Removal Of PCB Research Articles

Primena patentirane tehnologije za rešavanje problema PCB kontaminacije i korozivnog sumpora u energetskim transformatorima

The exploitation of PCB contaminated power transformers and those which contain corrosive sulphur is related to the greatest risks to the environment, due to possible environmental accidents and faults and failures of transformers. The equipment contaminated with PCB require special attention, more frequent testing of transformer condition and control of oil leaking, while for corrosive oils standards and requirements defined in CIGRE TB 378, CIGRE TB 625, IEC 60296 and IEC 60422 are restrictive for the use of corrosive oils. Overview of the problems with PCB contaminated equipment and corrosive sulphur is provided in accordance to the latest knowledge in these areas. PCB decontamination, desulfurization and oil regeneration process is described by the application of patented technology developed in the 'Nikola Tesla' Institute. Summarized results of decontamination process of 310 PCB contaminated power transformers with different voltage levels and power and removal of corrosive sulphur from 29 transformers show the efficiency of this process for simultaneous removal of PCB, corrosive sulphur and oil ageing products.

Simultaneous electrodialytic removal of PAH, PCB, TBT and heavy metals from sediments

Contaminated sediments are remediated in order to protect human health and the environment, with the additional benefit of using the treated sediments for other activities. Common for many polluted sediments is the contamination with several different pollutants, making remediation challenging with the need of different remedial actions for each pollutant. In this study, electrodialytic remediation (EDR) of sediments was found effective for simultaneous removal of heavy metals and organic pollutants for sediments from Arctic regions – Sisimiut in Greenland and Hammerfest in Norway. The influence of sediment properties and experimental settings on the remediation process was studied by employing multivariate analysis. The importance of the variables studied varied with the pollutant and based on these results it was possible to assess removal processes for the different pollutants. Desorption was found to be important for the removal of heavy metals and TBT, while photolysis was significant for removal of PAH, PCB and TBT. In addition, dechlorination was found to be important for the removal of PCB. The highest removal efficiencies were found for heavy metals, TBT and PCB (>40%) and lower removal efficiencies for PAH (<35%).

Influence of Selected Coagulants of Indicator and Dioxin-Like PCB Removal from Drinking Water

Abstract The aim of the research was to compare selected coagulants efficiency in indicator and chosen dioxin-like PCB removal from surface water. As coagulants, there were used aluminium sulfate and 5 hydrolyzed polyaluminium chlorides, with trade names: PAX-XL1, PAX-XL10, PAX-XL19, PAX-XL60, PAX-XL69. For the research, surface water was used, collected from dam reservoir. The water composition was modified with standard mixtures PCB MIX24 and MIX13, in order to obtain concentration of each congener equal to 300 ng/dm3. The PCB MIX24 mixture was composed of indicator congeners solution: 28, 52, 101, 118, 138, 153, and 180, whereas the MIX13 mixture - solution of three dioxin-like PCB 77, PCB 126, and PCB 169. It was demonstrated that the application of aluminium sulfate allowed for reaching better effects for purifying water of PCB, than with the usage of pre-hydrolyzed salts, polyaluminium chlorides. Out of the studied coagulants, the best effects for indicator PCB removal were obtained with the application of aluminium sulfate, total PCB concentration was decreased by 65%. The highest efficiency for indicator congeners removal (90%) was obtained for PCB 138 and 153. After the application of hydrolyzed polyaluminium chlorides PAX-XL1, PAX-XL10 decrease in higher chlorinated PCB concentration was obtained, in the range of 23 to 74%. Selectivity of chosen PCB congener removal, depending on applied coagulant, was demonstrated; with the usage of aluminium sulfate, removal of heptachlorobiphenyl PCB 180 at the level of 34% was obtained, whereas with the application of PAX-XL1 and PAX-XL10 higher reduction efficiency for this congener was obtained, i.e. 83 and 74% respectively. For dioxin-like PCB, after application of aluminium sulfate, total concentration reduction by 74% was obtained, efficiency of this congeners removal amounted to from 54 (PCB 77) up to 72% (PCB 126), similar results were obtained after the usage of PAX-XL1. The lowest PCB removal from water rate was stated for coagulants PAX-XL60 and PAX-XL69.

