Polychlorinated biphenyls, solid

s PCBs PCB s Polychlorinated biphenyls, 9 Polychlorinated biphenyls, liquid, 9 Polychlorinated biphenyls, solid, 9 Polyhalogenated biphenyls, liquid, 9 Polyhalogenated biphenyls, solid, 9 Polyhalogenated terphenyls, liquid, 9 Polyhalogenated terphenyls, solid, 9 

While any halogen may halogenate a polyphenyl, chlorine and bromine are by far the more usual. They result in a large number of possible polychlorinated biphenyls syn. p.c.b.s, PCBs, PCB s), polyhalogenated biphenyls, and polyhalogenated terphenyls. No longer produced commercially, halogenated polyphenyls were widely used for their exceptional qualities as heat-transfer fluids, solvents, lubricants, dust suppressants, and fire retardants (some equipment that relies on these chemicals, like electrical transformers and capacitors, remains in use). 

Due to their extensive use and resistance to decomposition, halogenated polyphenyls are almost universal environmental contaminants, present in waste sites, sediments, the human body, water supplies, and elsewhere. They are associated with many toxic and biochemical effects including wasting syndromes, bone marrow diseases, atrophy, chloracne, hyperplasin, liver damage, and cancer. 

Most halogenated polyphenyls in transportation, then, derive not from product shipments but from decommissioned equipment, drained fluids, soils and debris from waste site and riverbed cleanups, demolition work, scrap metal disposal, contaminated textiles and absorbents, and other wastes. 

Halogens, see Terminology, Elements, p.235 Liquid, see Terminology, Liquid, p.241 

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Hawthorne SB, Grabanski CB, Hageman KJ, Miller DJ. Simple method for estimating polychlorinated biphenyl concentrations on soils and sediments using subcriti-cal water extraction coupled with solid-phase microextraction. J. Chromatogr. A 1998 814 151-160. 

One advance in the area of LLE is the use of solid supports that facilitate the partitioning of the analyte(s) of interest. LLE extraction methods involving nonpolar matrices often suffer from the formation of emulsions, and using the solid support is a possible solution. In one study, polychlorinated biphenyls, dioxins, and furans were extracted from the lipid fraction of human blood plasma [32], using diatomaceous earth as the solid support. Long glass columns (30 cm) were packed with several layers of Chem-Elut (a Varian product) and sodium chloride. The plasma samples were diluted with water and ethanol and passed over the columns. A mixture of isopropanol and hexane (2 3) was passed over the column and the LLE was performed. It can be concluded that the LLE with the solid support is easier to perform and can be applied to other lipid heavy matrices such as milk [32]. 

Accelerated solvent extraction is a new technique for the extraction of a range of organic pollutants from soils and related material. The technique is based on the use of a solvent or combination of solvents to extract organic pollutants at elevated pressure and temperature from a solid matrix. The range of organic pollutants for which the technique is proposed includes semivolatile compounds, organochlorine pesticides, organophosphorus pesticides, chlorinated herbicides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons [53-56],... 

Polychlorinated biphenyls (PCBs) are colorless toxic organic substances that cause cancer and birth defects. There are more than 200 different types of PCBs, ranging in consistency from heavy, oily liquids to waxy solids, and each type further varying in the number and location of chlorine atoms attached to its molecular carbon rings. They are fire resistant and do not conduct heat or electricity well. Accordingly they have numerous commercial applications as insulation in electrical systems, for example, for transformers. 

Excerpt 4C is taken from an article in Analytical Chemistry. Headspace solid-phase microextraction (HSSPME) is coupled with GC to quantify polychlorinated biphenyls (RGBs) in milk. The RGBs are volatilized out of the liquid phase (milk) into the gas phase (headspace) and concentrated on an SPME fiber. The concentrated RGBs on the fiber are then injected into the GG. 

Z Determination of Polychlorinated Biphenyls in Milk Samples by Saponification—Solid-Phase Microextraction (from Llompart... 

Llompart, M. Pazos, M. Landin, R Gela, R. Determination of Polychlorinated Biphenyls in Milk Samples by Saponification—Solid-Phase Microextraction. Anal. Chem. 2001, 73, 5858-5865. 

The Universal Demercurization Process, or UNIDEMP , is an ex situ process for removing mercury from a variety of solid and aqueous mercury waste streams such as metals, concrete, soils, asbestos, plastic, and cable as well as amalgams and mercury compounds. The process can also treat polychlorinated biphenyls (PCBs) and halogenated organics. UNIDEMP is a mobile system that volatizes and condenses mercury in a countercurrent rotating furnace at temperatures from 550 to 650°C. Celsius. 

The Extraksol process can extract organic contaminants such as oils and greases, polynuclear aromatic hydrocarbons (PAHs), pentachlorophenols (PCPs), and phenols from a variety of solid matrices. The Extraksol process can extract polychlorinated biphenyls (PCBs) from clay-bearing soil, sand, and FuUer s earth. Extraksol has successfully treated various media such as activated carbons, refinery sludges, and wood treatment sludges. 

The PCB-REM process for the remediation of polychlorinated biphenyls (PCBs) in soils, sludges, and water uses both chemical and biological treatment. It is a combination of solids pretreatment... 

Capsur is an aqueous-based solvent system developed specifically for the cleanup of polychlorinated biphenyl (PCB) spills on solid surfaces, including concrete, asphalt, and metal. 

