Cindy 27 years experience
investigation remediation of contaminated sites and scolded mediation of technology
heat that has surfactant and extraction and groundwater
recirculation for distribution and hydrogeologic tactical
itinerary focuses on development -- and we have Emily
crown over words for TRS group and Emily is
our leader Ginger Fortier as
overseeing engineering supporting thermal remediation
projects through site design construction operations and research and development
and joints TRS after getting a PHD and
bioengineering from University of Washington assailed including
treatment of water soil and remediation and temperature
and has pathways and welcome ladies we are excited to
have you to present today.
>> Without further ado I'd like to turn it over to our presenters
and begin tactical presentation for today thank you.
>> Molly to
remind you to get started
when you are ready.
>> Okay the slides are not showing up on
my screen so there's some delay and I will go
ahead and if that's okay I will have you go ahead and click the
slides to the bathroom I think I'm behind everybody and I'm going
to VPN and don't know how to take it off without losing everything
and I will wing it. Thank you so much everybody
for our topic today Heat Enhanced Hydrolysis of
Energetic Compounds and will result in collected as formally as the
bedside through deer's Sydney Nebraska
the presentation will be three-part I am Molly Maxwell Omaha District
Omaha and start up with history and background and
discuss first of two thermopile studies be conducted at Emily crown
over will present in detail
the approach taken during the second thermopile study focusing on the
contamination and Cindy Crane with HDL weld
discuss the results. As a reminder there is
opportunity to ask watches every presenter as well as at the
end of the presentation.
>> Let's begin with overall programmatic
approach formal use this insight as SCD and properties
from DoD ownership branch October 17. 1986 and US
Army Corps of Engineers responsible for managing and executing the program
to investigate and remedy any DoD impacts and
SPDS is a process and uses appropriate environmental restoration program
with funds and Army Dep OR
and feasibility studies as you can
see it. The plot of teamwork for the product to come together and
I want to briefly recognize those whose efforts have resulted in the
successful execution of the thermopile study from the Corps of Engineers
from hydrogeologic in TRS group Inc. as well as
work from Nebraska Department of environment and energy and thank
you all.
>> It gives an overview of the Sioux Army Dep oh located
in and you can see it is within the lesser most
portion of the Panhandle of Nebraska in the outline shows
the property boundary just North by IET and located by city of Sydney
and established by the Department
of Army in 1941 operational in 1942. the specific
purposes activities include storage alteration
modification maintenance distribution and also
included the demilitarization involved diffusing removal of
propellants of energetics and of note
this ordnance production was not one of his primary functions
and additionally the depots used for vehicle equipment receiving
maintenance and storage and distribution during and after World War II. Operations
at the facility stopped in 1966
and transferred from DoD in 1967.
>> This slide shows how Army Dep oh
divided into functional areas during preliminary assessment each area
labeled a through U and a lot of areas here and
you can see from the topographic map and adjacent bottles
the property is generally flat with large open expanses with little
vegetation in the areas semi arid with an
average annual rainfall of about 18 inches and you can compare that
to the natural average which is about 38 inches. The added
arrow is the Army Dep oh what we completed the poll studies
an area.
>> Area of the largest section of
the depot many different functional operational areas in this presentation
will focus on the ammunition renovation area
and the a WR a consisted of 52 buildings or other structures that
include service magazines bundle munition buildings vacuum receiver
buildings and perimeter buildings in washout water and
a storage magazine and oil storage tank fuel tanks
leaking beds and numerous personnel support buildings and
most of the buildings were boarded and prior to decommissioning were
decontaminated by complete burning followed by demolition. According
to the site plan as there was for lychees beds in the operation or
you can see they use shown in the area with purple #means
and the designated tooth to evaporate
watching the game from the various washer buildings according to the
records a leech beds were decontaminated by complete burning however the
actual process is not documented.
So based on the results of the RI and highly contaminated areas
are the result of activity here, the first
yellow area the washout water from bomb washer
was from the bomb washer ledger building 10 as one -- zero and the
washer watch water was discharged to a take 10 -- one
-- P a blue box and discharge a leech beds
to that shop again you should see a second arrow
and this leech bed was the largest and most frequently used in this
facility and measures approximately 400 feet by 400 feet and recorded
the soils in the leech bed heaven out of his reddish coloration with
a depth of at least five feet per and talk about the geology and
hydrogeology here the formation is approximately 150
to 2 are 50 feet thick and predominant materials encounter was a
poorly to well graded sand silty clays, silty sand and
clay cells in predominant materials encounter at the water table were
clays and silty sand and the ash formation from the underlying
rule formation of an erosional unconformity top liberal
contains daily hotels in service are result
of alluvial down cutting and depth of groundwater is approximately
160 165 he would generally blow to the east in average groundwater
velocity is the team the per year with the horizontal gradient
tackling a zero.003 per foot there is essential no
vertical gradient.
>> So we completed
our remedial investigation and according to that report we essentially have
three major themes impacted that area B and the
top 10 feet of sale risk to human health
due to exposure for residential construction workers and depth of
the basement and if you look at the rudimentary conceptual site
model picture that is the light yellow to tan
area and the second impacted area is approximately 150 feet of soil
in a beta that -- and is a groundwater
and for the soil contamination of concern we have several
different exposes we have TNT, petrol RDX 13 and nitro benzene
I mean before six nitro tolling and 26 nitro tolling and in
the groundwater we have explosive 13 DMV, TNT,
26 DNT, two amino 46 DNT, nitroglycerin,
PET and, RDX and Detrol and also have nitrite and nitrite
as well as hexavalent chromium
-- in the first pilot study we conducted was to gather information
regarding evaluation of the remedy potential to potentially applied
to the service soil if you look at that model it is the red box
the top five feet of the surface soil impacted peer the second poll
of study and topic
of discussion for Emily and Cindy will be addressing contaminants
in the deeper beta cells and soils acting as a continuous
source of potentially leaching
contaminants into the groundwater data and next
life.
