Polychlorinated biphenyls recycled

Table 1 Concentrations of chlorinated polycyclic aromatic hydrocarbons (CIPAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in ambient air, soil, and human samples collected from e-waste recycling and reference sites in China... 

Wen S, Yang F, Li JG, Gong Y, Zhang XL, Hui Y, Wu YN, Zhao YF, Xu Y (2009) Polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) monitored by tree bark in an e-waste recycling area. Chemosphere 74(7) 981-987. doi 10.1016/j.chemosphere.2008.10.002... 

The vendor claims that the TDR process can be used to treat soil and sludge contaminated with polychlorinated biphenyls, polynuclear aromatic compounds, solvents, dioxins, furans, organic pesticides and herbicides, solvents, petroleum wastes, as well as nonhalogenated volatile and semivolatile compounds. The treated residuals from the process include recovered water, oil that can be used for recycling as an alternative fuel or for recycling or can be disposed, and clean soil that can be used as backfill. The volume of treated sludge is reduced by as much as 95% by this thermal process, depending on the initial level of contaminants. 

The mobile PPM process treats polychlorinated biphenyl- (PCB-) contaminated oU at ambient temperatures and pressures and results in a clean, recyclable oil, according to the vendor. PPM Canada, Inc., a wholly owned subsidiary of USPCI, was founded in 1983 to provide PCB destruction methods. According to the vendor, while the process has been used extensively for PCB-contaminated oil, the process is still in development for soils and is not commercially available. Safety-Kleen Corporation has since bought out USPCI. The process was developed for Union Pacific Railroads. All information is from the vendor and has not been independently verified. 

Baker, J.E., Eisenreich, S.J., and Eadie, B.J. (1991) Sediment trap fluxes and benthic recycling of organic carbon, polycyclic aromatic hydrocarbons, and polychlorinated-biphenyl cogeners in Lake Superior. Environ. Sci. Technol. 25, 500-509. 

Wu, J. P, Luo, X. J., et al. (2008) Bioaccumulation of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in wild aquatic species from an electronic waste (e-waste) recycling site in South China. Environment International, 34(8) 1109-1113. 

Tue NM, Takahashi S, Suzuki G et al (2013) Contamination of indoor dust and air by polychlorinated biphenyls and brominated flame retardants and relevance of non-dietary exposure in Vietnamese informal e-waste recycling sites. Environ Int 51 160-167 United Nations Environment Programme (UNEP) (2013) Recommendation by the persistent organic pollutants review committee to list hexabromocyclododecane in annex A to the Stockholm convention and draft text of the proposed amendment. Conference of the parties to the Stockholm convention on persistent organic pollutants sixth meeting, Geneva, Switzerland (28 April-10 May 2013)... 

The CD polymers can remove organic pollutants from water at parts per trillion levels. These polymers can be recycled at least 18 times without loss of their high adsorption efficiency. However the prolonged recycling destroys often their structural integrity and some loss of polymer mass was observed. In order to overcome these difficulties, small amounts (<5%) of multiwall carbon nanotubes (MWNTs) were added to polymers. It is known that carbon nanotubes are able to efficiently adsorb biphenyls, dioxins and polychlorinated dibenzofurans, while remaining chemically inert, but they are too expensive for removal of these water pollutants. However, carbon nanotubes may be used in combination with CD polymers. 

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