Technology Innovation News Survey

Department of the Interior, National Park Service, Port Angeles, WA.
Contract Opportunities from Beta.Sam.gov, Solicitation 140P8319R0013, 2019

This requirement is a total small business set-aside under NAICS code 562910, size standard 750 employees. The National Park Service requires targeted soil removal at the Decision Unit-Northeast-1 (DU-NE-1) site at the Ft. Vancouver National Historic Site, in Vancouver, Washington, to restore the site soil to safe levels for visitors and employees. In addition, the contractor will dispose of steel drums (55-gallon type) previously stockpiled with potentially lead-contaminated soil. Additional details are provided in the Statement of Work, Attachment 1 at https://www.fedconnect.net/FedConnect/?doc=140P8319R0013&agency=DOI. All work will be performed under a single firm-fixed-price construction contract. Contractor will have 210 calendar days to complete the project after Notice to Proceed. The estimated magnitude of this construction project is between $250,000 and $500,000. Responses are due by 12:00 noon ET on November 29, 2019. https://beta.sam.gov/opp/81a22befa4ef4640dffdb644c66d60bb/view

Army Contracting Command, ACC (W911SR), Aberdeen Proving Ground, Edgewood, MD.
Contract Opportunities from Beta.Sam.gov, Solicitation W911SR-20-R-EXPL, 2019

The purpose of this announcement is to gather information on state-of-the-art technologies to detect or identify potential chemicals and functional groups associated with explosives. These technologies can take the form of handheld, benchtop, or standoff detection constructs and might include but are not limited to X-ray diffraction, X-ray fluorescence, nuclear magnetic resonance, ion mobility spectroscopy, or FTIR spectroscopy. Specifically, the Government is attempting to identify systems that will work within operationally relevant environments and have the ability to detect or identify various compounds and explosives. The applicable NAICS codes for this RFI are 334516 and 541715. Submit relevant test reports and other applicable documents with the response by 11:59 PM ET on December 2, 2019. https://beta.sam.gov/opp/a6b16ac2474c51609c6ffcdb95c2ab9f/view

Naval Facilities Engineering Command Pacific, Pearl Harbor, Hawaii.
Contract Opportunities from Beta.Sam.gov, Solicitation N6274220CLEAN, 2019

This synopsis constitutes market research to identify potential Section 8(a), HUBZone, woman-owned, service-disabled veteran-owned, and small business concerns (NAICS code 541330) that are capable of providing professional A-E services in support of the Navy's Environmental Restoration Program (i.e., Installation Restoration and Munitions Response in compliance with CERCLA and other similar programs) at various Navy and Marine Corps facilities within the NAVFAC Pacific, Hawaii, Marianas, Southwest, and Northwest areas of responsibility. Work will be performed mainly in Hawaii, Guam, and Southern California. Procurement of these services will result in a cost-plus-fixed-fee IDIQ-type contract with a 12-month base period and four 12-month option periods or $249M, inclusive of award fee, whichever occurs first. NAVFAC Pacific will use the responses to this sources sought to make appropriate acquisition decisions for the planned procurement. Respond by 10:00 AM Hawaii Time on December 9, 2019. https://beta.sam.gov/opp/2b9fec1fde076f704e2a18fcc422b131/view

NAVFAC Southwest, Environmental Contracts, BRAC, San Diego, CA.
Contract Opportunities from Beta.Sam.gov, Solicitation N6247320R0024, 2019

This procurement is unrestricted under NAICS code 541330, small business size standard $16.5M. A-E firms desiring to be considered must submit a completed SF-330 package for a contract to provide range sustainability services for military training/testing range complexes and assets at various locations worldwide. Contract services also include environmental planning associated with NEPA and Executive Order 12114 (Environmental Effects Abroad of Major Federal Actions) in support of the Tactical Training Theater Assessment and Planning Program. The IDIQ contract will have a base period of 24 months and one 5-year option period for a total contract amount not to exceed $100M. Most of the work awarded under the contract will involve Navy training range complexes within the Pacific Fleet area of operations. SF-330 packages are due by 2:00 PM PT on December 9, 2019. https://beta.sam.gov/opp/bb83817fbf9785362926ce49c6d6ec51/view

Department of Homeland Security, U.S. Coast Guard, Norfolk, VA.
Contract Opportunities from Beta.Sam.gov, Solicitation 70Z08420R100001, 2019