>> The initial draft of
feasibility study indicated that hydrolysis as a alternative for
the service soil this is a common approach used
to treat explosives however due to the very arid nature of the area
and low soil moisture content, the team felt by adding some additional
hydration preferably in the form of steam there
would be an enhancement of the hydrolysis reaction and
Paul's study was designed to bother with the addition
of steam into the subsurface through steam array and mixed with hydrolyzed
to the top two feet of the soil and leech beds to --
selected area that has the highest Accor goal
concentration of exposure for the study and activity down to three
feet and installed the steam array and you can see the array at the
top right photo peer this story was operational during the date
using the steam generator continuously monitored by site personnel and
once in place the soils were replaced in 410 by 10
quadrants were Martin you can see those in the picture on
the left. Discrete baseline samples were collected
from each quadrant at the surface at one foot in two feet deep and
initial discrete sample of all
the collected five feet deep to act as a control to determine if
any leaching record due to additional steam injection and
next slide
>> So in this slide you can see that
we are adding the hydrated line and
soil from the top two feet from each of the four quadrants were
independently excavated mixed with the hydrated line at a 5% mixture
in this was determined to independent skill setting and placed back into
the respected quadrant.
There were daily readings taken collective for temperature
LRP in% moisture in the soil were analyzed by method 8320 1A
with prep method 8330 B and Pilate conducted for
a total of 20 days with daily readings as well as samples collected
on day 10 and Day 20. >>
So restart up these were the results
that we came about from the study, generally
the soil pH on average was 7.1 the potential was positive 256 millivolts
the soil temperature was 50 degrees Fahrenheit or 10 degrees
Celsius and soil% moisture was around 8 to 12%.
And after we put in the steam heater and makes the alkaline hydrolysis
treatment on day one the pH had elevated to the range
from 12 to 13. the ORP dropped to
-100 to 150 millivolts and the soil temperature
had increased to approximately 100 to 125 degrees Fahrenheit or
37 to 65 degrees Celsius in the soil moisture
increased to approximately 30 to 48%. And by day three however
we started to see the soil pH ORP levels to transition back to pretreatment
conditions and the pH started dropping to a range between
10.5 and 12.2 in the ORP started to increase
it was still negative but it was a -5 to -36 millivolts and the
soil temperature in the soil moisture would in the same range. As they
were for day one.
And by day five the soil pH and ORP were essentially back to pretreatment
conditions and the added alkalinity seemed to be
completely exhausted.
And it presented an issue for us to determine whether or not we would
collect samples at day five or if we would continue with our plan
to collect samples at day 10 and again at day 20. The team decided
to go ahead and continue with the plan according to the USB
and collect samples at day 10 and we continue to do continuous steam
treatment in the daily readings on day 10 we did take discrete samples
from each of the four quadrants and decided to go ahead and mix
into quadrants one and two another 5% alkaline mixture
and remix them independently. Quadrant three and four
were left undisturbed and continue to receive steam. And again we started
to see after about 3
to 4 days the alkalinity was exhausted and it was back to the original
pretreatment condition.
And on day 20 we continued the pilot study and
took our final samples on day 20 and the Steve steam treatment ended.
>> And
a summary of the results focusing primarily on
the two explosive our reacts and TNT which
are the largest effects. The data presented here so
there was a great impact with the alkaline from hydrolysis and you
can see the analytical results for each of the quadrants as well as
the present reduction.
And generally each explosive analyzed showed some
level of reduction but they were variable efficiencies and Cindy
will touch on these more in her presentation. Overall the averaging
four quadrants we average the four quadrants
and again the first arrow emphasizes RDX
showed an overall average present reduction of 69.9 present in 20
days and if you see again the second arrow shows that the process
was more effective for TNT and showed an average present reduction
of 96.9 present in 20 days. And in
conclusion that this team alkaline hydrolysis resulted in
significant reduction explosive concentration with quadrant average
conservation reductions relative to pretreatment
conduction from 64% 285% after 10 days and from 86 to 97% after
20 days per and despite two doses of lime the Viper's 5% mixing
intended to part one into concentration reductions
need to quadrant generally
similar or less than those found in quadrant three and four, and
a single dose of lime of 5% was applied
quadrant three and four had salt set that in the last
day of the politesse primarily because of heat loss in quadrant
one and two due to the mixing of the soil with the second treatment
or dose of alkaline hydrolysis.
So considerations additionally
5% lie makes her seem to be insufficient to consistently treat highly concentrated
explosives. The alkaline position lasted 3
to 4 days after each dosing event and shifted back toward ambient
or pretreatment conditions in a higher dose seems to be needed to
[ Indiscernible] ultimately comparing results of
quadrants wanted to without three and four grade reduction occurred
there was more consistent elevated heat versus more alkalinity perhaps
heat alone may be a remedial alternative for the soil.
And what is next? We have some answers for approach to these
and soils within the top 10 feet but how do we address
deeper soils that are acting
as continue source for the groundwater proven to be difficult and issue
an excavation is non-plausible alternative so
what about heat which we will discuss
in the next part of the presentation. At this point if there's any
questions I can go ahead and answer and try and answer them.
>> Thank you Molly.
To remind the audience the other Q&A window in the lower right corner
of the screen and they can privately send in questions
and comments at any time and again for those of you looking for copies
of the slides we did post them on the seminar resources page and it
is available on the seminar slide tab you can find it in the online
Webinar environment under related URL you will see a link to something
called seminar resources and so I don't see any live questions that
have come in so I think perhaps
in the interest of time we might move on with the presentation but
if there are questions on your topic, speak of the devil one came in Lesbos
and take this question -- one of the attendees wanted to note did
you consider Tadeusz quicklime to raise pH and add heat?
