" is not a list of "approved"
leak detection systems. Approval or acceptance of leak detection systems is the
responsibility of the implementing agency--in most cases the State
environmental agency. More information:
http://www.epa.gov/swerust1/pubs/ldlist.htm
Mapping the Norman, Oklahoma Landfill Contaminant Plume Using
Electrical Geophysics
Bisdorf, R.J.; J.E. Lucius.
Proceedings of
the USGS Toxic Substances Hydrology Program Technical Meeting, 8-12 March 1999,
Charleston, SC, Volume 3: Subsurface Contamination from Point Sources
U.S.
Geological Survey Water-Resources Investigations Report 99-4018C, p 579-584,
1999
The lateral extent of the electrically conductive portion of the
contaminant plume emanating from the Norman Landfill was mapped using
electrical geophysical measurements. EM induction and DC resistivity methods
measured the apparent electrical resistivity of the subsurface. Both methods
show an area of low resistivity indicating poor ground-water quality in the
alluvium, presumably due to leachate from the Norman Landfill. This area
extends from the southwest side of the main landfill mound toward the Canadian
River for no more than about 200 meters. Cross section and depth-slice maps
made from the interpretation of the DC resistivity soundings and maps of
measured resistivity from the EM measurements illustrate the lateral extent of
the landfill contamination and show that the contaminate plume, which is about
9 meters thick, does not appear to extend into the bedrock. The EM induction
method proved to be an easy and efficient procedure for rapidly determining the
lateral extent of the leachate plume. The DC resistivity method, although more
time consuming, provided better vertical resolution of the resistivity
distribution.
Spectral Induced Polarization Studies of Mine Dumps near
Silverton, Colorado
Campbell, David L.; D.V. Fitterman; R.J. Horton.
Science for Watershed Decisions on Abandoned Mine Lands: Review of
Preliminary Results, 4-5 February 1998, Denver, Colorado [Abs.].
U.S.
Geological Survey Open-File Report 98-297, p 40, 1998
To help study mechanisms that produce acid mine drainage (AMD),
the authors made spectral induced polarization (SIP) measurements at the Mayday
and Yukon mine dumps, in a Department of Interior Abandoned Mine Lands study
area near Silverton, Colorado. Induced polarization is a geophysical method
that has long been used to detect disseminated sulfides, and SIP is a
refinement of that method that can characterize electrochemical processes
taking place at mineral/pore-water interfaces. At Silverton, SIP measurements
were made at intervals of 1.5 meters (m) at the Mayday dump and 3.0 m at the
Yukon dump along profiles on the dump faces, investigating to depths of about 5
m below the surface. The study results suggest that the acid waters currently
draining from the Mayday mine dump probably result mainly from process(es)
involving already-oxidized minerals, rather than from primary oxidation of
sulfides at grain surfaces.
Accounting for Cyanide and Its Degradation Products at Three
Nevada Gold Mines: Constraints from Stable C- and N-Isotopes
Johnson,
Craig A.; David J. Grimes; Robert O. Rye.
U.S. Geological Survey Open-File
Report 98-0753, [16 pp], 1998
An understanding of the fate of cyanide (CN-) in mine
process waters is important for addressing environmental concerns and for
taking steps to minimize reagent costs. The utility of stable isotope methods
in identifying cyanide loss pathways has been investigated in case studies at
three Nevada gold mines. Freshly prepared barren solutions at the mines have
cyanide 15N and 13C values averaging -4% and -36%, respectively, reflecting the
nitrogen and carbon sources used by commercial manufacturers, air and natural
gas methane. Pregnant solutions returning from ore heaps display small isotopic
shifts to lower 15N and 13C values. The shifts are similar to those observed in
laboratory experiments where cyanide was progressively precipitated as a
cyanometallic compound, and are opposite in sign and much smaller in magnitude
than the shifts observed in experiments where HCN was offgassed. Offgassing is
inferred to be a minor cyanide loss mechanism in the heap leach operations at
the three mines, and precipitation as cyanometallic compounds, and possibly
coprecipitation with ferric oxides, is inferred to be an important loss
mechanism. Isotopic analysis of dissolved inorganic carbon (DIC) shows that
uptake of high d13C air CO2 has been important in many barren and pregnant
solutions. However, DIC in reclaim pond waters at all three mines has low 13C
values of -28 to -34%, indicating cyanide breakdown either by hydrolysis or by
other chemical pathways that break the C-N bond. Isotope mass balance
calculations indicate that about 40% of the DIC load in the ponds, at a
minimum, was derived from cyanide breakdown. This level of cyanide hydrolysis
accounts for 14-100 % of the dissolved inorganic nitrogen species present in
the ponds. Overall, isotope data provide quantitative evidence that only minor
amounts of cyanide are lost via offgassing and that significant amounts are
destroyed via hydrolysis and related pathways. The data also highlight the
possibility that significant cyanide may be either retained in the ore heaps or
destroyed via other chemical pathways. More information:
http://greenwood.cr.usgs.gov/pub/open-file-reports/ofr-98-0753/ofr-98-0753.pdf
Preliminary Materials Mapping in the Oquirrh Mountains Region
for the Utah EPA Project Using AVIRIS Data
McDougal, R.R.; R.N. Clark;
K.E. Livo; R.F. Kokaly; B.W. Rockwell; J.S. Vance.
Summaries of the 8th
Annual JPL Airborne Science Workshop, JPL Publication 99-17, p 297-298,
1998
This paper describes a project that is part of the Utah 1998
EPA-USGS AVIRIS study. The principal elements of this joint investigation
include mapping and characterization of surficial minerals, watershed
evaluation to better define effects of mineralization and related mining
activities, and vegetation studies. More information:
http://speclab.cr.usgs.gov/earth.studies/Utah-1/Jpl_pap.wpd.html
pick_xwell: A Program for Interactive Picking of Crosswell
Seismic and Radar Data
Ellefsen, K.J.
U.S. Geological Survey
Open-File Report 99-0534, 1999
Program 'pick_xwell' is used to interactively pick travel times in
crosswell seismic and radar data. In addition, the traces and the travel times
can be plotted on the computer screen or printed to a file in postscript
format. The program is written in the IDL programming language, and it is
executed, in command-line mode, within the IDL program. The IDL program must be
run from an X-window terminal that is connected to a computer with the Unix
operating system. The data must be in the SU format.
Magnetic Resonance Imaging of Hydrocarbon-Contaminated Porous
Media
Pervizpour, M.; S. Pamukcu; Horace Moo-Young, Dept. of Civil and
Environmental Engineering, Fritz
Engineering Lab., Lehigh Univ., Bethlehem,
PA.
Journal of Computing in Civil Engineering, Vol 13 No 2, p 96-102, Apr
1999
Nuclear magnetic resonance response measurement is a
nondestructive and nonintrusive technique that is potentially useful for in
situ characterization and mapping of hydrocarbon contamination in the
subsurface, including rock. Magnetic resonance measurements of a porous medium
allow the determination of necessary parameters to evaluate permeability and
porosity of the medium and the type of hydrocarbons present in the pore fluid.
This paper presents the results of a preliminary study intended to evaluate the
robustness of the magnetic resonance imaging technology using
well-characterized laboratory specimens of porous material containing
hydrocarbon liquids. The porous materials tested were 1) a dry uniform sand
pack impregnated with an aqueous coal tar mixture and 2) packed columns of
glass beads of various sizes permeated with distilled water and
trichloroethylene. The discernable images of the pore space and the interface
of the two liquids in the pore space indicated that magnetic resonance imaging
could be a viable tool to determine spatial distribution and mass fraction of
hydrocarbon liquids in subsurface contamination.
Detection of Persistent Organic Pollutants in the Mississippi
Delta Using Semipermeable Membrane Devices
Zimmerman, L.R.; E.M.
Thurman; K.C. Bastian.
The Science of the Total Environment, Vol 248 No
2-3, p 169-179, 2000
Semipermeable membrane devices (SPMDs) passively accumulate
hydrophobic organic compounds when placed in water. The devices consist of a
low-density polyethylene (LDPE) lay-flat membrane filled with 1 gram of a high
molecular weight lipid, triolein, that cannot diffuse through the membrane. The
LDPE membrane mimics a biological membrane in its ability to allow selective
diffusion of organic compounds. After the deployment period, SPMDs are
retrieved from the water (in the tests described here, surface water streams),
dialyzed, cleaned up with gel permeation chromatography and silica gel, and
analyzed using gas chromatography/ mass spectrometry (GC/MS) or gas
chromatography/electron capture (GC/ECD) techniques. From SPMDs placed in five
Mississippi Delta streams in 1996 and 1997, the persistent organic pollutants
aldrin, chlordane, DCPA, DDT, dieldrin, endrin, heptachlor, hexachlorobenzenes,
mirex, nonachlor, and toxaphene were detected, in addition to two insecticides
still in use, the organophosphate chlorpyriphos and the organochlorine
endosulfan. Two low-solubility herbicides not seen commonly in surface water,
pendimethalin and trifluralin, also were detected.
Chlorinated Ethenes from Ground Water in Tree Trunks
Vroblesky, Don A.; Christopher T. Nietch; James T. Morris.
Proceedings of the U.S. Geological Survey Toxic Substances Hydrology
Program Technical Meeting, 8-12 March 1999, Charleston, South Carolina. Volume
3 of 3: Subsurface Contamination from Point Sources.
U.S. Geological Survey
Water-Resources Investigations Report 99-4018C, p 607-614, 1999
The purpose of this investigation was to determine whether
tree-core analysis could be used to delineate shallow ground-water
contamination by chlorinated ethenes. Analysis of tree cores from baldcypress,
tupelo, sweetgum, oak, sycamore, and loblolly pine growing over shallow ground
water contaminated with cis-1,2-dichloroethene (cDCE) and trichloroethene (TCE)
showed that those compounds also were present in the trees. The cores were
collected and analyzed by headspace gas chromatography. Baldcypress, tupelo,
and loblolly pine contained the highest concentrations of TCE, with lesser
amounts in nearby oak and sweetgum. The concentrations of cDCE and TCE in
various trees appear to reflect the configuration of the chlorinated-solvent
ground-water contamination plume. Baldcypress cores collected along 18.6-meter
vertical transects of the same trunks showed that TCE concentrations decline by
30 to 70% with trunk height. The ability of the tested trees to take up cDCE
and TCE make tree coring a potentially cost effective and simple approach to
optimizing well placement at this site
Bethlehem Landfill Groundwater Containment Monitoring
Hasemeier, R.F.; M.A. Knight.
In Situ Remediation of the
Geoenvironment: Proceedings of the Conference held in Minneapolis, Minnesota,
5-8 October 1997.
American Society of Civil Engineers, Reston, VA. ISBN:
0-7844-0278-7. Geotechnical Special Publication No 71, p 473-488, 1997
No abstract available.
Identification of Contaminated Soils by Dielectric Constant and
Electrical Conductivity
Kaya, Abidin (Ctr. for Envir. Engrg. and Sci.
Technologies (CEEST), Dept. of Civ. and Envir. Engrg., Univ. of Massachusetts,
Lowell, MA); Hsai-Yang Fang (Dept. of Civ. and Envir. Engrg., Lehigh Univ.,
Bethlehem, PA).
Journal of Environmental Engineering, Vol 123 No 2, p
169-177, Feb 1997
The use of dielectric constant and electrical conductivity of the
soil-fluid system has been suggested to overcome deficiencies of current
identification and characterization methods. However, little is known about the
dielectric behavior of a contaminated soil-fluid system. The authors describe a
study undertaken to investigate the possibility of using dielectric constant
and electrical conductivity to characterize and identify contaminated
fine-grained soils. The dielectric constant and electrical conductivity of
kaolinite, bentonite, and local soil were determined at various ion
concentrations, organic liquids, and moisture content. Results showed both
dielectric constant and electrical conductivity of the soil-fluid system to be
mainly controlled by pore fluid.
Multicomponent Geophysical Surveys over Completed Landfill
Sites
Fennings, P.J.; B.S. Williams.
Modern Geophysics in
Engineering Geology.
Geological Society, London. ISBN: 1897799926.
Geological Society Engineering Geology special publication, 0267-9914; no 12, p
125-139, 1997
No abstract available.
The Use of Rayleigh Waves to Detect the Depth of Shallow
Landfill
Butcher, A.P.; W.S.A. Tam.
Modern Geophysics in
Engineering Geology.
Geological Society, London. ISBN: 1897799926.
Geological Society Engineering Geology special publication, 0267-9914; no 12, p
97-101, 1997
No abstract available.
Resistivity (-Method) Method for Environmental Monitoring: a
New Approach
Narayan, S.; M.B. Dusseault.
Modern Geophysics in
Engineering Geology.
Geological Society, London. ISBN: 1897799926.
Geological Society Engineering Geology special publication, 0267-9914; no 12, p
89-95, 1997
No abstract available.
Practical Bedrock Aquifer Characterization Using Borehole
Geophysics and Multi-Level Wells
Gernand, Jeff (Gannett Fleming, Inc.,
Baltimore, MD); Bruce Rundell (U.S. EPA, Philadelphia, PA); Chen-yu Yen
(Gannett Fleming, Inc., Baltimore, MD).
Practice Periodical of Hazardous,
Toxic, and Radioactive Waste Management, Vol 5 No 2, p 111-118, Apr 2001
This paper describes a strategy for characterizing contaminated
bedrock aquifers using borehole geophysics and multilevel wells that greatly
increases the chances of success. Although these methods can be expensive,
proper application may reduce long-term monitoring costs. The case study site
is a hilltop landfill overlying a heterogeneous bedrock aquifer and surrounded
by homes using domestic wells. Borehole geophysical and heatpulse-flowmeter
data identified the number of water-bearing zones (WBZs) per 30 meters drilled.
Multilevel wells focused sampling on WBZs and provided detailed plume
characterization and monitoring to help protect local domestic wells. A review
of logs from one monitoring well shows how borehole geophysics identified seven
individual WBZs, and sampling of the multilevel well revealed important
variations in chemical and potentiometric signatures between the WBZs. This
detailed characterization supported the site conceptual model and demonstrated
that domestic wells were not threatened. The increasing use of low-flow
sampling techniques and the rising popularity of monitored natural attenuation
remedies should lead to increased application of this strategy.
Laboratory and Field Tests for Studying Gas Flow Through
Municipal Solid Waste Landfill Cover
Maciel, Felipe Jucá;
José Fernando Thomé Jucá.
Advances in Unsaturated
Geotechnics (Proceedings of sessions of Geo-Denver 2000 held in Denver,
Colorado, 5-8 August 2000).
American Society of Civil Engineers, Reston,
VA. ISBN: 0-7844-0510-7. Geotechnical Special
Publication No. 99, p
569-585, 2000
Abstract not available.
Three-Dimensional Site Characterization Technologies for DNAPL
Contaminated Sites
Naval Facilities Engineering Command, Washington,
DC.
NFESC TDS-2072-ENV. 8 pp, Nov 1999
This technical data sheet briefly describes the results of several
demonstrations of high-resolution seismic reflection imaging surveys and
electromagnetic resistivity surveys to characterize DNAPL in the subsurface and
also addresses benefits/advantages, limitations, demonstration planning and
implementation, and cost effectiveness of the technologies. More information:
http://erb.nfesc.navy.mil/erb_a/restoration/technologies/invest/geo_phys/tds-2072.pdf
Rapid Characterization of Metals in Sediments Using X-Ray
Fluorescence (XRF) Technology
Naval Facilities Engineering Command,
Washington, DC.
NFESC TDS-2076-ENV. 2 pp, Feb 2000
XRF is not intended to replace the more rigorous laboratory-based
analysis for regulatory purposes.
Rather, XRF provides near real-time data to produce a contaminant
distribution map while the crew is in the field, without relying on time
consuming and costly laboratory analysis to complete the distribution picture.
XRF analysis allows better delineation of contaminant distribution by providing
higher data density in a time- and cost-effective manner. More information:
http://erb.nfesc.navy.mil/erb_a/restoration/technologies/invest/fld_chem/tds-2076-xray.pdf
QwikSed: A Bioluminescent Sediment Toxicity Test
Naval
Facilities Engineering Command, Washington, DC.
NFESC TDS-2077-ENV. 2 pp,
Feb 2000
The Navy has developed a rapid bioassay system (QwikSed) that is
proving to be a valuable asset for conducting bioassays on marine sediments.
The basis of detection is to measure a reduction in light from a bioluminescent
dinoflagellate such as Gonyaulux polyedra or Ceratocorys
horrida following exposure to a toxicant. The toxic response is usually
measured within 24 hours from the start of the test and can be conducted for a
4-day acute test or a 7- to 11-day chronic test. A measurable reduction or
inhibition in bioluminescence is an adverse effect. The endpoint used to
measure this light reduction is the IC50 (a 50% reduction in light output when
compared to control cells). The QwikSed unit has been licensed to Sealite
Instruments, Inc., of Ft. Lauderdale, Florida. The cost of the QwikSed analyzer
and supporting software is approximately $15,000. The instrument includes
built-in software that automatically prints the raw data and calculates the
mean, standard deviation, coefficient of variation, percent of control, and the
estimated IC50. The QwikSed unit can be connected to either a printer via a
serial port on the back of the unit for direct printouts, or it can be
connected to a computer for further manipulation or graphing of data using a
software program such as Excel. More information:
http://erb.nfesc.navy.mil/erb_a/restoration/technologies/invest/fld_chem/tds-2077-qwiksed.pdf
Rapid Sediment Characterization of PCBs with ELISA, an
Immunoassay Technique
Naval Facilities Engineering Service Center, Port
Hueneme, CA.
NFESC TSD-2086-ENV. 3 pp, Jun 2001
The enzyme-linked immunosorbent assay (ELISA) is used for
environmental field analysis because it can be optimized for speed,
sensitivity, and selectivity, has a long shelf life, and is relatively simple
to use. Immunoassay tests use antibodies to bind with a target compound or
class of compounds, in this case PCBs. Concentrations of the PCB and the target
analyte are identified through a colorimetric reaction. The determination of
PCBs presence is made by comparing the color developed by a sample of unknown
concentration with the color formed by the standard containing the analyte at a
known concentration. The concentration of the PCB is determined by the
intensity of color in the sample and is measured with a spectrophotometer.
Immunoassay kits are relatively quick and simple to use with a short training
session. Detection limits can vary depending on the dilution series used. The
detection limit for PCBs test kits in soil ranges from 50 to 500 ppb.
http://erb.nfesc.navy.mil/erb_a/restoration/technologies/invest/fld_chem/tds-2086-rsc.pdf
Innovative Field Technique Used at NSCS Athens, Georgia
Robinson, John (SOUTHNAVFACENGCOM); Scott Flickinger; Keith Henn; Steve
Ruffing (TetraTech NUS, Inc.).
RPM News, p 1-2, Spring 2001
An innovative field-screening method is available to profile soil
conductivity and volatile organic compounds (VOCs) in soil and ground water.
The Membrane Interface Probe/Soil Conductivity (MIP/SC) system developed by
Geoprobe assisted in the characterization of a low-level dissolved-phase
gasoline plume adjacent to the Naval Supply Corps School (NSCS) in Athens,
Georgia. The technique provided real-time results, which assisted in the
selection of optimal soil and ground-water sampling locations, thereby reducing
the overall number of samples required. Soil and ground-water contamination
originated from previously leaking pipes associated with underground storage
tanks (USTs) located at the Navy Exchange Gas Station. Ground-water
contamination migrated downgradient, and despite a remedial action to treat
both soil and ground water, legacy contamination remains in relatively
low-permeability soil approximately 200 to 300 feet from the source area. The
MIP/SC system was used to collect continuous vertical profiles of VOC data and
soil conductivity at the site. Using direct push technology (DPT), the
1.5-inch-diameter probe is driven into the ground at a rate of one foot per
minute. The MIP portion of the probe measures VOCs by heating the soil and/or
water to temperatures between 80 and 250 degrees Celsius. The VOCs diffuse
across a membrane and into a carrier gas. The gas is then analyzed, using a
combination of a flame ionization detector (FID), a photo ionization detector
(PID), and an electrical conductivity detector (ECD) (for chlorinated VOCs
only) in a laboratory-grade gas chromatograph at the surface. The SC portion of
the system uses a dipole measurement arrangement in which an alternating
current is passed from the center of the probe to the probe body. The voltage
response of the soil to the current is measured across these same two points.
