Polychlorinated biphenyls physical

Burkhard, L.P. (1984) Physical-Chemical Properties of the Polychlorinated Biphenyls Measurement, Estimation, and Application to Environmental Systems. Ph.D. Thesis, University of Wisconsin-Madison, Wisconsin. 

Metcalfe, D.E., Zukovs, G., Mackay, D., Paterson, S. (1988) Polychlorinated biphenyls (PCBs) physical and chemical property data. In Hazards, Decontamination and Replacement of PCB A Comprehensive Guide. Crine, J.P., Ed., pp. 3-33, Plenum Press, New York. 

The applicability of using these interdisciplinary approaches, which include incorporation of various physical and chemical properties of the pollutants, QSARs/QSPRs and multicomponent joint action modeling are discussed and evaluated using a group of toxic and carcinogenic pollutants, i. e., polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). 

Polychlorinated biphenyls (PCBs) are a family of compounds, manufactured in the United States from 1930-1975, which were used in a number of discard applications and extensively as an electrical insulating fluid (see Chap. 1). Environmental concerns have led to strict controls on the use of PCBs and standards for cleanup of PCB discharges. One of the purposes of this section is to present information on the chemical and physical characteristics of these compounds. Based on this, the mechanisms of their movement in the surface/subsurface environment can be explained. 

Shiu, W.Y. and Ma, K.C. 2000, Temperatrrre dependence of physical-chemical properties of selected chemicals of envirorrmental interest. II. Chloroberrzenes, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxirrs, and dibenzofurarrs. J. Phys. CherrL Ref. Data 29 387-462. 

In activated sludge, 80.6% degraded after a 47-h time period (Pal et al., 1980). Chemical/Physical. Zhang and Rusling (1993) evaluated the bicontinuous microemulsion of surfactant/oil/water as a medium for the dechlorination of polychlorinated biphenyls by electrochemical catalytic reduction. The microemulsion (20 mL) contained didodecyldi-methylammonium bromide, dodecane, and water at 21, 57, and 22 wt %, respectively. The catalyst used was zinc phthalocyanine (2.5 nM). When PCB-1221 (72 mg), the emulsion and catalyst were subjected to a current of mA/cm on 11.2 cm lead electrode for 10 h, a dechlorination yield of 99% was achieved. Reaction products included a monochlorobiphenyl (0.9 mg), biphenyl, and reduced alkylbenzene derivatives. 

The technology primarily treats clays because their physical and chemical properties, such as external and internal active surfaces produced by their fine crystalline structure, make them difficult to decontaminate. ARC asserts that pilot studies showed that the technology works well on perchloroethylene (PCE), xylene, phenols, and polychlorinated biphenyls (PCBs). 

The SoilTech anaerobic thermal processor (ATP) technology is a physical separation process that thermally desorbs organics such as polychlorinated biphenyls (PCBs) from soil and sludge. The SoilTech system distills organic contaminants from a solid matrix in an anaerobic environment, thus preventing oxidative degradation of contaminants such as PCBs into more harmful reaction products. Contaminants are collected in an oily condensate, which is disposed. 

Mackay and Shiu (1981) and Shiu and Mackay (1986) reviewed the physical-chemical properties of a variety of organic chemicals, polychlorinated biphenyls, and recommended H from a selected value of vapor pressure and aqueous solubility. Eastcott et al. (1988) and Suntio et al. (1988) also gave H for hydrocarbons and pesticide chemicals, respectively. Mackay, Shiu, and Ma (1992a, 1992b, 1993, 1995, 1997) compiled physical-chemical properties, including Henry s law constants for many organic chemicals of environmental interest. 

Mackay, D., W.-Y. Shiu, and K.C. Ma. 1992a. Illustrated Handbook of Physical - Chemical Properties and Environmental Fate of Organic Compounds. I. Monoaromatic Hydrocarbons, Chlorobenzenes and Polychlorinated Biphenyls. Lewis Publishers, Boca Raton, Florida, 697 pages. 

Gdaniec-Pietryka, M., L. Wolska, and J. Namiesnik. 2007. Physical speciation of polychlorinated biphenyls in the aquatic environment. Trends Anal. Chem. 26 1005-1012. 

Li, N., Wania, F., Lei, Y.D., Daly, G.L. (2003) A comprehensive and critical compilation, evaluation, and selection of physical-chemical property data for selected polychlorinated biphenyls. J. Phys. Chem. Ref. Data 32, 1545-1590. 

Mackay, D., Shiu, W.Y. (1977) Aqueous solubility of polynuclear aromatic hydrocarbons. J. Chem. Eng. Data 22, 399—402. Mackay, D., Shiu, W.Y, Billington, J.W., Haung, G.L. (1983) Physical chemical properties of polychlorinated biphenyls. In Physical Behavior of PCBs in the Great Lakes. Mackay, D., Paterson, S., Eisenreich, S.J., Simmons, M.S. Eds., pp. 59-69, Ann Arbor Sci. Publ., Ann Arbor, Michigan. 

US EPA (2007). EPA Method 8082A. Polychlorinated biphenyls (PCBs) by gas chromatography. Rev. February 1, 2007, in Test Methods for Evaluating Solid Waste, Physical/Chemical Methods (SW-846). 

Polychlorinated diphenyl ethers (PCDE) are common impurities in chlorophenol formulations, which were earlier used as fungicides, slimicides, and as wood preservatives. PCDEs are structurally and by physical properties similar to polychlorinated biphenyls (PCB). They have low water solubility and are lipophilic. PCDEs are quite resistant to degradation and are persistent in the environment. In the aquatic environment, PCDEs bioaccumulate. These compounds are found in sediment, mussel, fish, bird, and seal. PCDEs show biomagnification potential, since levels of PCDEs increase in species at higher trophic levels. PCDEs are also detected in human tissue. Despite the persistence and bio accumulation, the significance of PCDEs as environmental contaminants is uncertain. The acute toxicity and Ah-receptor-me-diated (aryl hydrocarbon) activity of PCDEs is low compared to those of polychlorinated di-benzo-p-dioxins (PCDD) and dibenzofurans (PCDF). Due to structural similarity to thyroid hormone, PCDEs could bind to thyroid hormone receptor and alter thyroid function. Furthermore, PCDEs might be metabolized to toxic metabolites. In the environment, it is possible that photolysis converts PCDEs to toxic PCDDs and PCDFs. 

Polychlorinated biphenyls (PCBs) were produced from 1930 to 1983 in the form of complex mixtures for a variety of uses (e.g. dielectric fluids in transformers and capacitors, and plasticizers in paint and rubber sealants). Because of their physical and chemical stability, and also of their lipophilic affinity, they are highly persistent and tend to accumulate in sediments and biota in the aquatic environment [253]. 

Since 1929, polychlorinated biphenyls (PCBs) have been produced and used as heat-transfer, hydraulic, and dielectric fluids. Because of their chemical and physical stability, PCBs have been found in many environmental samples. Generally, PCBs have been analyzed by GC with electron-capture detection. There are many reports on subcritical and supercritical fluid extraction of PCBs, but only a few on supercritical fluid separation of PCBs. 

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