PSA application for a PCB detoxification plant

 Polychlorinated biphenyls (PCBs), a type of persistent organic pollutants (POPs), are considered to be endocrine disrupters. According to the Stockholm Convention on POPs, PCB detoxification is being accelerated globally. We have developed an environmentally sound chemical PCB detoxification plant using the ultraviolet ray/catalyst method. The purpose of this paper is to check the design methodology for the PCB detoxification plant by the application of probabilistic safety analysis. First, possible hazardous events were determined; second, the weakest points in these hazardous events were established; and third, the impact when failures arise at the weak points in the system were studied. We clarified the preventive measures as follows. To prevent PCBs leaking into the environment, select leak-tight valves for the piping containing PCBs, and reduce the number of valves. To prevent fire or explosions due to leaks of an inflammable mixture, select leak-tight valves, reduce the number of valves installed in the piping, and improve the reliability of the suppression tank in the isopropyl alcohol (IPA) recovery unit. Received: February 27, 2001 / Accepted: June 17, 2002     

Solvent cleaning of pole transformers containing PCB contaminated insulating oil

In 1989, it was discovered that the recycled insulation oil in pole transformers for electric power supply was contaminated with trace amounts of polychlorinated biphenyls (PCBs; maximum 50 mg-PCB/kg-insulation oil). In order to remove the PCBs from transformer components using n-hexane as a solvent, we investigated the relationship between progressive stages of dismantling and cleaning results. The results are summarized as follows: (1) Based on the cleaning test results, we made an estimate of the residual PCB amount on iron and copper components. By dismantling the test pole transformers into the "iron core and coil portion" and cleaning the components, we achieved a residual PCB amount that was below the limit of detection (0.05 mg-PCB/kg-material). To achieve a residual PCB amount below the limit of detection for the transformer paper component, it was necessary to cut the paper into pieces smaller than 5 mm. We were unable to achieve a residual PCB amount below the limit of detection for the wood component. (2) Compared to Japan's stipulated limited concentration standard values for PCBs, the results of the cleaning test show that cleaning iron or copper components with PCBs only on their surface with the solvent n-hexane will satisfy the limited concentration standard values when care is taken to ensure the component surfaces have adequate contact with the cleaning solvent.     

Thermal desorption of PCB-contaminated waste at the waukegan harbor superfund site

In June 1992, SoilTech ATP Systems, Inc., completed the soil treatment phase of the Waukegan Harbor Superfund Project in Waukegan, Illinois, after approximately five months of operation. SoilTech successfully treated 12,700 tons of sediment contaminated with polychlorinated hiphenyls (PCBs) using a transportable SoilTech anaerobic thermal processor (ATP) system nominally rated at ten tons per hour throughput capacity. The SoilTech ATP technology anaerobically desorbs contaminants such as PCBs from solids and sludges at temperatures over 1,000° F. Principal products of the process are clean, treated solids and an oil condensate containing the hydrocarbon contaminants. At the Waukegan Harbor Superfund site, PCB concentrations in the sediments excavated and dredged from a ditch, lagoon, and harbor slip averaged 10,400 parts per million (ppm) (1.04 percent) and were as high as 23,000 ppm (2.3 percent). Treated soil was backfilled in an on-site containment cell. The removal efficiency of PCBs from the soil averaged 99.98 percent, relative to the project performance specification of 97 percent, and treated soil PCB concentrations were measured below 2 ppm. Approximately 30,000 gallons of PCB oil, desorbed from the feed material, were returned to the owner for subsequent off-site disposal. After modifications to the emissions control equipment, compliance with the 99.9999 percent destruction and removal efficiency (DRE) for PCBs in stack emissions required by the U.S. Environmental Protection Agency was achieved.     

