Persistent organic pollutants (pops)

Contamination by POPs is widespread because POPs are chemically stable, bioaccumulate, and circulate globally via the atmosphere, oceans, and other pathways. To address the threat posed by this widespread POPs contamination, remediation technologies continue to be developed to treat these pollutants.

Historically, POP-contaminated soil has been widely treated by combustion systems using high temperature incineration to destroy the contaminants.  Incineration is widely used because high-temperature incinerators can address large volumes of contaminated material and can treat most POPs contaminants.  Though incinerators can be used to treat POPs, many interested parties have expressed concern about potential environmental and health effects associated with this type of treatment technology. The combustion of POPs can create by-products such as polychlorinated dibenzo-p-dioxins (i.e., dioxins) and polychlorinated dibenzo-p-furans (i.e., furans), which can cause serious health problems. – two known human carcinogens.  Therefore, based on limitations associated with combustion technology, concerns with incineration, and an ongoing desire to find more cost effective solutions, environmental professionals are examining the application of non-combustion technologies to remediate POPs in stockpiles and soil.

The following reports provide information about non-combustion technologies for POPs

Persistent Organic Pollutants: Contaminated Site Investigation and Management Toolkit
Li, L.Y., A. Iwayemi, F. Li, T. Komives, and T. Chakrabarti.
United Nations Industrial Development Organization, 340 pp, 2010

This toolkit was compiled to aid developing countries with the identification, classification, and prioritization of POPs-contaminated sites and with the development of suitable technologies for remediation. The toolkit focuses exclusively on the 12 original POPs: Aldrin, Chlordane, DDT, Dieldrin, Endrin, Heptachlor, hexachlorobenzene, Mirex, toxaphene, PCBs, dioxins, and furans. The 9 POPs recently added to the Stockholm Convention are not discussed in this text. Important features of this toolkit are the sections on guidelines for site investigation, integration of risk assessment with contaminated site management, and a screening matrix for selection of remediation technologies. This toolkit also presents a step-by-step approach to economic analysis of POPs-contaminated sites.

Proven Technologies and Remedies Guidance: Remediation of Organochlorine Pesticides in Soil
Burger, K., H. Muniz-Ghazi, K. Shaddy, K. Siglowide, and D. Taylor.
California Department of Toxic Substances Control, 110 pp, 2010

This approach for remediation of organochlorine pesticides (OCPs) streamlines the cleanup process by limiting the number of evaluated technologies to excavation/disposal and containment/capping. The focus is on the following pesticides: DDT/DDD/DDE, toxaphene, chlordane, dieldrin, lindane, and heptachlor/heptachlor epoxide. Resources to facilitate remedy design and implementation are identified. This approach will not be applicable to all sites with OCP contamination, such as sites where OCPs have contaminated water resources or where ecological impacts are present.

Reference Guide to Non-combustion Technologies for Remediation of Persistent Organic Pollutants in Soil, Second Edition - 2010

This report is the second edition of the U.S. Environmental Protection Agency's (US EPA's) 2005 report and provides a high level summary of information on the applicability of existing and emerging noncombustion technologies for the remediation of persistent organic pollutants (POPs) in soil. Since the publication of this report in 2005, nine (9) additional chemicals have been listed in the Stockholm Convention; this brings the total number of chemicals currently listed as POPs under the Stockholm Convention to twenty-one (21). In addition, three (3) POPs are currently under consideration.

Technology Fact Sheets for Remediation of POPs were developed for the following three technologies and are available at the following links.

• Anaerobic Bioremediation Using Blood Meal for the Treatment of Toxaphene in Soil and Sediment
• Bioremediation Using DARAMEND^® for Treatment of POPs in Soils and Sediments
• In Situ Thermal Desorption for Treatment of POPs in Soils and Sediments

Review of Emerging, Innovative Technologies for the Destruction and Decontamination of POPs and the Identification of Promising Technologies for Use in Developing Countries

This report was developed by the Science and Technology Advisory Panel (STAP) of the Global Environmental Facility (GEF). This report provides a summary overview of noncombustion technologies that are considered to be innovative and emerging and that have been identified as potentially promising for the destruction of POPs in stockpiles. The report contains overviews of the following noncombustion technologies:

1. Base-catalyzed decomposition (BCD)
2. Bioremediation/Fenton reaction
3. Catalytic hydrogenation
4. DARAMEND^® bioremediation
5. Enzyme degradation
6. Fe (III) photocatalyst degradation
7. Gas-phase chemical reduction (GPCR)
8. GeoMelt^TM process
9. In situ bioremediation of soils
10. Mechanochemical dehalogenation (MCD)
11. Mediated electrochemical oxidation (AEA Silver II)
12. Mediated electrochemical oxidation (CerOx^TM)
13. MnO_x/TiO₂ - Al₂2O₃ catalyst degradation
14. Molten metal
15. Molten salt oxidation
16. Molten slag process
17. Ozonation/electrical discharge destruction
18. Photochemically enhanced microbial degradation
19. Phytoremediation
20. Plasma arc (PLASCON^TM)
21. Pyrolysis
22. Self-propagating high-temperature dehalogenation (SPHTD)
23. Sodium reduction
24. Solvated electron technology
25. Supercritical water oxidation (SCWO)
26. TiO₂ - based V₂O₅/WO₃ catalysis
27. White rot fungi bioremediation

Evaluation of Demonstrated and Emerging Remedial Action Technologies for the Treatment of Contaminated Land and Groundwater

This report was developed by International HCH and Pesticides Association (IHPA) and North Atlantic Treaty Organization (NATO) Committee on the Challenges of Modern Society (CCMS). The report describes emerging noncombustion alternatives for the economical destruction of POPs. Mr. John Vijgen of IHPA collected the technology data and authored the report. The report contains fact sheets for the 11 technologies listed below:

1. BCD
2. CerOx^TM
3. Gas-phase chemical reduction process
4. GeoMelt^TM
5. In situ thermal destruction
6. MCD^TM
7. SPHTD
8. Silver II^TM
9. Solvated electron technology
10. SCWO
11. TDR-3R^TM

Environmental Technology Verification Report for the Plasma Enhanced Melter ™

This Technology Verification report describes the nature and scope of the environmental evaluation of the performance of the Plasma Enhanced Melter™ (PEM™) system for waste treatment. The evaluation was conducted through a cooperative program established in 1998 between the Washington State Department of Ecology (WSDOE), Integrated Environmental Technology Inc. (IET), Allied Technology Group (ATG) and the Civil Engineering Research Foundation (CERF). The goal of this report is to provide potential users and purchasers of the PEMTM system with information they need to make more informed decisions regarding the performance of PEMTM as an equivalent or alternative to incineration for treating hazardous waste.