>> I am not specifically
-- I don't know if the contractor actually looked at quicklime versus
the product we use and I guess my quick answer is I am
not sure and I do not know it was not written up in RUSP and if
there's property to that that are beneficial I would love to hear
if you want to go ahead and send these something to my email.
>> We will be sure to include contact
information for presenters as well so we did have a couple
questions though about analysis and so one
of the attendees wanted to know if you looked for degradation products
of RDX?
>> Yes I did get into a lot of details
about all the different degradation products we have I believe Cindy
will be hitting more on that in her presentation. That is particularly
why we use that method.
>> We have also related questions
if you analyzed for HD breakdown products
particularly breakdown process by alkali hydrolysis so there's
a lot of questions about the alkali hydrolysis process.
>> We have another question here, was
there a non-heated hydrolysis plot?
>> Know we didn't feel like we needed
a non-heated hydrolysis spot for this particular poll study
we did feel it would be -- answer the question whether
or not adding the water would be beneficial but in hindsight it would
have been beneficial to have had a non-heated plot for comparison.
>> Okay so the questions I see now
getting to that alkaline hydrolysis and some breakdown processes so
I think what I will do is hold those in the queue until the next segment
and we can come back to them and take any other outstanding questions
there. Let's
go ahead and carry on with the rest of the presentation but if you are
in the middle of typing a question please feel free to finish we will
paused for questions later on in the broadcast without a want to
thank Molly and I think will move on to our next speaker.
>> Thank you Jean and Molly, as
Molly mentioned she provided an overview of the people sites
in previous private pilot study performed in effective stage for
I believe science behind
we want to evaluate a heat only demonstration with the Rh --
as mentioned they were able to see
evidence in that initial poll study that while they saw short-lived
pH impact in the effects 3 to 4 days when they would increase
the pH they would see it normalize back
to a baseline pH very quickly but they did across the site have the
same heat and in some of the areas where they were not
having pH adjustment and saw degradation and that's why
I set the stage for this particular demonstration in addition to that
pile study there's also literature describing this
and showing specifically looking at TNT
and showing prospect 2060 and 83 Celsius and evaluating
concentration of TNT overtime at five pH
and as you can see at 20 degrees Celsius that is pH 11 and white
triangle and you can see very quick degradation and
it is increasingly degradation is Tom's to a less
extent as you lower pH and when you increase
the temperature to 60 degrees Celsius there's an increase in degradation
at some of the lower pH is an as you increase it to 80 degrees
Celsius at seven and to bait for long enough a duration
able to see much closer to the degradation observed that the higher
pH and the data that is in the literature and also on the
data that Molly described helps us move forward with
[ Indiscernible] and
overall overview of RDX degradation won't go to a dawn of details
and we can talk about it later in the presentation but just wanted
to demonstrate that these degradation properties are
very complex this is only showing RDX but you can see that there are
a number of abiotic and biotic pathways that help you complete
degradation and it is very similar for all of the energetics that Molly
was describing that are prevalent.
>> Evaluating
the technologies that would be used for the thermal remediation as Molly
mentioned they did use up technology and there are additional technologies
that were evaluated thermal conduction heating is a thermal technology
that entails an element installed in the casing
and the element radiates heat similar to a toaster oven and
from the casing to the sub service and contrast electrical resistance
heating and electro installed in the sub service and
opposite based electrodes cause current to flow between them and
that resistance to the current is what generates heat and two distinct
differences between technologies and thermal conduction heating
overall you can reach about a range of temperatures but electrical resistance
heating due to the nature of how the tech knowledge he functions
it can lead to more even heating of those lower temperature ranges
because you're not radiating heat from a single source.
In addition this shows a range of different
[Indiscernible] and stress we talked about
the Molly mentioned in terms of targeting degradation of energetics
and also in terms of temperatures degradation here
and don't necessarily need a vapor covering to be able to enhance degradation
and targeted lower temperatures that do not generate steam and number
of our sites typically as a mechanism for
organic compound serving and in terms of
degradation targeted lower temperatures and based on the
[ Indiscernible] achieve reduction and not
have the infrastructure required for extraction or
covering the intent for the site is not to remove the contaminant
from the treatment area but rather to degrade them in
place and not looking to deconstruct and we are looking
to degrade and help enhance
degradation reaction by elevating the temperature
to temperatures below the poll boiling point of water --
and the schematic of an electrical resistance steam system you can
see it's a power source coming in and that provides
voltage to the power control unit and power control unit
delivers power to electrodes installed in the sub service electric
installed in a triangular pattern and opposite electrodes have
current flowing between them and that resistance generates
heat in the shows the infrastructure would be required
for the recovery system and if we are targeting lower systems that
infrastructure is not required.
This shows an overall layout of the electrodes at the site and relative
to the maximum soil concentrations observed at
the contaminant primary contaminant concern and see the electrodes are
shown in the red circles here and temperature monitoring points those
are shown in the inverted green triangle and we intentionally install
the temperature monitoring points within the center of the triangular
pattern of electrodes the intent is for us to monitor the
temperature at the core location within
an array of electrodes.