Analytical,Risk Assessment,and Remedial Implications Due to the Co‐Presence of Polychlorinated Biphenyls and Terphenyls at Inactive Hazardous Waste Sites

Investigations conducted at three inactive hazardous waste sites in New York State have confirmed the co‐presence of polychlorinated hiphenyls (PCBs) and polychlorinated terphenyls (PCTs) in soils, sediments, and biota. The PCTs at all three sites were positively identified as Aroclor 5432, with the most probable source being the hydraulic fluid Pydraul 312A utilized for high‐temperature applications. The identification of the lower‐chlorinated PCT formulations in environmental samples is problematical, since PCT Aroclors 5432 and 5442 are not chromatographically distinct from the higher‐chlorinated (PCB) Aroclors 1254, 1260, 1262, and 1268 using conventional gas chromatography–electron capture detection. Results from this study indicate that U.S. Environmental Protection Agency (USEPA) approved PCB methods routinely utilized by most commercial laboratories based on Florisil adsorption column chromatography cleanup are inadequate to produce valid chromatographic separation and quantitative results with soils, sediment, and biota samples containing both PCBs and PCTs. The presence of co‐eluting PCBs and PCTs precludes accurate quantitation due to significant differences in PCB/PCT electron capture detector response factors, and the potential for misidentification of PCT Aroclors as higher chlorinated PCB Aroclors. A method based on alumina column adsorption chromatography was used, allowing for the accurate identification and quantitation of PCB and PCT Aroclors. The results of this study suggest that the utilization of alumina adsorption column separation may have applicability and regulatory significance to other industrially contaminated sites which historically used Pydraul 312A. Inferences.     

Remediation of PCB‐Contaminated Soil Using Extraction and Destruction: Bench‐Scale Test

Polychlorinated biphenyls (PCBs) are a persistent environmental issue worldwide. This study summarizes the results obtained from a bench‐scale test of remediating PCB‐impacted soil. The research aimed to evaluate the effectiveness of extracting the PCB Aroclor 1260 from soil, transferring it to a liquid matrix, and then treating the PCB‐containing liquid using an Activated Metal Treatment System, a technology developed by NASA based on zero valent magnesium (ZVMg). The soil was from a former electrical plant area impacted by PCBs. The initial concentration of untreated soil contained an average of 4.7 ± 0.15 mg/kg of Aroclor 1260. The results showed that the mass transfer phenomena is possible using ethanol as a liquid matrix, reaching transfer results up to 93 percent. The ZVMg enabled the destruction of the Aroclor 1260, which reached 20 percent without any buildup of undesirable by‐products, such as less chlorinated PCBs.  ©2016 Wiley Periodicals, Inc.     

Removal of polychlorinated biphenyls from capacitors and pressure-sensitive paper by vacuum thermal recycling

This paper describes a new vacuum thermal recycling (VTR) method for treating discarded polychlorinated biphenyls (PCB)-contaminated capacitors and pressure-sensitive paper. Based on results demonstrating an exceptionally high PCB separation efficiency and recovery ratio from capacitors containing high-concentration PCBs, i.e. > 99.9%, respectively, the presented VTR method is verified to effectively remove PCBs. In addition, associated safety aspects of the employed procedure were confirmed.     

Legacy PCB building remediation

Polychlorinated biphenyls (PCBs) came onto the scene as an environmental threat quickly after they were discovered in humans and wildlife by Jensen in 1966. By October 1970, it was reported that PCBs were “truly ubiquitous pollutants” as PCBs were found at detectable concentrations in environmental samples throughout the world. Before 1971, the U.S. Environmental Protection Agency (EPA) reported that 26% of PCBs sold were used in open‐end use applications, such as caulks, sealants, plasticizers, surface coatings, ink, adhesive, and carbonless paper. Processing and distribution of PCBs in commerce were largely banned in the U.S. after July 1979 with certain continued uses authorized by the EPA. While PCBs were banned a long time ago, the ban had no immediate tangible effect on the continued use of regulated levels of PCBs in buildings constructed before the bans were implemented. Legacy buildings with PCB‐containing building materials continue to represent potential sources of indoor air, dust, outdoor air, and soil contamination. Where PCBs are present in building materials, they have the potential to pose a risk to building occupants. Proper removal of PCB‐containing materials is a highly effective approach to abating the risk. The removal can range from targeting specific building PCB‐containing materials through demolition of the building. Engineering and administrative controls can also be useful tools when addressing the risks posed by PCB‐containing materials.     