The U.S. Coast Guard's Shore Infrastructure Logistics Center seeks to identify interested sources capable of providing emergency response services for containment, cleanup, and/or mitigation of the harmful effects of oil spills and hazardous substance incidents on or in waters encompassing the entire United States and its territories, including but not limited to Puerto Rico, Virgin Islands, Guam, Mariana Islands, and American Samoa. The Coast Guard intends to negotiate a time-and-material-type basic ordering agreement with environmental contractors selected as a result of this sources sought. Respond by 4:00 PM ET on December 9, 2019. https://beta.sam.gov/opp/a872f1ebe45ded2ae52cc070e566b33e/view

U.S. EPA Emergency Response Branch, 106 pp, 2019

A time-critical removal action (TCRA) was performed within a 1.7-mi river reach of the Kalamazoo Superfund site to remove PCB sediments, bank soils, and a temporary water control structure (WCS), and to stabilize the channel under the new dam-out condition. The banks were restored using bioengineering techniques and riparian restoration to increase the strength of the bank treatment and reduce maintenance over time. Pre-design investigation activities allowed for significantly reduced bank remediation and sediment volumes. Design and construction brought unique challenges to riverbank remediation and stabilization that required specific engineering/construction solutions such as in-stream structures, bioengineering techniques, and on-site reuse of materials. A pilot channel was dredged through unimpacted sediment to control development of the river thalweg (the line of fastest flow or deepest water along a river's course) as the WCS was lowered to facilitate construction of the new banks. The pilot channel directed the river flow to the center of the channel, preventing the potential for the channel to undermine the adjacent steep bank and cause slope failure. Dredge spoils were re-located via pumping to the downstream side of the former dam spillway where a scour hole had previously formed and would, in the future, be relatively cut off from the main river channel. Since implementation of the TCRA, the river has experienced several flood events and the constructed design functioned as planned. The bioengineered bank treatments will increase in strength and provide a robust bank treatment that requires minimal maintenance over time. See Otsego Township Dam section to download zip file that includes attachments, figures, and final report: https://cumulis.epa.gov/supercpad/SiteProfiles/index.cfm?fuseaction=second.Stayup&id=0502325. Also see presentation by J. Caryl: https://www.michigan.gov/documents/egle/egle-tou-GLERRCpresentation-BankRemediationRestoration-Caryl-Wood_670760_7.pdf

Parker, J. and J. Crum. | Great Lakes Environmental Remediation & Redevelopment Conference, 16-18 October, Lansing, MI, 33 slides, 2019

Historical commercial activities at an orphaned site in Michigan resulted in 10 acres of PVOC and CVOC releases in the heart of a historic city and adjacent to a variety of active land uses, including an antique district and a residential neighborhood. An extensive intrusive off-site investigation utilizing direct push technology borings, groundwater monitoring wells, soil vapor monitoring, and indoor air sampling was completed in two phases over ~6 months. In 12 months, the project team investigated a three-block area to develop property-specific volatilization to indoor air pathway (VIAP) conceptual site models and successfully mitigated homes at five properties where sample results demonstrated that TCE posed an unacceptable risk to occupants. Immediate interim actions included installation of indoor air purifying units (APUs) and expeditious design and installation of sub-slab depressurization systems at four of the five buildings. A fifth commercial building is currently managed via operation of multiple APUs. The VIAP was also investigated at seven other properties, and one year of quarterly monitoring indicates that the VIAP is not complete. Source remediation began after the initial VIAP sampling events. After only 6 months of operation, in situ TCE groundwater treatment systems have produced notable reductions in the TCE-contaminated groundwater and vapor plumes. https://www.michigan.gov/documents/egle/egle-tou-GLERRCpresentation-VIAP-Parker-HampMathews_670763_7.pdf For more information on VIAP, see workshop presentations at https://www.michigan.gov/egle/0,9429,7-135-3308_3333-459064--,00.html.