>> Cindy will go into more detail
on the baseline sampling performed but wanted to show
to the relative maximum soil
concentration and their locations [ Indiscernible]
this will answer more detail on the electrical
resistance heating system design and you can see the electrodes
are for we cover the treatment area what the liner in our power control
unit was on the western portion of the site,
and then we did install residual [ Indiscernible]
intended to ensure we have sufficient current flow
between electrodes. And on the right a cross-section of
an electrode you can see we install to a depth of 75
and are electro design we have an element installed within the
borehole and that is what we energize with the power control
unit and then installed conductive backfill surrounding the element
and intended backfill is to increase the surface area
of the electrode and through testing we found that this increases to
surface area significantly increases the efficiency of a heat distribution
within the subsurface. And on the right
is showing a plotting pattern and you will see a cross later on in
the presentation we did install rhe wedding system at the site
just to help increase just moisture content just enough
to ensure current good flow so it shows a
plotting pattern within the elements and targeted at different depths
in the holes in touch on the system a little further we have our
site every site we use we have an automated system that we monitor
remotely and we had current transducers installed at every
electrode and those current transducers were used
to help us monitor the current in each electrode and monitor
its components and we are able to see if there
aligned system is applied to the system allocation able to
see that response in real time and what it does is help us significantly
minimize the amount of water added so that we are only using it to
enhance the current flow and as you see later on we use a rhe wedding
system to increase the efficiency and heat
operates but once we achieved our talk of temperatures we did not
apply any further rhe wedding of the site and it was used
to help efficiencies and you'll see that
a little later.
And showing process design and
our process applying for electrodes and
we also have a temperature monitoring point with a number of temperature
sensors and allows us to monitor the temperature profiles and across
the site and also have water sourcing and audible water into
the site and this was then as delivered to electrodes selectively
using a pump and piping Network and there are
solenoids used at every essentially automated we
valves we control remotely and control the amount of -- base
that off current transducers and current
data at each electrode to ensure applying minimal water as possible.
>> Next is a flyover.
ACL provided this footage in provides a nice snapshot of the site and
you can see as we are flying over closer to the
site, you can see in
the back this is our power source,
and the point able to use the video itself --
back pointer is floating on the video as well you can turn it on
or off as needed and you can click to where you want the pointer to
go.
>> Perfect thank you and here in the back is
showing our voltage source and this is a
applying power to the power control unit and you can see the cables
leading to the treatment area field and a liner in Network of
electrodes installed and each of these boxes these are
what we used to remotely monitor and
optimize our site in each of the boxes helps us monitor both temperature
and monitor the current at each electrode and also open and close
for rhe wedding system delivery and
-- rewetting -- and lower right-hand corner
an example of security sensor and have full coverage of our
site with security sensors and if there is in it interruption of
pathway of -- automatically deenergize electrodes
and allows or systems to provide notification to a security company
as well as personnel to address an additional had a 360 camera
this is not on the top of our debt power control unit and allows us
[ Indiscernible] see it real time.
In this shows water storage tank
and we can go to the next slide.
>> And this is the
snapshot of the electrical resistance heating system --
and as we discussed a little bit ago
the sub service rewetting in the data showed that
the application of the rewetting delivery did increase the rate
at which the temperature increased peer
and an area where we were targeting delivery and 25 and
60 to 70 foot lower grade interval and that is where we
had the rewetting system delivery and at 55 days
of operation and the green and yellow are showing previous time points
within the remediation and those intervals we were able
to see a faster increase in temperature and once we reach
128 days we ultimately were able to achieve comparable temperatures
of and apply the rewetting system shows the facts
and we achieve the targets temperatures we did conclude application
here and using it to help use energy more efficiently
and then a lesson learned for us if we were
to do this again we would want to also apply a middle interval and
we can help increase the rate at which you temperature
increased at intervals and energy a little more efficiently.
>> And
decide average temperature energy application you can see this includes
a site average temperature and then each has
also the average of temperature at each of the temperature
monitoring points and you can see those locations here in the inverted
green triangle and once again now it is early on in the review creation
once we reach the targeted temperature we did have a weather event which
in normal cases that would not be ideal but in a lot of ways
it provided valuable data to us if you are bound for
around about a month of downtime on average about four degrees Celsius
of an increase of site average temperature and what it
help show us is that this particular site really maintains temperature
very well and if we were to treat the site heat
the site longer we would certainly use power cycling modes
to turn the electricity on and off at different
time intervals to keep the energy more efficiently because of how
limited decrease or was in the temperature and
the shows over the past remediation we had 850
thousand kilowatt hours of sub service energy applied and this
was less than we were predicting and we think we could even achieve
minimal energy application if we had operated longer and maintained
the targeted temperature.
In general the average temperature was
87.4 degrees Celsius and as we discussed those amenable temperature
decrease for downtime.
In terms of the energy application we evaluated
that at the site and found that the rate of energy
input highs during heat of phase and evaluating
for the project and model that Lessons Learned were
majority of rate of energy output for that early stage and found that
sub service rewetting increased heat operates and delivery
was applied and found there was a lower power requirement for that
was used to unanticipated downtime but really showed heat capacity
or ability of the site to lose temperature ended up
being we could apply a little power here if
operating for a longer period of time. Minimal temperature decrease
of [ Indiscernible] power cycling an option future
site modeling looking at turning power on and off help you
see more energy efficiently.
Rewetting system heat up right
increased efficiency of energy application and applying heating
targets treatment volume found particularly at the site
we saw a reduced rate of energy input and if we were to a larger
scale implementation here we would want to
increase the rewetting system distribution to try to get those middle interval
to help increase heat operates and heat operates
-- and up rates and energy efficiency of
the site we could use a wider spacing and use less cost for the
overall structure and in addition looking a power cycling
when we are in a temperature menace phase and targeted and received
targeted temperature it can help us maintain temperature for longer
durations and help [ Indiscernible] work that I'd be happy to take
questions.
>> I see a number of
Quach is already in the queue and I will start with those and
the first question asked what are the power demands of the electrical
resistance heating system?
>> That is very dependent upon the treatment volume and it is something
that when we are modeling a site we will look at the overall treatment
volume and thickness as well as treatment
area and we do a lot of thermal modeling to look at heat losses
that will help determine our energy requirements and something every
site is a little different and also dependent on the morphology
and there's a lot of site parameters that go
into it but our power control unit is for instance they range anywhere
from 500 kilowatts to 4500 kilowatts per site if it is a larger site
sometimes we will have multiple power control unit but is very dependent
on the treatment volume and parameters.