Japan’s waste management policies for dioxins and polychlorinated biphenyls

We summarize the measures taken by the Japanese government to prevent the emission of dioxins and polychlorinated biphenyls (PCBs) into the environment. Because incineration is the main method of waste management in Japan, reducing the amount of dioxins emitted from waste incinerators is an essential aspect of proper waste treatment. Intensive measures to prevent the formation of dioxins at the source have been implemented, with a focus on waste treatment methods and improving comprehensive management. The efforts have been very successful, with a 95% reduction in the amount of dioxins emitted between 1997 and 2003. The toxicity of PCBs has been monitored with keen interest since the Yusho incident. Unfortunately, treatment facilities for PCB wastes were not built until long after PCBs had been removed from use, and PCB wastes remained in storage in an untreated state. The Japanese government has promoted the construction of facilities for treating PCB wastes, and five such facilities have commenced operations. To more completely eradicate dioxins, a future challenge will be to reduce the amount of PCB-derived dioxins, which are persistent in the environment and have a long exposure pathway from the environment media to the organism and the human body.     

An ultracompact photo-ionization time-of-flight mass spectrometer with a novel vacuum ultraviolet light source for on-line detection of organic trace compounds and as a detector for gas chromatography

A recently developed novel intense rare-gas excimer vacuum ultraviolet (VUV) light source, the electron beam-pumped excimer lamp (EBEL), has been applied to the soft single-photon ionization (SPI) of organic molecules in a compact orthogonal acceleration time-of-flight mass spectrometer (oaTOFMS). The SPI-oaTOFMS system was applied to the on-line monitoring of tobacco smoke. With this setup, it was possible to analyze the composition of individual puffs of cigarette smoke. Furthermore, a gas chromatograph (GC) was coupled to the EBEL SPIoaTOFMS system. Soft photo-ionization represents an additional separation dimension. By combination of the gas chromatographic and the soft-ionization mass spectroscopic separation dimensions, a truly multidimensional comprehensive analytical method could be derived.     

Method development and implementation for co-planar polychlorinated biphenyls (PCBs)

The Emission Measurement Center (EMC) in the Environmental Protection Agency's Office of Air Quality Planning and Standards was directed to conduct an emissions test program at a sewage sludge incinerator in support of a Maximum Achievable Control Technology (MACT) standard. One pollutant category of concern at these facilities was polychlorinated biphenyls, or PCBs. An objective of the test program was to measure co-planar PCBs in the incinerator emissions, the sewage sludge introduced to the incinerator, and the scrubber water effluent used in controlling the incinerator emissions. Co-planar PCB congeners are those having four or more chlorine atoms with only a few substitutions in the ortho positions, i.e. positions designated 2, 2', 6, and 6'. Thirteen PCB compounds are sometimes referred to as the "WHO PCBs," because the World Health Organization (WHO) has derived toxic equivalency factors for these congeners. Studies have shown that these dioxin-like compounds can react with the aryl hydrocarbon receptor. This same reaction is believed to initiate adverse health effects for dioxin and furan congeners. In order to conduct the co-planer PCB testing, the EMC had to develop analytical methods that could measure the 13 co-planar PCBs. The purpose of the test program was to develop, evaluate, and implement analytical test methods capable of measuring co-planar PCBs in three matrices: incinerator stack gases, sewage sludge, and scrubber water effluents. The paper summarizes the initial development work that was performed in preparation of analytical test protocols that could measure co-planar PCBs in air, water, and sludge matrices. Following the method development, a MACT emissions test program was conducted at a sewage sludge facility in July 1999 and these data are also summarized in the paper.     

Comparative evaluation of demonstration testing of two PCB detoxification technologies

This paper presents a summary of the comparative analysis of two polychlorinated biphenyl (PCB) detoxification technologies that were evaluated in pilot scale equipment. Two treatment technologies, base catalyzed decomposition (BCD) and gas phase chemical reduction, treated materials removed from the PCB landfill in Warren County, North Carolina. There has been a remarkable amount of public opposition to this landfill. Very stringent performance criteria for soil cleanup of PCBs and dioxins and for air emissions from the treatment equipment were used, along with a number of other factors to evaluate the two technologies. The BCD technology was selected as the best performing one for this project.     

