Polychlorinated biphenyls volatilization

Solvent extraction followed by gas chromatographic analysis is used to determine paraffin wax antioxidants (qv), ie, butylated hydroxyanisole and butylated hydroxytoluene and other volatile materials. Trace amounts of chlorinated organic compounds, eg, polychlorinated biphenyls, can be deterrnined by using a gas chromatograph with an electron-capture detector (22). 

Bushart SP, B Bush, EL Barnard, A Bott (1998) Volatilization of extensively dechlorinated polychlorinated biphenyls from historically contaminated sediments. Environ Toxicol Chem 17 1927-1933. 

Volatilization. Transfer of chemicals across the air/water interface can result in either a net gain or loss of chemical, although in many cases the bulk concentration in the air above a contaminated water body is low enough to be neglected (20). When the atmosphere is the primary source of the contaminant, as for example polychlorinated biphenyls in some parts of the Laurentian Great Lakes, atmospheric concentrations obviously cannot be neglected. The Whitman two-film or two-resistance approach (21) has been applied to a number of environmental situations (20, 22, 23). Transport across the air/water interface is viewed as a two-stage process, in which both phases of the interface can offer resistance to transport of the chemical. The rate of transfer depends on turbulence in the water body and in the atmosphere, the... 

The van t Hoff equation also has been used to describe the temperature effect on Henry s law constant over a narrow range for volatile chlorinated organic chemicals (Ashworth et al. 1988) and chlorobenzenes, polychlorinated biphenyls, and polynuclear aromatic hydrocarbons (ten Hulscher et al. 1992, Alaee et al. 1996). Henry s law constant can be expressed as the ratio of vapor pressure to solubility, i.e., pic or plx for dilute solutions. Note that since H is expressed using a volumetric concentration, it is also affected by the effect of temperature on liquid density whereas kH using mole fraction is unaffected by liquid density (Tucker and Christian 1979), thus... 

In addition to the chemicals included on the other lists, the CDC also included heavy metals such as arsenic, lead, and mercury volatile solvents such as benzene, chloroform, and bromoform decomposition products such as dioxins and furans polychlorinated biphenyls (PCBs) flammable industrial gases and liquids such as gasoline and propane explosives and oxidizers and all persistent and nonpersistent pesticides. Agents included in this volume are limited to those that are most likely to pose an acute toxicity hazard. 

GC-EI-MS permits the direct analysis of mixtures, e.g., to analyze synthetic byproducts an advantage that made GC-EI-MS benchtop instruments become widespread in modem synthetic laboratories. The GC-EI-MS combination is especially successful in monitoring environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-dioxins (PCDDs), polychlorinated dibenzofuranes (PCDFs), or other volatile organic compounds (VOCs). 

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. 

According to the vendor, this technology is capable of removing chlorinated hydrocarbons, aliphatic hydrocarbons, aromatics, benzene, toluene, xylene, carbon tetrachloride, vinyl chloride, dichloromethane, and trichloroethane. Polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), and volatile inorganic solvents can also be removed. The technology is currently in use and is commercially available. 

The technology treats polychlorinated biphenyls (PCBs), dioxins, volatile metals (such as mercury), and nonvolatile metals (such as lead or transuranic radioactive elements). 

Aquaplant is not suitable for the remediation of aromatic hydrocarbons benzene, toluene, ethylene, and xylene (BTEX), polychlorinated biphenyls, volatile chlorinated hydrocarbons, pesticides, dioxins, and furans. 

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. 

Because it is a nonselective treatment, chemical oxidation is best suited for media with low concentrations of contaminants. This technology has been demonstrated to be effective in treating wastes contaminated with halogenated and nonhalogenated volatile and semivolatile compounds, polychlorinated biphenyls (PCBs), pesticides, cyanides, and volatile and nonvolatile metals. 

This technology can treat materials contaminated with a wide range of organic contaminants, including solvents, volatile organic compounds (VOCs), and semivolatile organic compounds (SVOCs). CFBC is particularly suited for the treatment of media contaminated with polychlorinated biphenyls (PCBs). 

CESAR was developed to address the problem of locating, characterizing, and removing dense non-aqueous-phase liquids (DNAPLs) from contaminated aquifer systems. The process is particularly suited to remediating groundwater contaminated with chlorinated solvents, such as trichloroethylene (TCE), tetrachloroethene (PCE), trichloroethane (TCE), and carbon tetrachloride (CCE). According to the vendor, CESAR can also be applied to sites contaminated with creosote, polychlorinated biphenyls (PCBs), Freon 113, volatile organic compounds (VOCs),... 

The vendor states that tetrachloroethane (PCE), trichloroethene (TCE), and other volatile compounds are difficult to remove from saturated soils because they are relatively insoluble. The vendor states that the technology is especially applicable to sites contaminated with dense non-aqueous-phase liquids (DNAPLs). Using the ISSZT technology creates an unsaturated zone from which these contaminants can be readily air stripped. Other contaminants such as polychlorinated biphenyls (PCBs) or metals can be isolated from groundwater and contained within barriers preventing the spread of contamination. 

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. 

Chemical contaminants for which full-scale treatment data exist include primarily volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs). These SVOCs include polychlorinated biphenyls (PCBs), pentachlorophenol (PCP), pesticides, and herbicides. Extremely volatile metals, such as mercury and lead, can be removed by higher temperature thermal desorption systems. The technology has been applied to refinery wastes, coal tar wastes, wood-treating wastes, creosote-contaminated soils, hydrocarbon-contaminated soils, mixed (radioactive and hazardous) wastes, synthetic mbber processing wastes, and paint wastes. 

ESTD, ex situ thermal desorption VOCs, volatile organic compounds TPH, total petroleum hydrocarbons BTEX, benzene, toluene, ethylbenzene, xylene PCBs, polychlorinated biphenyls PAHs, polycyclic aromatic hydrocarbons ISTD, in situ thermal desorption. 

The Remediation Technologies, Inc. (RETEC), Thermatek thermal desorption system is an ex situ high-temperature treatment technology that treats soils, sediments, and sludges contaminated with volatile organic compounds (VOCs) and polychlorinated biphenyls (PCBs). The process uses a conventional Holo-Flite thermal desorption unit with RETEC s proprietary modifications, using an indirect heating source. 

According to the developer, the TDU removes volatile organic compounds and volatile metals from soil. The technology is designed to treat material contaminated with polychlorinated biphenyls (RGBs), polynuclear aromatic hydrocarbons (PAHs), dioxins, and volatile heavy metals (mercury). 

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