>> Another question asked how long did it take for the
area to revegetate after that pilot test?
>> That is an excellent question so I
am not sure Cindy if you might be able to answer that or if that would
be something that HCl I would look personally have not been on site
recently and don't know Molly if you have seen it more recently,
but I believe --
in general in terms of revegetation it varies but can be within
a matter of months but I doubt dependent on the liner
being removed but I believe everything has been
demobilize from that site and I don't know Molly if you've seen
more recently.
>> This is Molly we did finish demobilizing out there about three weeks ago
and that question is yet to be determined the answer is yet to
be determined good question though.
>> All right we did have a clarifying
question so someone wanted to be sure that this
is still alkaline hydrolysis but you do not need to increase the
pH due to faster kinetics of high temperature?
>> So you will find this in the literature
there is on the degradation pathways most of what you will find you reference
alkaline hydrolysis and in particular with the wrenching of pH it has
I read in literature that it says you have to [ Indiscernible]
for it to be considered alkaline hydrolysis we believe the pathways
are similar and we are not filling in that range quote unquote alkaline
hydrolysis but anticipate very similar pathways
and go into more detail on the pathways but I also
Jean you mentioned there were a number of questions about pathways
and would be happy to share more information
at a later date or [ Indiscernible] if more detail you would like.
>> We had a question as well about
pre-and posttreatment and water were there any pre-or post treatment
issues sample splendid or was it site focus just on temperature?
>> Yeah so Cindy will go into more
detail on this but we were primarily looking at the application of heat
and ability of heat to enhance degradation.
>> Another, came in one of the attendees assuming
that the wedding tubes were you set the electrodes and they would
not have any effect in the overall data zone and they went on to give
arid conditions house he maintained using GRH
in the sewing was in soil moisture range and the data
zone during treatment period?
>> That is a great point or whoever provided that and I'm glad
you mentioned so the trip itself the rewetting
is that the electric Oracle and just at the electrode in only used
to help enhance the correct current flow and not looking to impact
the data in terms of its ability to maintain temperature that is
really due to the heat capacity of the soil and what we are finding
is it ended up being quite a bit higher it was higher
and more energy to heat up but requires a lot more heat loss
to cool down in terms of ability to heat once we are able
to maintain temperature once we were able to achieve those temperatures
we were able to lower our power applications significantly and also
not apply any rewetting to maintain the temperature.
>> One more question so based on the
DSC TGA thermal stability test the RDX is thermally
stable below 200 degrees Celsius so they wanted to know
how did you actually establish the thermal degradation of the RDX?
>> Go into more detail on that
we did look at degradation byproducts and you will see more data on that
in evidence that shows degradation that is occurring and
not expecting to see any destruction here and not achieving those temperatures
were that can occur so really just looking at byproducts
and temperature ranges we would be targeting degradation.
>> This is Cindy, I want to emphasize
that thermal destruction was not a process we were attempting to
achieve.
Just like their was not the process we were attempting to achieve particularly
in these targeted temperatures at 80 degrees Celsius all we are doing
as Emily mentioned previously is leveraging the equation the increase
rate of natural hydrolysis.
>> Okay thank you don't see additional
Quach is in the queue right now, I think perhaps in the interest
of time we might move on to our next presenter and we will pause
again for questions so I encourage the audience to keep those comments
and questions coming in and let's carry on with our presentation.
>> Thank you Jean
and Emily.
My portion of the presentation focus on the actual soil data in
Leach data that we collected during the pilot study both before and
during heating.
While Emily's portion of the presentation focuses on the more
physical aspects of the yardage system the temperature changes in
electrical usage this section of the presentation focuses on the
analytical data.
This slide outlines a pilot study sampling
plan that we implemented and they collected baseline samples
nationally used the boreholes electrodes and temperature monitoring
were installed in so the baseline during construction
of the arid system and we collected performance samples and six
months after the start of heating in these performance include
heating period the use combination
of discrete samples of composite samples
the purpose of the discrete sample was to revisit two locations that
have been sampled during the site characterization process and where
we knew there were elevated concentrations in the purpose of the composite
samples was to mitigate the potential for heterogeneity
in soil in our field we encounter a lot of heterogeneity
and we were trying to see composite samples to even out that heterogeneity
to facilitate subsequent data analysis.
So we have two borings to
approximate locations where we had discrete samples and the composite
samples divided the site to four quadrants and collective a five-point
composite sample from each quadrant in all locations we collected samples
from 10 to 15 feet below grade and 20 to 25 feet below grade
and 65 to 70 feet below grade and the targeted heating interval for
the study was Ground Zero 270 feet and due to concerns
about the wetting system causing explosives to leash through the
treatment some one of the quad -- from 70 to 75 feet
below grade and all samples were analyzed for explosives with the
method and composite samples were with synthetic
leaching as PLT and Leach analyzed for explosives
and the reason we did this as PLT analysis
and previously and get to the deep son pathways concern
is leaching and one of the goals of the project
is to assess a method that can be applied to the to eliminate
migration in the future.
And illustrates the treatment piles study
in where we collect the samples and give an idea of scale
the piles study is approximately 80 feet in diameter it is centered
on identified as HLS 01 a boring during
remedial investigation where elevated concentrations of explosives
were detected and one of the discrete locations that we use
for the sampling program -- and the site divided
24 quadrants identified as Northeast Southeast Northeast and Northwest
in the second boring is off to the Eastern portion of the treatment
study area. And 80 feet diameter which gives you
an approximate treatment area footprint of 5000 square feet for each quadrant
encompassed all the lesson 1300 square feet and with a five-point
aliquot for the composite samples they are looking at
and aliquot density of essentially one location per 250
square feet providing fairly dense coverage of the treatment area.