Lower conductivities indicate sands (high-permeability material), while higher
conductivities indicate silts and clays (low-permeability material). The
continuously measured results are captured by data-logging software and
displayed in real time as the probe is advanced. At the Athens site, the soil
conductivity results with the MIP results indicate that the plume is being
contained in place by low-permeability soil. The data generated from the MIP/SC
system and media sampling enabled TetraTech NUS, Inc., to strategically locate
three additional monitoring wells at the point of highest subsurface
contamination. However, there are a few drawbacks to the MIP/SC system that
require additional evaluation: 1) the MIP/SC system is more costly to operate
than hand-held instruments, suggesting that a cost analysis should be done for
each project; 2) the results are qualitative for contaminants and will require
confirmation sampling to obtain quantitative results; 3) a separate DPT hole is
required for sample collection, meaning additional sample collection time; and
4) the system is only in the early stages of gaining regulatory approval as a
media delineation technique for UST programs.
Innovative Technology Applied at El Toro MCAS
Long,
Alexandria (NFESC); Lynn Hornecker (SWDIV); Crispin Wanyoike (Earth Tech).
RPM News, p 10, Spring 2001
A recently implemented innovative technology is capable of
continuously measuring air permeability as well as contaminant concentration
along a well screen during soil vapor extraction (SVE). The technology was
applied at El Toro Marine Corps Air Station (MCAS) by Earth Tech, Inc., using
PRAXIS Environmental Technologies patented PneuLog system. The technology
can be used to assess remediation progress and provide data to help optimize
the efficiency of the existing system. The primary contaminant at the cleanup
site on El Toro MCAS is trichloroethylene (TCE). An SVE system had been
installed late in 1999 and had worked effectively for more than six months. As
TCE vapor concentration levels leveled off below the closure thresholds,
PneuLog was implemented to evaluate the vertical distribution of residual
TCE vapors and vapor flow profiles. PneuLog was applied to ten
representative wells around the site. In general, the PneuLog technology
combines an airflow probe with a volatile organic compound (VOC) detector to
make in situ, real time measurements as a function of depth. The PneuLog
instrument, which consists of a probe attached to a cable, was lowered into
each SVE well. The probe continuously measures contaminant concentration and
airflow along the entire well screen length. Soil vapor flow measurements are
performed using a downhole flowmeter. VOC measurements are made using a
photoionizing detector. The contaminant concentration profiles are calibrated
with off-site analyses of vapor samples collected from the well head. The
PneuLog results produced useful information. The airflow data showed no
areas of restricted airflow, proving that the existing system was operating
effectively. The contaminant concentration profiles confirmed that there were
no individual pockets of high concentrations of TCE along the well screen.
Additionally, the concentration data demonstrated that the highest
concentrations were measured close to ground water and were a result of
offgassing from the contaminated ground water. PneuLog has been
successfully implemented on a variety of DoD and commercial sites across the
United States. The data it produces are not only useful for SVE optimization,
but can also be used for soil venting design, risk assessments, and accelerated
site characterization. Traditional alternatives are available; however, they do
not offer the simultaneous measurement of flow rates and vapor concentrations
while they are typically more time consuming and costly than PneuLog. At
El Toro MCAS, it is estimated that utilizing PneuLog cost approximately
50% of the amount needed to collect similar data using traditional methods.
Contact: Lynn Hornecker, RPM Naval Facilities Engineering Command, Southwest
Division, (619) 532-0783, horneckerlm@efdsw.navfac.navy.mil.
Potential Contaminant Migration at a Contaminated Soils
Landfill Site in Quebec
Cabral, A.; L. Demers; R. Ciubotariu.
Advances in Transportation and Geoenvironmental Systems Using Geosynthetics
(Proceedings of sessions of Geo-Denver 2000 held in Denver, Colorado, 5-8
August 2000).
American Society of Civil Engineers, Reston, VA. ISBN:
0-7844-0515-8. Geotechnical Special Publication No 103, p 68-80, 2000
Abstract not available.
Artificial Neural Networks in Remote Sensing of Hydrologic
Processes
Islam, Shafiqul; Ravi Kothari, Dept. of Electrical and
Computer Engrg. and Computer Sci., Univ. of Cincinnati, Cincinnati, OH.
Journal of Hydrologic Engineering, Vol 5 No 2, p 138-144, Apr 2000
Remote sensing technologies coupled with ongoing and planned
remote sensing can be used to generate hydrologic data at spatial, temporal,
and spectral resolutions never previously available. Artificial neural networks
(ANNs) are being developed to characterize, model, and predict complex
multisource remotely sensed hydrologic data. The authors review and examine the
utility of ANNs for hydrologic applications, with particular emphasis on remote
sensing of precipitation, soil moisture, and multisource land surface data.
Recurrent neural networks are reviewed in addition to more popularly used
multilayer feedforward networks for prediction and self-organization neural
networks in spatial characterization of heterogeneous land surface
processes.
Assessment of the Potential Risks of Landfills by Determination
of Trace Metals in Groundwater by ICP-MS
Ulrich, A.; H.-R. Zweifel;
A.C. Johnson.
Plasma Source Mass Spectrometry: Developments and
Applications.
Royal Society of Chemistry, Cambridge, UK. ISBN: 0854047271.
p 263-270, 1997
Abstract not available.
Coupling of GC with ICP-MS for Trace Metal Speciation
De Smaele, T.; L. Moens; R. Dams.
Plasma Source Mass Spectrometry:
Developments and Applications.
Royal Society of Chemistry, Cambridge, UK.
ISBN: 0854047271. p 109-123, 1997
Abstract not available.
Rapid On-Line Separation and Determination of Arsenic (III) and
(V) in Waters by Inductively Coupled Plasma Mass Spectrometry
Cox,
A.G.; C.W. McLeod; M. Nishikawa [et al.].
Plasma Source Mass Spectrometry:
Developments and Applications.
Royal Society of Chemistry, Cambridge, UK.
ISBN: 0854047271. p 145-151, 1997
Abstract not available.
Role of Geophysics in Expedited Site Characterization: Case
History
Kjartanson, B.H. (Civ. Engrg., Iowa State Univ., Ames, IA);
J.D. Wonder ( U.S. DOE Ames Lab., Spedding Hall, Iowa State Univ., Ames, IA);
R.C. Benson (Technos Inc., Miami, FL); L. Yuhr (Technos Inc., Miami, FL); A.J.
Bevolo (U.S. DOE Ames Lab., Spedding Hall, Iowa State Univ., Ames, IA).
Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management,
Vol 2 No 1, p 33-47, Jan 1998
Geophysical techniques were successfully incorporated into an ESC
project at an oil seepage basin site on DOE's Savannah River site to define the
limits of buried wastes, detect and map an inorganic plume emanating from the
waste trenches, and define the approximate depth and lateral continuity of
major stratigraphic units across the site. When integrated with minimally
intrusive direct push technologies, the geophysical techniques provided the
framework for the development of the conceptual site model.
The refined
model was then used to guide ground-water contaminant sampling to define the
spatial extent of the inorganic and organic plume emanating from the waste
trenches.
Inverse Modeling of Field Tracer Data to Characterize DNAPL
Contamination
Nicot, Jean-Philippe; Daene C. McKinney; Gary A. Pope.
Aesthetics in the Constructed Environment: Proceedings of the 24th Annual
Water Resources Planning and Management Conference, 6-9 April 1997, Houston,
Texas.
American Society of Civil Engineers, Reston, VA. ISBN:
0-7844-0228-0, p 420-425, 1997
Abstract not available.
Establishing Landfill Gas as a Cause of Groundwater
Contamination
Kraemer, T.A.; M. Carpenter; J. Hartley.
Water
Resources and the Urban Environment '98: Proceedings of the 1998 National
Conference on Environmental Engineering, 7-10 June 1998, Chicago, Illinois.
American Society of Civil Engineers, Reston, VA. ISBN: 0-7844-0349-X. p
20-25, 1998
Abstract not available.
Leak Detection in Pipes by Frequency Response Method
Mpesha, Witness; Sarah L. Gassman; M. Hanif Chaudhry, Dept. of Civ. and
Envir. Engrg., Univ. of South Carolina, Columbia.
Journal of Hydraulic
Engineering, Vol 127 No 2, p 134-147, Feb 2001
The authors describe the use of the frequency response method to
determine the location and rate of leakage in open loop piping systems. A
steady-oscillatory flow, produced by the periodic opening and closing of a
valve, was analyzed in the frequency domain by using the transfer matrix
method, and a frequency response diagram at the valve developed. In a leaking
system, this diagram has additional resonant pressure amplitude peaks that are
lower than the resonant pressure amplitude peaks for the system with no leaks.
Several piping systems have been successfully analyzed for all practical values
of the friction factor to detect and locate individual leaks of up to 0.5% of
the mean discharge. The method requires the measurement of pressure and
discharge fluctuations at only one location and has the potential to detect
leaks in real-life pipe systems conveying different types of fluids, such as
water and petroleum.
Underground Storage Tank Detects Leaks
Civil
Engineering ASCE, Vol 69 No 8, p 30, Aug 1999
Abstract not available.
Monitoring Subsurface Barrier Integrity Using Perfluorocarbon
Tracers
Sullivan, T.M.; J. Heiser; A. Gard; G. Senum, Brookhaven
National Lab., Upton, NY.
Journal of Environmental Engineering, Vol. 124,
No. 6, June 1998, pp. 490-497
Perfluorocarbon tracers (PFTs) have been tested as a means of
barrier verification at the Hanford geotechnical test facility, where a
soil/cement barrier was emplaced around a buried drum. PFTs were injected
beneath the drum for three days in the center of the barrier 3 meters below
grade. The concentration of PFTs in seven external and two internal monitoring
wells was measured as a function of time over a 17-day period. The data have
been analyzed to determine barrier integrity and PFT diffusion rates through
the barrier. This paper discusses the experimental design, test results, data
analysis, and modeling of PFT transport in the subsurface system.
Validation of Petroleum Hydrocarbon Extraction
Methodologies
Guerin, T.F., Rio Tinto's Research and Technology Group,
Hamersley Iron Technical Services, Rio
Tinto's Bioremediation Group, and
ICF Kaiser Engineers.
Remediation, Vol 10 No 2, p 85-94, 2000
The solvents, the extraction time, and the extraction method
influence the quantification of polycyclic aromatic hydrocarbons (PAHs) in
soil. This paper discusses the importance of establishing and being consistent
in the application of a vigorous extraction, particularly for commercial
laboratories that handle samples of soil in batches, at different times, from a
single site investigation or remediation process. It is important that
analytical laboratories communicate to the user of the data what variables
there are in soil contaminant extractions and how these can affect the final
data quality.
Biological Treatment of Oil-Contaminated Sand: Comparison of
Oil Degradation Based on Thin-Layer Chromatography/ Flame Ionization Detector
and Respirometric Analysis
Oh, Y.-S.; W.-Y. Choi; Y.-H. Lee; S.-C.
Choi; S.-J. Kim, Microbiology Lab., Marine Biology Div., Korea Ocean Research
& Development Inst., Ansan, Korea.
Biotechnology Letters, Vol 22 No 7,
p 595-598, 2000
Oil biodegradation in oil-contaminated sand was measured by both
respirometric and thin-layer chromatography/flame ionization detector (TLC/FID)
methods. Amendments of inorganic nutrients and an oil-degrading yeast increased
the initial CO2 production rate by 5-15 fold, which was not detected by the
TLC/FID analysis. However, it was possible to monitor the accumulation of
resin/asphaltene fraction up to 130% by the TLC/FID analysis during the
biodegradation process.
Five More Canadian Airports Purchase New Fuel Leak Detection
System As a Result of Successful Installation in Montreal
Business
Wire, 15 Mar 2001
After the success of its innovative new underground pipeline leak
detection systems at two major Montreal airports, Vista Research, Inc.
(Sunnyvale, California), has installed the equipment at airports in five
additional Canadian cities: Calgary, Edmonton, Halifax, Toronto and Vancouver.
The leak detection system, which is being used in airports throughout North
America, was first installed at Montreal's Dorval and Mirabel International
Airports, locations chosen by Air Canada as test sites in 1998. Air Canada
investigated leak detection technologies that would perform tightness or
pressure testing of underground high-pressure airport hydrant systems. Among
those examined was the Vista HT-100 leak detection system. Several other
pressure testing methods were tried, but it was determined that the Vista leak
detection technology, with its testing methodology, leak threshold criteria,
ability to improve accuracy through repetitive testing, and competitive price,
was the most compatible with the requirements of Air Canada, the Canadian Fuel
Consortia and the operation of the Montreal fuel systems. The two units at
Montreal have exceeded the vendor's performance claims and fully comply with
the testing requirement for hydrant systems. The advantage of Vista's fuel-line
pressure tests is that they can, in a few hours, accurately account for changes
in fuel volume caused by temperature variations. Alternative pressure-test
methods require that fuel systems be shut down for long periods, which is
impractical at major airports. The only other systems on the market require
airports to include fuel additives that can be detected by sensors in the
ground, or to install tracer wires in trenches along pipelines. The Vista
system can detect leaks as small as 0.00214 percent of the pipeline volume
within a three-hour test, typically conducted late at night. It works by
calculating the expected change in volume as the outside ground and air
conditions cause temperature changes in the fuel in the pipeline. If the fuel
volume does not change in accordance with the expectations, it is an indication
that there is a leak in the system. Vista's equipment can be permanently
installed and designed to test pipeline systems as often as daily, or a mobile
version can be trucked in for periodic tests. There are two versions of the
Vista equipment: the HT-100 is designed for underground pipelines containing
more than 3,000 gallons, and the LT-100 is designed for truck loading racks and
medium-length lines containing up to 10,000 gallons. Both systems feature
automatic compensation for thermal expansion and contraction of liquid in the
line, thus eliminating the major source of error in leak detection tests based
on fuel
Application of Borehole-Radar Methods to Image Two Permeable
Reactive-iron Walls at the Massachusetts Military Reservation, Cape Cod,
Massachusetts
Joesten, P.K. (U.S. Geological Survey); J.W. Lane Jr.;
J.G. Savoie; R.J. Versteeg.
SAGEEP 2001: Symposium on the Application of
Geophysics to Engineering and Environmental Problems, 4-7 March 2001, Denver,
Colorado.
Environmental and Engineering Geophysical Society (EEGS), Wheat
Ridge, CO. CD-ROM, 2001.
A pilot-scale study was conducted at the Massachusetts Military
Reservation on Cape Cod to assess the use of a hydraulic-fracturing method to
create vertical permeable reactive barriers (PRBs) of zero-valent iron to
remediate ground water contaminated with chlorinated solvents at depths
exceeding the range of conventional iron-wall installation methods. At the test
site, ground-water contamination extends from 24 to 37 meters (m) below land
surface. A treatment zone consisting of two parallel reactive-iron walls 12 m
long, 13 m high, and 0.15 m thick, separated by about 6 m, was designed to
intersect and remediate a portion of the CS-10 plume. The U.S. Geological
Survey used a cross-hole, common-depth radar scanning method to test the
continuity and estimate the lateral and vertical extent of the two walls. The
cross-hole radar surveys were conducted in boreholes on opposite sides of the
iron injection zones. Significant decreases in the amplitude of the radar pulse
observed in scans traversing the injection zones were interpreted by comparing
radar field data to results of two-dimensional, finite-difference, time-domain
models and laboratory-scale physical models developed to predict the effects of
wall edges and discontinuities on common-depth cross-hole radar measurements.
As part of a feasibility study, single-hole radar reflection data was used
successfully to image the walls. More information:
http://water.usgs.gov/ogw/bgas/publications/SAGEEP01_131/
Accuracy of Cyanide Analyses: Lessons from On-Site Analyses in
the USGS Mobile Geochemical Laboratory, and Implications for Heap Leach
Regulatory and Closure Issues
Grimes, D.J.; C.A. Johnson; R.O. Rye.
Closure, Remediation and Management of Precious Metal Heap Leach
Facilities, Proceedings, 14-15 January 1999.
University of Nevada Reno
Center for Environmental Sciences and Engineering/Division of Continuing
Education and North American Mining, Reno, NV. p 63-70, 1999
Using a USGS mobile geochemical laboratory outfitted with an ion
chromatograph system, the researchers sampled both effluent and solids from the
Pinson mine in Nevada and the Standard Hill mine in California and analyzed the
important Fe- and Co-cyanocomplexes directly onsite using methods developed in
FY00.
Automatic Monitoring of Heavy Metals in Waters
Beinrohr, Ernest, Dept. of Analytical Chemistry, Slovak Technical
Univ., Bratislava, Slovakia.
11th Annual International Conference on Heavy
Metals in the Environment, 6-10 August 2000, Ann Arbor, Michigan.
University of Michigan, School of Public Health, Ann Arbor, MI (CD-ROM).
Contribution #1371.
This paper describes an automatic system for continuous monitoring
of trace concentrations of heavy metals in water. The computer-controlled
analyzer consists of a simple flow system with a robust coulometric cell
enabling the measurement of various trace elements such as Ag, As, Bi, Cd, Cr,
Cu, Fe, Hg, Mn, Pb, Sb, Se, Zn, as well as chlorides, bromides, iodides,
phosphates, acids, bases, and ammonia. The device was tested with the
monitoring of Hg in industrial waste waters and Fe and Mn in mineral water.
Metal concentrations down to the µg/L (ppb) level were measured at
measurement frequencies up to 10-40 in an hour. More information:
http://www.sph.umich.edu/ehs/heavymetals/TechnicalProgram.html
Determination and Speciation of Copper in Natural Waters by
Square Wave Anodic Stripping Voltammetry
Bazzi, Ali (Univ. of Michigan
at Dearborn); Donna Hollandsworth; Nicholas Irish, Jerome Nriagu (Univ. of
Michigan at Ann Arbor).
11th Annual International Conference on Heavy
Metals in the Environment, 6-10 August 2000, Ann Arbor, Michigan.
University of Michigan, School of Public Health, Ann Arbor, MI (CD-ROM).
Contribution #1372.
Although square wave voltammetry (SWV) has been reported to be
more sensitive than differential pulse techniques by a factor of 2 to 4, most
of the speciation and analysis studies of natural waters for heavy metals by
electrochemical methods have been done using differential pulse anodic
stripping voltammetry (DPASV). The authors report on the determination of total
dissolved copper in samples taken from Saginaw Bay, Michigan, by square wave
anodic stripping voltammetry (SWASV) using a hanging mercury drop electrode
(HMDE). Samples were analyzed for total dissolved copper after filtration and
proper digestion with ultra pure nitric acid using standard addition technique.
Analyses were carried out with a deposition time of 15 minutes at a deposition
potential of -0.75 V vs. Ag/AgC1. Values ranging from 5.11 to 19.73 nM of
copper were obtained from different stations and at various depths.
In Situ Measurement of Trace Metals in an Oligotrophic Lake:
Comparison of Results Obtained by Peepers and DGT
Alfaro-De la Torre,
Ma. Catalina; André Tessier, INRS-Eau, Univ. du Québec,
Sainte-Foy, Québec, Canada.
11th Annual International Conference on
Heavy Metals in the Environment, 6-10 August 2000, Ann Arbor, Michigan.