Removal of Pcb from Residual Soil using Nanoalumina

This paper presents the findings of a study on adsorption of poly chlorinated biphenyl (PCBs) nano-alumina. PCBs are of significant concern due their high toxicity and long environmental half-lives. Experiments were conducted using batch adsorption procedures at different PCBs concentrations, from 10 to 60 mg/L. The amounts of nano-alumina used were 0.25%, 0.50%, 0.75%, 1%, 2% and 10%. The adsorption of PCBs solution onto the nano-alumina was characterized by an initial rapid adsorption which eventually became constant within 17 hours. Results of this study indicated that nano-alumina was a good adsorbent material for PCB in this study. While at 10% of nano-alumina 54% PCB were removed by nano-alumina. The effect of pH and temperature were also investigated. The Freundlich isotherm adsorption and Langmuir isotherm adsorption were used to analysis the result of the study.

Removal of dioxins and PCB from fish oil by activated carbon and its influence on the nutritional quality of the oil

AbstractFish oils are well‐known sources of nutritionally valuable components such as the n‐3 FA EPA and DHA as well as the fat‐soluble vitamins A, D, and E. However, some fish oils can be contaminated with considerable amounts of dioxins and dioxin‐like PCB. The most important challenge during fish oil refining is to remove these contaminants without altering the levels fining is to remove these contaminants without altering the levels of nutritionally valuable compounds and the oxidative status and stability of the oil. Treatment with an apolar adsorbent, e.g., activated carbon (AC), seems to be the most efficient process today. Very little information about the adsorption of different dioxin and PCB congeners is available. Four grades of AC were evaluated for their efficiency in removing these compounds. In addition, the effects of the treatment on the nutritional and oxidative quality of the oil were evaluated. After treatment of contaminated cod liver oil [5.4 ppt toxic equivalents (TEQ) polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/F), 18.1 ppt TEQ dioxin‐like PCB] with 0.5% AC, almost all PCDD/F and up to 80% of the dioxin‐like PCB could be removed. AC showed low affinity for mono‐ortho PCB (&lt;30% removal), which could be explained by their noncoplanar structure. Removal efficiencies were dependent on the grade and percentage of AC used. The treatment of contaminated cod liver oil caused no important effects on oil quality or FA composition in the conditions tested.

Contribution of earthworms to PCB bioremediation

Twenty cm deep columns containing Aroclor 1242 contaminated soil were bioaugmented with the PCB-degrading micro-organisms, Ralstonia eutrophus H850 and Rhodococcus sp. strain ACS, each of which were grown on sorbitan trioleate, and induced for PCB degradation by salicylic acid and carvone, respectively. Treatments consisted of soils with and without earthworms. Earthworms were utilized to enhance the dispersal of the bioaugmented PCB-degrading micro-organisms, while simultaneously improving soil aeration, increasing soil carbon and nitrogen content, and modifying the soil microbial community. Bioaugmented soils containing the earthworm Pheretima hawayana achieved 55% removal of total soil PCB as compared to only 39% in identically treated soils without earthworms. Earthworm-treated soils achieved upwards of 65% PCB degradation at subsurface depths, as compared to 44% in soils without earthworms and prior reports of only 10% degradation in soils treated without manual mixing of the inoculum into the soil (McDermott et al., 1989. Two strategies for PCB soil remediation: biodegradation and surfactant extraction. Environmental Progress 8, 46–51). A methane diffusion study demonstrated that soils containing earthworms attained greater gas diffusion rates. Breakthrough of the methane tracer through the 20-cm column was detected after only 10min in soils with earthworms, while 340min was required before breakthrough in soils without earthworms. Using a gas diffusion model, the experimental diffusion coefficients were calculated to be 4.45×10−3 and 5.0×10−4cm2s−1, respectively. The higher diffusion rate of oxygen into the soil profile provided greater concentrations of the necessary terminal electron acceptor for aerobic PCB degradation. Methane depletion was observed only in soils with earthworms and was attributed to microbial communities unique to the earthworm treated soils. The potential contribution of these communities toward PCB degradation is discussed.