Also as
I noted earlier the baseline samples were collected from the borings
used to install the subsurface structures for the ERH system and when
went back out six months had to avoid those
damaging subsurface structures in the four-month and six-month
samples are offset by approximately five feet from the original baseline
locations.
In the baseline samples the most common explosives we detected
were RDX, HMX, TNT, try natural Benson,
died natural Benson, TNT isomers in both amino TNT
isomers and had only the Tetreault aniline
and no detection of natural telling natural
benzene and nitroglycerin and in the four-month six-month
sampling events we still had no detection of nitro Talley went natural
benzene and nitroglycerin and these explosives are not discussed further
in the presentation.
This slide summarizes the baseline results for identified
in the previous slide as primary contaminants
and you can see we have a fairly wide range of initial concentrations
are to with the highest concentrations were TNT
and RDX with maximum defections around 30 milligrams per kilogram
and HMX that was
try natural 30 milligrams and HMX TNT slightly
lower concentrations -- and at the lower end of the concentration
range we have 260 TNT and
one of the aspects about 260 TNT is our detection limit for
most of the compounds was.05 ppm and you can see from the range
of TNT 268 concentrations they went from.0 262.13 ppm in difficulty
with the 26 TNT soil data is a lot of our results were
a lot of our detections were less than are
approximately equal to the purported limits.
>> SQL P data as PLP the
highest concentration reported for RDX try natural benzene
and lower concentrations for HMX TNT and
the lows concentrations 260 TNT interestingly enough we
had a higher section frequency of 26 in Leach a sample and
we get to the performance side of we will rely more on as PLP
to show what's going on in the total soil data.
We evaluated the analytical results by
depth to assess whether we could pool any of the depths interval
results for subsequent statistical analysis and to assess
whether there is any variation in distribution through the treatment
zone and most of the explosives had a relatively
uniform distribution with depth, a couple oddball so to speak and
HMS and try benzene
they had a substantial decrease in concentration at deeper depths
and TNT was slightly reversed and had higher concentrations with depth.
In general the S SPLP data was correlated with the
soil concentration in the primary exception is that the two highest
baseline as PLP results were formulated to 60 TNT associated
with non-detected soil results.
>> As you can see on the slide which is a graph
of the SPLP shape concentration as of function of soil
concentration or select explosives with the
highest concentrations in the baseline samples and
a very strong correlation between Lee Chase concentration and
soil concentration. First we look at the four-month data
-- don't worry I have slides and graphs
of the words and numbers and bullets if it's too much to look
at a once and to summarize, for RDX the SPLP
leaching and total soil concentration decreases all
locations for HMX, both soil and leachate concentration
decreased it all but one of the locations that and for 246 TNT
soul concert duration decreased approximately
75% of the location where Elsie SPLP leachate decreased all
but one of the locations and for 24 TNT soil
TNT all but to the location step four
months is evidence we have degradation of these explosives.
This slide provides a plot
comparing the four-month and baseline data for RDX in soil you can see
is very little RDX left in the soil after
four months of heating. And similarly for 24 D NT
at -- decrease in concentration throughout
the treatment zone -- and
the results for the remaining contaminants were somewhat more mixed and if
you look at try natural benzene there was equal proportions of an
increase in no change in sample concentration
between the baseline event and four-month event. In one for benzene
all but one locations showed up no subs substantial change
of soil concentration in the 260 day that difficult to
because [ Indiscernible] difficult to tell between real
change in concentration and analytical sensitivity issues in the SPLP
-- 46
D NT health location decrease in interesting
love formula to 60 TNT
saw an increase in substantial change soil concentration and to me the
biggest surprise was for the three results were we sought
increase in both soil concentration SPLP leachate concentration essentially
all the locations.
Moving onto the six-month data, the six-month data confirm the
degradation that we observed with a four-month data from RDX at the
end of our period there was a sample location with
RDX detection in soil and also the SPLP leaching we had a greater than
94% increase in soil concentration and nine greater than
95% decrease in SPLP leachate concentration and HMX there's only one location
with the soil concentration did not decrease at the other locations
we observed decreases between 58% two greater than 99 present in
the one interesting to note the one location, 65 to 70 foot
interval in the Northeast quadrant where there was not
essentially a slight increase in the HMX concentration at this particular
interval, the leachate concentration was
66% lower than the baseline value and even though soil
data were not suggestive of degradation the leachate data were.
And the results are illustrated in the response pots we can see
six months there's very little RDX left in the soil and again at six
months very little HMX left in the soil.
TNT very strong decrease in concentrations and in the
oil leachate and greater
than 99 present in the soil 95 present greater 299 present in the leaching
-- and DNT concentration throughout the
10 to 70 foot below grade interval decreased between 56% and 99 present
in the soil at that location the 70 to 75 foot interval and southwest
quadrant given analytical variability it
is not clear so six-month result is
actually a decrease in the baseline value bet at all locations including
the steeper location the SL PT SPLP decreased between and greater than
99 present and it is interesting
to note as 70 to 75 foot interval the 2.4-D NT
concentration in that leachate sample was 95
94% lower than baseline value essentially went from second-half
parts per billion in the
baseline sample to non-detectable after six
months. In sunrise we have very strong
evidence of degradation RDX HMX TNT in 2.4-D NT
over the course of the six month study period and the
box illustrates a decrease in the TNT concentration with time,
and this plot illustrates the
solar concentration of 24 TNT over the course of the study --
D NT --
>> For 26 D NT
six months soil samples in which explosive was effective both detections
were less than reporting limit and there's a greater detection
frequency in the leachate results and so we
did some hypothesis testing and the hypothesis testing suggests
or concludes that the baseline data in six-month data
set are statistically the same but as you will see
in the plot there was a decrease in concentration
occurring and if you like at the location sample locations
individually, that nine of the 13 sample locations six-month SPLP
is seems to be indicative of degradation and here's the
box comparing the six-month results in the baseline results.
