Distribution Characteristics Of POPs In Coal Mining Subsidence Area

In recent years, POPs has been paied more popular attention by governments, academia, industry and the publics, becoming a new focus of global environmental problems. At present, a certain amount of research on POPs was carried out in the domestic, but these studies are more concentrated in the delta of Yangtze, Beijing, Shanghai and other economic regions whose economy developed highly, while the research on rural areas is very little. China is a country with a lot of coal, and POPs can be affected by coal mining, but the distribution of POPs in coal mining subsidence has not been studied at present, therefore, based on exploration of POPs experimental scheme, and putting mining subsidence basin of huainan Yang Zhuang as research object,distribution of POPs in coal mining subsidence is studied in this paper. The main ideas can be concluded as followed in this paper:(1) Suitable pollution indexes of POPs in coal mining subsidence are determined based on research status of our country and abroad, which including16kinds of PAHs,15kinds of PCBs and19kinds of PCBs. And exploring the analysis conditions of POPs by using PE type Clarus meteorological chromatography-mass spectrometry. Several kinds of interference are determined, and the ways to eliminate the substances of interference are found out.(2) The SPE column is choosed to enrich POPs in water and feasibility of this method is ensured by the measurement of recovery, and15mL methylene chloride/n-hexane (1:1) eluent is the most suitable water eluent of POPs by changing the factors such as the type and dosage of eluent.(3) The soxhlet extraction and ultrasonic extraction are used to explore the methods of POPs’ extraction in solid in the paper, and the results show that ecovery of soxhlet extraction is a little higher than ecovery of ultrasonic extraction overall, but when considering the soxhlet extraction cycle longer, and the dosage of extraction liquid needs more, while combining with the existing resources of laboratory, ultrasonic extraction is chosen to be the final extraction solution at last.(4) Commercial SPE column purification and chromatography column purification are choosed to explore POPs’ purification scheme in solid samples, the results show that recovery rate of commercial SPE column purification is better than that of chromatography column purification overall, but taking solid material of sediment and soil is more complicated, and purification substances of commercially SPE column contained is less, while when not pure samples are used to analyze, commercial SPE column may not be able to remove the interfering substance of solid sample completely. Finally, chromatography column purification is choosed to extract of solid samples.(5) In order to ensure the precision and quality of experimental data, the corresponding quality control and assurance are established in this study, such as generation standard recovery rate, substrate and standard, solvent blank, blank instrument, etc.(6) Combining with theory, sampling plan and actual situation, water, sediment, soil and coal gangue samples of Yang Zhuang coal mining subsidence are collected and determinated. But POPs is not detected in coal gangue and suspende substances, perhaps because the matrix of coal gangue is complex, and low POPs is exsited in the suspended solids.(7) Taking PAHs and OCPs for example, POPs’ distribution characteristics of coal mining subsidence are analysed in this study, showing that PAHs is less than most of studied area in China, and coming from coal combustion mainly, shows that coal mine takes contribution to POPs’ concentration of coal mining subsidence; There is no PCBs pollution in coal mining subsidence; OCPs of coal mining subsidence is less than the readings in most of studied area in China, and less than the concentration and standard requirements, but the OCPs’ source of coal mining subsidence should be further researched.