| Beijiang River is one of the main rivers of the Pearl River in China and it is one of the most important rivers in Guangdong Province.Beijiang River not only runs through the entire Qingyuan,but also is the main drinking water source for local residents.Qingyuan is located in the middle and lower reaches of Beijiang River.In recent years,with the transfer of industrial structure in the Pearl River,the economy of Qingyuan had been growing at a rate of over 10%.There had been a great deal of attention about environmental safety in Beijiang with rapid economic development and intensified activities of industrial enterprises along the river.Thus,in this study,the water and sediments were collected in Qingyuan section of Beijiang in July and December 2016.In order to provide technical support for the management decision of the the environment protection of Beijiang river,the persistent organic pollutants(POPs)of polycyclic aromatic hydrocarbons(PAHs),organochlorine pesticides(OCPs)and phthalic acid esters(PAEs)was selected as the three typical research targeted pollutants in this present study.The 3 kinds of POPs were detected by Gas Chromatography-Mass Spectrometer(GC-MS).The ruselts of the 16 PAHs showed that the detection limits ranged from 0.09 to 1.08 ng/L and 1.02 to 3.34 ng/g,respectively.The recoveries ranged from 77% to 101%(RSD% = 11.8%,n = 4)and 71% to 99%(RSD% = 13.8%,n = 4).The total PAHs concentrations were 0.4-110.2 ng/L(the flood season)and 41.2-413.8 ng/L(the dry season)in water.The total PAHs concentrations were 54.4-819.2 ng/g(the flood season)and 54.8-951.5 ng/g(the dry season)in sediment.The PAHs in water were dominated by low-ring and at a moderate level pollutant,wthereas the PAHs in the sediment were mainly high-ring and at a lower level of pollution.The main sources of PAHs in water were petroleum source and mixed sources,whereas the main sources of PAHs in sediment were the emission of coal,biomass combustion.The incremental lifetime cancer risk(ILCR)was used to assess the health risk in water.The ecological risk of water was assessed by the value of risk quotient(RQ),and it was found that the pollution risk in water of PAHs was at a moderate level.It showed that there were potential risks in 5 life stages of BJ-7 and BJ-8 sampling sites in flood season,and the carcinogenic risk of each sampling site in dry season was negligible.The method of using the ration of effects rang low(ERL)/ effects rang median(ERM)was adopt to evaluate the ecological risk of PAHs in sediments.And the result showed that PAHs in sediments had a negative effect on environment.The toxic equivalent factors(TEQ)was used to evaluate the carcinogenic risk of PAHs in sediments.The result showed that the carcinogenic risk of BJ-4,BJ-6,BJ-10 and BJ-13 sampling sites were higher.About the 15 OCPs,the detection limits ranged from 1.09 to 10.16 ng/L and 0.88 to 5.34 ng/g,respectively.The recoveries rangde from 68% to 84%(RSD% = 8.9%,n = 4)and 67% to 91%(RSD% = 14.3%,n = 4).The detection rates of OCPs in water and sediment of Qingyuan in Beijiang River were low and the pollution concentrations of OCPs were at a low level.Particularly,only 2 kinds of OCPs,HCB and Endrin,were detected in water,and 5 kinds of OCPs,HCB,p,p'-DDE,o,p'-DDT,Dieldrin and ?-HCH were detected in sediment,respectively.The total OCPs concentrations in water were 0.25-12 ng/L(the flood season)and nd-3.29 ng/L(the dry season).The total OCPs concentrations in sediment were 0.14-5.58 ng/g(the flood season)and 0.02-2.16 ng/g(the dry season).?-HCH in sediment was derived from the use of pesticides.The detection of DDT was related with the past history use and residue problem.Risk assessment showed that the carcinogenic risk of OCPs in water were negligible,whereas the non-carcinogenic risk of OCPs of all sampling sites were potential.Using the method of Consensus-Based Sediment Quality Guidelines(CB-SQGs)and the ration of EML/ERM to assess the ecological risk of OCPs in sediments,the result showed that OCPs in sediment had adverse effects on aquatic animals,especially the sediment of BJ-6 sampling sites had posed toxic effects.The result of 6 PAEs indicated the detection limits ranged from 1.11 to 6.25 ng/L and 0.88 to 3.46 ng/g,respectively.The recoveries ranged from 72% to 103%(RSD% = 13.2%,n = 4)and 74% to 96%(RSD% = 13.4%,n = 4).The total PAEs were at a moderate level pollutant and the concentrations were nd-47.71 ?g/L(the flood season)and 0.55-7.92 ?g/L(the dry season)in water.The total PAEs in sediments were at a high levels of pollution and the concentrations were 0.34-63.31 ?g/g(the flood season)and 0.66-91.35 ?g/g(the dry season).During the flood season,the main sources of PAEs in water came from plastic and chemical industries,and municipal solid wastes.And the sources of PAEs in water in dry season were mainly household waste.The agricultural pollution and household plastic garbage should have important effects on the pollution source of PAEs in sediments.The carcinogenic risk of DEHP and ?PAEs of BJ-3 sampling sites in water was at potential level in dry season.There was no carcinogenic risk at other sampling sites in water in dry season.As for the PAEs in flood season was also no carcinogenic risk.However,each sampling point had potential or even unacceptable non-carcinogenicity to human.PAEs had a toxic effect on algae,crustaceans and fish in sediment. |
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