Proving test on removal of PCB from pole transformer by vacuum heating separation method

In 1989, PCB was found in recycled insulation oils used in some pole transformers at a concentration of 50 mg per kg of insulation oil, prompting quick establishment of their safe separation method. One of the prospective methods for removing, for example, recycled insulation oils attached to and impregnated into the transformer coils, may be a vacuum heating separation method which heats and vaporizes PCB under vacuum conditions for separation. A proving test for the applicability of the specific vacuum heating separation method was carried out with actually used transformers, which confirmed that residual PCB on coils was minimized to less than the quantitative determination threshold of 0.05 mg per kg of insulation oil under the following standard applicable conditions: vacuum lower than 0.05 Torr; heating temperature 200 °C; and vacuum holding time 10 hours. Thus, the reduction of effects on the environment was verified. © 1997 Scripta Technica, Inc. Electr Eng Jpn 120(3): 17–28, 1997

Proving test on removal of PCB from pole transformer by vacuum heating separation method

In 1989, PCB was found in recycled insulation oils used in some pole transformers at a concentration of 50 mg per kg of insulation oil, prompting quick establishment of their safe separation method. One of the prospective methods for removing, for example, recycled insulation oils attached to and impregnated into the transformer coils, may be a vacuum heating separation method which heats and vaporizes PCB under vacuum conditions for separation. A proving test for the applicability of the specific vacuum heating separation method was carried out with actually used transformers, which confirmed that residual PCB on coils was minimized to less than the quantitative determination threshold of 0.05 mg per kg of insulation oil under the following standard applicable conditions: vacuum lower than 0.05 Torr; heating temperature 200 °C; and vacuum holding time 10 hours. Thus, the reduction of effects on the environment was verified. © 1997 Scripta Technica, Inc. Electr Eng Jpn 120(3): 17–28, 1997

The behavior of selected chlorinated organic micropollutants in the activated sludge process: A pilot plant study

An activated sludge pilot plant was operated at 4, 6, and 9 d sludge ages with influent settled sewage from a full scale treatment works. The behavior of the chlorinated organic micropollutants was examined at their background levels by analysis of influent settled sewage, mixed liquor and effluent by gas chromatographic methods. Highly significant removal at all sludge ages m terms of the reduction m micropohutant concentration in influent sewage to final effluent was observed for dieldrin, PCB, 4-C-3-MPol and dimethylphenol. Significant removal at some sludge ages was observed for Y-HCH, DDE, pentachloro phenol and 2,4-DCPol. Calculated mass balances indicated that removal of Y-HCH, PCB, and DDE was by adsorption onto MLSS rather than by air stripping or a degradative process. A comparison of the effluents from the activated sludge tanks run at 4 and 9 d sludge age with the same influent settled sewage indicated that significantly higher concentrations of pentachlorophenol, 2,3,4,6-TcCPol, 2,4,6-TCPol, and 4-C-2-MPol were seen in the effluent from the unit run at 4 d sludge age. The effluent from the 9 d sludge age tank had significantly higher concentrations of dieldrin, Y-HCH and 4-C-3-MPol. Significant biological degradation was concluded to have taken place for 4-C-3-MPol and pentachlorophenol since they exhibited poor association with sludge solids and on theoretical grounds are unlikely to be removed by air stripping.

4623464 Removal of dioxins, pcb's and other halogenated organic compounds from wastewater: Wei-ch Ying, Stanley Sojka assigned to Occidental Chemical Corporation

4623464 Removal of dioxins, pcb's and other halogenated organic compounds from wastewater: Wei-ch Ying, Stanley Sojka assigned to Occidental Chemical Corporation

4662948 On-site removal of PCB and dioxins from soils: Leo Weitzman assigned to Electric Power Research Institute

4662948 On-site removal of PCB and dioxins from soils: Leo Weitzman assigned to Electric Power Research Institute

Destruction/removal of polychlorinated biphenyls from non-polar media. Reaction of PCB with poly (ethylene glycol)/KOH

We have found that polychlorinated biphenyls (PCB's) and other unactivated chlorobenzenes react with poly (ethylene glycols) and potassium hydroxide under mild conditions. Complete reaction with PEG occurs at 75–120°C in under two hours, to produce aryl polyglycols, the products of nucleophilic aromatic substitution. This reaction has been applied to the destruction and removal of PCB's from non-polar media, including transformer oil.