Ross, I., S. Manivannan, E. Houtz, J. Mcdonough, and P. Storch.
Real Property Institute of Canada Federal Contaminated Sites Regional Workshop, 4-5 June, Halifax, NS, 38 slides, 2019

Loss of concentrated aqueous film-forming foam at Brisbane Airport in Queensland resulted in PFAS impact to domestic/industrial sewer and stormwater systems and nearby surface water. The sewer and stormwater systems were subsequently isolated to prevent further impact on the environment. About 6 million liters (ML) of wastewater and 6 ML of stormwater were collected, contained in 20 m³ capacity tanks, and treated to a concentration of <0.25 µg/L (sum of 28 PFAS compounds), as measured by total oxidizable precursor (TOP) assay. An innovative ozofractionation treatment process was designed, installed, and commissioned in four weeks to treat the contaminated water. The primary waste generated from the process was a highly concentrated aqueous PFAS stream. The ozofractionation process demonstrated the ability to treat high PFAS concentrations up to 4,000 µg/L as well as much lower PFAS concentrations whilst also handling the high organic load and other co-contaminants of the mixture of raw domestic and industrial sewage. A reduction of > 99.9% of PFAS was routinely achieved. The system reliably removed long-chain and short-chain PFAS < 2 µg/L. To reach the final treatment objective, a membrane filtration system was installed to reduce concentrations reliably < 0.25 µg/L TOP assay. https://www.rpic-ibic.ca/images/2019_FCSRW/presentations/Decontamination_of_PFAS_Impacted_Infrastructure_and_Full-Scale_Treatment_of_PFAS_Impacted_Wastewater_Using_Ozofractionation_with_Treatment_Validation_using_TOP_Assay.pdf

U.S. DOE, Office of Environmental Management, EM2018-0008, 124 pp, 2018

In 2015, a soil-vapor extraction (SVE) system operated at two vapor extraction wells in Material Disposal Area (MDA) L, Technical Area 54 of Los Alamos National Laboratory. Within 10 months, the two SVE units removed 1,217 lbs of total organic vapor mass, primarily from within a ~150-ft radius surrounding the extraction wells. Following the initial 10-mo SVE operation, short-duration rebound testing was performed in 2016 (2 days) and 2017 (25 days). Pore-gas sampling results collected within the 150-ft radius of the SVE units confirmed SVE operation had reduced the concentrations at most sampling ports to below their baseline values. Data collected during the interim measure was used to calibrate and validate a 3D model of the site, explore scenarios of hypothetical future releases, and present suggestions to support the selection and design of a final remedy for MDA L. https://www.energy.gov/sites/prod/files/2019/01/f58/EMID-700039-01_MDA_L_SVE_IM_Rpt_080618.pdf

Sweet, B., K. Davidson, and C. Lake. | RemTech 2019: Remediation Technologies Symposium, 16-18 October, Banff, 18 slides, 2019

Recent research has explored the potential of an in situ laser-induced fluorescence technique to spatially delineate organic-rich industrial sediments contaminated with dioxins and furans to collect unique optical signatures of materials based on their physiochemical properties. Lab and field work were conducted at a stabilization basin that has received industrial wastewater over the past 50+ years in Nova Scotia, Canada. Preliminary lab and field testing on sediments within the basin served as proof of concept for the application. The system's performance was compared to standard gravity cores, the results of which are included in the presentation. This system has the potential to vertically delineate the presence or absence of contaminated sediments, which will assist in producing more accurate volume estimates for remedial dredging operations with implications for similarly contaminated environments undergoing assessment and/or remediation. Longer abstract: https://www.esaa.org/wp-content/uploads/2019/09/51-RT-2019-Abstract.pdf Slides: https://www.esaa.org/wp-content/uploads/2019/10/19-Sweet-1.pdf See pages 97-115 for pilot study results https://procurement.novascotia.ca/pt_files/addendums/NSLAND107.pdf

Spurlin, M.S., B.W. Barker, B.D. Cross, and C.E. Divine.
Remediation 29(2):63-73(2019)

Several nuclear magnetic resonance (NMR) field investigations were conducted to demonstrate the technology's viability as a site characterization tool for near-surface investigations. Use of NMR to detect vadose zone water provided hydrostratigraphic details that were used to evaluate drainable pore water versus pore water bound by capillary forces or electrochemically clay-bound water. While NMR produced hydraulic conductivity estimates like those from conventional hydraulic tests, it improved vertical resolution to provide additional information regarding the vertical heterogeneity of the formation along the entire length of the well or borehole. Bench-scale tests are presented that confirm NMR capability to reliably detect and quantify LNAPL saturation in situ. https://onlinelibrary.wiley.com/doi/epdf/10.1002/rem.21590

Clutterham, M., A. Nolan, R. Denny, P. Hutson, C. Robb, and D. Meric.
10th International Conference on the Remediation and Management of Contaminated Sediments, 11-14 February, New Orleans, Louisiana, 25 slides, 2019