University of Michigan, School of Public Health, Ann Arbor, MI (CD-ROM).
Contribution #1376, 2000
The technique of Diffusion Gradients in Thin (DGT) films is a
potentially powerful means of obtaining information on the in situ speciation
of trace metals. This study moves beyond the simple synthetic solutions used so
far in the laboratory to test DGT samplers, and compares the concentrations of
Cd and Ni measured by DGT and dialysis samplers (peepers) that were deployed in
the water column of an oligotrophic acidic lake. Cadmium and Ni concentrations
measured by DGT films in the lake were higher than those measured by in situ
dialysis. Co-diffusion of major cations, which was not taken into account in
the original DGT film theory, could explain the field results. More
information:
http://www.sph.umich.edu/ehs/heavymetals/TechnicalProgram.html
Earthworms as Bioindicators of Mercury Pollution
Hinton, Jennifer; Marcello M. Veiga, Dept. of Mining and Mineral
Process Engineering, Univ. of British Columbia.
11th Annual International
Conference on Heavy Metals in the Environment, 6-10 August 2000, Ann
Arbor,
MI.
University of Michigan, School of Public Health, Ann Arbor, MI
(CD-ROM). Contribution #1018.
A simple, cost-effective indicator that might be used to identify
Hg toxicity and bioavailability in soil would be particularly beneficial in
regions of the world such as developing countries, where mercury pollution can
be extensive, yet resources limited. Earthworms are simple, well-studied
creatures that can quickly provide indications of bioavailability at relatively
low costs. A methodology using the earthworm Eisenia foetida has been
developed to evaluate the bioavailability of Hg in mining tailings and aqueous
solutions. Results indicate that E. foetida do accumulate Hg, and a
positive correlation exists between Hg concentrations in worm tissues, the
substrate they consume, and the length of exposure. The effect of natural
organic acids as mediators of Hg bioavailability was investigated. Metallic Hg
was dissolved in tannic acid and made available to the worms in a substrate of
paper and silica sand. Total Hg and MeHg were analyzed to determine whether
methylation of Hg was occurring in the substrate, directly within the worms
(e.g. in the intestines), or in the tannic acid-Hg solution. The MeHg:Total Hg
ratio was up to 160 times higher in worm tissues than both the tannic acid-Hg
solution and the substrate. This result is particularly significant in
darkwater systems, where naturally occurring organic acids may be facilitating
methylation internally within organisms. More information:
http://www.sph.umich.edu/ehs/heavymetals/TechnicalProgram.html
Determination of Mercury Species Using ICP/MS Techniques
Hintelmann, Holger, Trent Univ., Dept. of Chemistry, Peterborough, Ontario,
Canada.
11th Annual International Conference on Heavy Metals in the
Environment, 6-10 August 2000, Ann Arbor, MI.
University of Michigan,
School of Public Health, Ann Arbor, MI (CD-ROM). Contribution #1104.
This paper presents an overview of different analytical methods
using ICP/MS as a detector to determine mercury species in environmental
samples. Total mercury is measured using either cold vapor flow injection
analysis or cold vapor gold amalgamation preconcentration. Both techniques have
absolute detection limits of approximately 1 pg of Mercury per isotope.
Methylmercury is determined after GC separation on-line by ICP/MS. These
techniques are used to carry out isotope dilution analyses and stable isotope
tracing experiments. The RSD for isotope ratio measurements was in the range of
0.5- 2%, depending on the individual method used. More information:
http://www.sph.umich.edu/ehs/heavymetals/TechnicalProgram.html
Environmental Mercury Speciation Analysis by Flow-Hyphenation
Techniques
Tseng C.M. (Dept. of Marine Sciences, Univ. of Connecticut,
Avery Point, Groton); D. Amouroux (Laboratoire de Chimie Bio-Inorganique et
Environnement, CNRS, Univ. de Pau et de l'Adour, Pau, France); O.F.X. Donard;
W.F. Fitzgerald.
11th Annual International Conference on Heavy Metals in
the Environment, 6-10 August 2000, Ann Arbor, MI.
University of Michigan,
School of Public Health, Ann Arbor, MI (CD-ROM). Contribution #1105.
To follow the pathways of mercury speciation in the environment,
several analytical approaches were developed to determine mercury species in
different ecosystem compartments. For gas-phase samples, mercury species were
concentrated on chromatographic phases and desorbed in a
cryotrapping/separating (CT-GC) unit coupled to a detector. For water samples,
the mercury species were determined with a field cryofocusing device using flow
injection and hydride generation. For environmental solid samples, mercury
species were detected by an online D-CT-GC-QFAAS system after sample
preparation by a microwave-assisted technique. The proposed approaches were
successfully applied to estuarine environmental matrices for investigating the
occurrences and fates of Hg. More information:
http://www.sph.umich.edu/ehs/heavymetals/TechnicalProgram.html
Aqueous Speciation of Copper, Manganese, Cadmium and Zinc in
the Elizabeth River Estuary (Norfolk, VA) Measured Using the Diffusion Gradient
in Thin-Film Technique
Twiss, Michael R. (Ryerson Polytechnic Univ.,
Toronto, Ontario, Canada); James W. Moffett (Woods Hole Oceanographic Inst.,
Woods Hole, MA).
11th Annual International Conference on Heavy Metals in
the Environment, 6-10 August 2000, Ann
Arbor, MI.
University of
Michigan, School of Public Health, Ann Arbor, MI (CD-ROM). Contribution
#1134.
The Diffusion Gradient in Thin-film (DGT) analytical technique was
applied to samples from the metal-contaminated Elizabeth River estuary in
Virginia. DGT probes were deployed in the estuary over a 6-day period, in
addition to deployment in discrete water samples collected from the same sites.
The authors found the use of DGT suitable for assessing water quality, provided
that the flux of organic metal into the DGT probes can be controlled. More
information:
http://www.sph.umich.edu/ehs/heavymetals/TechnicalProgram.html
Analytical Application of Supported Liquid Membranes in Trace
Metal Extraction And Speciation
Ndungu, Kuria (Environmental Toxicology
Dept./WIGS, Univ. of California at Santa Cruz); Nii-Kotey Djane (Dept. of
Analytical Chemistry, Lund Univ., Lund, Sweden); Lennart Mathiasson; Jan
Åke Jönsson.
|11th Annual International Conference on Heavy
Metals in the Environment, 6-10 August 2000, Ann Arbor, MI.
University of
Michigan, School of Public Health, Ann Arbor, MI (CD-ROM). Contribution
#1133.
The supported liquid membrane (SLM) procedure is an emerging trace
metal preconcentration
technique that lacks many of the problems (e.g., labor intensity,
time, and use of large amounts of reagents) attendant on liquid-liquid
extraction (LLE), which has been a standard extraction and preconcentration
method for trace metal analysis for several decades. SLM takes advantage of
LLE's ability to tune the extraction selectivity by chemical means, but unlike
LLE, it is easily automated and can be readily coupled to sensitive detectors
such as electrochemical or spectroscopic. Since SLM is selective to the free
and/or lipophilic species of the analyte, it often provides a more accurate
measure on bioavailability and toxicity of metals in solution than the total
dissolved (e.g., < 0.45 mm) metal concentration measurements. Additionally,
more rigorous speciation measurements can also be performed by combining
different SLM units in series; for example, cationic trivalent chromium and
anionic hexavalent chromium can be selectively enriched without an independent
chromatographic procedure. These advantages are illustrated in preliminary
applications of SLM to measure trace metal concentrations and speciation in
natural waters. More information: http://www.sph.umich.edu/ehs/heavymetals/TechnicalProgram.html
Sonic CPT Probing in Support of DNAPL Characterization
Gildea, Martin L.; J.W. Haas; S.P. Farrington; D.E. Chitty; W.L.
Bratton, Applied Research Associates, Inc., South Royalton, VT. New England
Div.
Report Number: ARA-4717. NTIS: ADA384783. 104 pp, Nov 2000
Cone Penetrometer Technology (CPT) offers advantages over other
site characterization technologies in that it is generally faster, less
expensive, safer, and generates far less secondary waste than conventional
drilling methods. As a result, DoD and DOE are supporting the development of
advanced sensors for delivery by the cone penetrometer. To accommodate these
new sensors, probe sizes have increased from 1.44-in OD to 1.75-in OD, and
currently to 2.25-in OD, and the ability of CPT to reach desired depths has
been increased. To enhance the penetration capability of the CPT, a sonic
vibratory system was integrated with conventional CPT to advance cone
penetrometer sensor packages to even greater depths. This CPT enhancement
provides an efficient tool for hazardous waste site characterization,
remediation, and monitoring. The report is available full text in a PDF file
through the DTIC search engine at http://stinet.dtic.mil/str/tr_fields.html
Ceramic Dosimeters for Time-Integrated Contaminant Monitoring
Martin, H.; M. Piepenbrink; P. Grathwohl, Univ. of Tuebingen,
Geological Inst., Applied Geology Group, Tuebingen, Germany.
Proceedings of
the 2000 Contaminated Site Remediation Conference: From Source Zones to
Ecosystems, 4-8 December 2000, Melbourne, Victoria.
Centre for Groundwater
Studies, CSIRO, Wembly, W.A., Australia. Vol 1, p 231-238, 2000
Sampling with ceramic dosimeters (passive samplers, patent
pending) is a new method for long-term, time-integrated monitoring of organic
pollutants in ground water and surface water. Problems with sample integrity
common to other water sampling methods due to transport or storage are avoided
with this new sampling method, and the number of necessary analyses is reduced
to only a few while monitoring the contaminant concentrations (representative
mean values) over the whole sampling period. This concept of time-integrated
concentration measurements can be used equally for contaminant monitoring in
ground water, rivers, lakes, and wastewater. So far, the method has been
developed and tested for polycyclic aromatic hydrocarbons (PAHs), volatile
chlorinated hydrocarbons, and volatile aromatic compounds (BTEX), but it can
also be used for other organic and inorganic aqueous contaminants.
Probe to Make Mine Waste Safer
Commonwealth Scientific
& Industrial Research Organisation (CSIRO-Australia) Media Release No
2001/37, 8 Feb 2001
A probe developed by CSIRO is poised to revolutionize the way
mining companies monitor the rehabilitation of Australia's mine sites,
especially where acidic mine wastes are present. The presence of oxygen in
sulphidic mine wastes results in oxidation of the sulphide minerals, and with
water forms sulphuric acid. The resultant acid mine drainage causes
contamination of surface and ground water. To reduce or eliminate this
contamination, the mineral wastes are commonly covered with earth or synthetic
covers. The CSIRO probe provides a detailed and accurate assessment of the
long-term stability and effectiveness of these covers to prevent oxygen
reaching the mineral wastes by accurately, cheaply, and continually monitoring
oxygen levels in mine waste sealed under the covers. Placed at various depths
in the earth cover and buried waste, the oxygen probes monitor the
effectiveness of the cover by detecting the amount of oxygen present. No oxygen
means the covers are doing their job. The oxygen probes eliminate sampling
error, reduce processing time and give a clearer indication of trends in the
oxygen concentration. The probes can also be used at remote sites and data
retrieved using mobile phones and modems (telemetry). Contact: Dr. Brad
Patterson, CSIRO Land and Water, 08 9333 6276; Dr. Graham Taylor, CSIRO Land
and Water, 08 8303 8437; Ms. Margaret Bryant, CSIRO Land and Water, 08 9333
6215.
Pipeline Leak Detector
Montgomery, Joe M., 700 N.
Interchange, Strafford, MO 65757.
U.S. Patent 5,821,403, 13 Oct 1998
A pipeline leak detection apparatus is provided for a fluid
dispensing system having a dispenser, a storage tank, and a pump and an
electric cut-off valve arranged in hydraulic series with the outlet of the
storage tank. The pipeline to be monitored extends between the cut-off valve
and the dispenser. A control circuit that operates the cut-off valve such that
the valve opens with use of the dispenser and closes with non-use in order to
hydraulically isolate the storage tank and pump from the pipeline and dispenser
during periods of non-use. The leak detection apparatus is connected in a
by-pass loop around the pump. It includes a small pot or plenum, a float
switch, and a return line for fuel to spill back into the storage tank. The
plenum inlet is connected to a branch in the pipeline near the cut-off valve,
and its outlet is connected to the return line to the storage tank. The float
switch is mounted to the plenum so that its float extends into the plenum
chamber. The electrical side of the float switch is connected in the control
circuit so that for as long as the float is floated the switch is maintained in
one state and produces no effect on the control circuit, but when the float
falls the switch changes state and disables the operability of the electric
cut-off valve. That way, during use of the dispenser, a fractional amount of
the outflow of the pump is diverted through the plenum to keep the float
floated; however, during non-use of the dispenser, the falling of the float
corresponds to fluid draining out of the plenum chamber as caused by a leak in
the pipeline, the result being the disablement of the electric cut-off valve.
Pipeline Leak Detector
Fiechtner, Bradley T. (San
Diego, CA). Owned by Dover Corporation, New York, NY.
U.S. Patent
5,557,965, 24 Sep 1996
This patent describes an apparatus for detecting leaks in a
pipeline in a liquid dispensing system. The apparatus generally includes a tank
containing a liquid, a dispenser valve disposed remote from the tank, a
pipeline connected between the storage tank and the dispenser valve, a pump at
the tank for supplying liquid under pressure to the pipeline and an isolation
valve between the pump and the dispenser valve to isolate the pump pressure
from the pressure in the pipeline between the isolation valve and the dispenser
valve. The apparatus further has a pressure sensor between the isolation valve
and the dispenser valve for measuring any pressure change in the pipeline
between the isolation valve and the dispenser value. A leak simulation valve
alternatively may be provided for draining the pipeline to simulate a leak.
High-Precision Leak Detector and Locator
Baumoel,
Joseph (c/o Controlotron Corporation, 155 Plant Ave., Hauppauge, NY 11788).
U.S. Patent 5,548,530, 20 Aug 1996
This patent describes a method for detecting the presence of a
leak in a segment of a pipeline. The method includes providing a site station
having an ultra-sonic transducer assembly at the beginning and end of the
pipeline segment, each assembly having two pairs of ultrasonic transducers for
determining the sonic propagation velocity Vs of ultrasonic energy
emitted by the transducers through fluid in the pipeline. Each pair of
ultrasonic transducers is displaced along the pipeline by a preset distance and
each defines an ultrasonic energy flow path. The value of Vs for
each ultrasonic energy flow path through the fluid in the pipeline is
determined at each site station at predetermined time intervals. Values
.DELTA.Vs defined as the difference between sequential values of
Vs at the predetermined time intervals for each flow path at each
site station are formed. The .DELTA.Vs values for each flow path are
stored in a memory having a predetermined number of memory cells, where a value
of .DELTA.Vs is stored in each cell. A determination is made if
there is a correlation in the stored values of .DELTA.Vs for each
flow path. If there is a correlation between the .DELTA.Vs values
for each path, a discrimination is performed between a correlation caused by
zero values of .DELTA.Vs stored in the memory for each path and a
correlation of .DELTA.Vs values reflecting that a transient in the
fluid in the pipeline has arrived at each site station. Then a determination is
made whether the correlation corresponds to a leak.
Method for Characterization of Fuels
Alexander; William
R. (Huntington, WV), Assignee: Marathon Ashland Petroleum LLC.
U.S. Patent
6,035,705, 14 Mar 2000
In a principal embodiment, the invention relates to a method in
which a water sample containing dissolved hydrocarbon fuel to be identified is
contacted with a fiber optic element adapted to adsorb a hydrocarbon fuel on at
least a portion of the element, for a time sufficient to adsorb a
characterizing amount of the fuel from the water sample. The fiber optic
element containing adsorbed hydrocarbon fuel is then removed from the water
sample, and then at least the portion of the fiber optic element containing
adsorbed fuel is immersed in or surrounded with water. The adsorbed hydrocarbon
fuel is allowed to desorb from the fiber optic element while the rate of
desorption of the fuel from the fiber optic element is measured by a fiber
optic chemical sensor system of which the fiber optic element is a part. The
set of values derived from the concentration measurements together identify or
characterize the hydrocarbon fuel, and may further be represented
mathematically by a desorption ratio value which is characteristic of the fuel.
Selective Multi-Chemical Fiber Optic Sensor
Sanghera;
Jasbinder S. (Greenbelt, MD); Pureza; Pablo C. (Burke, VA); Aggarwal; Ishwar D.
(Fairfax Station, VA); Nau; Gregory (Alexandria, VA), Assignee: The United
States of America as represented by the Secretary of the Navy (Washington, DC).
U.S. Patent 5,525,800, 11 Jun 1996
A fiber optic sensor for detecting at least one chemical by
evanescent wave spectroscopy comprises a generator of a light signal, a mirror
for introducing the light signal into a fiber, a clad optical chalcogenide
glass fiber, a mirror for directing the light signal from the fiber into a
detector, and a detector for detecting chemicals by the fiber. The fiber
comprises a core and a clad having lower refractive index than the core
enveloping and being in continuous contact with the core, at least one region
on the fiber completely or partially devoid of the clad, and a polymer disposed
in the region having affinity for the chemical(s). There being a different
polymer in each region if there is more than one region.
Method and Apparatus for Calibrating a Leak Detector
Filippi, Ernest A.; Kenneth L. Miller, Campo/Miller, Porterville, CA.
U.S. Patent 5,883,301. 28 pp, 16 Mar 1999
An automated calibration apparatus and method for calibrating an
electronic leak detection system for a fluid piping system uses a calibrated
leak device with an orifice that releases fluid at a constant calibrated leak
rate. The calibrated leak device is connected to the fluid piping system and a
pump is activated to pressurize the fluid piping system. The pump is
deactivated, and pressure decay in the fluid piping system resulting from fluid
release from the calibrated leak device is measured. The leak sensitivity of
the leak detector is then adjusted based on the measured pressure decay versus
time with the calibrated leak. More information:
http://www.uspto.gov/patft/index.html
Automatically Calibrated Pressurized Piping Leak Detector
Inventors: Filippi, Ernest A.; Kenneth L. Miller. Patent Assignee:
Campo/Miller, Porterville, CA.
U.S. Patent 5,526,679, 18 Jun 1996
A pressure decay leak detection system is calibrated for a
particular piping system using a leak mechanism with a known leak rate attached
to the piping system. Pressure decay in the piping system is monitored while
the system is leaking, pressure versus time data defining an acceptable
pressure decay profile is stored. In one embodiment, this data is scaled to
obtain a profile applicable to different leak rates. The detection system
performs a test by sensing decaying pressure in the piping system, determining
a slope of measured pressure decay versus time for an increment of pressure
decay, comparing a slope of the observed pressure decay with a slope of the
acceptable pressure decay profile, and providing a failure indication if the
slope of the observed pressure decay exceeds the slope of the acceptable
pressure decay profile.
Hazardous Fluid Leak Detector
Inventors: Gray, Harold
E.; Felder M. McLaurin; Monico Ortiz; William A. Huth. Patent Assignee: The
United States of America as represented by the United States Government,
Washington, DC.
U.S. Patent 5,517,181, 14 May 1996
A device or system for monitoring for the presence of leaks from a
hazardous fluid is disclosed that uses two electrodes immersed in deionized
water. A gas is passed through an enclosed space in which a hazardous fluid is
contained. Any fumes, vapors, etc. escaping from the containment of the
hazardous fluid in the enclosed space are entrained in the gas passing through
the enclosed space and transported to a closed vessel containing deionized
water and two electrodes partially immersed in the deionized water. The
electrodes are connected in series with a power source and a signal, whereby
when a sufficient number of ions enter the water from the gas being bubbled
through it (indicative of a leak), the water will begin to conduct, thereby
allowing current to flow through the water from one electrode to the other
electrode to complete the circuit and activate the signal. The invention
described here was developed under Contract No. DE-AC08-88NV10617 between the
United States Department of Energy and EG&G Energy Measurements, Inc.
