Destruction of polychlorinated biphenyls

This is a short item that provides information on the European Union regulations regarding the disposal/ destruction of polychlorinated biphenyls and other injurious substances. Very brief details of the regulations are provided. 

Destruction of Polychlorinated Biphenyls in Acoustically Cavitating Systems , Guangming Zhang and Inez Hua. at American Chemical Society Meeting, March 1998, Dallas, TX. 

T0472 Lawrence Livermore National Laboratory, Destruction of Polychlorinated Biphenyls Using High-Energy Ionizing Radiation... 

Greaser, C. S., A. R. Fernandes, andD. C. Ayres. 1988. Oxidation of aromatic substances, VIII. Oxidative destruction of polychlorinated biphenyls by ruthenium tetroxide. Chem. Ind. 15 499-500. 

Kolaczkowski, S. T., B. D. Crittenden, U. Ullah, and N. Sanders. 1987. Catalytic combustion the search for efficient commercial techniques for the destruction of polychlorinated biphenyls. In Management of Hazardous and Toxic Wastes Process Industry, S. T. 

Shultz, C. G. 1986. Destruction of polychlorinated biphenyls and other hazardous halo-genated hydrocarbons. European Patent 170,714, Feb. 12 cited in Chem. Abstr. CA 105(6) 48445n. 

High-Temperature Destruction of Polychlorinated Biphenyls and Related Compounds," United States Environmental Protection Agency, Municipal Environmental Research Laboratory, Cincinnati, OH, (December 1977), EPA-600/2-77-228. 

Mitsubishi Heavy Industries Ltd., a licensee of the SRI International AHO process, has built the most recent full-scale SCWO plant. The plant was built for the Japan Environmental Safety Corp, (a company owned by the Japanese government) to destroy that nation s large stockpile of polychlorinated biphenyl (PCB) waste. It consists of three reactor systems, each having a capacity of 2 tons PCB/day and 100 tons water/day, and a treatment requirement of <3 ppb PCB in the liquid effluent (representing six 9s destruction efficiency). The plant began operation in 2005. 

SW-846, is used to measure emissions of semivolatile principal organic constituents. Method 0010 is designed to determine destruction and removal efficiency (DRE) of POHCs from incineration systems. The method involves a modification of the EPA Method 5 sampling train and may be used to determine particulate emission rates from stationary sources. The method is applied to semivolatile compounds, including polychlorinated biphenyls (PCBs), chlorinated dibenzodioxins and dibenzofurans, polycyclic organic matter, and other semivolatile organic compounds. 

The IT Corporation thermal destruction unit is a mobile unit that uses infrared incineration technology. The main objective of this process is to transform the feedstock into another form (an ash acceptable for delisting) while assuring safe discharge of exhaust gas products to the environment. The unit is capable of on-site remediation of wastes and soils contaminated with polychlorinated biphenyls (PCBs) and other organics. This technology is based on a conveyor belt furnace process. 

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. 

For scale-up operations, the selection of the reactor is considered to be the key element in designing SCWO systems. Environmental regulations set the requirement for the destruction efficiency, which in turn sets requirements on the temperature and residence time in the reactor (as an example, the required DRE is 99.99% for principal hazardous components and 99.9999% for polychlorinated biphenyls, PCBs). The reactor parameters for the scale-up designs can be extrapolated from the available bench-scale data. A detailed discussion on available reactor types is given below. 

Abstract. Polychlorinated biphenyl (PCB) can be destroyed in a variety of ways. Currently, for PCB concentrations >500 mg/kg, incineration at an ANNEX I (or equivalent) facility is generally the only EPA approved method. There are additional options for destruction of liquids containing PCB at concentrations <500 mg/kg. Use of a high-efficiency boiler is an attractive option. Also, EPA has selectively approved chemical dechlorination for PCB concentrations <1%. 

An initial photolysis reaction can result in the generation of reactive intermediates that participate in chain reactions that lead to the destruction of a compound. One of the most important reactive intermediates is the hydroxyl radical, HO-. In some cases, sensitizers are added to the reaction mixture to absorb radiation and generate reactive species that destroy wastes. Hazardous waste substances other than 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) that have been destroyed by photolysis are herbicides (atrazine) 2,4,6-trinitrotoluene (TNT) and polychlorinated biphenyls (PCBs). The addition of a chemical oxidant, such as potassium peroxydisulfate, K2S20g, enhances destruction by oxidizing active photolytic products. 

---