Sediments in Kendall Bay were contaminated with PAHs and total recoverable hydrocarbons from the former Mortlake operations on the bay's shore. In situ stabilization/ solidification (ISS) was selected as the remediation technology, which reduced the need to move contaminated material for off-site treatment and disposal and the potential for odor emissions associated with traditional dredging approaches. A Phase 1 lab treatability study identified the optimal additive mix design required to meet the project performance criteria, including unconfined compressive strength, contaminant leachability, and hydraulic conductivity. A Phase 2 pilot study took place at a location in Kendall Bay, selected based on similar physical sediment properties and contamination as the remediation areas. The Phase 3 work involved the construction of a 1.5 m-thick ISS raft to remediate contaminated sediments and 8 deeper ISS columns for structural support and constructability of the raft within one of the remediation areas. Using multiple lines of evidence, the trials demonstrated the successful application of ISS for the remediation of contaminated sediments in Kendall Bay. The project will now progress to full-scale remediation of contaminated sediments. https://www.battelle.org/docs/default-source/conference-proceedings/2019-sediments-conference-proceedings/b11.-in-situ-stabilization/b11_1300_-77_clutterham.pdf?sfvrsn=e5079f2e_2 [Note: It might be necessary to copy/paste the URL into your browser.] More information: http://jemena.com.au/documents/remediation-projects/kendall-bay/planning-approval-documents/3-ssd-6701-assessment-report-signed.aspx.

Battye, N., L. Turner, O. El-Sharnouby, D. Patch, K. Jaansalu, B. Kueper, and K. Weber.
Real Property Institute of Canada Federal Contaminated Sites Regional Workshop, 4-5 June, Halifax, NS, 25 slides, 2019

A study employed ball milling to destroy PFAS in soils from a 50+-year-old firefighting training area and silica-based sand spiked with PFAS. The mechanical action of milling promotes reactivity and surface chemistry states that are not attainable in ambient conditions. Three different-sized ball mills were used to evaluate and demonstrate scalability. A suite of 13 PFAS compounds spanning and extending beyond those with Canadian guidance values were tracked in all cases. Results demonstrated up to 97% of PFAS destruction within minutes in two types of soil, sand, and clay, and no identifiable PFAS products were produced. This patent-pending, ex situ remediation technology for PFAS-contaminated soils will be scaled on-site to develop detailed operational requirements. https://www.rpic-ibic.ca/images/2019_FCSRW/presentations/Successful_Scale-up_and_Destruction_of_PFAS_in_Soil_Via_Ball_Milling.pdf

Lundquist, N.A., M.J. Sweetman, K.R. Scroggie, M.J.H. Worthington, L.J. Esdaile, et al.
ACS Sustainable Chemistry & Engineering 7(13):11044-11049(2019)

In this study, a sulfur polymer support was added to powdered activated carbon (PAC) to overcome commonly experienced dust generation and caking issues that can block filters when using PAC to remediate contaminated water. The sorbent/PAC mixture was used to remediate artificial water contaminated with PFOA and PFOS. Fundamental discoveries of PFOA self-assembly are also reported, as well as testing on a field sample of contaminated surface water.

Kim, U., J.C. Parker, and R.C. Borden.
Stochastic Environmental Research and Risk Assessment 33(1):73-89(2019)

A computer program was developed to optimize in situ chemical oxidation (ISCO) design to meet specified source zone remediation objectives at DNAPL sites. In addition to the remediation objectives, the program determined optimal design parameters to meet remediation cost and took uncertainty in site characterization data and model predictions into consideration. The ISCO model was implemented in the Stochastic Cost Optimization Toolkit. ISCO design parameters considered for optimization include oxidant concentration and injection rate, frequency and number of soil or groundwater samples, and cleanup criteria for termination of subregion injection. Sensitivity studies and example applications are presented to demonstrate the benefits of the proposed stochastic optimization methodology. The Stochastic Cost Optimization Toolkit can be accessed via http://scotoolkit.csuohio.edu/. See more on this SERDP-sponsored project at https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Persistent-Contamination/ER-2310l.