Determination of Organochlorine Pesticides by Gas Chromatography Mass Spectrometry Utilizing Negative Ion Chemical Ionization

負イオン化学イオン化(NCI)法を用いたガスクロマトグラフ質量分析(GC/MS)法により土壌,底質土,河規水中に残留する13種の有機塩素系農薬およびその関連化合物を同時に一斉分析する方法を確立した。本法は従来の電子捕獲型検出器を用いるGC法よりも高選択的測定が可能であった。すなわち被定量成分のNCIスペクトルで特徴的なピークを生ずる質量数2個を選び,それらのマスフラグメントグラムにおけるピーク面積比が標準品のそれと10%以内で一致することを確かめ,同定を確実に行なってから定量を行なった。また迅速な測定と,GCでの分離をよくするために溶融石英製の5mの短い毛管カラムをGC/MS装置のイオン源近くに直接接続して用いたが,GC/MSでの測定に必要な時間は15分以内であった。なお,土壌,河川水中に共存するポリクロ律ピフェニル(PCB),フタル酸エステルの影響はまったく受けないことが判明した。この方法の絶対定量下限は.0.2～50P9で,多くは1Pg前後であった。

Studies on the Behavior of Trace Components in Oils and Fats during Processing for Edible Use. II

Five kinds of organochlorine pesticides and PCB were added to purified soybean oil and the oil was hydrogenated in a 20l autoclave under 11 different conditions, varying the amount of the catalyst, reaction temperature, and hydrogen gas concentration, but giving oils with almost the same melting points of ca. 35°C. The amounts of residual organochlorine pesticides and PCB were determined and change of the amount of these chemicals by hydrogenation condition was examined. (1) Amounts of these chemicals decreased markedly by hydrogenation but the degree of decrease was not uniform, there being a selectivity between the kind of catalyst used and the kind of organochlorine pesticide removed. The decrease was larger when the catalyst contained copper or chromium. DDT, Dieldrin and r-BHC were removed almost completely. (2) PCB also decreased by hydrogenation like the organochlorine pesticides and this decrease was especially great when the catalyst contained copper or chromium. A high residual rate was found when hydrogenation was carried out under a high pressure, using nickel catalyst alone, showing almost no removal of PCB. (3) Taking the decrease of organochlorine pesticides and PCB as a simple firstorder reaction, reaction rate constants under various hydrogenation conditions were calculated and they were found to be larger under high-pressure than under atomospheric pressure. This result suggested that the decrease of organochlorine pesticide and PCB during hydrogenation was due to the chemical changes such as reduction and dechlorination rather than their evaporation out of the reaction system.

Studies on the Behavior of Trace Components in Oils and Fats during Processing for Edible Use. III.

Five kinds of organochlorine pesticides and PCB were added to purified soybean oil and the oil was hydrogenated in a 20l autoclave under 11 different conditions, varying the amount of the catalyst, reaction temperature, and hydrogen gas concentration, but giving oils with almost the same melting points of ca. 35°C. The amounts of residual organochlorine pesticides and PCB were determined and change of the amount of these chemicals by hydrogenation condition was examined. (1) Amounts of these chemicals decreased markedly by hydrogenation but the degree of decrease was not uniform, there being a selectivity between the kind of catalyst used and the kind of organochlorine pesticide removed. The decrease was larger when the catalyst contained copper or chromium. DDT, Dieldrin and r-BHC were removed almost completely. (2) PCB also decreased by hydrogenation like the organochlorine pesticides and this decrease was especially great when the catalyst contained copper or chromium. A high residual rate was found when hydrogenation was carried out under a high pressure, using nickel catalyst alone, showing almost no removal of PCB. (3) Taking the decrease of organochlorine pesticides and PCB as a simple firstorder reaction, reaction rate constants under various hydrogenation conditions were calculated and they were found to be larger under high-pressure than under atomospheric pressure. This result suggested that the decrease of organochlorine pesticide and PCB during hydrogenation was due to the chemical changes such as reduction and dechlorination rather than their evaporation out of the reaction system.