Polychlorinated Biphenyl (PCB) Wastes

Vacuum 70(1), 59-66 (2003). Non-transferred DC steam (H2O) plasma working with 100 kW was applied to minimize production of the toxic byproducts such as dioxins and furans of which formation is not avoidable in the conventional incineration. In the steam plasma process of polychlorinated biphenyl (PCB) mixture waste, content of combustible gas that can be used as gaseous fuel was about 30% based on wet gas. For the mixture of 27% PCB and 73% CCl4, total toxic equivalent concentration of PCDD/PCDF was about 0.056 ng TEQ/N m3. It is concluded that the steam plasma torch process was more effective for waste-to-energy and hazardous waste treatment than the air plasma torch process injected steam and the conventional incineration process.

Environmental Science and Technology 38, 5458-5464 (2004). The addition of activated carbon as particulate sorbent to the biologically active layer of contaminated sediment is proposed as an in-situ treatment method to reduce the chemical and biological availability of hydrophobic organic contaminants (HOCs) such as polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). We report results from physicochemical experiments that assess this concept.

Bench-scale tests were conducted to investigate the feasibility of a two phase detoxification process that would have application to the treatment of soils contaminated with polychlorinated biphenyls (PCBs) abd 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The first of the process was to degrade the contaminants by using Ultraviolet (UV) radiation facilitated by the addition of a surfactant to mobilize contaminants. Biological degradation, the second step, was then used to further detoxify the soil. Results from UV testing indicated that there was no apparent destruction of the dioxin on the soil. PCB reductions ranged from less than 15% to 69%.

Environmental Science and Technology 22(5), 557-561 (1988). Air containing 200-1000 ppm of Aroclor 1254 vapors [a mixture of polychlorinated biphenyls (PCBs)] was passed through a 22.86 cm long heated section of 0.64 cm i.d. monolithic a-alumina support, which had been previously treated with one or more catalytic agents. At 600 degrees C, with a residence time of about 9.4 s, results showed that the overall PCB destruction efficiency ranged from a high of 97.3% for supported CuO to a low of 69.3% for Cr203. Supported Catalysts of Co304, CuCrz04, and Pt-Pd were intermediate in activity. Relative activity for this group of p-type catalysts in deep oxidation was in accordance with Sabatier's principle, decreasing with increasing heats of O2 chemisorption. Selectivity toward oxidation of the more toxic high-chlorine-containing PCBs was found to be greater for catalysts made from transition metal oxides than for noble metal systems or homogeneous (thermal) decomposition.

U.S. EPA guidance on PCB site remediation.

Journal of Physical and Chemical Reference Data 15, 911 (1986). Relationships between the environmentally relevant physical chemical properties of the polychlorinated biphenyls, namely, aqueous solubility,vapor pressure, Henry’s law constant, and octanol–water partition coefficient are discussed. Reported experimental data are tabulated and critically reviewed. Recommended values are given for 42 of the 209 congeners; however, procedures are suggested for estimating the properties of the other congeners. Properties of mixtures are not treated.

Environmental Science & Technology 48 (14), 8094-8100 (2014). A total of 179 countries (parties) ratified the Stockholm Convention on persistent organic pollutants (POPs) and agreed to destroy polychlorobiphenyls (PCBs) and develop a sound management plan by 2028. Currently, still 3 million tons of PCB-contaminated oil and equipment need to be managed under the Stockholm Convention. Thus, the development of a facile and environmentally benign method to treat large amounts of oil stockpiles contaminated with PCBs is a crucial subject. Herein, we report that cyclodextrin (CD) polymers, which are easily prepared by cross-linking the renewable cyclic oligosaccharide γ-cyclodextrin (γ-CD) with dibasic acid dichlorides, are a new selective and powerful adsorbent to remove PCB contaminants in oil.

The mission of this document is to review emerging technologies for in situ remediation of PCB-contaminated sediments and soils and to assess their viability for future employment. Emphasis is placed on bioremediation and the use of nano-sized zero-valent iron for reductive dechlorination. This document was prepared by a student participating in the Cornell University Internship Program for the U.S. Environmental Protection Agency (EPA) and was not subject to EPA peer review or technical review.

Biodegradation 23(6), 917-926 (2012). Current technologies for remediation of contaminated sites include chemical and physical remediation, incineration and bioremediation. With recent advancements, bioremediation offers an environmentally friendly, economically viable and socially acceptable option to remove contaminants from the environment. Three main approaches of bioremediation include use of microbes, plants and enzymatic remediation. All three approaches have been used with some success but are limited by various confounding factors. In this paper, we provide a brief overview on the approaches, their limitations and highlights emerging technologies that have potential to revolutionise the enzymatic and plant-based bioremediation approaches.

