Study On The Sediment Quality Guidelines And Risk Assessment Of Pentachlorophenol In Poyang Lake

Pentachlorophenol(Pentachlorophenol)is a typical persistent organic pollutant and excellent control pollutants,causing continuous harm to the environment.Poyang Lake used a large amount of pentachlorophenol to kill schistosomiasis host snails,and pentachlorophenol remained in the environment for a long time,affecting people's production and life.Sediment quality guidelines(SQG)is one of the effective means of sediment pollution management.At present,there are few studies on the relevant benchmarks of Poyang Lake sediments.Equilibrium partitioning method(EqPA)and Species sensitivity distribution method(SSD)of toxicity database are used to discuss it.According to the physical and chemical properties and characteristics of Poyang Lake sediments,the baseline value of pentachlorophenol sediments in the Poyang Lake Basin was obtained,and according to the sediment benchmarks,the risk quotient method was used to evaluate the risk.The main results are summarized below:(1)Three dominant organisms(Misgurnus anguillicaudatus,Bellamya quadrata and Corbicula fluminea)were selected from the benthic organisms in Poyang Lake to carry out pentachlorophenol sediment toxicity test as a supplement to the toxicity database.The results showed that the higher the concentration of PCP,the more obvious the toxic effect of the organism.The acute toxicity of pentachlorophenol to M.anguillicaudatus,B.quadrata and C.fluminea was 96h-LC50 at 31.39 mg/kg,65.19 mg/kg and 61.89 mg/kg,respectively;its chronic toxicity at 21d-LC50 was 5.26 mg/kg,12.89 mg/kg and 9.68 mg/kg.(2)The results of phase equilibrium distribution method(EqPA)showed that:using the toxicity database data,the final chronic value(FCV)was 21.389 ?g/L,and the experimentally measured value of Koc of pentachlorophenol was 2.71,foc of sediment was 3.09%,and and the pentachlorophenol SQG obtained was 0.335 mg/kg.Calculated by species sensitivity distribution method(SSD),using phase equilibrium transformation to convert the water toxicity data in the database to the toxicity data in sediments,the resulting pentachlorophenol sediment benchmark has a CMC of 6.38 m/kg and a CCC of 0.399 mg/kg.(3)The concentration was range from 0.34?46.58 ?g/kg,by measuring the content of pentachlorophenol in 17 sampling points of the sediments in Poyang Lake,neither exceeding the baseline value of the obtained sediment nor its predicted no-effect concentration(PNEC,Predicted No Effect Concentration).The hazard quotient method shows that there is no ecological risk for pentachlorophenol in the sediment of 12 sampling points in 17 sampling points,while there is a lower risk of pentachlorophenol in the sediments of 4 sampling points,namely S2,S3,S7 and S12,located in Wucheng,Nanjishan and Sanjiangkou areas.Overall,the risk of pentachlorophenol in the sediments at the sampling site is low.