Airborne Geophysical Surveying for Hazardous Waste Site
Characterization on the Oak Ridge Reservation, Tennessee
Doll, W.E.
(Oak Ridge National Lab., Oak Ridge, TN); J.E. Nyquist (Temple Univ.,
Philadelphia, PA); L.P. Beard (Geological Survey of Norway, Trondheim, Norway);
T.J. Gamey (Oak Ridge National Lab., Oak Ridge, TN).
Geophysics, Vol 65 No
5, p 1372-1387, Sep-Oct 2000
Airborne geophysical methods that were developed for mineral and
petroleum exploration can, with some modification, be applied to environmental
problems where large areas must be characterized. A helicopter survey that
deployed magnetic, electromagnetic, and radiometric sensors carried out one of
the first large-scale airborne environmental surveys at a U.S. government
facility at Oak Ridge, Tennessee in 1993 1994. The survey included testing of a
new airborne electromagnetic system designed specifically for environmental
applications and for controlled field tests of magnetic systems.
Helicopter-borne magnetic measurements were capable of discriminating groups of
as few as ten metallic 208-liter (55-gallon) storage drums under representative
field conditions. Magnetic and electromagnetic sensors were able to distinguish
groups of metal-filled waste disposal trenches within disposal sites, but were
unable to resolve individual trenches. Electromagnetic data proved to be the
most effective airborne technique for geological mapping in this portion of the
Appalachian fold-and-thrust belt and for locating karst features. Radiometric
measurements were useful both in geological mapping and in detecting zones of
high radiation related to hazardous waste. The Oak Ridge survey proved valuable
for quickly screening large areas and for locating anomalies for subsequent
ground follow-up. On-board video was used to reduce the number of instances of
ground follow-up by allowing the visual screening of anomalous areas.
DC Resistivity and IP Methods in Acid Mine Drainage Problems:
Results from the Copper Cliff Mine
Tailings Impoundments
Yuval;
Douglas W. Oldenburg, U.B.C.-Geophysical Inversion Facility, Dept. of
Geophysics and Astronomy, Univ. of British Columbia, Vancouver, BC, Canada.
Journal of Applied Geophysics, Vol 34 No 3, p 187-198, 1996
Oxidation of sulfide minerals in the mine tailings impoundments at
Copper Cliff, Ontario generates acidic conditions and elevated concentrations
of dissolved metals and sulfates in the pore water. The pore water migrates
away from the tailings to pose a potential environmental hazard if it should
reach nearby water systems. There is a need to characterize this potential
environmental problem and to assess the future hazards. A combined DC
resistivity and Induced Polarization (IP) survey was carried out along one of
the major flowpaths in the tailings and the data were inverted to produce
detailed electrical conductivity and chargeability structures of the cross
section below the survey line. The conductivity distributions are directly
translated, through theoretical and empirical relations, to a map of the
concentration of the total dissolved solids (TDS) along the cross section and
thereby provide insight about the current pore water quality. The sulfide
minerals are the source of the IP response and thus, when combined with
borehole data, the chargeability model can be used to estimate the amount and
distribution of the sulfides.
3D Resistivity Imaging of Buried Oil- and Tar-Contaminated
Waste Deposits
Chambers, Jonathan (Fluid Processes and Waste Management
Group, British Geological Survey, Keyworth, Nottingham, UK); Richard Ogilvy;
Philip Meldrum; Johan Nissen (ABEM Instrument AB, Sundbyberg, Sweden).
European Journal of Environmental and Engineering Geophysics, Vol 4, p
3-15, 1999/2000
This case study illustrates the advantages of 3D resistivity
surveys for mapping concealed, highly irregular tarpits containing industrial
waste, mainly from oil reprocessing and coal mining. The survey was carried out
using a network of individual lines within a grid measuring 95 m x 95 m. The
data were modelled using a 3D inversion program (RES3DINV) and the resulting
resistivity distributions were then displayed as volumetric 3D tomograms. Three
zones of low resistivity were identified as pits 4N, 4S, and 1A, respectively.
The model provided valuable diagnostic information on the geometry of the pits,
the distribution and nature of in-filling waste materials, and zones where
leachate had infiltrated the bedrock. The results were confirmed by trial pits,
cone penetration tests, historic photographs, and boreholes.
Chemical Soil Physics Phenomena for Chemical Sensing of Buried
UXO
Phelan, James M.; Stephen W. Webb, Sandia National Lab.,
Albuquerque, NM.
UXO Forum 1999, 25-27 May 1999, Atlanta, GA
Technology development efforts are under way to apply chemical
sensors to discriminate inert ordnance and clutter from live munitions that
remain a threat to reutilization of military ranges. The chemical signature is
affected by multiple environmental phenomena that can enhance or reduce its
presence and transport behavior and affect the distribution of the chemical
signature in the environment. For example, the chemical can be present in the
vapor, aqueous, and solid phases. The distribution of the chemical among these
phases, including the spatial distribution, is a factor in designing
appropriate detectors, e.g., gas, aqueous or solid phase sampling instruments.
To minimize the consequences of a false negative, a fundamental understanding
of the environmental conditions that affect the chemical signature is needed to
describe the favorable and unfavorable conditions of a chemical detector-based
survey. UXO source emission measurements are being made to estimate the
chemical flux from a limited set of ordnance items. Phase partitioning analysis
has been completed to show what the expected concentrations of chemical
analytes would be from total concentrations measured in the soil. The soil
moisture content in the dry region has been shown to be critical in the
attenuation of soil gas concentrations by increased sorption to soil particles.
Numerical simulation tools have been adapted to include surface boundary
conditions such as solar radiation, surface boundary layer (which is a function
of wind speed), precipitation and evaporation, and plant cover/root density to
allow transport modeling and evaluate long term processes. Results of this work
will provide performance targets for sensor developers and support operational
decisions regarding field deployments. More information:
http://www.uxocoe.brtrc.com/UXOForumDocs/Forum99/UT_Phelan.pdf
DC Resistivity and Induced Polarisation Investigations at a
Waste Disposal Site and Its Environments
Aristodemou, E.; A.
Thomas-Betts, T.H. Huxley School of Envt., Earth Science and Eng., Royal School
of Mines, Imperial College of Science, Technology and Medicine, London, UK.
Journal of Applied Geophysics, Vol 44 No 2-3, p 275-302, 2000
The authors relied on the results of geoelectrical surveys carried
out to monitor the spread of contamination in underlying aquifers from a
landfill site to estimate the hydraulic conductivities in a contaminant
transport model. The type of waste deposited and the influence of the
geological environment were the crucial factors investigated via DC resistivity
and time domain induced polarisation (IP) methods. The landfill was mainly a
liquid disposal site with existing borehole information showing that the waste
contained high concentrations of both inorganic (chlorides, sulphates) and
organic matter (indicated by high values of chemical oxygen demand and total
organic carbon). The aquifer system consists of three sand aquifers with
intervening semi-pervious clay aquitards. The presence of organic waste was a
factor in suggesting that the IP method could be employed as a diagnostic tool.
The IP measurements showed high apparent chargeability values (80-120 ms) on
top of the landfill, possibly due to the presence of disseminated solid
metallic waste or the high organic load of the liquid waste present. The IP
line parallel to the ground-water flow direction and close to the landfill
produced chargeability anomalies that may be associated with a plume of organic
waste. No chargeability anomalies were observed on the second IP line. The bulk
resistivities o obtained from the resistivity inversions and the
fluid resistivities w from adjacent boreholes allowed hydraulic
conductivities to be estimated.
First LC/MS Determination of Cyanazine Amide, Cyanazine Acid,
and Cyanazine in Groundwater Samples
Ferrer, I.; D. Barcelo; E.M.
Thurman.
Environmental Science & Technology, Vol 34 No 4, p 714-718,
2000
Cyanazine and two of its major metabolites--cyanazine amide and
cyanazine acid--were measured at trace levels in ground water using liquid
chromatography/atmospheric pressure chemical ionization/mass spectrometry
(LC/APCI/MS). Solid-phase extraction was carried out by passing a 20 mL
ground-water sample through a cartridge containing a polymeric phase (PLRP-s),
with recoveries ranging from 99 to 108% (n) 5. Using LC/MS detection in
positive ion mode, useful structural information was obtained by increasing the
fragmentor voltage, which permitted the unequivocal identification of the
compounds in ground-water samples with low sample volumes. The newly developed
method was evaluated for the analysis of ground-water samples from a New York
site affected by the compounds under study. The results suggest that the
metabolites cyanazine acid and cyanazine amide may leach to ground water and
serve as sources for deisopropylatrazine.
OINT 3D Interpretation of Radio-Magnetotelluric (RMT) and
Transient Electromagnetic (TEM) Data from an Industrial Waste Deposit in
Mellendorf, Germany
Hordt, A. (Inst. für Geophysik und
Meteorologie der Univ. zu Köln, Köln, Germany); S. Greinwald
(Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover,
Germany); A. Hoheisel; F.M. Neubauer; G. Schaumann; B. Tezkan.
European
Journal of Environmental and Engineering Geophysics, Vol 4, p 151-170,
1999/2000
A radiomagnetotelluric (RMT) and central loop transient
electromagnetic (TEM) survey was carried out over an industrial waste disposal
site in Germany. The combined application was intended to obtain a good
resolution over the entire depth of the range of interest. The RMT data provide
information on the shallower structures, while the TEM data are sensitive to
the deeper section, with an overlapping range in between. First, the data are
interpreted separately, using 1D inversion for the TEM data, and 2D inversion
for the RMT data. The results are combined into a 3D starting model for the TEM
data, which is modified using a trial-and-error forward modeling strategy. In
the joint interpretation step, the model is further modified until a
satisfactory fit to both data sets is obtained. The waste disposal site was not
sealed at the bottom; hence, the focus of the interpretation is on whether
chemical compounds of the wastes (mainly magnesium drosses) might have
penetrated into the deeper environment. A modeling study based on the final 3D
model shows clear evidence for a significant amount of conductive material
below the assumed bottom of the disposal. The migration was confirmed by
drilling tests. The joint interpretation reduced ambiguity and provided greater
confidence in the result when it was compared to a separate interpretation.
Secondary Ion Mass Spectrometry Investigation of Interfacial
Chemistry of Intact Microorganisms
Ingram, J.C. (Idaho National
Engineering and Environmental Lab., Idaho Falls, ID); F.S. Colwell; R.M.
Lehman; W.F. Bauer; A.D. Shaw (Westminster Christian Academy, St. Louis, MO).
Eos: Transactions of the AGU, Vol 81 No 48, Fall Meeting Supplement,
2000
Rapid detection of intact microorganisms remains a difficult
problem, despite its importance in environmental remediation and subsurface
science. The authors are evaluating static secondary ion mass spectrometry
(SIMS) methods as a means for rapidly detecting and identifying intact
microorganisms. The basis for the approach is to use SIMS to probe the top
layers of the surface to collect unique mass spectral signatures of the cell
membrane chemistry of a microorganism by analyzing intact cells with no sample
preparation. In a previous study, a method for identifying the mineral phases
of basalt surfaces utilizing imaging SIMS was developed to provide a tool for
investigating the interfacial chemistry of contaminants present in subsurface
basalt and sediments. SIMS provides an advantage over other techniques as it
probes only the top few layers of the sample surface, and it is highly
sensitive for both elemental and molecular species. An extension of this work
is to apply SIMS to the detection of microorganisms with the end goal of
utilizing SIMS to investigate microbial communities directly on the rock
surface. Initial work involved collecting SIMS spectra of 38 microorganisms to
be were compared to fatty acid profiles determined by the Microbial
Identification System, which is based on gas chromatographic data. The results
indicate that surface bombardment using a molecular primary beam cleaves the
ether linkage characteristic of Archea at the glycerophosphate backbone of the
phospholipid components of the cell membrane. Similar cleavage at the ester
linkage in Eubacteria is also observed. This cleavage enables direct detection
of the fatty acid conjugate base by static SIMS. In addition to the fatty acid
detection, partial least squares analyses of the SIMS data were performed to
determine if SIMS was capable of differentiating Gram positive and Gram
negative bacteria. These results show a clear grouping of the Gram-positive
species and Gram-negative species We have observed evidence that suggests SIMS
has the capability of probing other chemistries present in the cell membrane.
An example of this is the comparison of SIMS spectra of two strains of
Shewanella alga (BrY and adhesion deficient RAD20), which differ
mainly in their ability to bind to ferric oxides. Biochemical evidence showed
that the BrY strain contained proteins on the cell surface which enabled
adhesion to occur whereas those proteins were absent in the adhesion-deficient
RAD20 strain. The SIMS cation spectra of these strains shows marked differences
in the even mass ions which suggests that the differences in protein
composition of these two strains is reflected in the SIMS data.
VLPI Develops Test for Major Contaminant: PurTest® MTBE
Leads Water Industry
Vital Living Products, Inc., News Release, 17 Jul
2001
Vital Living Products, Inc., of Matthews, North Carolina,
announces that it has developed PurTest® MTBE, part of a comprehensive line
of do-it-yourself home water testing kits. This is the first consumer test for
widespread water contamination caused by MTBE (methyl tertiary-butyl ether), a
potential carcinogen. MTBE is a gasoline additive used over the past 20 years
to enhance gasoline combustion and reduce tailpipe emissions, especially carbon
monoxide. MTBE readily dissolves in water and moves rapidly through soils and
aquifers, thus contaminating water supplies in both private and public wells.
PurTest® MTBE will give a positive test result when 15 parts per billion
are detected with the at-home test. The MTBE test kit will be available at
retail locations nationwide for under $20.00.
Gas Chromatographic Techniques and Applications
Handley, Alan J.; Edward R. Adlard.
Sheffield Academic Press,
Sheffield, UK. ISBN: 0849305217. 320 pp, 2001
This volume provides an overview of the state of the art in gas
chromatography with an emphasis on new technologies. The authors--all drawn
from respected industrial and academic laboratories --consider developments in
gas chromatographic techniques over the last decade. Application areas are
addressed within individual chapters.
VLF-R and EM-31 Measurements at Three Closed Landfills in
Western Finland (DeP1)
Rajala, P.
Proceedings of the Fifth
International Meeting of the Environmental and Engineering Geophysical Society,
September 1999, Budapest, Hungary
Abstract DeP1 is not available.
Detection of Subsurface Hydrocarbon Contamination Using Various
Geophysical Methods (DeP2)
Holczinger, I.
Fifth Meeting of
Environmental & Engineering Geophysical Society European Section, 6-9
September 1999, Budapest, Hungary
Anstract DeP2 not available.
DC Resistivity Monitoring of the Unsaturated Zone Beneath a
Lined Landfill Site in the UK (DeP3)
Taylor, S.B.; R.D. Barker.
Fifth Meeting of Environmental & Engineering Geophysical Society
European Section, 6-9 September 1999, Budapest, Hungary
Abstract DeP3 not available.
Resistivity and Inductive Electromagnetics for Delineation
Studies of Leakage from a Waste Deposit in Southern Sweden (DeP4)
Wisén, R.; T. Dahlin; C. Bernstone.
Fifth Meeting of
Environmental & Engineering Geophysical Society European Section, 6-9
September 1999, Budapest, Hungary
Abstract DeP4 not available.
Landfill Monitoring by Airborne EM and Ground Resistivity
Measurements (DeP6)
Lohva, J.; T. Jokinen; H. Vanhala; M. Lahti.
Fifth Meeting of Environmental & Engineering Geophysical Society
European Section, 6-9 September 1999, Budapest, Hungary
Abstract DeP6 not available.
Application of Geoelectrical Methods to the Detection of
Polluted Soils at Shallow Depth (DeP7)
Zuberek, W.M.; B. Zogala; J.
Pierwola.
Fifth Meeting of Environmental & Engineering Geophysical
Society European Section, 6-9 September 1999, Budapest, Hungary
Abstract DeP7 not available.
Detection of Hydrocarbon Contaminated Soils by Electromagnetic
Techniques (INCO-Copernicus IC-15-CT96-0801) (DeP8)
Derobert, X.; Ph.
Cote; M. Piccolo.
Fifth Meeting of Environmental & Engineering
Geophysical Society European Section, 6-9 September 1999, Budapest, Hungary
Abstract DeP8 not available.
Remediation of As-Organic CW Contaminated Sites (DeP9)
Spyra, W.P.W.
Fifth Meeting of Environmental & Engineering
Geophysical Society European Section, 6-9 September 1999, Budapest, Hungary
Abstract DeP9 not available.
Difference Inversion of ERT Data: a Fast Inversion Method for
3-D In Situ Monitoring
LaBrecque, Douglas J. (Multi-Phase Technologies
LLC, Sparks, NV); Xianjin Yang (Advanced Geosciences, Inc., Austin, TX).
Journal of Environmental & Engineering Geophysics, Vol 6 No 2, p 83 89,
2001
A 3-D Occam's inversion algorithm for electrical resistivity
tomography was modified to allow for inversion on the differences between the
background and subsequent data sets. The algorithm has been optimized for in
situ monitoring applications. The resistivity obtained by the inversion of
background data serves as the a priori model in the difference inversion. There
are several advantages to this method: convergence is fast, since the inverse
routine needs only to find small perturbations about a good initial guess; and
systematic errors such as those due to errors in field configuration and
discretization errors in the forward modeling algorithm tend to cancel. The
result is that we can fit the difference data far more closely than the
individual potentials. Better data fits often equate to better resolution with
fewer inversion artifacts. The difference inversion technique was applied to
monitoring in situ steam remediation in Portsmouth, Ohio, and monitoring flow
in fluid fractures at the Box Canyon site near the Idaho National Engineering
Laboratory. Difference inversion produced high-quality images with fewer
artifacts, and only took 25 to 50% of the run time of standard Occam's
inversion in the Box Canyon case.
The Effects of LNAPL Biodegradation Products on Electrical
Conductivity Measurements
Cassidy, Daniel P. (Western Michigan Univ.,
Kalamazoo, MI); D. Dale Werkema Jr.; William Sauck; Estella Atekwana; Silvia
Rossbach (Univ. of Missouri Rolla); Joe Duris.
Journal of Environmental
& Engineering Geophysics, Vol 6 No 1, p 47-52, 2001
Laboratory experiments were conducted to test the hypothesis that
anomalously high conductivities in and below the free-product zone found at
many sites with aged contamination by LNAPLs can result from products of LNAPL
biodegradation. Soil from a hydrocarbon-impacted site with anomalously high
conductivities was washed repeatedly to remove soluble constituents,
re-contaminated with diesel fuel (DF), and the pores filled with water to
simulate a saturated smear zone. Nutrients were provided at levels
approximating those observed at the site, which resulted in anaerobic
conditions due to DF biodegradation. Within 120 days, the increase in specific
conductivity from microbial activity was 2,100 S/cm, caused by an increase in
total dissolved solids (DS) of over 1,700 mg/L. The results show that products
of LNAPL biodegradation can dramatically increase the conductivity at impacted
sites.
Geophysical Mapping of a Shallow Contaminant Plume in Thin
Glacial Till, Northeast Newfoundland
Guzzwell, G. Keith, Dept. of
Environment and Labour, Government of Newfoundland and Labrador,
St.
John's, Newfoundland, Canada.