Environmental Science and Technology 47, 13721-13729 (2013). In situ amendment of activated carbon (AC) to sediments can effectively reduce the bioavailability of hydrophobic organic contaminants. While biochars have been suggested as low-cost and sustainable alternatives to ACs, there are few comparative sorption data especially for mercury (Hg) and methylmercury (MeHg) at the low porewater concentrations in sediments. Here we compare the ability of a wide range of commercially available and laboratory synthesized ACs and biochars to sorb PAHs, PCBs, DDTs, inorganic Hg, and MeHg at environmentally relevant concentrations.

This document provides generic remedies to facilitate remedy selection for sites with soils contaminated with polychlorinated biphenyls (PCBs). Assumptions made in the development of this guidance were based on experience with typical PCB-contaminated sites and the best currently available data on the physical, chemical and toxicological properties of PCBs. Supporting documentation which summarizes the information reviewed and the conclusions reached by the DEQ is included in the appendices. (Oregon Department of Environmental Quality, 1997)

Environmental Pollution 182, 201-208 (2013). The in situ use of carbon amendments such as activated carbon (AC) and biochar to minimize the bioavailability of organic contaminants is gaining in popularity. In the first in situ experiment conducted at a Canadian PCB-contaminated Brownfield site, GAC and two types of biochar were statistically equal at reducing PCB uptake into plants. A complementary greenhouse study which included a bioaccumulation study of Eisenia fetida (earthworm), found mechanically mixing carbon amendments with PCB-contaminated soil (i.e. 24 h at 30 rpm) resulted in shoot, root and worm PCB concentrations 66%, 59% and 39% lower than in the manually mixed treatments (i.e. with a spade and bucket). Therefore, studies which mechanically mix carbon amendments with contaminated soil may over-estimate the short-term potential to reduce PCB bioavailability.

The major effort in this study addresses the feasibility of using a coal-derived sorbent (e.g., coke or granular activated carbon) for in-situ stabilization of persistent organic contaminants such as PCBs and PAHs in marine sediments.

International Journal of Life Cycle Assessment 17(3), 325-336 (2012). A life-cycle assessment (LCA) was performed to evaluate the environmental impacts of the remediation of industrial soils contaminated by polychlorobiphenyl (PCB). Two new bioremediation treatment options were compared with the usual incineration process. In this attributional LCA, only secondary impacts were considered. The contaminated soil used for the experiments contained 200 mg of PCB per kilogram.

This literature review contains a description and analysis of existing methods for management of PCBs in construction materials. Information on the strengths and limitations, efficacy, cost, and byproducts of each remediation method is presented, where available. The report is based upon a comprehensive review and synthesis of conference proceedings, and technical reports by government and commercial organizations.

Applied Microbiology and Biotechnology 97(23), 9909-9921 (2013). In this review, the strategies being employed to exploit the inherent durability of biofilms and the diverse nutrient cycling of the microbiome for bioremediation are explored. Focus will be given to halogenated compounds, hydrocarbons, pharmaceuticals, and personal care products as well as some heavy metals and toxic minerals, as these groups represent the majority of priority pollutants.

Environmental Health 11:24 (2012). Sealants and other building materials sold in the U.S. from 1958 - 1971 were commonly manufactured with polychlorinated biphenyls (PCBs) at percent quantities by weight. Volatilization of PCBs from construction materials has been reported to produce PCB levels in indoor air that exceed health protective guideline values. The discovery of PCBs in indoor air of schools can produce numerous complications including disruption of normal operations and potential risks to health. Understanding the dynamics of building-related PCBs in indoor air is needed to identify effective strategies for managing potential exposures and risks. This paper reports on the efficacy of selected engineering controls implemented to mitigate concentrations of PCBs in indoor air.

There are a number of polychlorinated biphenyl (PCB) contaminated sites requiring remediation of soil, sediment, sludge and groundwater. PCB contaminated soils are typically found at electric substation sites as a result of spills and equipment leaks. At present, relatively expensive excavation and off-site disposal methods are used to remediate these substation sites. The objective of the present study was to evaluate the feasibility of chemical and biodegradation methods that can be adapted for in situ treatment of PCB contaminated soils. If successful, this approach could eliminate the cost of excavation and disposal.

The technology for controlling polychlorinated biphenyls (PCBs) in utility transformers and capacitors has changed significantly in recent years, as have the regulations governing disposal methods. This revision of a 1979 PCB disposal manual updates information on disposal and treatment options and offers guidance on developing a PCB management program.

Provides links to EPA research on a number of PCB treatment technologies.

