Polychlorinated biphenyls wastewater

Common examples of compounds that are amenable to carbon adsorption are aromatics (benzene, toluene) and chlorinated organics (trichloroethylene, trichloroethane [71-55-6, 75 -(9(9-j5y, tetrachloroethylene, polychlorinated biphenyls (PCBs), DDT /T(9-77-77, pentachlorophenol [87-86-5J. Compounds that are not adsorbed effectively by carbon include ethanol [64-17-5], diethylene glycol [111-46-6], and numerous amines (butylamine [109-73-9, 13952-84-6, 75-64-9], triethanolamine [102-71-6], cyclohexylamine [108-91-8], hexamethylenediamine [108-91-8] (1). Wastewater concentrations that are suitable for carbon adsorption are generally less than 5000 mg/L. 

Extraction, employs a liquid solvent to remove certain compounds from another liquid using the preferential solubility of these solutes in the MSA. For instance, wash oils can be used to remove phenols mid polychlorinated biphenyls (PCBs) from die aqueous wastes of synthetic-fuel plants and chlorinated hydrocarbons from organic wastewater. 

Quensen et al. [69] showed that micro-organisms isolated from Hudson river sediment dechlorinated most polychlorinated biphenyls in Aroclor 1242 under anaerobic conditions in the laboratory. The higher the polychlorobiphenyl concentration, the more rapid the rate of dechlorination. The possible mechanisms involved are discussed. The products of dechlorination were less toxic than the original compounds and were more readily degraded by aerobic bacteria wastewater containing... 

Biological. Reported degradation products by the microorganism Alcaligenes BM-2 for a mixture of polychlorinated biphenyls include monohydroxychlorobiphenyl, 2-hydroxy-6-oxochlorophenylhexa-2,4-dieonic acid, chlorobenzoic acid, chlorobenzoylpropionic acid, chlorophenylacetic acid, and 3-chlorophenyl-2-chloropropenic acid (Yagi and Sudo, 1980). When PCB-1016 was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, no significant biodegradation was observed. At a concentration of 5 mg/L, percent losses after 7, 14, 21, and 28-d incubation periods were 44, 47, 46, and 48, respectively. At a concentration of 10 mg/L, only 22, 46, 20, and 13% losses were observed after the 7, 14, 21, and 28-d incubation periods, respectively (Tabak et al., 1981). 

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. 

Unterman, R., Brennan, M. J., Brooks, R. E. Johnson, C. (1987a). Biological degradation of polychlorinated biphenyls. In Proceedings of the International Conference on Innovative Biological Treatment of Toxic Wastewaters, Ed. R.J. Scholze et al., pp. 379-89-Champaign, IL U.S. Army, CERL, N-87/12. 

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. 

Aparicio, I., J.L. Santos, and E. Alonso. 2007. Simultaneous sonication-assisted extraction, and determination by gas chromatography-mass spectrometry, of di-(2-ethylhexyl)phthalate, nonylphenol, nonylphenol ethoxylates and polychlorinated biphenyls in sludge from wastewater treatment plants. Anal. Chim. Acta 584 455 -61. 

Zorita, S., R.Westbom, L.Thorneby, E. Bjorklund, and L. Mathiasson. 2006. Development of a combined solid-phase extraction-supercritical fluid extraction procedure for the determination of polychlorinated biphenyls in wastewater. Anal. Sci. 22 1455-1459. 

Although several peroxidase enzymes obtained from plant, animal, and microbial sources have been investigated for their ability to catalyze the removal of aromatic compounds from wastewaters, the majority of studies have focused on using HRP. In particular, it has been shown HRP can transform phenol, chlorophenols, methoxyphenols, methylphenols, amino-phenols, resorcinols, and various binuclear phenols [7], HRP was also used for the treatment of contaminants including anilines, hydroxyquinoline, and arylamine carcinogens such as benzidines and naphthylamines [7,8]. In addition, it has been shown that HRP has the ability to induce the formation of mixed polymers resulting in the removal of some compounds that are either poorly acted upon or not directly acted upon by peroxidase [7], This phenomenon, termed coprecipitation or copolymerization, has important practical implications for wastewaters that usually contain many different pollutants. This principle was demonstrated when it was observed that polychlorinated biphenyls (PCBs) could be removed from solution through coprecipitation with phenols [20]. However, this particular application of HRP does not appear to have been pursued in any subsequent research. 

Not only analytical or preparative separations can be performed on cyclodextrin polymer columns, but also undesired components can be removed from aqueous solutions, bitter tasting substances (narin-gin, limonin) can be removed or at least their concentration can be strongly reduced after treatment of citrus juice with cyclodextrin polymers in batch or column process (65,66). Phenylalanine can be eliminated from dietetic protein hydrolysates (67), water-soluble organic substances (e.g. polychlorinated biphenyls (68), 2-naph-talenecarboxylate or phenol can be removed from aqueous solutions (e.g. from pharmaceutical wastewater) by polystyrene-cyclodextrin derivatives (69), by 8-cyclodextrin immobilized on cellulose (70) or by 6-cyclodextrin-polyurethane polymer (71). 

Preliminary results on the development of a eomprehensive approaeh for the assessment of the inputs, fates and effeets of urban wastewaters in eoastal areas are reported. These inelude a eommon analytieal proeedure for the determination of characteristic anthropogenic compounds, namely linear alkylhenzenes (LRBs), linear alkylbenzenesulphonates (LRSs), alkylphenolethoxylates (APEO), alkylphosphates (APs) polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and steroidal alcohols (coprostanol), in the dissolved and partieulate water phases and sediments. The decoupling of these eontaminants among the eompartments ean be interpreted in terms of their physicochemical properties and the equilibrium eonditions of the system. 

Choi PSK, Nack CH, Flinn JE. 1974. Distribution of polychlorinated biphenyls in an aerated biological oxidation wastewater treatment system. Bull Environ Contam Toxicol 11 12-17. 

Morris S, Lester JN. 1994. Behaviour and fate of polychlorinated biphenyls in a pilot wastewater. Water Res 28(7) 1553-1561. 

Unactivated aromatic rings such as benzene show little tendency to chlorinate under water treatment conditions. Biphenyl has been studied somewhat intensively because of concerns that polychlorinated biphenyls might form in wastewaters containing the parent compound, a common dye carrier particularly in the carpet industry. Wastewaters may contain this hydrocarbon at up to 2 mg/L (Gaffney,... 

Hernandez HF, Lopez BFJ, Medina EJ, etal. 1987. Sulfuric acid cleanup and potassium hydroxideethanol treatment for confirmation of organochlorine pesticides and polychlorinated biphenyls Application to wastewater samples. J Assoc Off Anal Chem 70 727-733. 

Most wastewater streams contain significant amounts of carcinogenic, toxic, mutagenic, or genotoxic substances in addition to conventional pollutants. These harmful compounds originate from industrial processes and households. Some of these toxic chemicals may also exhibit endocrine-disrupting effects. Therefore, organic micropollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), nonylphenol, xenobiotics, dioxins, pesticides, and heavy metals create important environmental health risks [3-7]. 

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