Emission of dioxins/furans and other U-POPs from test burns of non-POP pesticides in a hazardous waste incinerator

This paper presents the results of test burns for obsolete pesticides (OPs) of the permethrin group in a high temperature incinerator (HTI) in Southeast Asia. Three test burn runs were conducted, a baseline run when no OP was fed to the incinerator, and two test runs with different mixtures of OP compounds (formula 1 and 2, refer to Table 1 for detail) containing chlorine in the feeding wastes. The unintentional formed persistent organic pollutants (U-POPs) including 17 dioxins/furans, 12 dioxin-like PCBs and 12 chlorobenzenes (CBs) were monitored in all input materials and all discharges (flue gas, scrubbing liquid and solid residues). The results show relatively high levels of the U-POPs in the flue gas emission with total dioxins/furans of 4.4, 3.4, and 8.4 ng I-TEQ/m³ in the baseline, test run 1 and test run 2, respectively, which are above international acceptable emission levels. The PCB levels in flue gas were, respectively, 0.01, 0.3 and 0.4 ng I-TEQ/m³. The baseline thus had similar U-POPs levels with the OP test runs.In stack emission, approximately 90% of the U-POPs and 100% of CBs were present in gas phase. The emission factors, mass of pollutants per metric ton (tonne) of input waste, of U-POPs associated with fly ash (from bag house) were the highest, followed by flue gas and bottom ash while those associated with scrubbing liquid were relatively low. Among the waste input material only the black toner power contained U-POPs, but at low levels. The profiles of the dioxins/furans and PCBs in the toner waste were significantly different from that in the discharges. Despite the overall good destruction and removal efficiency of permethrin (better than 90%) the high emission of U-POPs and CBs from the test burn is of another more serious concern. To our best knowledge the findings of this study are the first of this kind for the Southeast Asia. The findings emphasize that if not properly conducted a standard destruction technology of a non-POP chemical can lead to a release of a range of more dangerous U-POPs into the environment.     

Effects of cosolvency in the fate and transport of PCBs in soil

Under the purview of EPA's Remedial Engineering Management (REM III) Superfund contract, a CERCLA RI/FS was performed at the Pinettes Salvage Yard site located in Washburn, Maine (EPA Region I). The purpose of the RI/FS was to fully characterize the nature, extent, and fate and transport of PCB contamination resulting from an alleged surface spill of transformer dielectric fluid containing Arochlor 1260 (a polychlorinated biphenyl) and various volatile and semivolatile organic constituents. The RI/FS was performed subsequent to both an immediate removal action (IRA) and a deletion remedial investigation (DRI) performed by EPA contractors. Results of both efforts indicated that the site was unsuitable for deletion from the National Priorities List (NPL) because the site soils contained elevated levels of PCBs. This article presents a case history of the extensive field investigations performed to characterize the contaminant source and evaluate the fate and transport of PCBs in site soils. These investigations included on-site mobile laboratory gas chromatograph (GC) analytical techniques for PCBs and targeted volatile and semivolatile organic compounds; confirmatory Contact Laboratory Program (CLP) laboratory analyses of soils, sediments, surface water, and groundwater samples; statistical analyses and correlation of field mobile laboratory GC data with CLP laboratory analytical results; and an evaluation of the potential effects of cosolvency in the fate and transport of PCBs in subsurface soils.     

Bench-scale studies on the simultaneous formation of PCBs and PCDD/Fs from combustion systems

