Research On Pollutants In Waste Transformer Oil And Environmental Risk Assessment

Waste pollutions and disposal problems of transformer substation in electric power industry were paid more and more attention by people. Waste transformer oil contained many kinds of toxic substances. Transformer oil belongs to hazardous waste according to the definition of the United Nations Environment Programme(UNEP) and the National Hazardous Waste Inventory in China. The related research on environmental pollutants in waste transformer oil was less. The sites that were suitable for researching the risk assessment of waste transformer oil were limited, usually limited to the space where the oils product, use and store such as transformer substation and transformer plants.The composition and content of particular pollutants which is harmful to human health and ecological environment in waste transformer oil was studied in this paper. Gas chromatography-mass spectrometry was chosen to detect the organic pollution composition and content of particular pollutants in transformer oil, based on investigation and analysis. Different voltage levels, different running time and different degrees of deterioration of the transformer oil samples were detected. The test results of transformer oil samples that running different time under 10 kV voltage level showed that with turbidity of oil rising, the content of polycyclic aromatic hydrocarbons in waste transformer oil increased, while benzene content changed in the opposite trend. Compared with the new transformer oil, the content of pollutants in waste transformer oil was much more. Complex composition, different origin and different operating conditions were the reasons of difficulty to separate organic components in transformer oil during detection.Through the study of particular pollutants and to analyze the results of Toxicology tests, multimedia-multichannel exposure risk assessment model was chosen to evaluate the population exposure of 3 age groups to PAHs in Beijing and Tianjin area. Environmental background values were taken into account for more comprehensive environmental risk assessment. Evaluation results showed that polycyclic aromatic hydrocarbons pollutants and human impacts on the environment were more prominent. In accordance with the criteria of toxic chemicals to identify hazardous waste(GB5085.6-2007), the proposed exploratory waste transformer oil contamination hazard rating, disposal of PAHs priorities.This study is helpful for safe disposal of waste transformer oil. And it also can provide some theoretical support to eliminate the harm of the polycyclic aromatic hydrocarbons and benzene series.