For me a note to six TNT
-- D NT if you look a couple slides
ago performance data suggested increase or no change in
concentration of this compound during the first four months of heating
period and the trance for six months there appear to be degradation
and at six months it to 6D NT
detected in one of 19 samples and that the textual 92 present
less than the corresponding baseline value that in the baseline
SPLP samples for me in 02 60
detective and for the samples and for those locations
the six-month results showed a 70% to 99 present decrease in concentration.
And moving onto those nine locations that had non-detected
baseline results, eight had deductions of four months
that illustrates that increase in formula DNT concentrations
during that phase of the study but as seven of the eight locations
the SPLP location decreased and when you look at
hypothesis testing and -- indicated decrease in
leachate concentration during the last two months of the
pilot study.
That decrease is illustrated in this box. During the four-month
leachate concentration to the six-month [ Indiscernible] concentrations.
>> Two amino 46 TNT
the compound was not detected in any of these six samples which is
great and die natural benzene not much
something happen with the compound hypothesis testing and
increasing the concentration between baseline and four months no change
between four and six months and compare the
baseline six-month that a hypothesis test indicates they are statistically
the same and a decrease between four and six months stay the same,
and not really clear in the box
looks to be very little change overall concentration of time. Very
much looks like this process does not affect the die natural benzene
much.
And try natural benzene no evidence there was any degradation of this
compound and going to four-month data this
is the one showed a significant increase
of concentration over first four months of the pilot study and hypothesis
testing indicated no change in concentration between four and six
months and if you look at the intervals maybe there is a decrease --
and summarize we had strong evidence of
RDX HMX TNT 24 DNT and two amino
DNT was formed during the early stages
of the heating period and degraded during the last two months and
SPLP suggest degradation is occurring and
that is somewhat confirmed by the observation of
the explosive detected in nine of the baseline sample soil samples
and only two of the six-month soil samples
and results for
die natural benzene is inconclusive as are just as explosive as a responding
to the heat alone and try natural benzene -- and
clearly degradation 35 diametric aniline some type of
product -- and just we don't know whether continued
heating of the service would love that product to go away with time.
>> Results are illustrated
on the next two slides. These are the data for
one specific location this is the Northeast quadrant at 20 to 25 feet
below grade and I divided the explosives into two
different slides because of the princes skillfully baseline results
and the slideshows RDX
very high at baseline level and four-month
in six-month results are non-detect results out reporting limit of.05
ppm and here very little change
try natural benzene concentration and moving to TNT
initial concentration around 656 ppm down to 90 detected four months
and six months -- and D NT decreasing
eventually 90 detected six months and HMX also completely degraded
at four and six months.
This shows had much lower baseline
results and as you look at the figure keep in mind that
the non-detect results are being shown at the purported limit of
0.05 ppm and looked at 24 and six TNT
initial concentration lesson two ppm and 90 detected at four months
and six months or not detected during the baseline event, at
four months and degradation between four and six months and 26 TNT
detected during baseline sampling but not subsequently
and 35 DMA and not detected during baseline
result in an increase in concentration throughout the study period and
die natural benzene no change between baseline between four months and
was going on in six months..
>> I
did an online search to see if I can find more information on potential
degradation pathways and 246 TNT can through
then degraded through intermediates we did not analyze unfortunately
and it is possible that what we saw
for the first four months was some type of enhanced biodegradation
of TNT to formula 260
TNT and you think the temperature would
be somewhat above the optimal range for that bacterium -- and aniline
I did look online and found
relative information little information on the compound what I could glean
from the literature it could be a TNT degradation product but interestingly
enough it has also going back to some
literature from the 1990s and identified as a biodegradation process of try
natural benzene which would be surprising there doesn't seem to be evidence
of try natural benzene degradation during the pilot study.
The purpose of this slide is to
have the results of the heat alone pilot study back to the alkaline
steam and enhanced hydrolysis poll study that Molly
described her in her presentation and granted you're looking at a
pilot alkaline steam enhanced pilot study had a duration of 20 days
in heat alone pilot study had a duration of six months so it is
not apples to apples comparison but we thought it would be helpful
to do a qualitative analysis.
In looking through the results in general RDX and for formula DNT
better removal what the heat alone 2019 Paul setting
as compared to the alkaline steam enhanced pilot study done in
2015 and try natural benzene has definitely better
degradation during the alkaline steam enhanced pilot study than
the current one, and die natural benzene I could not
form any conclusion on because most of the analytical results for
2015 study were non-detect
values of very elevated reporting limits I could not assess what that
poll study achieved in terms of diametric benzene degradation and
for TNT 24 DNT 26 DNT HMX in two amino 46 TNT both approaches seem
to work very well. In summary heat alone appears to be
more effective than alkaline hydrolysis for RDX TNT, both the amino DNT
is in both DNT's and
HMX were as alkaline hydrolysis is more effective at heel than try
natural benzene -- Lessons Learned -- and some
of this wish I'd known when we are working
on the poll study workplan certainly heat enhanced hydrolysis
achieved during degradation in several explosives in terms of our site-specific
DRGs for RDX the RDX results both
soil and all but one location and I've
a feeling a longer operating period would achieve throughout
the treatments on all of our TNT and amino for 60 results lesson
pure Geez and as a side note I was
not able to compare the HMX formula and results to PRG they are not
contaminants concerns they don't actually appear Geez for the site
-- and little effect on
die natural benzene formation of 35 diametric Emily
needs to be studied and also whether further or longer heating could
promote degradation of this compound needs to be studied.