According to the vendor, the technology can effectively treat almost aU hydrocarbons (inclnd-ing gasoline, crnde oil, diesel fnel, and jet fnel), pentachlorophenols, polychlorinated biphenyls, benzene, tolnene, ethyl benzene, xylene, polynuclear aromatic hydrocarbons, trichloroethylene, trichloroethane, and suspended solids. The granules can also be used to remove vegetable-based oils and fats. Another technology advantage is the ability of the SFC system to remove oil emulsified in water to concentrations less than 15 mg/hter. 

The process is used on petroleum sludges, used tires, biomedical waste, automobile shredder residues, bark residues and municipal solid wastes. It is limited to treating organic wastes and contaminated soil. For soil contaminated by polychlorinated biphenyls (PCBs), vacuum pyrolysis cannot destroy the PCBs but will concentrate them in the pyrolytic oils. The process cannot be used to treat mine tailings. 

The desorption and vapor extraction system (DAVES) uses a low-temperature fluidized bed to remove volatile and semivolatile organics such as polychlorinated biphenyls (PCBs), polynuclear aromatic compounds (PAHs), pentachlorophenol (PCP), volatile inorganics (tetraethyl lead), and some pesticides from soil, sludge, and sediment. The process generally treats waste containing less than 10% total organic contaminants and 30 to 95% solids. The process does not treat nonvolatile inorganic contaminants such as metals. 

VAC TRAX is an ex situ thermal desorption process that separates contaminants such as volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs), and radioactive materials from soils, sludges, and solid trash. This process can be applied to mixed and unmixed waste streams. Because the nitrogen atmosphere in which the process occurs is inert, no combustion of organic material takes place. 

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. 

Supercritical carbon dioxide extraction (SCDE) is an ex situ process currently being researched for the treatment of soil and debris contaminated with polychlorinated biphenyls (PCBs) and polycyclic aromatic compounds (PAHs) as well as for the removal of solvents from low-level solid mixed wastes and land disposal restricted (LDR) wastes. 

According to the vendor, ZEROS can treat hydrocarbons and chlorinated compounds such as polychlorinated biphenyls (PCBs) and dioxins. The vendor claims that the technology can treat contaminated soils, liquid wastes in metal and plastic containers, asbestos, medical and biomedical wastes, contaminated sludges, waste fuels, fuel residues, and municipal solid waste. The technology is commercially available. 

It would lie far beyond the aim of this chapter to introduce the state-of-the art concepts that have been developed to quantify the influence of colloids on transport and reaction of chemicals in an aquifer. Instead, a few effects will be discussed on a purely qualitative level. In general, the presence of colloidal particles, like dissolved organic matter (DOM), enhances the transport of chemicals in groundwater. Figure 25.8 gives a conceptual view of the relevant interaction mechanisms of colloids in saturated porous media. A simple model consists of just three phases, the dissolved (aqueous) phase, the colloid (carrier) phase, and the solid matrix (stationary) phase. The distribution of a chemical between the phases can be, as first step, described by an equilibrium relation as introduced in Section 23.2 to discuss the effect of colloids on the fate of polychlorinated biphenyls (PCBs) in Lake Superior (see Table 23.5). 

May, H. D., Boyle, A. W., Price, W. A. Balke, C. K. (1992). Subculturing of a polychlorinated biphenyl-dechlorinat ing anaerobic enrichment on solid media. Applied and Environmental Microbiology, 58, 4051-4. 

Zeddel, A., Majcherczyk, A. Huttermann, A. (1994). Degradation and mineralization of polychlorinated biphenyls by white-rot fungi in solid-phase and soil incubation experiments. In Bioremed tation of Chlorinated and Polycyclic Aromatic Hydrocarbon Compounds, ed. R. E. Hinchee, A. Leeson, L. Semprini S. K. Ong, pp. 436-40. New York Lewis Publishers. 

Polychlorinated biphenyls (PCBs) have been known for sometime as persistent pollutants, which can be readily bioaccumulated through the food chain causing well-documented toxic effects in number of species including humans [191]. Consequently, PCBs are commonly routinely monitored as potential industrial pollutants. Due to their environmental persistence and toxicity, detection limits in the ng ml-1 region are generally required. Consequently, such work has generally required solvent or solid extraction and concentration steps prior to separation by GC in conjunction with electron capture detection, or mass... 

Baker JE, Eisenreich SJ, Swackhamer DL (1991) Organic substances and sediments in water. In Baker RA (ed) Field-measured associations between polychlorinated biphenyls and suspended solids in natural water an evaluation of the partitioning paradigm, vol 2. Lewis, Chelsea, MI, p 79... 

Lopez-Avila et al. [107] showed that microwave-assisted extraction of pesticides and polycyclic aromatic hydrocarbons from soil is a viable alternative to Soxhlet extraction and needs a smaller sample volume and extraction time [108,109]. These techniques have also been compared in the case of chlorophenols. Lopez-Avila et al. compared microwave-assisted extraction with electron capture gas chromatography to ELISA for the determination of polychlorinated biphenyls in soils. Both techniques are applicable to field screening and monitoring applications. Microwave-assisted extraction [111, 112] and solid-phase microextraction [113] have been applied to the extraction of pesticides from soil. It was observed by these and other workers [114] that the selectivity of microwave-assisted extraction is highly dependent on the soil composition. 

Chlorinated aromatic compounds are commonly found as contaminants in environmental soil samples. For example, chlorobenzenes have been listed as priority pollutants and can be found in various matrixes such as water, soils, sediments and sewage sludges. Polychlorinated biphenyls are probable human carcinogens but have been applied in large doses in various industrial products. Analysis of these compounds in solid matrixes, such as soils and sediments, requires several steps. 

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