The presence of endocrine disrupting chemicals (EDCs) in the environment has wide-ranging potential ecological and health impacts on animals and humans. A significant amount of experimental and theoretical work has been performed the examining formation and control of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), which account for only part of the EDCs being emitted from combustion devices. Generally accepted mechanistic theories for PCDD/F formation propose heterogeneous reactions in the cooler regions of the combustor involving gas-phase organic precursors (such as chlorobenzenes or chlorophenols), a chlorine donor [such as hydrogen chloride (HCl)], and a flyash-bound metallic catalyst (such as copper chloride). There is evidence that some other proposed EDCs, including polychlorinated biphenyls (PCBs), are formed through a similar mechanistic pathway as PCDD/Fs. In addition, there is evidence that certain important steps in the catalytic reaction between the copper catalyst and the organic precursors may suggest a common rate limiting step for the heterogeneous formation of the previously mentioned EDCs. This paper reports on a bench-scale experimental study to characterize a newly built reactor system that was built to: produce levels and distributions of PCDD/F production similar to those achieved by previous researchers; verify similar responses to changes in independent variables; examine the hypothesis that PCB formation rates exhibit trends similar to PCDD/F formation rates as reactor variables are changed; and begin to explore the dependence of PCB formation on temperature and precursor type. The reactor system has been built, and initial reactor characterization studies have been performed. Initial experiments yielded results that support the hypothesis of a similar formation mechanism of PCBs and PCDD/Fs in combustors. Initial experiments uncovered potential deficiencies with the reactor system and the experimental procedures and have suggested corrective action to improve the experimental system.     

Recovering metallic fractions from waste electrical and electronic equipment by a novel vibration system

The need to recover and recycle valuable resources from Waste Electrical and Electronic Equipment (WEEE) is of growing importance as increasing amounts are generated due to shorter product life cycles, market expansions, new product developments and, higher consumption and production rates. The European Commission (EC) directive, 2002/96/EC, on WEEE became law in UK in January 2007 setting targets to recover up to 80% of all WEEE generated.Printed Wire Board (PWB) and/or Printed Circuit Board (PCB) is an important component of WEEE with an ever increasing tonnage being generated. However, the lack of an accurate estimate for PCB production, future supply and uncertain demands of its recycled materials in international markets has provided the motivation to explore different approaches to recycle PCBs.The work contained in this paper focuses on a novel, dry separation methodology in which vertical vibration is used to separate the metallic and non-metallic fractions of PCBs. When PCBs were comminuted to less than 1 mm in size, metallic grades as high as 95% (measured by heavy liquid analysis) could be achieved in the recovered products.     

Environmental Technology Verification (ETV) test of dioxin emission monitors

The performance of four dioxin emission monitors, including two long-term sampling devices, the Dioxin-MonitoringSystem (DMS) and AMESA (the adsorption method for sampling dioxins and furans), and two semireal-time continuous monitors, the resonance ionization with multimirror photon accumulation time-of-flight mass spectrometer (RIMMPA-TOFMS) and the jet resonance-enhanced multiphoton ionization (jet-REMPI) system were tested. A package boiler burning a simulated chlorinated hazardous waste was used for a total of nine tests. Reference samples were collected during each test and analyzed for polychlorinated dibenzodioxins and dibenzofurans (PCDDs/Fs) using gas chromatography mass spectrometry. The PCDD/F concentrations of the reference samples measured by EPA Method 23 ranged from 0.9 to 6.0 ng toxic equivalence (TEQ)/dry standard cubic meter. The relative accuracies achieved by DMS, AMESA, and jet-REMPI varied from 22.6% to 78.2%, with 100% data completeness. The RIMMPA-TOFMS produced no quantifiable results due to various difficulties associated with the instrument during the testing. The two long-term samplers were easy to install and operate and provided a cumulative, averaged emission for the sampling period. The operations of the two semi-real-time continuous monitors were relatively complex, but one of them provided on-site, real-time data for PCDD/F emissions from measurement of a TEQ correlative indicator compound. This article summarizes results from the individual Environmental Technology Verification reports for the four dioxin monitors. This work was presented, in part, at the Fourth International Conference on Combustion, Incineration/Pyrolysis and Emission Control (i-CIPEC)     