Journal of Environmental & Engineering
Geophysics, Vol 4 No 4, p 241-249, 1999
Geophysical techniques have been used to map the lateral extent of
a ground-water contaminant plume in a region of thin glacial till overburden at
a domestic waste disposal site in Newfoundland. This site is typified by waste
cells that have significant quantities of material above the water table. VLF
tilt angle, VLF-Resistivity, and terrain conductivity data were collected. The
depth to bedrock at each of the ten water monitoring wells located on the site
was known from drilling and used to derive the top layer resistivity
distribution over the grid. This resistivity was then used in an algorithm to
determine the depth to bedrock at each grid point and to produce a bedrock
topography map. Two bedrock channels, along which contaminant can flow down
slope, have been identified, one on each side of the site. The presence of
contaminant in these channels is identified from the terrain conductivity data
and the processed VLF tilt angle data. Ground probing radar (GPR) data were
collected along the road traversing the site. The GPR data clearly indicate the
boundaries of the waste cells, but bedrock cannot be unambiguously discerned.
The results from the geophysical surveys are highly correlated with chloride
ion concentrations in water samples from the wells in the study area.
Electromagnetic Induction and GPR Measurements for Creosote
Contaminant Investigation
Guy, Erich D. (U.S. EPA, Region V, Chicago,
IL); Jeffrey J. Daniels; Jennifer Holt; Stanley J. Radzevicius; Mark A. Vendl
(Dept. of Geological Sciences, Ohio State Univ., Columbus).
Journal of
Environmental & Engineering Geophysics, Vol 5 No 2, p 11-19, 2000
Multifrequency EM induction and GPR parallel dipole (co-pole) and
orthogonal dipole (cross-pole) surveys were conducted to assist in the
characterization of a former industrial site prior to its cleanup by the Ohio
EPA and the U.S. EPA. High concentrations of creosote are present in clay-rich
surficial soils as a result of many years of wood treating at the site. The
approximate extent of contamination at the site and the locations of several
contaminant-filled structures were determined through the use of
quadrature-phase EM data and cross-pole GPR data. These data formed basis for
the site remediation plan. Geophysical data interpretations were confirmed
through exploratory trenching and soil sampling subsequent to the completion of
the study, which demonstrates the potential for mapping the extent and
variation with depth of resistive compounds under circumstances where high
levels of contamination are present with relatively conductive background
materials. Cross-pole GPR data were more useful than co-pole data at the site
for imaging several structures containing creosote that would have remained
undiscovered and acted as future sources of contamination.
A New Method of Subsurface Imaging--the LASI High Frequency
Ellipticity System: Part 1. System Design and Development
Sternberg,
Ben K., Lab. for Advanced Subsurface Imaging (LASI), Dept. of Mining and
Geological Engineering, Univ. of Arizona, Tucson, AZ.
Journal of
Environmental & Engineering Geophysics, Vol 4 No 4, p 197-213, 1999
An electromagnetic (EM) imaging system has been developed that
allows enhanced identification of buried hazardous waste and contaminated soil
or ground water. This system utilizes frequencies in the range of 31 kHz to 32
MHz, a frequency range that lies between conventional low-frequency EM
induction surveys and high-frequency ground-penetrating radar (GPR) surveys.
This capability permits interpretation of both conductivity and dielectric
permittivity in loessy soils. Mapping the dielectric permittivity will allow
location of environmental targets that are not detectable with more commonly
used conductivity or resistivity tools. This paper details design and
development of the system. The design incorporates unique transmitter and
receiver coils which combine wide bandwidth and high sensitivity. It also
includes a method for eliminating electric-field interference, which is vital
for accurate measurements in this frequency range.
A New Method of Subsurface Imaging--the LASI High Frequency
Ellipticity System: Part 2. Data Processing and Interpretation
Birken,
Ralf A., Lamont-Doherty Earth Observatory of Columbia Univ., Palisades, NY.
Journal of Environmental & Engineering Geophysics, Vol 4 No 4, p
215-226, 1999
This paper is Part 2 of a three-part series. The author describes
data processing and interpretation for the subsurface imaging system developed
by the Laboratory for Advanced Subsurface Imaging (LASI) at the University of
Arizona. A unique, simultaneous-calibration method is used to measure the
magnetic-field ellipticity with very high accuracy. Four calibration signals at
frequencies f1, f2, f4, and f5) are injected into the receiver coils at the
same time that the data signal at frequency f3 is being received. The
calibration signals are interpolated in order to derive a calibration response
at the data frequency. A three-dimensional ellipticity is calculated from the
three components of measured magnetic field data.
A New Method of Subsurface Imaging--the LASI High Frequency
Ellipticity System: Part 3. System Tests and Field Surveys
Birken, Ralf
A., Lamont-Doherty Earth Observatory of Columbia Univ., Palisades, NY.
Journal of Environmental & Engineering Geophysics, Vol 4 No 4, p
227-240, 1999
This paper is Part 3 of a three-part series. It details five case
histories showing the use of the subsurface imaging system developed by the
Laboratory for Advanced Subsurface Imaging (LASI) at the University of Arizona.
The first case history involved tests over a "perfectly conducting earth,"
which was used for verification of the system response. The test was made over
an 8 m by 15 m aluminum sheet, which provided a good approximation to a
perfectly conducting earth. Since the electrical properties of a perfectly
conducting earth are precisely known, the researchers were able to accurately
calculate the expected electromagnetic response over the subject area. These
measurements were used to verify the system response and demonstrate that field
data that accurately matches model results can be produced. The second test was
over a homogeneous earth. The soil electrical properties at this site had been
previously characterized with well logs and with laboratory electrical-property
measurements. The third test used large-scale physical modeling. Measured
electromagnetic responses over barrels, pipes, and metal sheets closely matched
theoretical responses. The next two case histories were demonstration surveys
performed at DOE's Idaho National Engineering Laboratory (INEL). The first was
at a site known as the acid pit in the Radioactive Waste Management Complex
(RWMC) at INEL. This survey successfully mapped the subsurface extent of an
acid plume containing various hazardous materials. The second demonstration
took place at INEL's Cold Test Pit, which was designed to simulate hazardous
waste of the type that is buried at many DOE sites. The survey effectively
mapped the distribution of the various waste forms.
DC Resistivity Monitoring of Potassium Permanganate Injected to
Oxidize TCE In Situ
Nyquist, Jonathan E. (Temple University,
Philadelphia, PA); Bradley J. Carr (Oak Ridge National Lab., Oak Ridge, TN); R.
Kim Davis (Geophex, Inc., Raleigh, NC).
Journal of Environmental &
Engineering Geophysics, Vol 4 No 3, p 135-147, 1999
DOE's Office of Science and Technology selected the X-701B Site at
the Portsmouth Gaseous Diffusion Plant, Piketon, Ohio, for a demonstration of
in situ chemical oxidation. The goal was to oxidize trichloroethylene (TCE),
present in both the soil and ground water, by circulating a solution of
potassium permanganate between two horizontal wells. Potassium permanganate is
a salt. Laboratory measurements showed that the addition of 1% potassium
permanganate increased the fluid conductivity of a Portsmouth ground-water
sample from 339 to 7,250 mS/m, or equivalently, decreased the electrical
resistivity from 2.9 ohm-m to 0.14 ohm-m. Although the contaminated aquifer is
only about 1.5 meters thick at this site and is overlain by nearly 8 meters of
clay, geophysical modeling showed that if the injection flooded a sufficient
portion of the aquifer, the change in resistivity would be detectable from the
surface using DC resistivity. Field measurements made using a multi-electrode
resistivity system along two lines one parallel and one perpendicular to the
two horizontal wells showed that the potassium permanganate injection was
detectable as a subtle change in the resistivity data. The resistivity data
showed that the potassium permanganate did not migrate uniformly between the
two horizontal wells. Instead, both the resistivity data and a bromide tracer
test conducted in 1992 showed a zone of preferential flow at the southern end
of the wells. The agreement of the resistivity data with both the tracer test
data and with potassium permanganate levels measured in a network of monitoring
wells showed that it is feasible to use resistivity to monitor an electrolyte
injected in situ to oxidize contaminants. This study provides an example of how
geophysical methods can be used to reduce the number of ground-water wells
needed to monitor site remediation.
How Important is the Orientation of a Horizontal Loop EM
System? Examples from a Leachate Plume and a Fault Zone
Nobes, David
C., Dept. of Geological Sciences, Univ. of Canterbury, Christchurch, New
Zealand.
Journal of Environmental & Engineering Geophysics, Vol 4 No 2,
p 81-85, 1999
The coupling between a horizontal loop EM (HLEM) system and a
buried object, e.g., a buried pipe, is well-established; the response depends
on the orientation of the transmitter-receiver loop system relative to the
object in question. However, diffuse boundaries between terrain materials,
which even when highly contaminated are orders of magnitude less conductive
than metallic targets, do not respond like discrete buried objects. Survey
results from different sites illustrate that the difference due to system
azimuth is generally negligible.
Characterization of Disposal Sites from Surface Wave
Measurements
Haegeman, W.; W. F. Van Impe, Laboratory of Soil
Mechanics, Ghent University, Belgium.
Journal of Environmental &
Engineering Geophysics, Vol 4 No 1, p 27-33, 1999
Nonintrusive Rayleigh wave investigation using the
Spectral-Analysis-of-Surface-Waves (SASW) technique is a tool for
characterization of waste disposal sites in a broad range of waste materials.
Applications of SASW surveys for site characterization at waste fills include
determination of stiffness parameter profiles for the waste mass, evaluation of
cover thickness, location of native ground interface, and quantitative
monitoring of improvement techniques. SASW surveys at five waste fills in
Belgium composed of municipal waste, dredging sludge, and cinders or slags
demonstrate the potential applications of SASW and provide insight into typical
shear wave velocity profiles for treated and untreated waste materials. This
paper highlights some important areas in which the SASW technique can be used
successfully.
Landfill Delineation and Characterization Using Electrical,
Electromagnetic and Magnetic Methods
Lanz, Eva; Alan Green; David E.
Boerner; Hansruedi Maurer, Inst. of Geophysics, ETH-Hoenggerberg, Zurich,
Switzerland.
Journal of Environmental & Engineering Geophysics, Vol 3
No 4, p 185-196, 1998
Three geophysical techniques have been used to determine the
boundaries and contents of a small composite landfill. Initial widely spaced
electrical resistivity soundings and profiles provided gross information on the
distribution of electrical conductivity with depth and the approximate position
of the landfill. Frequency-domain electromagnetic data were then collected on a
dense grid that encompassed the landfill and surrounding sediments. Using a
simple new technique, these vertical- and horizontal-mode data were inverted
jointly to yield shallow electrical conductivities and approximate estimates of
magnetic susceptibility. Finally, optically pumped Cesium-vapor sensors were
employed in the acquisition of total-field and vertical-gradient magnetic data
over the same area as the electromagnetic data. Together, the resultant
geophysical data sets revealed two distinct waste pits separated by a zone of
undisturbed ground 20-40 meters wide. The irregular boundaries of the two waste
pits were determined equally well on the electrical conductivity, magnetic
susceptibility, and vertical-gradient magnetic maps. By comparing anomalies on
these maps, it was possible to distinguish ferrous and non-ferrous metallic
objects outside of the landfill and to identify sand- and gravel-rich units
within the dominantly fine-grain sediments of the region.
Hydrogeologic Site Characterization Using Azimuthal Resistivity
Surveys
Marin, Luis E. (Univ. Nacional Autonoma de Mexico, Mexico
City); Birgit Steinich; D. Jaglowski (Dept. of Civil and Environmental
Engineering, Univ. of Michigan, Ann Arbor); M.J. Barcelona.
Journal of
Environmental & Engineering Geophysics, Vol 3 No 4, p 179-184, 1998
The purpose of this paper is to evaluate whether azimuthal
resistivity surveys (ARS) provide diagnostic information for mapping preferred
hydraulic conductivity directions in unconsolidated sediments as they do in
fractures/jointed media. Nineteen azimuthal resistivity surveys (ARS) were
conducted in three different places within a shallow, unconsolidated, sand and
gravel aquifer located at the Michigan Integrated Remediation Technology
Laboratory (MIRTL). The observed electrical anisotropy ratios were not
significant enough to represent changes in the regional ground-water flow
direction. However, the results from this work suggest that ARS may be used as
part of an integrated hydrogeological study that may yield semi-quantitative
information of the electrical anisotropy with increasing electrode spacing.
Contributions of Surface Geophysics to Environmental Site
Investigation of Former Oil Distribution Terminals
Vickery, Anna C.;
Bruce A. Hobbs, Dept. of Geology and Geophysics, Univ. of Edinburgh King's
Buildings, Edinburgh, UK.
Journal of Environmental & Engineering
Geophysics, Vol 3 No 3, p 101-109, 1998
Before the start of invasive investigations at a site formerly
used to house oil distribution terminals, a trial geophysical survey was
conducted involving magnetics and electromagnetics. The trial demonstrated that
the electromagnetic technique, involving a Geonics EM31 soil conductivity
meter, was capable of detecting subsurface metal pipes and contaminant
concentrations resulting from the oil terminal works. Trial pits and trenches
validated the geophysical interpretation, even to the extent of finding tarry
contaminants emanating from the ends of broken pipes.
Choice of the Best Model in 2-D Geoelectrical Imaging: Case
Study from a Waste Dump Site
Olayinka, Abel I.; Ugur Yaramanci, Dept.
of Applied Geophysics, Technical Univ. of Berlin, Berlin, Germany.
European
Journal of Environmental and Engineering Geophysics, Vol 3, p 221-244, 1998
A procedure is presented for choosing the best model in 2-D
geoelectric imaging in the presence of a high-resistivity contrast. Inversion
of synthetic data using an algorithm based on the smoothness-constrained
non-linear least squares optimisation technique has shown that for high
resistivity contrasts the model misfit between the inverted model and the
original model increases with the iteration number. Consequently, the model
that best approximates the true model is attained at a relatively low iteration
number whereas the data misfit reduces to a minimum at higher iterations. A
case history from a waste dump site in Ibadan, south-western Nigeria, is
described. The solid geology comprises quartzite and quartz-schist that have
been extensively weathered and fractured. Inversion of the Wenner pseudosection
data indicates that the model bedrock resistivities at about the second
iteration are geologically realistic. The thickness of the waste dump varies
between about 2 to 17 m, while its resistivity is low and lies between 4 to 8 W
m. The low resistivity is due to the presence of leachate emanating from the
site and this has also polluted the surface waters and ground waters in the
immediate vicinity. The authors concluded that geoelectric imaging, with
appropriate geologic constraints provided a realistic subsurface image for the
noisy environment of the waste dump.
Heavy Metal Pollution Monitoring by Magnetic Susceptibility
Measurements Applied to Sediments of the River Mur (Styria, Austria)
Scholger, R., Inst. for Geophysics, Univ. of Leoben, Paleomagnetic
Lab., Frohnleiten, Austria.
European Journal of Environmental and
Engineering Geophysics, p 25-37, Vol 3, 1998-1999
The applicability of environmental magnetic methods to delineate
polluted areas and to quantitatively assess the degree of pollution was tested
for sediments of the river Mur in Styria (Austria). More than 500 samples from
a 190 km river section between Judenburg and Spielfeld were analyzed by means
of petrology, chemical and magnetic methods. The magnetic susceptibility of the
sediments was dominated by scale, which is a waste material from
metal-producing and metal-manufacturing processes. The linear regression of
magnetic susceptibility versus scale content was significant, with 2500*10-6 SI
= 1 percent scale (mass content). Chemical analyses of the samples established
a clear correlation of heavy metal concentration (especially Cr, Pb, and Zn)
with the scale content. Magnetic susceptibility thus provided an indicator for
the heavy metal contamination of the river sediments.
Investigation of Environmental Pollution Using Magnetic
Susceptibility Measurements
Gelioli, K.; A. Aydin, Dept. of Geophysical
Engineering, Karadeniz Technical Univ., Trabzon, Turkey.
European Journal
of Environmental and Engineering Geophysics, Vol 3, p 53-61, 1998
Magnetic susceptibility measurements were carried out to map
heavy metal pollution from an industrial plant and from cars on a major
highway. In the first case, magnetic susceptibility measurements were made to
determine the distribution of tailings including heavy metals from a flotation
plant. Both the magnetic surface susceptibility in the creek where the tailings
are discharged and the magnetic susceptibility of samples collected from the
creek and sea floor in a narrow area where the creek reaches the sea were
measured in the laboratory. In a mix of the clean sediment samples and tailings
collected from the outlet of the flotation plant, it was found that the
susceptibility decreases with increasing percentage of tailings. Subsequent
geochemical analysis confirmed that samples with low magnetic susceptibility
values had high heavy metal content. In the second case, surface magnetic
susceptibility measurements were made to find out the distribution of Pb
deposited from exhaust gases in an area near the highway west of Trabzon where
there is little variation in the sediment type. In the laboratory, a decrease
was observed in the magnetic susceptibility of a clean sediment sample which
was exposed to exhaust gases for some time. Geochemical sampling confirmed that
samples near the highway had relatively low magnetic susceptibility values,
whereas sediments away from the highway exhibited relatively high magnetic
susceptibility levels consistent with normal background geology. The authors
concluded that magnetic susceptibility surveys could provide a rapid
reconnaissance tool for mapping elevated levels of heavy metals and
anthropogenic pollution, by virtue of anomalous low susceptibility values.
Imaging of Industrial Waste Deposits and Buried Quarry Geometry
by 3-D Resistivity Tomography
Ogilvy, R. (British Geological Survey,
Keyworth, Nottingham, UK); P. Meldrum; J.Chambers (Dept. of Earth Sciences,
Univ. of Sheffield, Sheffield, UK).
European Journal of Environmental and
Engineering Geophysics, Vol 3, p 103-113, 1998
The authors present a case study to show the advantages of
non-invasive 3-D resistivity surveys for mapping spatially complex and
hazardous waste landfills, sites where industrial wastes had been deposited
over many years in abandoned sandstone quarries. The survey was undertaken to
determine the buried quarry geometry, the depth and nature of overlying
backfill, and possible fluid infiltration of the bedrock. The study confirmed
that where fluid invasion of the quarry walls is negligible, the strong
resistivity contrast with the confining sandstone provided a basis for mapping
the quarry boundaries and depth to bedrock. Where fluid migration into the
surrounding rocks and fill occurs, the geometry and physical limits of the
quarry edge are more difficult to establish. The results showed that the fill
material and minimally invaded sandstone had similar or overlapping resistivity
values; however, these respective units could usually be distinguished on the
basis of their differing spatial geometry when viewed in 3-D space. The results
demonstrate the importance of full 3-D inversion for accurate target diagnosis.
A 3-D visualization software was used to show the volumetric distribution of
intrinsic resistivities obtained from the 3-D inversion models for each area.
The software was used to interactively slice and view user-defined
iso-resistivity volumes. This approach allowed irregular or complex features to
be visualized more readily than in the case of 2-D vertical or horizontal
sections.
DC Resistivity and Time-Domain Induced Polarization Survey for
the Study of Groundwater Contamination in Bahia, Brazil
Ruhlow, A.
(Inst. of Geophysics and Meteorology, Univ. of Köln,
Albertus-Magnus-Platz, Köln, Germany); B. Tezkan; O.A.L. de Lima
(Universidade Federal de Bahia, Campus Univ. da Federaço,
Inst. de
Geociências, Salvador, Bahia, Brazil).
European Journal of
Environmental and Engineering Geophysics, Vol 3, p 143-160, 1998
DC resistivity and time-domain induced polarization (IP)
measurements were performed near an open-air basin which was used for many
years by a huge petrochemical complex in Bahia, Brazil, as a site for liquid
organic and inorganic waste disposal. 1-D inversion of resistivity measurements
delineated the local geological structure, as well as contaminated zones
indicated by conductive anomalies. 3-D DC forward modeling was employed to
examine lateral effects of a lake as a possible reason for these anomalies.
Finally, the interpretation of the chargeability data allowed the distinction
between the local occurrence of lenses of shale and contaminated ground
regions, which could not be inferred through resistivity measurements
alone.
