Polychlorinated biphenyls surfaces

The major energy-related sources of water pollution are from thermal pollution, surface water pollution from oil spills, polychlorinated biphenyls, and groundwater contamination. 

The amount of solute also appears to be altered by the presence of other material already on the surface. Between 70% and 80% of the total polychlorinated biphenyls stayed in the aqueous phase when bis (2-ethylhexyl) phthalate was not present. When approximately 400 ng bis (2-ethylhexyl) phthalate was absorbed to each test tube, only 55% of the total polychlorinated biphenyls stayed in the aqueous phase. The increased lipophilicity due to the presence of bis (2-ethylhexyl) phthalate apparently increased the adsorption of polychlorinated biphenyl by the glass test tubes. 

Colenut and Thorburn [51,52] have also described the procedure using gas stripping of the aqueous sample followed by adsorption onto active carbon from which surface they are taken up in an organic solvent for gas chromatographic analysis. They optimized conditions for the determination of parts per billion of pesticides and polychlorinated biphenyls. 

Kang YH, Sheng GY, Fu JM, Mai BX, Zhang G, Lin Z, Min YS (2000) Polychlorinated biphenyls in surface sediments from the Pearl River delta and Macau. Mar Pollut Bull 40... 

Galanopoulou S, Vgenopoulos A, Conispoliatis N (2005) DDTs and other chlorinated organic pesticides and polychlorinated biphenyls pollution in the surface sediments of Keratsini harbour, Saronikos gulf, Greece. Mar Pollut Bull 50(5) 520-525... 

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. 

Booij, K. and van Drooge, B.L. 2001, Polychlorinated biphenyls andhexachlorobenzene in atmosphere, sea-surface microlayer, and water measured widi semi-permeable membrane devices (SPMDs). Chemosphere 44 91—98. 

Such analytical measurements are necessary to establish concentrations for most agents in the environment. How much benzene is present in the air at gasoline stations as a result of its evaporation from gasoline What is the concentration of arsenic in water running off the surface of a hazardous waste site where unknown amounts of arsenic were buried over many years What is the polychlorinated biphenyl (PCB) concentration in fish swimming in waters next to a hazardous waste site known to contain this substance How much aflatoxin is in a batch of peanut butter The most reliable answers to these questions are those resulting from chemical analysis. 

TechXtract is an extraction technology that has been used to remove a variety of contaminants from the surfaces of concrete, steel, brick, and other materials. Target contaminant types include organics, heavy metals, radionuclides, and polychlorinated biphenyls (PCBs). The technology uses proprietary chemical formulations in successive steps to remove these contaminants. The process employs as many as 25 different components in 3 separate chemical formulations that are applied to the contaminated surface and then removed in a multi-step, multicycle sequence. TechXtract is commercially available and has been used at multiple sites. 

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 duration of the remediation is dependent on the soil type, water content, and the nature of the contaminants. The HRUBOUT process cannot remove metals from soils. Polychlorinated biphenyls (PCBs) cannot be totally removed. The in situ HRUBOUT process is designed for removing contaminants from the vadose zone, (i.e., the zone between the surface aud the water table). Low permeability lowers system effectiveness and raises remediation costs. Soils with variable permeabilities may cause uneven delivery of air to contaminants. VOC removal rates may be reduced by high organic content in the soil because soil orgauics have a high VOC-sorption capacity. 

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. 

Micro-Flo has been used at many sites throughout Canada to treat wastewater and surface water contaminated with polychlorinated biphenyls (PCBs), chlorophenols, polycyclic aromatic hydrocarbons (PAHs), phenols, dioxins, furans, hydrocarbons, metals, oil, and grease. The technology has also been used to treat water contaminated with paint, paint thinner, and paint solvents. 