The deepest sample interval is 70 to 75 sample interval indicates
that if water addition the TURP water addition did not
cause explosives to migrate through treatment some.
In hindsight it would be great to extend the
data collection through the coaling period to evaluate both the rate
of heat loss and also how much additional degradation
occurred during that cooling period. And
it would be beneficial to work with them analytical laboratory to expand
the analytical suite to include the degradation products that are
not part of method 8330 B and even if that means using nonstandard
methods most of us in the DoD world using standard
methods and this is a situation where nonstandard
methods would be very helpful indeed I think.
A potential future application currently this
technology looks very promising for deep data zones that are difficult
to reach her access through conventional means and it looks like it could
be very effective for a number of explosives RDX, HMX
TNT, DNT and immunity DNMTs as Emily discussed
with the potential to sports likely that would be very interesting to
use to evaluate the subsurface thermal inertia
to optimize energy usage and it would be interesting to see if this
technology could be extended to groundwater perhaps using lower
temperatures decrease the energy required may be heated to 40 degrees
instead of 40 degrees Celsius instead of 80 degrees Celsius,
's back and
going back to the remediation process Molly described
for Army tempo in her presentation,
and the process are preparing feasibility study for
the site looking at various alternatives for the deep data zone and I think
all of us would love to see technology like this be able to in the future
enhance or facilitate remediation of these
deeper data zones at a cost effective manner. And with
that I will entertain any questions.
>> Thank you so
very much and thank you and want to remind the audience as well that
the Q&A window is available in the lower right corner to send in questions
and comments we have a few that were put into the queue and number
of them are honing in on cost. So someone generally wants to know
if you can provide a ballpark cost estimate for the ERH study and I'm
I can into some specific ones looking for cost per
cubic yard, or if you were like expanded between
pilot and go full scale what would those costs be?
>> This is Emily I'd be happy to help
provide information on that so typically when we are
providing information regarding cost we like to do it in terms of
cost per cubic yard it is something that can help compare to other technologies.
In general we are looking at lower temperature heating demonstrations
it can range it is dependent upon the size of
the treatment volume is dependent upon the lithology in a number
of parameters but in general $75-$100 hundred
and $50 per cubic yard is what we commonly see and
there are factors that can drive the cost lower but that is a general
rank and we talked about deep recovery system for temperature heating
applications where deeper extraction and management
and treatment of the surface is not required that can help drive
the cost lower but in general that is the range that we would expect
to see.
>> Wonderful.
I wanted to circle back to the participants
who sent in questions about some of the more specific breakdown products
and processes and to see if you still had
additional questions or things you may have put in earlier have
been addressed if you would not mind replying into the
Q&A window and let me know if you're process questions have been addressed
and you don't have additional once you can type
in the Q&A orphan question still stands you can also let me know.
We had a few individuals waiting to see if there's any response regarding
the processes as give copies of your materials are available or
if the session is going to be recorded and I wanted to let the audience
know that yes to both copies of the slides are available for reference
and we will talk about how you can exit those at the very end and they
were right on the seminar homepage you used to check in for today's
session and then same thing for the question on recording we are
recording today's session and we will provide a link to that
recording to everyone who registered usually takes us about a week and
you'll be able to play the session back on demand wants that recording
is available.
And waiting to see if you have additional questions
that might come into the queue and it looks like some people have chimed
in confirming that your questions or their questions on the process
and degradation products were addressed in the
later portion and I want to thank all of our presenters for sharing
their expertise and for participants confirming pure
for the remote audience if you do not have any additional questions
for the speakers, go ahead and put that in I want to be sure we
keep the lines on one if someone is typing more detail, the question
for speakers and a lot of that time but if you have no particular questions
please put that into the window as well if you have
learned a lot, you need to digest what they may have shared and again
you don't have any following questions want to get the feedback as well
as I see a lot of comments coming in here with a lot of thank youse
and echoes they don't have questions but was a lot of information and
wanted to thank you all and sharing it was a great presentation
and wanted to provide that feedback to the presenters today. And thank
our speakers for sharing that expertise in again for that live audience
seen back into this loop and letting me know they have the questions
answered and I did see one that is coming here and this gets into
the sampling of soils, so the one question that popped
in sampling soils again after 6 to 12 months of's locally
would be interesting. They wanted to know if you could do that
and they note that it could
potentially show lower concentrations for your
COC which due to grade and that you might be able to address that
one.
>> That would be me Molly,
I would love to be able to go out there and I currently do not have
a program in the funding usually the driver for everything, but
it is not to say we can't go back out and it would not be immediate
but having a follow-on sample would be very helpful. Hopefully that
answers your question if we can find the funding I think
it would be interesting. Thank you.
>> And Molly in a lot of ways leading even a year
or for it to reach ambient temperatures or more
than a year that would be very interesting
data sets and maybe even longer waiting longer could result in more
information regarding the overall degradation at the site.
>> And a few following a number of
people commented they wanted to take some time to digest the information
they might have follow-on questions, so I wanted to put this to the
speakers if individuals have follow-on questions for you that might
happen after this live event today, can we show your contact information
with them so they can reach out to you directly?
>> Absolutely. I would actually ask if you could include all three
speakers so we can see what
the questions are and work as a team together to answer them would
be my only request.
>> All right excellent so we have emails posted and as part
of our follow-on email to everybody that we make sure the contact information
for our presenters is included as a follow-up message. And so what
that I want to see if any of our speakers have any final
thoughts they want to lead with the audience before I walked to
our closing procedures today?
>> This is Molly I am good thank you
everybody for listening. Hopefully you found it informative.
>> Excellent.
Well what that
>> Thank you so much for your time
>> Thank you Emily
>> This is Cindy and I'd like to
thank everyone for listening in.
>> Excellent thank you Cindy. Well
let me walk through a quick closing item people we officially conclude
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Thank you.