Hospital waste management and toxicity evaluation: a case study

Hospital waste management is an imperative environmental and public safety issue, due to the waste's infectious and hazardous character. This paper examines the existing waste strategy of a typical hospital in Greece with a bed capacity of 400-600. The segregation, collection, packaging, storage, transportation and disposal of waste were monitored and the observed problematic areas documented. The concentrations of BOD, COD and heavy metals were measured in the wastewater the hospital generated. The wastewater's toxicity was also investigated. During the study, omissions and negligence were observed at every stage of the waste management system, particularly with regard to the treatment of infectious waste. Inappropriate collection and transportation procedures for infectious waste, which jeopardized the safety of staff and patients, were recorded. However, inappropriate segregation practices were the dominant problem, which led to increased quantities of generated infectious waste and hence higher costs for their disposal. Infectious waste production was estimated using two different methods: one by weighing the incinerated waste (880 kg day(-1)) and the other by estimating the number of waste bags produced each day (650 kg day(-1)). Furthermore, measurements of the EC(50) parameter in wastewater samples revealed an increased toxicity in all samples. In addition, hazardous organic compounds were detected in wastewater samples using a gas chromatograph/mass spectrograph. Proposals recommending the application of a comprehensive hospital waste management system are presented that will ensure that any potential risks hospital wastes pose to public health and to the environment are minimized.     

Remediation of PCB-contaminated sediments: Volatility and solubility considerations

Through volatilization and long distance atmospheric transport, polychlorinated biphenyls (PCBs) have been redistributed throughout the global environment. Over the last 70 years, these compounds have permeated every known environmental niche including the remote polar regions of the globe. In this article, the solubility and volatility of the PCB congeners are reviewed relative to the remedial technologies that are currently in use or under consideration. The following discussion focuses primarily on the management options for PCB-contaminated, subaqueous solids that require removal, dewatering, drying, and other treatment to degrade the target contaminants and/or containment in engineered facilities including constructed islands, upland secure landfills and subaqueous pits. Environmental mobility resulting from natural and engineered processes is discussed in relation to the potential for contributing to the global loading and redistribution of PCBs. Additionally, select emerging technologies and management options are reviewed relative to their potential to produce secondary environmental impacts resulting from the soluble and/or volatile redistribution of PCBs. Based on a lack of long-term experience and the recognition that contaminants will remain unaltered for decades, technologies involving engineered containment structures should be considered temporary remedial measures until cost-competitive, destructive processing of contaminated sediments is feasible.     

Persistent organic pollutant emissions from medical waste incinerators in China

The huge amount of medical waste (MW) has caused a tough challenge to environmental protection in China because of its serious infectious potential. At present, incineration is the most common technology for MW disposal. Unfortunately, the medical waste incinerator (MWI) is considered one of the major sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study was conducted to investigate the generation and the components of MW; the fingerprint of PCDD/Fs in MWI; and PCDD/F, polychlorinated biphenyl (PCB) and hexachlorobenzene concentrations in residue ash. The estimated annual production of MW was estimated to be 0.97 million tons in China in 2008; in addition, plastic and rubber accounted for 24.5% of MW contents. PCDD/F emissions from MWI could be divided into two main groups according their fingerprints, and the ratio of PCDFs/PCDDs was mostly over 1.5, with a mean value of 3.43. The toxic equivalent of PCDD/Fs was over 30 times that of the value of PCBs in the residue ash, and PCDD/F contents in fly ash accounted for approximately 67% of the total output of PCDD/Fs, which was in line with the UNEP default emission factors for MWI (class 3, 63.7%).     

Measurements of PCB Fluxes into the Atmosphere from a Site Receiving Stabilized Dredged Material

A 50 ha known contaminated site in Bayonne, New Jersey, U.S.A. is permitted to receive up to 3 × 10⁶ m³ of sediment dredged from navigation channels in the New York/New Jersey Harbor. Much of the sediment is expected to contain low to moderate concentrations of industrial and agricultural chemicals, including Polychlorinated Biphenyls (PCBs). The dredged material brought to the site is stabilized with cement and then placed as a capping and grading layer. The flux of PCBs from drying stabilized dredged material has been estimated from measurements of PCB air concentrations at two heights above the ground along with micrometeorological observations. A statistically significant gradient in PCB concentrations has been consistently measured in the first 3 m above the ground. Observed PCB fluxes were highest over freshly placed stabilized dredged sediment and decreased as it cured. The highest flux observed in this study was 7214 ng/m²/h, but during subsequent sampling intervals at the same site, the flux estimates decreased by an order of magnitude over a 5-day interval.