VLF Used for Waste-Site Assessment
Beamish, D.; P.
Meldrum; R. Ogilvy.
European Journal of Environmental and Engineering
Geophysics, Vol 3, p 161-178, 1998
The authors examine the applicability of the electromagnetic VLF-R
(Resistivity) method for waste-site assessment. The frequencies used in
conventional VLF (15 to 30 kHz) provide the deepest penetrations of the
multi-frequency extended method of RadioMT. Both methods are appraised. VLF
data, being effectively single frequency, are insufficient to resolve 1-D
(vertical) structure in any detail. However, at the site investigation scale,
the departures from the background, vertically uniform structure are of
interest. The purpose of this paper is to demonstrate the degree to which
quantitative resistivity information can be obtained from VLF-R data in the
context of waste-site assessment when highly conductive leachates are
encountered. Improved methodologies for the quantitative assessment of VLF data
derive from advances in standard inversion techniques. VLF-R survey data at a
former industrial waste site, aided by wide-band (VLF/RadioMT) synthetic
modeling and inversion studies, are used to illustrate their shallow (0 to 20
m) resolution capabilities in conductive environments. The application of 2-D
standard (smooth-model) inversion to single-frequency VLF-R survey data is
found to be effective provided the noise (non-2-D) components of profile data
are understood.
DC Resistivity Mapping of Old Landfills: Two Case Studies
Bernstone, Christian; Torleif Dahlin, Dept. of Geotechnology, Lund Univ.,
Lund, Sweden.
European Journal of Environmental and Engineering Geophysics,
Vol 2, p 121-136, 1997
Geophysical investigations were carried out on two old
waste-disposal sites in the province of Scania in southern Sweden. The
objectives of the surveys were to map the internal structure and to delineate
the extent of deposited waste, as well as to gain information about the local
geology. The methods used were 2-dimensional DC resistivity, frequency-domain
electromagnetics (slingram/FDEM), and magnetics. The resistivity data sets were
interpreted with 2-D smoothness-constrained inversion, and the FDEM and the
magnetic data sets were contoured. The surveys identified the positions of
buried metal objects and delineated sludge ponds, a coastal saltwater front,
and geological structures. In addition, leakage plumes were identified at
Lernacken by the resistivity survey. The slingram EM equipment was rapid,
whereas the 2-D DC resistivity surveys provided valuable depth information that
allowed the construction of quasi-3-D models of the ground. The in-phase
component in slingram measurements was especially good in localizing individual
metal objects, but the total field magnetic measurements also worked well.
Theoretical Solutions for Calculating Leakage Through Composite
Liner Systems
Rowe, R.K.; J.R. Booker.
Developments in Theoretical
Geomechanics, Proceedings. 16-17 November 2000, Sydney, Australia, p 589-602,
2000
No abstract available.
Application of Remote Sensing Data for Monitoring of Gas
Pipeline Right-of-Way
Fung, K.B.; D.W. Fraser; R.P. Gauthier.
Proceedings of GIS '98/RT'98, 6-9 April 1998, p 401-404, 1998
Even though most of the Canadian oil and gas pipelines are buried
underground, they can still pose a threat to a fragile environment. Over the
last 10 years, monitoring of the network has been done mainly through the use
of black and white aerial photographs, ground surveys, and airborne inspection
to locate disturbances to the network by accidental spills, encroachment from
human activities, and land form changes due to fires, floods, and other natural
events. Under the Local Environmental Applications Program, NOVA Gas
Transmission Ltd. is collaborating with the Canada Centre for Remote Sensing
(CCRS) in a demonstration project to use remote sensing techniques for
monitoring the pipeline right-of-way. This paper presents some of the GIS
concerns in the project.
True Elemental Speciation in Liquid Chromatography Through
Particle Beam Glow Discharge Mass and Optical Spectrometries
Marcus, R.
Kenneth (Clemson Univ., Clemson, SC); Terri E. Gibeau; Melissa A. Dempster;
Brad Knippel.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
The researchers have coupled a particle beam LC-MS interface to a
hollow cathode discharge source (PB-HC) to develop a new type of atomic
emission and mass spectrometry detector for speciation studies employing HPLC
separations. In the case of AES, trace metals can be determined at the ppb
level, with C and H (from ligands) being quantified at the single ppm level.
Ratios of non-metal responses provide empirical formula data. For example, each
of the natural amino acids can be identified by the ratios of the C/H/N
components. Mass spectrometric sampling of the HC plasma produces electron
impact-type spectra for organic and organometallic compounds, while free metal
ions permit the use of isotopic patterns for identification and quantification
through isotope dilution. The paper presents the analytical figures of merit
for the PB-HC-AES/MS systems described here. The ability of the PB-HC couplings
to characterize combined organic/inorganic sample types has been demonstrated
through the analyses of dietary supplements and mixtures of organometallic
compounds. Much work remains to be done to make this a truly viable approach.
Gas Chromatography Coupled with Plasma Mass Spectrometry for
Speciation: Current Status
Evans, E. Hywel (Univ. of Plymouth,
Plymouth, UK); Gavin O'Connor; Bernd Rosenkranz.
PITTCON 2000, 12-17 March
2000, New Orleans, Louisiana
In the search for an analytical method that is both universal and
selective in nature, and is also highly sensitive, no single instrument has
been developed yet that will accomplish this task. No single source exists that
is truly capable of producing molecular ions, fragment ions, and atomic ions
solely by varying operating conditions. Such a source would facilitate
selective quantitative analysis and qualitative characterization of analyte
compounds. This paper outlines the different types of sources coupled with mass
spectrometry that the authors have been investigating for use in speciation
analysis. Examples are given of microwave and inductively coupled plasmas at
atmospheric and low pressure used for element selective detection and as
tuneable sources. The authors present examples of applications for
environmental monitoring of organo-halide and organo-metallic compounds and
describe recent progress in coupling liquid chromatography with a low pressure
ICP.
Structural Elucidation of Phospholipid Fatty Acids of
Sedimentary Marine Bacteria by GC/MS Analysis of N-acylpyrrolidides Derivatives
and Dimethyldisulfides Adducts: A Potential Tool to Evaluate Bioremediation of
Oil-Contaminated Areas
Aries, Eric (Faculté des Sciences de
Saint-Jérôme, Univ. d'Aix-Marseille, Marseille, France); Pierre
Doumenq; Monique Acquaviva; Jacques Artaud; Jean-Claude Bertrand; Mille
Gilbert.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
Marine sedimentary bacteria involved in degrading crude oil
trapped in marine sediments are known to modify their phospholipid fatty acids
(PLFA) in response to environmental shills. This study was undertaken to
determine effects of petroleum hydrocarbons on PLFA profiles of two consortia
of hydrocarbonoclastic bacteria. The goal was to identify possible biomarkers
or characteristic PLFA profiles indicative of hydrocarbonoclastic bacterial
activity. Bacterial consortia were reconstituted in vitro by assembling pure
marine bacterial hydrocarbonoclastic aerobic strains from a highly contaminated
sediment collected near the petroleum industry site of Lavera (Golfe de Fos,
France). The consortia were grown successively on a soluble ammonium acetate
medium, then on an hydrophobic substrate made of blend Arabian light oil (BAL
250). PLFA methyl esters derivatives were analyzed by GC/MS. Double bond and
alkyl branches in fatty acids were confirmed by GC/MS analysis of N-acyl
pyrrolidides derivatives and dimethyldisulfides adducts. Growth of consortia on
BAL 250 resulted in complex phospholipid fatty acids profiles, exhibiting high
amounts of odd saturated, odd monounsaturated, and series of branched fatty
acids. Based on those data, a petroleum-utilization index was proposed to
discriminate bacterial grown on ammonium acetate and on petroleum. This index
is of potential interest for monitoring bioremediation in oil-contaminated
areas, because it might offer in situ evidence of the development of
hydrocarbonoclastic strains actively involved in biodegradation processes.
A Novel, Inert, Low-Bleed Column for GC/MS
Vickers,
Allen K. (J&W Scientific, Inc., Folsom, CA); Roy M. Lautamo; Eberhardt R.
Kuhn.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
In recent years, attempts to create new low-bleed phases often
were based on arylene-type polymer chemistry. However, this approach is not
possible for 100% dimethyl silicone phases. Through the development of an
innovative manufacturing technique it is now possible to make inert, low-bleed
columns that are truly 100% dimethyl siloxane. The new DB-1 ms shows
exceptional inertness towards both acids and bases. The creative manufacturing
process reduces the bleed, making this new column a true 100% dimethyl phase
specifically designed for GC/MS. And, since it is truly 100% dimethyl, its
selectivity is virtually identical to regular 100% dimethyl phases. This paper
presents examples of this inertness and low bleed, comparisons to other 100%
dimethyl columns, and applications where those characteristics are
important
Design and Optimization of Capillary Column Stationary Phases
for Volatiles by GC/PID-ELCD and GC/MS
English, Chris M. (Restek Corp.,
Bellefonte, PA); Dinesh Patwardhan; Frank L. Dorman; Mike J. Feeney.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
With recent changes in U.S. EPA methods for the analysis of
volatiles by GC/PID-ELCD, many laboratories have been struggling to achieve
resolution of a compound list that is continually expanding. All of the current
phases available for these types of analysis suffer from lack of resolution
between specific compounds, and many also suffer from low thermal stability and
long analysis times. The first half of this paper will discuss an alternative
GC column that addresses these issues, designed using computer modeling and new
stationary phase functionalities. For years laboratories have been using the
"624 / 1301" phase for the analysis of volatiles by GC/MS. There are a variety
of problems associated with this column such as co-elutions of target
compounds, which share the same primary quantitation ions. This paper discusses
the limitations of current columns and the thermodynamic modeling that was used
in the development of a new stationary phase, taking into account the specific
requirements of the MS system. Compound lists and phase requirements were
determined using EPA methods in collaboration with environmental laboratories
across the country.
The Design of a New Capillary Gas Chromatographic Column for
the Analysis of Dioxins and Furans
Dorman, Frank L. (Restek Corp.,
Bellefonte, PA); Eric J. Reiner; Mike J. Feeney; Chris M. English.
PITTCON
2000, 12-17 March 2000, New Orleans, Louisiana
Laboratories performing dioxin and furan analyses (ca. U.S. EPA
8290) struggle with achieving the desired resolution for the specific congeners
in a reasonable amount of time because no commercially available phase was
designed with this separation in mind. This has lead to laboratories using 5%
phenyl/95% methyl polysiloxane phases for their thermal stability, and
high-cyano-propyl phases for their ability to separate a few specific
congeners. The 5% phenyl phases do not separate all congeners as well as
desired, resulting in laboratories needing to confirm analyses on the
high-cyano phases, which have short lifetimes under the conditions that must be
used for this method. The authors describe the historical difficulties with
this separation, discuss the concern over the coelution of the most important
congeners, and assess the need for development of computer models necessary to
design new stationary phases. High-resolution GC/MS data are shown confirming
the ability to develop a column with a predicted separation, with a discussion
of how this new column can yield more accurate automatic integration and an
increase in sample throughput.
Applications of Integrated Analyser Systems Incorporating GC
and Continuous Monitors for On-Line Analysis of Gases and Gas Mixtures
Smith, Martin J.C. (Unicam Chromatography, Bar Hill, Cambridge, UK); David
Burges; Andrew H. Ditchman.
PITTCON 2000, 12-17 March 2000, New Orleans,
Louisiana
A variety of on-line analytical applications are presented that
involve the use of gas chromatography in combination with other technologies
such as electrolytic oxygen analyzers and aluminum oxide moisture sensors.
Integrated analyzer systems are described with facilities for automatic stream
selection, automatic testing of the analyzer calibration, and the output of
integrated results and alarm conditions to the production control system.
Application examples include measurement of trace impurities in a food/beverage
grade carbon dioxide plant, analysis of the natural gas fuel supply for ceramic
firing ovens, and control of emissions from a toxic gas scrubber.
Rapid Analysis of PAHs in Fly Ash Using Thermal Desorption and
Fast GC/TOF-MS
Riley, John T. (Western Kentucky Univ., Bowling Green,
KY); Daozhong Zou; Wei-Ping Pan.
PITTCON 2000, 12-17 March 2000, New
Orleans, Louisiana
Thermal desorption of samples followed by rapid GC/TOF-MS analysis
of PAHs can be completed in less than one hour. In the procedure described, the
sample is loaded into the pyrocell and heated to 320 degrees C. The compounds
that evolve are swept by an inert gas into a cryo-focusing system, where they
are trapped, desorbed on to the GC column, and determined by rapid GC/TOF-MS
analysis. The results of a comparative study of the Thermal Desorption - Fast
GC/TOF-MS and the conventional purge and trap GC/MS analysis of PAHs in a group
of fly ashes are presented in this paper. The study focused on the 16 U.S. EPA
priority-pollutant PAHs. Thermal desorption followed by GC/TOF-MS is more
efficient than purge-and-trap GC/MS (quadrupole) for identification of the
PAHs, and can detect lower concentrations of the PAHs. Also, the Thermal
Desorption GC/TOF-MS procedure can produce results from a smaller sample.
Detection of Chemical Vapors by Multispectral Infrared Remote
Sensing Imaging
Zhang, Lin (Ohio Univ.,Athens); Gary W. Small.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
This paper describes work on the development of automated
detection strategies for the detection of chemical species in multispectral IR
remote sensing imaging data. The goal of the work is to use the RS-800
multispectral infrared line scanner (Raytheon TI Systems, McKinney, TX) to
image and detect chemical vapor species from an airborne platform. The
strategies involve the implementation of an automated detection system and
signal processing, image processing, and pattern recognition methods. The
chemical species to be detected include ethanol, methanol, ammonia, and sulfur
dioxide as released from a hot stack. The resulting chemical vapor plume is
imaged with the line scanner system. The researchers are pursuing an "automated
intelligent detection system" that can yield qualitative identification results
for each analyte against a variety of infrared backgrounds and
interferences.
New Potentiometric Sensors for Environmental Monitoring
Pretsch, Erno (Swiss Federal Inst. of Technology (ETH), Zurich,
Switzerland); Patrick Bodmer; Alan Ceresa; Monia Fibbioli; Urs Mathis; Titus
Zwickl; Werner E. Morf.
PITTCON 2000, 12-17 March 2000, New Orleans,
Louisiana
The presentation focuses on optimizing the composition of ISE
membrane and inner reference system as well as the calibration and measurement
procedures to obtain rugged ISEs suitable for trace level measurements in
environmental samples. A simplified theoretical model accurately accounts for
the influence of all relevant parameters of the measuring system. Based on
recent developments of solid-contact ISEs, miniaturized potentiometric sensor
arrays consisting of 10-100 sensing membranes/mm2 will become
feasible. This will allow the simultaneous monitoring of interfering ions and
introduce redundancies by using several membranes to measure the activity of
the same ion.
Cross-Reactive Optical Sensor Arrays for Multi-Analyte Sensing
Walt, David R. (Tufts Univ., Medford, MA); Shannon Stitzel; Keith J.
Albert; Caroline Schauer; Todd Dickinson.
PITTCON 2000, 12-17 March 2000,
New Orleans, Louisiana
Cross-reactive optical sensor arrays combine coherent optical
fiber bundles with micron-sized bead sensors. The bead sensors have an
incorporated solvatochromic dye and fluorescence changes are monitored by
employing a custom built imaging system with CCD detection. Each bead sensor
has a unique, characteristic and reproducible temporal fluorescence response
profile upon pulsatile delivery of analyte vapor. Multiple bead sensor types
are combined to create randomized high-density cross-reactive arrays on the
distal tip of an optical imaging fiber. The bead sensors are randomly
distributed within the array and are positionally registered by the unique
sensor-analyte fluorescence response patterns. Employing micron-sized bead
sensors is advantageous because they can be mass-produced and have good
sensor-to-sensor reproducibility. This reproducibility is a result of the
sensor production method in which polymer and silica beads are dyed in large
batches with a solvatochromic dye, producing billions of bead sensors at once.
Another benefit to using bead sensors is the redundancy of beads in an array.
Each bead is an individual sensor, and every array has hundreds to thousands of
each bead type dispersed within the array. By summing the responses of like
beads, there is a significant signal-to-noise enhancement in the overall
response.
Characterization and Application of a Novel
Electro-Chemiluminescent Reaction Involving Cadmium
Whitchurch,
Christian (Ohio Univ., Athens); Anthony Andrews.
PITTCON 2000, 12-17 March
2000, New Orleans, Louisiana
Electrochemiluminescence (ECL) is the generation of light during a
chemical reaction with at least one of the reagents being generated in situ at
the electrode. Electrochemiluminescent reactions involving aqueous metal ions
can offer an alternative method for quantitation of dissolved metals. In this
case a flow injection system using 1,10-phenanthroline as an ECL reagent in
conjunction with Cd2 ions provides sufficient emission for reliable cadmium
quantitation. The high throughput of flow injection analysis combined with the
relatively simple ECL instrumentation grants a potentially fast and inexpensive
method for routine aqueous cadmium determinations. A survey of possible
interferent ions has proven the reaction to be quite selective for Cd2, the
ion.
Application of a New Anion Exchange Column for the
Determination of Inorganic Anions in Environmental Waters by Ion Chromatography
Jackson, Peter E. (Dionex Corp., Sunnyvale, CA); M.J. Coffey;
Christopher A. Pohl; Charanjit Saini.
PITTCON 2000, 12-17 March 2000, New
Orleans, Louisiana
U.S. EPA Method 300.0 describes the use of ion chromatography (IC)
with a Dionex IonPac AS4A anion exchange column, a carbonate/bicarbonate
eluent, and suppressed conductivity detection for the determination of
inorganic anions in environmental waters, such as drinking water, wastewater
and aqueous soil extracts. The scope of the method allows an optional column to
be used, provided that comparable resolution of peaks is obtained and method QC
requirements can be met. This paper describes the use of a new anion exchange
column for the routine determination of common inorganic anions in
environmental waters. The IonPac AS14A provides the speed and efficiency of the
AS4A-SC column, along with improved separation of fluoride from the column void
volume (water dip) and better overall separation selectivity. The potential
interferences, linear range, method detection limits, and analyte recoveries
obtained with this column for a variety of environmental samples is
described.
Solid Phase Microextraction for Metal Speciation
Mester, Zoltan (Univ. of Waterloo, Waterloo, Ontario, Canada); Janusz B.
Pawliszyn.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
The authors have examined the potential of solid phase
microextraction (SPME) technique for metal speciation. Head-space SPME
technique was studied for the determination of arsenic, mercury, and lead
species using direct extraction or different derivatization methods
(ethylation, phenylation). The quantification was carried out using gas
chromatography / mass spectrometry (GC/MS). In-tube solid phase
microextractions was applied for the extraction of non-volatile metal species.
A schematic shows the in-tube solid phase microextraction system coupled with
HPLC separation arid electrospray MS detection. It is essentially an open tube
capillary, coated on the inside with a suitable extraction polymer, connected
to the HPLC system in place of the sample introduction loop. In-tube SPME-HPLC
was used to determine different seleno-aminoacids (Selenomethyonine,
Selenoethionine), organo-arsenic species (Mono- and Dimethylarsenic acid,
Arsenobetain, Arsenocholine), and Organolead compounds. Electrospray mass
spectrometer (ES/MS) was employed for the detection of metal species.
Dual Sampling High-Speed GC Monitoring of VOC Degradation in a
Bioreactor
Borgerding, Anthony J. (Univ. of North Dakota, Grand Forks);
Robert W. Current; Evguenii I. Kozliak.
PITTCON 2000, 12-17 March 2000, New
Orleans, Louisiana
HSGC with cryofocussing injection was used to monitor a
fiber-based bioreactor system for the removal of VOCs from air. Two bacterial
strains, Pseudomonas fluorescens Y2 and Pseudomonas putida,
were immobilized on nylon fiber mats and used to degrade styrene and toluene.
