Study On Migration Behavior Of POPs In Sediment-Water Interface Of Coal Mining Subsidence

Persistent organic pollutants (POPs) is a kind of pollutant with properties as follows:persistent for a long-term, accumulate in the living bodies, semi-volatility and high toxicity. These persistent organic pollutants can be artificially synthesized, which can cause great harm to human health and environment. During recent years, POPs pollution has become a more and more serious environment problem. POPs can be detected in every corner of the world, incuding the continent, the desert, the ocean, and even the south and north poles.The mining subsidence area of the Panyi Yangzhuang mine lot of Huainan has been taken as the object of this paper. In order to understand the distribution characteristics of the POPs, POPs in the water, the suspended solids and the sands of the area have been analyzed by qualitative and quantitative methods. The dependency between the POPs and the physicochemical property of the water, suspended solids and the sands have been studied respectively. The migration mechanism of the POPs in the phase interface of the water and the suspended solids, and the interface of the sediment phase and the suspended solids have been studied respectively so as to predict the migration and transformation trend of the POPs in this mine area. The results indicate that:(1)In the studied water area, the concentriton of the poly chlorinated biphenyl is16～32.01ng/L, the average value is20.9513ng/L. Among the pollutants, the concentration of the trichlorodiphenyl is the largest. The average value is48.28%. The concentration of the polycyclic aromatic hydrocarbon is163.7-209.65ng/L. Its average value is185.8473ng/L. Among the results, the proportion of the PAHs with three rings is the largest, which accounts for34.47%of the total. The specific value of the anthracene/(anthracene+phenanthrene) is larger than0.1. The specific value of the fluoranthene/(fluoranthene+pyrene) is larger than0.5.(2) The concentration of polychlorinated biphenyl in the suspended solids is10.135～19.7925ng/L. Its average value is15.7585ng/L. Among the pollutants, the concentration of the trichlorodiphenyl is the largest. The average value is75.24%. The concentration of the polycyclic aromatic hydrocarbon is1117.93～2729.215ng/L. Its average value is1863.838ng/L. Among the results, the proportion of the PAHs with three rings is the largest, which accounts for58.04%of the total. (3) The concentration of the polychlorinated biphenyl in the sediment mud of the studied area is2.1893-4.3597ng/L. Its average value is3.551ng/L. Among the pollutants, the concentration of the trichlorodiphenyl is the largest. The average value is64.35%. The concentration of polycyclic aromatic hydrocarbon is68.014-391.656ng/L. The average value is243.1101ng/L. Among the results, the proportion of the PAHs with three rings is the largest, which accounts for41.93%of the total. The specific value of the anthracene/(anthracene+phenanthrene) is larger than0.1. The specific value of the fluoranthene/(fluoranthene+pyrene) is larger than0.5.(4) There is a strong positive correlation between the concentration of PCBs and the DOC in the water of the coal mine area. The content of the dissolved organic carbon in the water has great influence on the distribution of organic pollutants in water. There is a strong positive correlation between the concentration of PAHs and the DOC in the water, which indicate that the content in the water can affect the concentration of PAHs.(5) There is a strong positive correlation between the concentration of PCBs and the organic substance in the sediment mud, the concentration of the PCBs is directly proportional to the organic substance in the sediment mud. When there is more organic substance in the sediment mud there will be more PCBs in it. The concentration of PAHs is strongly positive correlated to the organic substance in the sediment mud, which indicate the content of the organic substances in the mud can affect the concentration of the PAHs.(6) There is a strong negative correlation between the PCBs in the mud of the mine lot and the granularity of the sediment mud, so does the concentration of the PAHs. It indicates that the content of the POPs in the mud is reciprocal to the granularity of the sediment mud. The granularity of the sediment mud has great influence on the content of POPs.(7) There is a weak correlation between the concentration of PCBs in the superstratum water of the mining subsidence area and the concentration of PCBs in suspends in the water. There is a medium negative correlation between the concentration of PCBs in the middle level water and the concentration of PCBs in suspends in the water. The same situation will be happen in the underlying water. The concentration of PAHs in the superstratum water is medium negative correlation to the concentration of the PAHs in suspends in the water. In the middle level water the correlation is weak. While in the underlying water the correlation between them is medium nagetive.(8) There is a moderate negative correlation between the concentration of the PCBs in the sediment mud and in the water of the mining subsidence area. The concentration of the PCBs is moderate positive correlation to the concentration of PCBs in the suspended solids.(9) The concentration of the PAHs in the sediment mud is wealy negative correlated to the concentration of the PAHs in the underlying water. The concentration of the PAHs in the sediment mud is moderate nagetive correlation to the concentration of the PAHs in the suspended solids.