Environmental Contaminant Characteristics And Ecological Risk Assessment Of New Typical Brominated Flame Retardant In Surface Water From Longgang District, Shenzhen City

As an important economic district in Shenzhen City,Longgang District has become an advanced industrial base for electronic information,biotechnology and new materials in Shenzhen City.With the time of rapid economic development,its ecological environment has been destroyed among which,polybrominated biphenyl ether(PBDEs)and hexabromocyclododecane(HBCDs)are two important organic pollutants.In this study,23 surface water samples and 13 surface sediment samples collected from Longgang River and Pingshan River from Longgang District.The concentrations of PBDEs and HBCDs in surface water and sediment samples were analyzed by gas chromatography mass spectrometry(GC/MS)and high performance liquid chromatography-mass spectrometry(LC-MS/MS).The ecological risks of PBDEs and HBCDswere evaluated using aquatic toxiclogical data from USEPA and the Ministry of Canada Enviromental Protective.The results are as follows:The concentrations of PBDEs in surface water samples were in range of 71.94-28991.50pg/L(with an average of 1997.20pg/L)and 2.96-137.00pg/L(with an average of 33.34pg/L)in dry season and wet season from Longgang River and Pingshan Rvier,respectively.The concentrations of PBDEs in surface sediment samples were ranged from 0.09ng/g dry weight to 111.99ng/g dry weight(with an average of 32.54 ng/g dry weight)from Longgang River and Pingshan River.PBDEs in surface water samples showed obvious temporal and spatial distribution trends,and in dissolution phase,the low bromine congeners of PBDE were the dominant congeners,and in particle phase,BDE-209 was the dominant congeners.The higher concentrations of PBDEs in sediments are mainly distributed in the middle and lower reaches,and BDE-209 was the dominant congeners.The results of factor analysis showed that PBDEs in surface water samples were mainly influence by three major factors,which reflected more than 70% of the information,PBDEs in surface sediment samples were mainly affected by two major factors,which reflected more than 90% information.The concentrations of HBCDs in surface water samples were in range of 0.31-2.00 ng/L(with an average of 1.03ng/L)and 0.16-1.02 ng/L(with an average of 0.47 ng/L)in dry season and wet season from Longgang River and Pingshan River,respectively.The congcentrations of HBCDs in surface sediment sanples were ranged from 0.19 ng/g dw to 49.43 ng/g dw(with an average of 14.58 ng/g dw)from Longgang River and Pingshan River.The percentage content of HBCDs in particle phase and dissolved phase showed obvious temporal trend,and the percentage content of ?-,?-,?-HBCDs didn't show obvious temporal trend.The congtent of HBCDs in the two main streams showed significant temporal and spatial changes.?-HBCD is the dominant isomer in surface water and sediment,and values of ?/? are far lower than the industrial product HBCDs,indicating the transformation of HBCDs' isomers in the environment.The results of ecological risk assessment showed that PBDEs and HBCDs in water and sediment samples were not to cause potential ecological risks,but the contamination of Persistent Organic Pollutant(POPs),et al PBDEs,HBCDs and so on,should be concerned in the Longgang District of Shenzhen City.