Study On The Influence Of DOM On The Environmental Behavior Of PAHs In Coal Mining Subsidence Area

This paper taked Huainan Panyi Yangzhuang and Xieqiao coal mining subsidence area as the study object,through field survey sampling,sample index detection and data analysis,the qualitative and quantitative analysis of 16 kinds of priority control PAHs in the water,the surrounding soil and the sediment in the subsidence area had been carried out,finding out the content and pollution characteristics of PAHs in multiple environmental media in subsidence area,the content of DOM in each sample was studied and the composition of the samples was analyzed simply,discussing the influence of DOM on the environmental behavior of PAHs in coal mining subsidence area in a changing environment.The main conclusions were as follows:1.The total content of PAHs was 79.72-205.70 ng/L in Yangzhuang water,with an average content of 142.31 ng/L,the total content of PAHs was 109.00-6540.64 ng/g in Yangzhuang soil,with an average content of 1191.88 ng/g,the total content of PAHs was 60.67-5460.57 ng/g in Yangzhuang sediment,with an average content of 1145.07 ng/g;The total content of PAHs was 123.27-194.79 ng/L in Xieqiao water,with an average content of 158.14 ng/L,the total content of PAHs was 26.58-1597.87 ng/g in Xieqiao soil,with an average content of 267.37 ng/g,the total content of PAHs was 44.64-180.49 ng/g in Xieqiao sediment,with an average content of 99.06 ng/g.2.The distribution characteristics of PAHs in Yangzhuang coal mining subsidence area:The total content of PAHs in water and sediment was higher in the West and north of the subsidence area there was a downward trend from west to east,the content of PAHs in soil was higher in the northwest of the subsidence area,the center to both sides had a downward trend with YZTR12;The distribution characteristics of PAHs in Xieqiao coal mining subsidence area:The total content of PAHs in water and sediment was higher in the south of subsidence area,there was a downward trend from from south to north,the distribution of PAHs in the north of the subsidence area was uniform and the content was low.3.The content of DOM was 4.29-5.60 mg/L in Yangzhuang water,with an average content of 4.85 mg/L,showed a gradual downward trend from northwest to southeast,related to the distribution of the coal gangue pile;The content of DOM was 2.94-6.53 mg/L in Yangzhuang water,with an average content of 5.21 mg/L,showed the regulation of the north south high-low,the main reason was there were many fired brick factories on the south side of subsidence area.4.The soil samples with high content of PAHs both in Yang Zhuang and Xie Qiao coal mining subsidence,the corresponding main peak position of DOM were in regionⅠ or Ⅲ,belonged to the protein-like substances,The samples with low content of PAHs,the corresponding main peak position of DOM were in region Ⅱ or Ⅳ,belonged to the humic-like substances;But it Showed the opposite pattern in sediment,the samples with high content of PAHs,the corresponding main peak position of DOM were in region Ⅱor Ⅳ,the samples with low content of PAHs,the corresponding main peak position of DOM were in region Ⅰ or Ⅲ.5.The distribution characteristics of PAHs and DOM were very similar both in Yang Zhuang and Xie Qiao water,the possible reason was DOM and PAHs were adsorbed by the water medium in the form of CO adsorption or cumulative adsorption,thus increasing the adsorption capacity of PAHs in water,reducing the mobility of PAHs in water;The humic-like substances had a strong effect on PAHs,which can promote the desorption of PAHs and improve its mobility in soil;The humic-like substances can promote the adsorption of DOM and PAHs in the form of CO adsorption or accumulative adsorption,thus increasing the adsorption capacity of PAHs and reducing the migration of PAHs in sediment.