| Coal mining subsidence is a large area of water after rainfall and infiltration of groundwater due to excessive mining,leading to the top of the Goaf Collapse through large area subsidence,which makes the original terrestrial environment into the water environment,and the persistent organic pollutants will migrate to a series of transformation behavior.The organochlorine pesticides in the environment with persistence and bioaccumulation will accumulate in the body,and ultimately endanger human health,So the study of the behavior of OCPs is of great significance.This paper selected Huainan Yangzhuang coal mining subsidence area as the research object,through the collection of Yangzhuang water sample and sediment subsidence area,it analysis the content of the OCPs,and established a steady sediment-water fugacity model,the subsidence area y-HCHs and p,p'-DDTs fate was simulated,the concentration prediction ofy-HCHs and p,p'-DDTs in sediment calculation,and made a comparison and analysis of the feasibility of the model,draw the following conclusions:1.Through the analysis of Yangzhuang coal mining subsidence area OCPs content in 2015 and 2016,found near the affected by coal gangue and slime of the river,some sampling point of organochlorine pesticides content high,showing the law of vertical distribution:the overlying water pore water<Surface water<overlying water<interstitial water,and y-HCH.In two of the samples were accounted for a higher percentage,is one of the main components of HCHs;p,p'-DDT in 2015 and 2016 in DDTs larger proportion,is one of the main components of DDTs.Therefore,it is more representative to choose two organochlorine pesticides to simulate fugacity.2.Through the analysis of 2015 and 2016,Yang OCPs content in sediment samples of subsidence results can be found:the No.9,No.10,and No.11 point HCHs and DDTs concentration than other points may be high,the main reason is that these points are close to the nearby coal gangue and mud river entrance and vertical;is with the increase of the depth of the sediment,organochlorine pesticides content gradually reduced the law.3.The content of TOC in water is also closely related to the surrounding environment,and the content of TOC in the waters near the mud river basin and residential area is higher.The correlation between OCPs content and TOC content analysis in the water and sediment,and find a significant correlation between OCPs content and TOC content in the sediment,i.e.the higher the TOC content in sediment,organochlorine pesticides is also higher.4.The y-HCH and p p'-DDT,for example,by measurement and reference value method to determine the parameter values,and then establishes a model of steady-state fugacity of water two phase sediment,organochlorine pesticides on migration in the subsided water area environment behavior is simulated,and the predicted and measured values were compared.Found in good agreement,the numerical deviations within an order of magnitude,it indicated that the model is successful and can reflect the transformation behavior of organochlorine pesticides in the migration area in Yangzhuang collapse.5.The sensitivity coefficient through the analysis and calculation of key parameters to find the parameters has great influence on the model,and analysis the suspended sedimentation rate sensitivity coefficient is the highest,that of suspended solids in water sediment system plays an important role in the process of settlement of the migration of contaminants to the sediment. |
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