In most wastes and wastewater, polychlorinated biphenyls (PCBs) and particulate matter are found in the aqueous phase. The fraction of PCBs associated with each phase depends on the hydrophobicity. The congeners containing more chlorine substituents have a stronger tendency to associate with particulate. PCBs sorbed to surfaces such as diatomaceous earth are not oxidized by aqueous OH at an appreciable rate relative to the reaction rate of OH with solution-phase PCBs. Sedlak and Andren (1994) performed a quantitative evaluation of the effect of sorption to particulate matter on the rate of PCB oxidation by OH. The transformations of three PCB congeners — 2-monochlorobiphenyl (MClBp) 2,2, 5-trichlorobiphe-nyl (TrCIBp) and 2,2, 4,5,5 -pentachlorobiphenyl (PeCIBp) — were studied at an initial concentration of 1 pM of PCB solution. Data from the experiments were compared with predictions from quantitative kinetic models that used independently determined data on reaction rates and OH concentrations. 

Grittini, C., Malcomson, M., Fernando, Q., and Korte, N., Rapid dechlorination of polychlorinated biphenyls on surface of a Pd/Fe bimetallic system, Environ. Sci. Technol, 29(11), 2898-2900, 1995. 

Gjessing, E. T., Steiro, C., Becher, G., and Christy, A. (2007). Reduced analytical availability of polychlorinated biphenyls (PCB s) in colored surface water. Chemosphere 66, 644-649. 

Yang, Y., Liu, M., Xu, S.Y., Hou, L.j., Liu, H.L., 2003a. Distribution of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the tidal beach surface sediments of Yangtze estuary. China Environ. Sci. (Chinese) 23, 215-219. 

Shimomura, M., Y. Nomura, W. Zhang, et al. 2001. Simple and rapid detection method using surface plasmon resonance for dioxins, polychlorinated biphenyls and atrazine. Anal. Chim. Acta 434 223-230. 

In this chapter we shall discuss LCA in the context of protocols for the analysis of polychlorinated biphenyl (PCB) and polycyclic aromatic hydrocarbon (PAH) in surface water using two different extraction techniques,11 and the LCA of the utilization of different solvents.12-26 Generally speaking, this is the beginning of the use of LCA to assess the environmental impact of analytical protocols at the moment, there are not many papers on this subject, but this situation is sure to improve in the near future. 

Haque, R., Schmedding, D. (1976) Studies on the adsorption of selected polychlorinated biphenyl isomers on several surfaces. J. Environ. Sci. Health Bll(2), 129-137. 

PGC sorbents have even more highly homogeneous hydrophobic surfaces than GCB sorbents. PGCs are macroporous materials composed of flat, two-dimensional layers of carbon atoms arranged in graphitic structure. The flat, homogeneous surface of PGC arranged in layers of carbons with delocalized n electrons makes it uniquely capable of selective fractionation between planar and nonplanar analytes such as the polychlorinated biphenyls [92,94,95],... 

In addition to transformation by corrodable metals (such as Fe° and Zn°), bimetallic combinations of a catalytic metal with a corrodable metal (such as Pd/Fe or Ni/Fe) have also been shown to transform a variety of contaminants. In most cases, rates of transformation by bimetallic combinations have been significantly faster than those observed for iron metal alone [26,96,135-139]. Not only have faster transformation rates been observed with bimetallic combinations, but, in some cases, transformation of highly recalcitrant compounds, such as polychlorinated biphenyls (PCBs), chlorinated phenols, and DDT has been achieved [24,140,141]. The mechanism responsible for the enhanced reactivity with bimetallic combinations is still unclear however, it has been suggested that electrochemical effects, catalytic hydrogenation, or intercalation of H2 may be responsible. A likely limitation to the full-scale application of bimetallic combinations to groundwater remediation is deactivation of the catalytic surface either by poisoning (e.g., by sulfide) or by formation of thick oxide films [136,142,143]. 

Menassa, P. E. Mak, M. K. S. Langford, C. H. A study of the photodecomposition of different polychlorinated biphenyls by surface modified titanium (IV) oxide particles, Environ. Technol. Lett. 1988, 9, 825. 

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