Using a dual sample loop system, 0.785 mL samples were taken on-line from a
total gas flow of 800 ml/min by pulling 25 ml/min with a vacuum pump. Loop
samples taken alternately from the gas flow before and after treatment by the
bioreactor are then sent to the cryofocussing injector of the HSGC and analyzed
with separation times of less than 20 seconds. By analyzing first the flow into
the bioreactor followed immediately by analysis of the air that had passed
through and been cleaned, the percent removal of analytes from air was
determined. Both remediated and unremediated air could be analyzed together in
less than one minute. The analytical system was effective only in monitoring
nonpolar analytes. Because of the high water content of the air required to
grow the bacteria, a Nation dryer was installed between the sample loops and
the cryofocussing injector of the high-speed GC to prevent freezing. Polar
analytes such as ethyl acetate were removed along with water by the dryer,
preventing them from being effectively analyzed. For toluene and styrene, the
analytes studied in this paper, there was no loss due to the Nation dryer.
Reproducibility and the possibility for analyte to carry over from one analysis
to subsequent ones was determined by alternately measuring a standard sample
and a blank.
This dual sampling HSGC system was used to study the
biodegradation of styrene and toluene in the bioreactor. Samples were taken
every minute for a period of 90 minutes. Approximate removal rates were 25% for
styrene, and 10% for toluene. Concentration fluctuations were observed when
analyte and bioreactor properties were modified during the period over which
the system was monitored.
High Speed Field Screening of MTBE and BTEX in Water Using
Membrane Introduction Mass Spectrometry (MIMS)
Bauer, Scott (MIMS
Technology Inc.); Harold K. Brown.
PITTCON 2000, 12-17 March 2000, New
Orleans, Louisiana
Abstract not available.
Development and Evaluation of a Portable
Spectro-Electrochemical Sensor
Stegemiller, Michael L. (Univ. of
Cincinnati, Cincinnati, OH); William R. Heineman; Carl J. Seliskar; Thomas H.
Ridgway.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
The work described here is based on an optically transparent
electrode (OTE) consisting of an indium-tin oxide (ITO) layer on a glass slide
coated with a sol-gel derived charge selective film. Light is coupled into the
slide through a prism in such a way that total internal reflection is achieved.
For an analyte to be detected, it must partition through the charge selective
film and undergo electrolysis at the applied potential; the analyte and its
electrolysis product must have different spectral characteristics. In response
to the need for small and portable sensors, a new prototype sensor was
developed. A fiber-coupled blue LED provides a suitable light source. Several
optical bandpass filters were evaluated for use with the LED to improve the
large bandwidth associated with blue LEDs. The fibers are held in place with a
"chuck" made out of PVC tubing. The chuck is then held at fixed angles to the
prism face to allow for total internal reflection to be attained. The majority
of the sensor is made out of black delrin. This includes a base piece to hold
the ITO covered slide, a solution chamber piece (chamber volume less than 1 mL)
that allows for solution to flow through the detection area, and a top cover
piece to hold the incoming fiber and the detector. A small photodiode provides
a simple and inexpensive detector. Sensor performance was evaluated with
ferrocyanide as a representative analyte, and a composite film of PDMDAAC-SiO2
(PDMDAAC = poly(dimethyldiallylammonium chloride)) was used as the charge
selective film. This composite film preconcentrates anions at the surface of
the ITO slide. Quantification of ferrocyanide was accomplished in a complex
sample matrix.
Development of a Total Internal Reflectance
Spectroelectrochemical Sensor Utilizing Paraquat as the Target
Analyte
Clager, Michael R. (Univ. of Cincinnati, Cincinnati, OH);
William R. Heineman; Carl J. Seliskar.
PITTCON 2000, 12-17 March 2000, New
Orleans, Louisiana
A spectroelectrochemical sensor for paraquat (methyl viologen) is
being developed that consists of a planar substrate of glass coated with a thin
layer of indium tin oxide (ITO), which functions as the working electrode. Over
the working electrode surface is a controlled thickness layer of sol-gel
encapsulated Nafion. The purpose of this sol-gel layer is to concentrate
paraquat into the sensing region while excluding potentially interfering
anions. Sensing is accomplished by launching light into the glass substrate at
an angle such that several internal reflections occur in the sensing region. At
these reflection points, an evanescent wave is generated. This is where the
optical sensing occurs.
Soil Screening for Polycyclic Aromatic Hydrocarbons
Zhang, Hongyan (Ohio Univ., Athens); Anthony Andrews.
PITTCON 2000,
12-17 March 2000, New Orleans, Louisiana
Solvent microextraction (SME) was investigated as a fast, simple,
safe, inexpensive alternative method to conventional liquid-liquid extraction.
The technique uses the principle of liquid-liquid extraction applied to small
volumes. Although polycyclic aromatic hydrocarbons (PAHs) have limited
solubility in water, with some amount of organic modifier added, water can be
used as an extraction solvent for simple screening purposes to determine the
extent of PAH contamination. SME and solid-phase microextraction in conjunction
with a water-based partial extraction have been used as preliminary screening
procedures. The PAHs were the measured by GC. Experimental conditions and
results are discussed, and a comparison is made between a conventional flame
ionization detector and a pulsed-discharge helium ionization detector.
A GC/MS Method Used for the Detection and Identification of
More Than 567 Potential Pesticide and Suspected Endocrine Disrupters in Complex
Matrices
Meng, Kai (Agilent Technologies); Phillip L. Wylie; Michael J.
Szelewski.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
Previous analytical methods for analysis of endocrine disrupters
were narrowly defined and/or based on an out-of-date technology. Even with the
specificity of GC/MS, it is still a very difficult and time-consuming task to
identify all pesticides and endocrine disrupters in complex matrices such as
food. A GC/MS method and a database have been developed to screen for over 567
pesticides and suspected endocrine disrupters. A technique called retention
time locking (RTL) ensures the analyte retention times between and among GC
systems match those in the database. After a GC/MS screening analysis, results
are automatically compared against entries in the library using small retention
time windows (for example, 0.3 min). The software uses a target ion and three
qualifier ions for each library entry. The possible matches are limited to the
library entries that have the retention times within the small 0.3-minute
window. The small time window makes the database matching much quicker and,
most importantly, cuts down false positives.
Fast Sampling and Analysis of Volatile Organic Compounds in
Indoor Air by Solid-Phase Microextraction/Field-Portable GC
Jia, Mingyu
(Univ. of Waterloo, Waterloo, Ontario, Canada); Jacek Koziel; Janusz B.
Pawliszyn.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
Solid-phase microextraction (SPME) was used to sample five target
VOCs (benzene, toluene, ethylbenzene, xylenes, and hexane) in indoor air.
Concentrations of target VOCs were determined using SPME with a
poly(dimethylsiloxane)/ divinylbenzene (PDMS/DVB) porous coating and one minute
exposure time. A portable SRI 8610C GC, equipped with a series of devices--a
photoionization (PID), a flame ionization (FID), and a dry electrolytic
conductivity (DELCD) detector--was modified and used for onsite field analysis.
The method detection limits for the target VOCs in air ranged from 10 to 20
parts-per-trillion (ppt). NIOSH method 1501 was used to validate SPME air
sampling. Compared to the liquid-phase PDMS fiber, PDMS/DVB fiber had much
higher sensitivity and capacity for extracting VOCs.
Speciated Isotope Dilution Mass Spectrometry: Application to
Mercury Speciation
Boylan, Helen M. (Duquesne Univ., Pittsburgh, PA);
Robert C. Richter; Howard M. Kingston.
PITTCON 2000, 12-17 March 2000, New
Orleans, Louisiana
The trend in environmental analysis is proceeding from total
elemental analysis to the analysis of individual species. The technique of
Speciated Isotope Dilution Mass Spectrometry (SIDMS) has been successfully
applied to the speciation of different oxidation states of chromium. The
researchers then applied SIDMS to mercury species, both inorganic and organic
forms, with special emphasis on methylmercury. SIDMS is a definitive technique
for species analysis that has the ability to track and deconvolute
transformations among species during sample preparation and measurement
processes. The method involves spiking the sample with isotope-labeled species;
each species of interest is labeled with a unique isotope. The species are then
separated, and isotope ratios are measured using ICP-MS. The authors discuss
parameter optimization of the separation and analysis steps involved in
SIDMS.
Evaluation of Mobile Phases for LC-ICP-MS Speciation of Arsenic
Compounds in Diverse Matrices
Akinbo, Olujide T. (Research Triangle
Inst., Research Triangle Park, NC); Reshan A. Fernando; James H. Raymer; Edo D.
Pellizzarri.
PITTCON 2000, 12-17 March 2000, New Orleans, Louisiana
One of the major factors in developing a chromatographic method
for elemental speciation is the selection of suitable mobile phase that will
elute the analytes in reasonable time. Added to this requirement is the need
for the mobile phase to be compatible with the mode of detection without
degrading the sensitivity of the detector. An assessment of the literature
suggests that the authors have used either the carbonate or phosphate buffers
as mobile phases for speciation arsenic compounds and that the selection of
mobile phases for LC-ICPMS is primarily influenced by factors with direct
implications on the chromatographic separation of the analytes and plasma
performances only. The effect of salt deposition on the sampling and schemer
cones of the ICPMS cannot be overlooked since these affect the ion transmission
and could cause a degradation of analytical performance of the ICPMS. The
authors present the results of a study in which four mobile phases--carbonate,
phosphate, acetate, and TRIS-acetate buffers--were evaluated for long-term
application to speciation of arsenics in diverse matrices.
Real-Time Analysis of Trace Elements in Synthetic Silicate and
Limestone Stream Sediments Soil Samples Measured by Laser Induced Breakdown
Spectrometer
Lu, K.T. (Atomic Engineering Corp., Gaithersburg, MD);
Dennis Baba; Thomas Leffler.
PITTCON 2000, 12-17 March 2000, New Orleans,
Louisiana
In situ detectors may be affected by calibration problems because
of the lack of reliable library data for environmental matrix effects, such as
soil matrix, moisture, pressure, and so forth. The commonly used practice of
precalibrating single species detectors before their use in the field does not
stand up to the challenge presented by field conditions. Reliable calibration
procedures must be developed to determine the detection limits of analytes in
unknown and mixed samples in real time and under field conditions. The
researchers have developed a software able to perform real-time calibration and
determine the detection limits of metal element concentration in real time and
under field conditions. The ACAS software offers improvement in both speed and
ease of use over the early AMCS developed by Atomic Engineering Corporation
(AEC). The software has been used to produce two databases: limestone stream
sediments soil samples and a trace elements database in synthetic silicate soil
samples. These databases were then used as precalibrated standards to determine
detection limits of metal element concentrations in synthetic silicate soil
sample and limestone stream sediments soil samples by laser-induced breakdown
spectroscopy. It is essential to calibrate the detector with databases under
field matrix conditions because the sensitivity of detection limit of certain
metals is masked by the environmental matrix effect in the soil sample
generated by the laser-induced plasma. The databases with field matrix
conditions were created using the ACAS Spectral Analysis module. The database
files were determined by calibrating selected fingerprints of the analyte
relative to the AEC's reference database and to the total background base
sample fingerprints. The accuracy of the results depend on the selection of the
finger prints of the analyte as well as on the selection of the finger prints
of the background base sample finger prints. These database files can be loaded
by the search program when needed to be compared against similar files to
determine the detection limit. The detection limits of analyte concentrations
are determined by the Concentration Analysis Module, in which all files with
similar structure are organized in groups so they can be loaded, searched, and
analyzed in a few steps with reference to the database created earlier. The
combination of improved software and the reference databases make the real-time
analysis of trace elements (Be, Ba, Sr, Cr, Cu, Pb, Ti, Fe, Zn, Mn, etc.) in
soil possible under field conditions.
Side-By-Side Comparison of Small, Hand-Held Ion Mobility
Spectrometers and Surface Acoustic Wave Devices
Davis, Dennis M. (U.S.
Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD); Charles
S. Harden; Vincent M. McHugh; Donald B. Shoff.
PITTCON 2000, 12-17 March
2000, New Orleans, Louisiana
The U.S. DoD has entered into a significant development program
aimed at production of small, unobtrusive chemical warfare (CW) agent
detectors. Side-by-side evaluations of prototype Ion Mobility Spectrometry
(IMS) and Surface Acoustic Wave (SAW) field instruments have been performed at
the U.S. Army Edgewood Chemical Biological Center. Among the devices evaluated
were small field prototype instruments that fit in the palm of a human hand and
weigh about 2 pounds. The evaluators undertook to describe the relative
performance characteristics of devices based on the two technologies in
experiments consisting of exposures to the same sample conditions at the same
time; hence, ambiguities resulting from exposures to different analyte
concentrations, water vapor concentrations, and sample gas temperatures would
be eliminated. Analytes used in these evaluations included toxic and non-toxic
organophosphorus compounds, organosulfur compounds, hydrogen cyanide, and
cyanogen chloride. Performance was tested in relative humidity conditions of 80
to 90%, because conditions of high temperature and humidity are generally
problematic for hand-held detection systems. The prototype devices were
simultaneously exposed to analyte vapors in air and in mixtures of air and
other substances that were known to cause undesirable responses in both IMS and
SAW devices. Ion mobility spectra were compared with SAW crystal frequency
shifts for each of the analyte / interference / water vapor mixtures. Results
noted include signal-to-noise near limits of detection, response times,
recovery times, ability to distinguish analytes by group and by type within a
group, and ability to distinguish between analytes of interest and potentially
interfering substances. This paper reviews the state of the art in the
development of small, hand-held field detection devices based on IMS and SAW
technologies.
Investigation on Microsensors for In-Situ Characterization of
Mixed Waste Using Steady-State Fluorescence Polarization
Yan, Yuan
(Univ. of South Carolina, Columbia); H. Li; Michael L. Myrick.
PITTCON
2000, 12-17 March 2000, New Orleans, Louisiana
The authors discuss their efforts to develop steady-state
fluorescence polarization (SSFP) techniques that selectively retard
depolarization effects for small molecules in fluid solution without
sacrificing the inherent sensitivity of fluorescence spectroscopy by the
introduction of micelles. In their research, fiber optics have been used to
conduct the excitation source from an Coherent Argon laser to the sample and
get the emission back to a CCD camera for recording. The results show that
sub-part-per-billion sensitivity, which is much better than the sensitivity of
most fluorescence polarization methods currently used, can be achieved for most
analytes by the instrument. Some discussions on SSFP for small molecules on the
instrument also are presented.
UV-VIS Alternative Method for the Determination of Metals in
Soils
Boudenne, Jean-Luc (Univ. De Provence, Marseille, France);
Frederic Theraulaz; Bruno Coulomb; Christophe Brach-Papa.
PITTCON 2000,
12-17 March 2000, New Orleans, Louisiana
A new procedure is proposed to reduce the cost and the duration of
analysis by the simultaneous determination of different metals (Fe, Cu, Ni, Zn,
and Pb) by direct or indirect UV-VIS analysis of EDTA extracts. Fe-EDTA
complexes are detected directly in the UV range, and speciation of different
forms of Fe is possible. Other metals require a two-step procedure. First, the
metals-EDTA complexes are submitted to a photo-oxidation step with a UV
deuterium lamp, then they are complexed again with another reagent whose nature
depends on the metals of concern. The UV-VIS spectra obtained are computed with
a multiwavelength deconvolution procedure to achieve the selectivity and
sensitivity of the method. This method has been validated by comparison of
results given by the atomic spectroscopy analysis, and a good correlation
coefficient has been obtained. This analytical procedure can be automated for
field determination of metal ions in soils.
Development of a New Laser-Induced Fluorescence (LIF)
Spectrometer for Environmental In-Situ Analysis of Water and Soils
Schultze, R.H. (Inst. fuer Physikalische Chemie, Erlangen, Germany); E. von
der Heide; T. Hengstermann; H.G. Lohmannsroben; P. Wagner.
PITTCON 2000,
12-17 March 2000, New Orleans, Louisiana
For in situ detection and analysis of fluorescence tracers and
petroleum products (oils) in water and soils a mobile and flexible
LIF-spectrometer was developed called OPTIMOS, the Oil Pollution Transportable
Independent Monitoring System. OPTIMOS is designed for use in the field. The
full version consists of a Nd:YAG/dye-laser combination, providing a wide range
of excitation wavelength, and an ICCD multichannel detection system. In the
case of the simplest configuration of OPTIMOS a UV-LED is employed as light
source, and a PMT or a photodiode as detector is used. This paper addresses
characterization of different configurations of the OPTIMOS system, evaluation
of analytical parameters for in situ detection of fluorescence tracers in water
and in situ analysis of oil-contaminated soils, and construction,
characterization, and employment of different LIF sensors, e.g. a lance for
bulk soil analysis or a sensor head for applications in a penetrometer for
subsurface measurements.
Public Access to Air Toxics Data: the Tosco-Rodeo Oil Refinery
Air Quality Monitoring Project
U.S. EPA Region 9 website, 11 May
2001
The Tosco-Rodeo Oil Refinery in Contra Costa County, California,
has installed three kinds of air monitors: FTIR, UV, and laser. All are "open
path monitors," meaning they measure ambient air pollutants occurring over a
1,000-meter light beam path. Monitors are located along both the north and
south fence lines to scan for 38 air pollutants, including some chemicals
defined as hazardous in the Clean Air Act, Section 112. The monitors operate
every five minutes, 24 hours a day, seven days a week and can generate millions
of data points in a year. This website offers operating information on the
fenceline monitoring systems in use at the site -
http://www.epa.gov/region09/features/tosco/monitoring.html
Optical Remote Sensing Devices: Some Manufacturers and
Consulting Firms
Fenceline Monitoring Homepage of the Shoreline
Environmental Alliance
In July of 1997, The Tosco Oil refinery in Rodeo, California,
completed the installation of its new fenceline monitoring system after an
incident in which hazardous gases were released to the surrounding
neighborhood. This monitoring network, which incorporates ten optical remote
sensing devices, is designed to detect and track concentrations of a wide range
of hazardous gases, and to provide early warning to the surrounding communities
in the event of a chemical emergency. The Shoreline Environmental Alliance
(SEA) has developed a website to keep the public informed of developments in
the monitoring effort. SEA has devoted one page of its site to a list of
commercially available optical remote sensing devices with addresses and links
to the companies who manufacture open-path monitoring equipment, as well as to
environmental consulting firms who have experience in operating this equipment.
SEA has attempted to include as many companies in this field as could be
located, not just those that have provided service to the Tosco/Unocal Refinery
monitoring effort. More information:
http://sea.enviroweb.org/mfgrs.html
Open-Path Monitoring with Ultraviolet or Infrared Light
Canadian Environmental Solutions. Industry Canada, Environmental Affairs
Branch. 25 Jul 2001
Optical remote sensing for gaseous pollutants at ground level is
an advancement equivalent to satellites for monitoring the earth. No longer
does the gas needing to be detected have to be sampled or make contact with a
surface of a detector. Various methods of remote sensing have the ability to
identify and quantify gaseous compounds of interest up to 1 km away from the
instrument. The scientific methods used encompass radiation absorption and
scattering. A very basic description of the principle of operation of this
technology is that a light beam is directed, potentially in several directions,
into the ambient air. As the light beam intersects the compounds of interest, a
unique spectral signature is detected for each compound. From each signature
the quantity of gas present in the beam is derivable. At minimum, this
technology complements gas point monitors. At maximum, this technology replaces
gas point monitors. Spatial coverage is greatly enhanced, sensitivities are
equivalent or better, capital expenditures are low along with maintenance
costs, installation is straightforward, existing staff is conveniently trained
to operate the instruments and disseminate the data. Applications cover the
areas of fenceline monitoring, industrial hygiene, facility safety, and process
control. Provider: SCI-TEC Instruments Inc., 1503 Fletcher Road, Saskatoon,
Saskatchewan, S7M 5S5, Canada. http://strategis.ic.gc.ca/SSG/es30972e.html
Air Quality Monitoring Technology Licensed
Aerospace
Technology Innovation, Vol 5 No 4, Jul/Aug 1997
Technology originally developed for monitoring atmospheric air
quality now is being used to help U.S. industries reduce smokestack pollution.