Journal of Hazardous Materials 229-230, 15-19 (2012). The simultaneous use of catalytic amount of palladium on carbon (Pd/C) and Mg metal (1.5–2.0 equiv vs. Cl numbers of the substrates) in MeOH achieved the complete dechlorination of a variety of aryl chlorides at room temperature under a nitrogen atmosphere in the absence of hydrogen gas. The present method could be successfully used for the detoxification of PCBs based on the dechlorinaton reaction. Both virgin PCBs, such as Aroclors 1242, 1248 and 1254, and used PCBs as a high-tension capacitor oil, were smoothly dechlorinated into harmless biphenyl without any byproducts within 2 h at rt. The distinctive features of this method are convenience and safety due to no needs for the pretreatment of catalyst and Mg and complete degradation of PCBs under mild conditions without hydrogen gas.

Journal of Hazardous Materials 278, 189-202 (2014). This review summarizes the bioremediation and phytoremediation technologies proposed so far to detoxify PCB-contaminated sites. A critical analysis about the potential and limits of the PCB pollution treatment strategies by means of plants, fungi and bacteria are elucidated, including the new insights emerged from recent studies on the rhizosphere potential and on the implementation of simultaneous aerobic and anaerobic biodegradation processes. The review describes the biodegradation and phytoremediation processes and elaborates on the environmental variables affecting contaminant degradation rates, summarizing the amendments recommended to enhance PCB degradation. Additionally, issues connected with PCB toxicology, actual field remediation strategies and economical evaluation are discussed.

Previous salvage and transformer recycling activities by the F. O'Connor Company at what is now an EPA Superfund site led to uncontrolled releases of oil-containing polychlorinated biphenyls (PCBs). The primary goal of this project was to determine the level of reductions in PCBs and carcinogenic polycyclic aromatic hydrocarbons (cPAHs) that could be achieved using a proprietary solvent extraction process. Results of treatability testing revealed that the present solvent extraction technology cannot overcome the physical problems associated with preparing or treating clayey soils at the site. Geotechnical evaluations further showed that treated soil would not be suitable for backfill.

A user-friendly tool for screening potentially applicable technologies for a remediation project. The matrix allows you to screen 49 in situ and ex situ technologies for either soil or groundwater remediation. Variables used in screening include contaminants, development status, overall cost, and cleanup time. In-depth information on each technology is also available, including direct links to the database of cost and performance reports written by FRTR members.

Electrical insulating mineral oils in a number of transformers contain measurable amounts of polychlorinated biphenyls (PCBs). An EPRI project investigated four possible approaches for removing PCBs from contaminated mineral oil. Overall, the investigation singled out one process for scale-up and demonstrated that PCBs can be removed from transformer oil by a wide range of processes, resulting in oils suitable for reuse.

Science of The Total Environment 445-446, 237-260 (2013). Polychlorinated biphenyls (PCB) are persistent organic pollutants used worldwide between the 1930s and 1980s. Although their use has been heavily restricted, PCB can be found in contaminated soils and sediments. The most frequent remediation solutions adopted are “dig and dump” and “dig and incinerate”, but there are currently new methods that could be more sustainable alternatives. This paper takes a look into the remediation options available for PCB-contaminated soils and sediments, differentiating between biological, chemical, physical and thermal methods. The use of combined technologies was also reviewed.

Chemosphere 93(4), 626-636 (2013). Phytoremediation is a sustainable process in which green plants are used for the removal or elimination of contaminants in soils. Both organic and inorganic contaminants can be removed or degraded by growing plants by several mechanisms However, the restoration of a contaminated site by phytoremediation requires a long treatment time since the remediation depends on the growth and the biological cycles of the plant. It is only applicable for shallow depths within the reach of the roots, and the remediation efficiency largely depends on the physico-chemical properties of the soil and the bioavailability of the contaminants. Combining phytoremediation with electrokinetics may avoid some of phytoremdiation's limitations.

Waste Management & Research 29(1), 107-121 (2011). The landfilling and dumping of persistent organic pollutants (POPs) and other persistent hazardous compounds, such as polychlorinated biphenyls (PCBs), hexachlorocyclohaxane (HCH), polybrominated diphenylether (PBDEs) or perfluorooctane sulfonic acid (PFOS) can have significant adverse environmental consequences. This paper reviews past experiences with such disposal practices and highlights their unsustainability due to the risks of contamination of ecosystems, the food chain, together with ground and drinking water supplies.

Chemosphere 87, 573-578 (2012). The aim of the present study was to investigate whether there are differences between pollutant sorption to biomass and coal-based activated carbon in the presence and absence of sediment.

