Distribution, Sources And Risk Assessment Of Semi-Volatile Organic Compounds In Water And Sediment Of Shanghai

With the growth of population,rapid development of industry,the problem ofurban pollution has become increasingly prominent.Semi-volatile organic compounds?SVOCs?have becomes widespread pollutants in the environment and now represent a global contamination problem.The pollution level of SVOCs in water and sediment directly affects the health of urban residents.Therefore,it is of great theoretical and practical significance to study the pollution status of SVOCs.SVOCs are typical organic pollutants in the environment,which are widely distributed and exhibit complex environmental behaviour.Majorities of SVOCs compounds in environment were listed as priority pollutants by United States Environmental Protection Agency?USEPA?of America.The contamination levels,spatial distribution,isomeric composition,possible sources and potential risk of SVOCs including OCPs,PAHs,PAEs from water and sediment in Shanghai were systematically investigated.The study aimed to understanding the water and sediment contamination status and potential risk posed by typical SVOCs in Shanghai region,and to supplying data of the pollution relations between those environmental mediums,and to providing the scientific basis for implementing the Stockholm Convention as well.The main conclusions are summarized as follows:?1?The method has been developed for the detection of 90 SVOCs in water and sediment samples by SPME and ASE respectively.Variables affecting the extraction efficiency such as the extraction membrane,extraction temperature,and extraction solvent were studied and optimized.The results showed that dichloromethane-acetone mixture displays the best extraction performance,HLB is the best extraction membrane for SPME and 80?is the best extraction temperature for ASE.Compared SPME with LLE method,not only did the efficiency of SPME was generally better than LLE,but more highly automated.In addition,and compare ASE with SE,not only did the efficiency of ASE was generally better than SE,but reduced solvent consumption.?2?This study unveiled the pollution levels,spatial distributions and component characteristics of SVOCs in the water and sediment from principal watersheds of Shanghai for the first time.SVOCs were ubiquitous in riverine environment of Shanghai.The total concentrations of 90 SVOCs ranged from 1.47 to 19.5?g/L in water and 2.38 to9.48 mg/kg in sediment.The results showed?₉₀SVOCs concentration was the highest in the three inland river of Shanghai,and it was the lowest in Dianshan Lake.?1??₂₀OCPs concentrations ranged from 0.049 to 0.274?g/L in water,and?₁₉PAHs concentrations ranged from 0.216 to 0.992?g/L,and?₆PAEs concentrations ranged from0.425 to 16.4?g/L,with means of 0.123?g/L,0.516?g/L and 4.60?g/L,respectively.The major ingredient of OCPs is HCHs,and HCHs are more than 50 percent in some sampling sites.According to the measured concentrations,?-HCH and?-HCH were the most dominant compounds among the HCHs.Among different ring PAHs,the higher levels of PAHs were 2-ring PAHs,followed by 4-ring,3-ring,5-ring,and the low concentrations of PAHs were 6-ring.The sequence of different concentrations PAEs was DBP,BBP,DOP,DEP,DMP,DNOP.?2??₂₀OCPs concentrations ranged from 4.82 to 24.7?g/kg in sediment,and?₁₉PAHs concentrations ranged from 0.477 to 3.65 mg/kg,and?₆PAEs concentrations ranged from 0.302 to 2.93 mg/kg,with means of 11.6?g/kg,1.76 mg/kg and 1.12 mg/kg,respectively.The major ingredient of OCPs is HCHs,Methoxychlor and DDTs,accounting for 28.9%,21.7%and 17.1%of the?₂₀OCPs concentrations,respectively.According to the measured concentrations,the upper and lower rings PAHs have the same concentration,while 6-ring PAHs is lowest of all.DBP is the highest concentrations of PAEs,it is more than half of ten percent of?₆PAEs concentrations.?3?This article investigated potential sources of SVOCs in water and sediment from principal watersheds of Shanghai for the first time.?1?The different compositions of DDTs,HCHs,Chlordane and endosulfan indicated that the residues of these compounds in most water samples originated from historical application,besides slight recent introduction at some sampling locations.The PAHs isomeric ratios indicated that PAHs in water from Shanghai originated mainly from petroleum spill disaster.The principal component analysis?PCA?showd that PAEs in water from Shanghai originated mainly from the drainage of industrial waste and sewage runoff.?2?Most of?DDE+DDD?/DDTs ratios was over 1,and ratios of?-HCH/?-HCH ranged from 0 to 5.83,with with means of 0.734,which indicated the residues of OCPs in most sediment samples originated from historical application.The ratios of Flu/?Flu+Pyr?ranged from 0.235-0.614,and Ant/?Ant+Phe?ranged from 0.094-0.562,with means of 0.442 and 0.292,respectively.It indicated that PAHs in sediment from Shanghai originated mainly from combustion.The principal component analysis?PCA?showd that PAEs in sediment from Shanghai originated mainly from the drainage of industrial waste,sewage runoff and agriculture discharges.?4?This paper studied risk assessment of SVOCs in water and sediment from principal watersheds of Shanghai for the first time.?1?The research indicated that the female health risk was higher than the male's,and two types and degrees of health risks are acceptable.No carcinogenic and non-carcinogenic risk of the SVOCs was identified by a health risk assessment through drinking water and bathing,except for the Benzo?a?pyrene and DBP that might cause cancer at several sites.Nevertheless,the integratedhealth risk of the SVOCs should not be neglected and needintensive investigations.?2?In conclusion,adverse effects related to OCPs,PAHs,and PAEs would occur occasionally at all 30 stations.However,they were all below the ERM,indicating these ecological risk would infrequently occur in surface sediments from Shanghai.Besides,the risk assessment showed that SVOCs in sediment did not pose much risk to the geobiont therein,while BBP posed some risk to aquatic organisms.