A remote gas sensor with NASA technology could detect industrial pollution with
a "fence" system that would allow the sensor to see around an area with help of
mirrors. NASA has worked with MERCO Incorporated, Golden, Colorado, to jointly
develop and commercialize the technology through a patent license agreement.
The Sensor Systems Branch at Langley Research Center will transfer its
fast-response, non-mechanical, remote gas-sensing technology for monitoring
gaseous pollutants emitted from petroleum refineries and chemical manufacturing
facilities to MERCO. The technology originally was developed to measure gases
in the Earth's atmosphere from aircraft and satellite platforms, and its
improved design makes it attractive for many Earth-based monitoring
applications. Called the Gas Filter Correlation Radiometer, the device
possesses many distinct advantages over conventional gas sensors such as remote
sensing capability, area source monitoring, higher reliability, faster response
and more compact design. The Mid-Continent Technology Transfer Center
facilitated the agreement. MERCO anticipates rapid commercialization of the
instrument. Contact: MERCO, Inc., 1667 Cole Blvd. Building 19, Suite 400,
Golden, CO 80401; (303) 274-9686.
SBIR Leads to Plant Fluorescence Sensor
Aerospace
Technology Innovation, Vol 9 No 3, May/Jun 2001
The work of a Billerica, Massachusetts, company funded through the
Small Business Innovation Research (SBIR) Program at NASA Stennis Space Center
can help growers assess the help of crops. Aerodyne Research, Inc. has
successfully developed the Plant Fluorescence Sensor (PFS), a real-time sensor
that passively monitors plant health by remotely sensing plant responses
related to the fundamental process of photosynthesis. As NASA's lead center for
the commercialization of remote sensing technologies, the NASA Earth System
Science Office (ESSO) at Stennis incorporates the technology of remote sensing
into its efforts. One focal area of research is the pre-visual sensing of
unhealthy, or stressed, plants. Aerodyne's development of the PFS through the
SBIR Program is in response to one of the ESSO's challenges. Aerodyne designed
and built the PFS as a robust sensor of sunlight-excited chlorophyll
fluorescence. It provides for the real-time, in situ remote sensing of
photosynthetic activity in plants. This sensor, which operates as a Fraunhofer
line discriminator, detects light at the cores of the lines comprising the
atmospheric oxygen A-band and B-band, centered at 760 nanometers (nm) and 688
nm respectively. Fraunhofer lines identify the spectral regions where little or
no solar radiation reaches the surface of Earth, providing an area free of
solar background interference. These bands also correspond to wavelengths in
the red and far-red chlorophyll fluorescence bands. The intensity and spectral
band shape of chlorophyll fluorescence in green plants has been linked to the
physiological status of plants, thus providing a good indicator of general
plant health. Aerodyne Research sees a market for the Plant Fluorescence Sensor
as a passive remote monitor of plant health. Applications include agriculture,
forestry, and environmental monitoring of soil remediation projects. Aerodyne
has elected to retain title to this invention, which has been credited to Dr.
Paul Kebabian. For more information about the Plant Fluorescence Sensor,
contact Dr. Herman Scott at Aerodyne Research, 978/663-9500, ext. 267. More
information: http://nctn.hq.nasa.gov/innovation/6-sb-pfsensor.html
Using Ternary Diagrams to Characterize Transport And
Attenuation of BTX
Lipson, D.; D.I. Siegel, Blasland, Bouck & Lee
Inc., Syracuse, NY.
Ground Water, Vol 38 No 1, p 106-113, 2000
Dissolved aromatic hydrocarbon concentration data commonly are
interpreted only within the context of regulatory maximum allowable
concentration levels. This paper illustrates how ternary diagrams can clearly
characterize from routine monitoring data the physical and chemical controls
governing the fate and transport of aromatic hydrocarbons in ground water. The
results of type mathematical modeling experiments for BTX solute transport show
that changes in BTX concentrations, when plotted as proportions on ternary
diagrams, form clear trajectories documenting major attenuation or transport
processes. Ternary diagrams can be used to determine from monitoring data
whether proposed natural attentuation processes are in fact present and the
efficiency of different remediation efforts used to clean up leaking
underground storage tank sites.
Bound Pesticide Residues in Soils and Plants and Their
Determination
Tiryaki, O.; P. Aysal, Turkish Atomic Energy Authority,
Ankara Nuclear Research and Training Center, Ankara,Turkey.
Turkish Journal
of Nuclear Sciences, Vol 26 No 2, p 43-60, Dec 1999
The environmental significance of pesticide residues in soil and
plants was examined in two types of residues: those residues that are
extractable with solvents, and those that are not extractable with solvents.
The extent of bound (non-extractable) residues varies with the plant and
pesticide involved and generally increases with time after treatment. Bound
pesticide residues have been detected in the organic matter fractions of soil
(i.e., humic acid, fulvic acid, and humin). Several studies have shown that
lignin, hemicellulose and pectic polysaccharide are the major bound residues
fraction of pesticide in plants. Attempts have been made to extract bound
pesticide residues by a variety of methods. Drastic extractive procedures
destroy the structure of soil or plants often result in the destruction of the
identity of bound residues. The High Temperature Distillation (HTD) and
Supercritical Fluid Extraction (SFE) techniques may provide possible means for
extraction and identification of bound residues.
Speciation of Inorganic Sulphur in Aquifer Sediments
Contaminated by Landfill Leachate Using Chemical Extraction Techniques
Crouzet, C.; M.A.M. Kedziorek; R.S. Altmann; A.C.M. Bourg, Laboratory of
Analytical, Bioinorganic and Environmental Chemistry, Univ. of Pau, Helioparc
Pau-Pyrenees, Pau Cedex, France.
Environmental Technology, Vol 21 No 3, p
285-296, 2000
This paper describes a protocol for determining the distribution
of sulphur forms in aquifer solids. A series of single parallel extractions and
two-step treatments derived from a combination of previously described
extractions were tested on simple Fe and/or S minerals (goethite, alkageneite,
hematite, ferrous sulphide, pyrite, flower elemental sulphur and ferrous
sulphate). Monosulphides were extracted with hot HCl. Iron disulphides were
determined using a Cr(II) digestion after preliminary elimination of
monosulphides, elemental sulphur, and sulphates with HI. Sulphate was extracted
by NaH2PO4 followed by HI treatment. Elemental sulphur
was estimated from differences between total sulphur and the fractions
quantified above. The protocol was applied to analysis of reduced and oxidized
sediments from a well-characterised sandy aquifer system downgradient from the
Danish Vejen landfill, and the results are described.
BYU Researchers Create Fluorescent Molecules That Detect Metal
Pollutants in Water, Waste
Brigham Young University News Release, 23
Jul 2001
A team of Brigham Young University researchers has developed
synthetic molecules that glow in the presence of certain metal pollutants. BYU
researchers devised the molecules as an improved method of detecting and
monitoring increased metal levels in the environment caused by mining,
smelting, fossil fuel combustion, and industrial use. The research goal is to
create a sensor that continually measures metal in a sample of water as it
flows by, making it easier to respond to contamination problems more quickly.
The team designed and created the molecules in the laboratory. The molecules
respond to zinc in the presence of ultraviolet light, and can also indicate the
presence of mercury and cadmium. To detect metals such as zinc in water, BYU
researchers first created compounds that seek out and bind to metal ions--those
atoms with extra electrons. Next, they created small molecules that attach to
the metal-binding compounds. The small molecules reveal the presence of bound
metal ions by acting as fluorescent "reporters" when ultraviolet light is
shined on them, the "reporters" glow brightly. If no metal ion is bound, the
compounds remain dark. The color of the glow depends on the type and
concentration of the metal ions present. Plans are under way to develop a
device that will allow industrial plants and water treatment facilities to
track the concentration of metal ions in water and wastestreams over time. The
lead researcher was emeritus professor of chemistry Jerald S. Bradshaw.
Assisting Bradshaw and Savage were BYU researchers Reed M. Izatt, R. Todd
Bronson, Saowarux Fuangswasdi, Sang Chul Lee, and collaborator Krzysztof E.
Krakowiak.
Using Stable Isotopes of Carbon and Nitrogen as In-Situ Tracers
for Monitoring the Natural Attenuation of Explosives
Miyares, P.H.;
C.M. Reynolds; J.C. Pennington; R.B. Coffin; T.F. Jenkins; L. Cifuentes, U.S.
Army Corps of Engineers, Cold Regions Research and Engineering Laboratory
(CRREL).
CRREL Special Report 99-18, 26 pp, Dec 1999
The use of carbon and nitrogen stable isotope measurements from
TNT was examined as a possible tool for monitoring the natural attenuation of
TNT. Incubation studies of spiked soil samples were conducted. The
concentration of TNT and the del () values for 13 C and 15 N of the soil and of
TNT were measured with time. Results indicated that no measurable changes in
the 13 C or 15 N value of the soil or 13 C values for TNT could be detected as
the concentration of TNT decreased. Measurable changes in the 15 N value of TNT
with changing TNT concentration suggested a possible monitoring route. Field
studies using both soil and ground-water samples support the laboratory finding
that changes in the 15 N for TNT extracted from ground water could be detected
in samples collected at different points along transects at the Louisiana Army
Ammunition Plant and that no measurable change in the 13 C values for soil or
TNT could be seen.
More information:
http://www.crrel.usace.army.mil/techpub/CRREL_Reports/reports/SR99_18.pdf
Evaluation of H.E.L.P. Mate 2000 for the Identification and
Quantification of Petroleum Hydrocarbon Products
Hewitt, Alan D., U.S.
Army Cold Regions Research and Engineering Laboratory (CRREL), Engineer
Research and Development Center (ERDC), Hanover, NH.
ERDC/CRREL TR-00-20,
20 pp, Sep 2000
The H.E.L.P. Mate 2000 (HM 2000) is a spectrophotometric
instrument developed for use with the Hanby Test Kits to rapidly assess of
total petroleum hydrocarbon contamination (TPH) in environmental matrices
onsite. This spectrophotometer is designed to remove the subjectivity
associated with the present visual method of analysis, and to eliminate the
requirement for prior knowledge of the type of petroleum hydrocarbon
contamination present at a given site. Both the HM 2000 and the current visual
method of analysis measure the color that is produced by the Friedel-Crafts
reaction with the aromatic hydrocarbons present in petroleum-based fuels, oils,
and solvents. Laboratory and field studies were used to evaluate the HM 2000.
Different results were obtained, depending on the type of sample matrix. In
general, the HM 2000 was more accurate and precise for soil samples than for
water samples. However, in comparison to the visual method, the HM 2000 was
neither as accurate nor did it offer any qualitative advantages.
More information:
http://www.crrel.usace.army.mil/techpub/CRREL_Reports/reports/TR00-20.pdf
Field Gas Chromatography/ Thermionic Detector System for
On-Site Determination of Explosives in Soils
Hewitt, Alan D.; Thomas F.
Jenkins; Thomas A. Ranney, U.S. Army Cold Regions Research and Engineering
Laboratory (CRREL), Engineer Research and Development Center (ERDC), Hanover,
NH.
ERDC/CRREL Technical Report TR-01-9, 29 pp, May 2001
Onsite determination of nitroaromatic, nitramine, and nitrate
ester explosives compounds in soils was performed using a field-portable gas
chromatograph (GC) equipped with a thermionic ionization detector (TID)
selective for compounds with nitro-functional groups. Soil samples were
extracted with acetone. A 1-µL volume of the filtered soil extract was
manually injected into the GC, allowing for the rapid qualification and
quantification of the suite of explosives that often coexist in soils at
military training facilities and other defense-related sites. Good agreement
was established for the concentrations of several explosives analytes when this
method of analysis was compared to either high-performance liquid
chromatography (Method 8330) or GC electron capture (Method 8095) analysis.
Comparisons were performed for sample extracts and for soil subsample
replicates distributed for onsite preparation and analysis during a field
verification test performed under the auspices of the U.S. Environmental
Protection Agency 's Environmental Technology Verification (ETV) Program.
More information:
http://www.crrel.usace.army.mil/techpub/CRREL_Reports/reports/TR-01-9.pdf
Non-Intrusive Liquid Level Detection Technology
Hanford
Environmental Restoration Project Innovative Technology Opportunities,
Technology Deployment Fact Sheet, 2 pp, 1999
Non-Intrusive Liquid Level Detection technology (NLLDT) uses
infrared thermography to assay tanks and equipment for the presence of liquids.
As such, liquid level information in tanks or equipment can be obtained for use
in planning decommissioning activities. The canyon deck of the 221-U Facility
contains numerous vessels and equipment. The NLLDT System was deployed to assay
selected equipment for the presence of liquid. This information was gathered in
support of the Canyon Disposition Initiative (CDI) Project. The CDI Project is
analyzing alternatives for the final disposition of the five large chemical
processing facilities (canyons) at the Hanford Site. The 221-U Facility serves
as the pilot facility for the CDI Project. Non-intrusive liquid level detection
technology is the use of infrared thermography coupled with either normal
ambient temperature changes or local, low-level heating or cooling to passively
and non-intrusively detect liquids in tanks and piping. Specifically, infrared
imaging cameras are used along with specialized testing procedures to exploit
physical property variations in the tanks/pipes and contained liquid and air to
produce temperature contours of images that identify the liquid levels.
Infrared thermography is the process of converting heat emitted from an object
into a visible dynamic television-like picture. The technology provides a
non-intrusive method that can determine presence/absence of liquids in
congested facility equipment. Visual inspection, boroscopic visual inspection,
and dipsticks are the baseline technologies for determining the presence or
absence of freestanding liquids in facility equipment. Liquid detection in
pipes is accomplished by finding low points and tapping the pipe for inserting
sampling parts. The NLLDT was deployed to detect liquids in a number of
selected targets. More information:
http://www.hanford.gov/techmgmt/99accomplish/55.PDF
Leak Detection 2000 CD-ROM
Ken Wilcox Associates, Inc.,
Grain Valley, MO. 2000
This CD-ROM contains summaries of over 300 leak detection methods
from 100+ vendors and is searchable by vendor or method type. It holds
third-party evaluation procedures from the U.S. EPA, KWA, MRI, and other
organizations, and full copies of third-party certifications from leading
vendors. Also present are those parts of the U.S. Code of Federal Regulations
pertaining to underground storage tanks and leak detection. Several kinds of
tank inventory-calculating software are provided.
Optimisation of the Experimental Conditions of a New Method,
Based on a Quartz Crystal Microbalance, for the Determination of Cyanide
Gomes, M.T.S.R.; A.A.F. Silva; A.C. Duarte; J.A.B.P. Oliveira.
The
Analyst, Vol 122 No 10, p 1139-1141, 1997
Two procedures for cyanide determination are described. A modified
simplex algorithm was used to optimize the experimental conditions with regard
to solution pH, temperature, and N2 flow rate. Sensitivity increases of 1.5 and
1.7 were obtained for the two procedures with 27 and 12 experiments,
respectively. Under the optimized conditions, the calibration graphs were
linear for 0.05-0.5 and for 0.24-0.86 ppm cyanide for the two procedures.
Techniques for the Determination of Cyanide in a Process
Environment: a Review
Barnes D.E.; P.J. Wright; S.M. Graham; E.A.
Jones-Watson.
Geostandards Newsletter: The Journal of Geostandards and
Geoanalysis, Vol 24 p 183-195, 2000
The determination of cyanide in various forms is important for
industrial processes as well as for environmental investigations and monitoring
associated with these processes. The accurate determination of cyanide is
difficult for various reasons: depending on the pH of the solution, cyanide is
present both in molecular form (HCN) and ionic form (CN-); cyanide is a good
complexing reagent and reacts with almost all cations resulting in complexes
with widely varying properties, such as stabilities, solubilities, and rates of
reaction; and cyanide also breaks down in sunlight and air, so that sampling
and sample treatment become very important aspects to consider in the
methodologies. During the last fifty years the determination of cyanide has
been approached from various angles and a variety of methods have been
developed for its determination. This study represents a survey of methods
commonly used in industrial laboratories for the analysis of cyanide-containing
solutions. The authors provide an overview of the nomenclature often used for
the various forms of cyanides and an interpretation of the values resulting
from a particular analysis.
Assessment of Different Fluorimetric Reaction for Cyanide
Determination in Flow Systems
Miralles, E.; M.D. Prat; R.
Compañó; M. Granados, Univ. of Barcelona, Spain.
The Analyst,
Vol 122 No 6, p 553-558, 1997
Abstract not available.
On-Line Gas-Diffusion Separation and Fluorimetric Detection for
the Analysis of Acid Dissociable Cyanide in Water Samples
Miralles, E.;
M.D. Prat; R. Compañó; M. Granados. Univ. of Barcelona, Spain.
The Analyst, Vol 123, p 217-220, 1998
Abstract not available.
Simultaneous Determination of Trace Amounts of Free Cyanide and
Thiocyanate by a Stopped-Flow Spectrophotometric Method
Sun, Bianting;
B.N. Noller, Univ. of Queensland, Australia.
Water Research, Vol 32, p
3698-3704, 1998
Abstract not available.
Simplifying Cyanide Analysis with Microdistillation
Volmer, Wolfgang; Günter Giesselmann.
American Laboratory News, p
20-22, Jan 2000
In accordance with Sections 13 and 14 of the DIN 84051 standard,
this paper outlines the simplification of sample distillation and photometric
analysis, and highlights cyanide determination using ion chromatography as a
possible alternative. Since 1992, the ad hoc Cyanide Study Group (Wiesbaden,
Germany) has been developing a new standard process for the determination of
cyanide. The use of ion chromatography or agentometry (instead of photometry)
for this purpose has also been examined. The MicroDistiller (Eppendorf -
Netheler - Hinz GmbH, Hamburg, Germany) is designed for distillation processes
that use a maximum distillate volume of 10 mL. The program-controlled process
ensures the separation of the volatile contents of complex substance mixtures.
Universal sample-receiving liquids enable the enrichment and separation of
solid and liquid samples. All processes in which the volatile components are
released chemically (e.g., during cyanide determination) are fully automated.
The distillation process takes place using a sample vial and collection vial
that are connected via a capillary. Quantitative enrichment of volatile
compounds is achieved by placing one or more borosilicate glass frits into the
heating vessel. This results in the continuous formation of vapor bubbles
during boiling. This compact arrangement means that large-volume micro test
tubes and expensive cooling equipment are not necessary. The device is very
easy to handle. Up to six samples are placed in the heating positions in
sealed, beaded-rim vials. At the same time, the corresponding number of sealed
collection vials are placed in the cooling positions. The sample vials and
collection vials are connected via a capillary that is inserted through the
septum seals of the vials. The desired program is then called up, and the time-
and temperature-controlled distillation process begins. Each program has a
maximum of four different heating cycles with different temperatures. Each
cycle has a heating rate, an individual sample temperature (25-120°C), and
a time during which this temperature can be maintained before the next cycle is
processed. The cooling temperature of the collection vial within one cycle can
be selected by the user (from -9 to +15°C). Individual profiles can
therefore be compiled very easily. The simple-to-follow display allows the
distillation process to be monitored while it is in progress. Both the cycle in
progress and the exact time at which distillation finishes are on permanent
display. More information:
http://www.iscpubs.com/pubs/al/articles/n0001/n0001vol.pdf