Ghosh, J., G.R. Tick, N.H. Akyol, and Y. Zhang.
Journal of Contaminant Hydrology 223:103471(2019)

A pore-scale study was conducted to understand and quantify the trapping and mobilization mechanisms and in situ emulsification processes of heavy crude oil distributed within increasing complexity unconsolidated sands during surfactant-enhanced remediation. Pore-scale imaging analyses quantified the changes in oil blob morphology before and after surfactant flushing events to assess the primary factors that control the recovery. Results showed relatively low (10%) net recovery from the homogeneous sand after 5 pore volumes (PVs) of surfactant flushing. Negligible net oil recovery was achieved from the mildly heterogeneous sand, likely due to the medium's lower associated permeability. The oil-phase distribution within sand medium primarily consisted of small disconnected blobs more readily exposed than the surfactant solution. For the highly heterogeneous sand experiments, an average of 20% heavy-oil recovery resulted after each flushing event (total of ~37% after 5 PVs) and was attributed to a more efficient reduction of interfacial tension associated with the increased surfactant-oil contact. The associated higher pH sand/fine-carbonate system may have aided in maintaining a water-wet porous medium, a condition more conducive to higher oil recovery and displacement efficiency.

Lee, T.-H., D.C.W. Tsang, W.H. Chen, F. Verpoort, Y.T. Sheu, and C.M. Kao.
Chemosphere 219:444-455(2019)

An emulsified polycolloid substrate (EPS) was developed and applied to form a biobarrier for the containment and enhanced bioremediation of a toluene-contaminated groundwater plume. EPS had a negative zeta potential (-35.7 mv), which promoted its even distribution after injection. Batch and column experiments conducted to evaluate the effectiveness of EPS on toluene containment and biodegradation resulted in a partition coefficient of 943. Groundwater containing toluene (18 mg/L) was pumped into the three-column system at a flow rate of 0 28 mL/min, while EPS was injected into the second column to form a biobarrier. A significant reduction of toluene concentration to 0.1 mg/L was observed immediately after EPS injection, indicating its effectiveness to contain the toluene plume and prevent migration farther downgradient. About 99% of toluene was removed after 296 pore volumes of operation via sorption, natural attenuation, and EPS-enhanced biodegradation. An increase in total organic carbon and bacteria was also observed after EPS supplement. Supplement of EPS resulted in a growth of petroleum-hydrocarbon degrading bacteria, which enhanced the toluene biodegradation.

U.S. EPA, Office of Land and Emergency Management, Washington, DC.
EPA 560-B-19-001, 134 pp, September 2019

This guide updates the 2017 edition to aid in the cleanup and redevelopment of brownfields. Each federal agency or organization involved is summarized with respect to its mission and connection to brownfields. Each summary identifies relevant programs organized according to whether technical or financial assistance is available. Where applicable, a description is provided of eligibility requirements, availability, uses, and applications, as well as any restrictions on use or eligibility. "Snapshots" of brownfield projects that have successfully leveraged funding from these programs are included to illustrate how federal programs have stimulated brownfields cleanup and redevelopment around the country. The section on "Other Support for Brownfields Cleanup and Redevelopment" explains options for using federal tax incentives and bringing state and local partners into the funding mix. Tapping into these additional funding sources often can provide the additional resources that a brownfields project needs. EPA encourages stakeholders to think broadly about a brownfields project and plan early for its success by considering the many options available for technical and financial assistance. This guide provides a useful tool. A quick-reference table gives an overview of brownfields federal programs to help narrow the search for assistance. https://www.epa.gov/sites/production/files/2017-06/documents/final_2017_bf_fed_guide_5-8-17.pdf

Rong, Y. (ed). CRC Press, Boca Raton, FL. ISBN: 978-1-138-10515-7, 340 pp, 2018

In 12 chapters, this book examines all aspects of environmental site assessment and remediation and outlines the interdisciplinary skills needed for field assessments. Included is a comprehensive overview for students, environmental professionals, and real estate developers, as well as recent information on environmental regulations, environmental site assessment and remediation practices, and industry standards. Topics covered include pollution sources, related impacts on drinking water supplies, and associated health risks; how to protect water resources; surface water, groundwater, and soil monitoring; and vapor intrusion. Practical case studies are also provided. See a preview of the book at https://content.taylorfrancis.com/books/download?dac=C2017-0-49302-4&isbn=9781351590433&format=googlePreviewPdf, or examine the chapter abstracts at https://www.taylorfrancis.com/books/e/9781315101897.