Environmental Progress 23(3), 222-231 (2004). The remediation of PCB polluted soils/sediments, left to classical technologies such as incineration and bioremediation, is an overwhelming problem, given that vast amounts of spilled PCBs still exist in the environment after nearly three decades of PCB production ban. Other innovative, alternative cleanup technologies demonstrated that a better solution might exist. A two-step remediation process proposed for real-world PCB-contaminated soils/sediments, based on supercritical fluid extraction (SCFE) and supercritical water oxidation (SCWO), is economically analyzed in this paper.

This document is intended as a reference guide for those interested in technologies participating in the SITE Demonstration, Emerging Technology, and Measurement and Monitoring Programs. The two-page profiles are organized into two sections for each program, completed and ongoing projects, and are presented in alphabetical order by developer name. Reference tables for SITE Program participants precede the sections and contain EPA and developer contacts. Inquiries about a SITE technology evaluation. Each technology profile contains (I) a technology developer and process name, (2) a technology description, including a schematic diagram or photograph of the process, (3) a discussion of waste applicability, (4) a project status report, and (5) EPA project manager and technology developer contacts. The profiles also include summaries of demonstration results, if available.

This document is intended as a reference guide for those interested in technologies participating in the SITE Demonstration, Emerging Technology, and Measurement and Monitoring Programs. The two-page profiles are organized into two sections for each program, completed and ongoing projects, and are presented in alphabetical order by developer name. Reference tables for SITE program participants precede the sections and contain EPA and developer contacts. Each technology profile contains (1) a technology developer and process name, (2) a technology description, including a schematic diagram or photograph of the process, (3) a discussion of waste applicability, (4) a project status report, and (5) EPA project manager and technology developer contacts. The profiles also include summaries of demonstration results, if available.

Researchers at the University of Iowa Superfund Research Program (Iowa SRP) Center have found that switchgrass, a plant native to central North America, can effectively remove polychlorinated biphenyls (PCBs) from contaminated soil. When PCB-degrading bacteria is added, removal of PCBs from the soil can increase further. This phytoremediation method may be an efficient and sustainable strategy to removing PCBs from hazardous waste sites.

Protocol for minimum technical requirements to treat solid media contaminated with hazardous chlorinated organics such as chlorinated solvents, chlorinated pesticides, and polychlorinated biphenyls, through the application of thermal desorption technologies. The requirements presented in this document are directed toward relatively small, short term, on-site projects as opposed to permanent treatment, storage and disposal facilities.

The U.S. Environmental Protection Agency (EPA) Engineering Issue papers are a series of documents that summarize the available information on specific contaminants, selected treatment and site remediation technologies, and related issues. This Engineering Issue paper is intended to provide remedial project managers (RPMs), on-scene coordinators (OSCs), contractors, and other state or private remediation managers with information to facilitate the selection of appropriate treatment and disposal alternatives for soil and dredged sediment contaminated with polychlorinated biphenyls (PCBs). This information includes the type of data and site characteristics needed by site cleanup managers to evaluate ex-situ technologies for potential applicability to their hazardous waste sites.

Waste Management 30 (8-9), 1670-1682 (2010). The present paper illustrates the findings of a full-scale thermal treatment performed on SR samples obtained from various shredding plants. The outcome of the study provides an important contribution towards assessing the feasibility and reliability of the process, thus constituting a basic prerequisite for process performance evaluation.

In 1998, under the sponsorship of the New Hampshire - Department of Environmental Services (NHDES), Green Mountain Laboratories, Inc. (GML) and the USEPA agreed to carry out a Superfund Innovative Technology Evaluation (SITE) project to evaluate the effectiveness of GMLs Bioremediation Process for the treatment of PCB contaminated soils at the Beede Waste Oil/Cash Energy Superfund site in Plaistow, New Hampshire (hereinafter referred to as the Beede site). The treatment process involved inoculation/augmenting of the PCB bulk microbial inoculum and nutrients, and allowing the microbes to aerobically degrade the PCBs. The bulk inoculum was produced on-site by the developer using animal feed-grade oatmeal as the substrate, shredded pine needles that provided certain specific co-metabolite compounds, nutrients and a proprietary consortium of microorganisms capable of degrading the PCBs to their eventual endpoints - carbon dioxide and mineral halides.

Science of The Total Environment 437, 76-82 (2012). Biochar is a carbon rich by-product produced from the thermal decomposition of organic matter under low oxygen concentrations. Currently many researchers are studying the ability of biochar to improve soil quality and function in agricultural soils while sustainably sequestering carbon. This paper focuses on a novel but complimentary application of biochar – the reduced bioavailability and phytoavailability of organic contaminants in soil, specifically polychlorinated biphenyls (PCBs).

Environmental Science & Technology 29(9), 2460-2463 (1995). We report that at temperatures greater than 300 degrees C, PCB mixtures undergo hydrogenolytic dechlorination and other reactions in the presence of iron powder that lead to the virtually complete loss of chlorinated congeners.