U.S. EPA Engineering Forum Greener Cleanup Workgroup, CLU-IN Website, 2019

EPA's "Principles for Greener Cleanups" [https://www.epa.gov/greenercleanups] provide a foundation for planning and implementing cleanups that protect human health and the environment while minimizing the environmental footprint of cleanup activities. EPA has developed 14 greener cleanup metrics to use to quantify specific portions of the footprint, such as the amounts of refined materials, public water, or diesel fuel that are used or the amount of wastewater and hazardous waste that is generated. The metrics provide an optional means for regulators, private industry and other cleanup partners to collect and track site-specific footprint information across multiple sites in a uniform and transparent manner. On a project level, metrics use is anticipated to help the cleanup stakeholders identify best management practices that could be implemented to minimize the footprint. A spreadsheet tool, the Excel-based Greener Cleanup Metrics Workbook, is available to help parties document and report the metrics. https://clu-in.org/greenremediation/greenercleanupmetrics

Mok, C.M. and P. Kulkarni. | SERDP & ESTCP Webinar Series, Webinar #101, October 2019

SERDP and ESTCP sponsored two presentations on managing contaminated groundwater. The first presentation featured hydraulic tomography (HT), a cost-effective high-resolution site characterization technique to delineate the spatial distributions of hydraulic conductivity and storativity. A field-scale demonstration confirmed that HT can be readily applied at other DoD sites using existing networks of groundwater extraction/injection and observation wells. The presentation also described further enhancements by integrating HT with geophysical tomography as well as applications for remediation reliability evaluation and optimization. The second presentation described a recently completed ESTCP project on a contaminant flux reduction barrier. The discussion included 1) results from a small-scale field demonstration of the permeation grouting technology, 2) a permeation grouting decision flowchart, and 3) an overview of the ESTCP Source Barrier Toolkit. https://www.serdp-estcp.org/Tools-and-Training/Webinar-Series/10-24-2019

Besha, A.T., D.N. Bekele, R. Naidu, and S. Chadalavada
Environmental Technology & Innovation 9:303-322(2018)

This review introduces surfactant enhanced in situ chemical oxidation (S-ISCO) technology and compares it to traditional in situ chemical oxidation. An overview of the three most important components of S-ISCO (surfactant/co-solvent mixtures, the catalyst and/or the oxidant and the free radicals) and major factors affecting the application of S-ISCO for the remediation of contaminated sites are included. The review concludes with a detailed explanation of the recent case studies and field applications of S-ISCO and factors affecting its implementation.

The Association for Environmental Health & Sciences (AEHS) Foundation, 201 pp, 2019

Over the past 35 years this conference has evolved from a meeting about underground storage tanks into one of the premier environmental conferences in the United States, attended annually by 700-800 individuals from a wide variety of disciplines, including state and federal agencies, military, industry, utilities, environmental consulting, and academia. International participation has continued to expand, with some years boasting representation from over 40 different countries. Topics encompass emerging contaminants, advances in site remediation, health risks, vapor intrusion, risk assessment, environmental forensics, sustainable remediation, and site characterization. http://www.aehsfoundation.org/Member/aehsfoundation/Files/Abstract%20Book%20EC2019.pdf

Wang, L., D. Hou, Y. Cao, Y. Ok, F.M.G. Tack, J. Rinklebe, and D. O'Connor
Environmental International [Published online 11 November 2019 prior to print]

Recent developments in technological approaches for the remediation of Hg-contaminated soil, water, and air with a focus on emerging materials and innovative technologies are covered in this publication. Emerging materials include various nanomaterials graphene, biochar, metal organic frameworks, covalent organic frameworks, layered double hydroxides as well as other materials such as clay minerals and manganese oxides. The performance of innovative technologies, such as adsorption/desorption, oxidation/reduction and stabilization/containment, with the aid of these materials is then evaluated. In addition, the publication reviews technologies involving organisms, such as phytoremediation, algae-based mercury removal, microbial reduction, and constructed wetlands as well as the role of organisms in these techniques.

Kobya, M., R. Darvishi, C. Soltani, P.I. Omwene, and A. Khataee
Environmental Technology & Innovation 17:100519(2019)

Electrocoagulation (EC) applications, performance results, drawbacks, and limitations for As removal are the focus of this review. Topics covered include mechanisms and theoretical aspects; effects of operational parameters on the efficiency of the process, including current density, charge loading, and initial pH; reactor configurations and operating cost of the process; the EC sludge production, including characterization and disposal methods ; and the simultaneous As removal with other contaminants from water. The publication concludes with examples of pilot and full-scale applications of EC for As removal and the outlook of this field of study with respect to new areas of research.