东海沉积物汞形态分布及控制因素
|
摘要
为研究东海近海沉积物中不同形态汞的分布特征及关键控制因素,分别于2014年秋季和2015年夏季采集了东海近海表层沉积物样品,测定了总汞和甲基汞浓度。结果表明,东海沉积物总汞整体呈现由近岸向远海递减的趋势,表明其受陆源输入影响较大;甲基汞分布趋势相反,外海高于近岸,说明原位生成相对陆源输入作用更大。与其它海洋环境相比,东海沉积物中甲基汞浓度较高;总汞浓度高于开放海区,与其他海湾和近海体系相比处于中间水平。汞富集因子(EF)计算结果表明东海沉积物汞污染总体处于轻度至中度污染水平。沉积速率估算结果表明,与其他海洋体系相比,东海总汞和甲基汞沉积较快。同时测定了沉积物烧失量(LOI)、含水率、Fe、Mn等环境参数,通过Spearman相关分析与多元线性回归分析探究了影响东海总汞和甲基汞分布的主要因素,结果表明:有机质含量和微生物群落等环境因素可能是影响沉积物中甲基汞浓度的关键因素,而人为输入和铁含量是影响沉积物中总汞浓度的关键因素。
Sediment samples were collected in autumn 2014 and summer 2015 in the East China Sea(ECS)to investigate the distribution of mercury species and theirmajor controlling factors in this marine system.The results showed thattotal mercury(THg)generallypresented a decreasing trend from the nearshore to offshore,suggesting the importance ofterrestrial discharge in controlling THg in ECS sediment.A contrary distribution trend was observed for methylmercury(MeHg)in ECS sediment,indicating that in situmethylation may play a more important role in controlling MeHg levels.MeHgconcentrations in ECS sediment were higher than that in most marine systems,while THg in ECS sediment was higher than those in most open seas andcomparable to those in the bays andcoastalseas.The results of enrichment factors(EF)suggest that ECS sediment is minorly or moderately polluted by mercury.Compared to other marine systems,higher sedimentaccumulation of THg and MeHg was observed in the ECS.Loss of ignition(LOI),moisture content,Fe and Mn contents in ECS sediment were also measured to identify the major factors controlling THg and MeHg in ECS sediment.The results of Spearman correlation and multiplelinear regression analyses suggest thatLOI and the microorganisms in the sediment may be the major factors controlling MeHg in thesediment,while anthropogenic dischargeand total iron were identified to be the main controlling factor for THg.
Sediment samples were collected in autumn 2014 and summer 2015 in the East China Sea(ECS)to investigate the distribution of mercury species and theirmajor controlling factors in this marine system.The results showed thattotal mercury(THg)generallypresented a decreasing trend from the nearshore to offshore,suggesting the importance ofterrestrial discharge in controlling THg in ECS sediment.A contrary distribution trend was observed for methylmercury(MeHg)in ECS sediment,indicating that in situmethylation may play a more important role in controlling MeHg levels.MeHgconcentrations in ECS sediment were higher than that in most marine systems,while THg in ECS sediment was higher than those in most open seas andcomparable to those in the bays andcoastalseas.The results of enrichment factors(EF)suggest that ECS sediment is minorly or moderately polluted by mercury.Compared to other marine systems,higher sedimentaccumulation of THg and MeHg was observed in the ECS.Loss of ignition(LOI),moisture content,Fe and Mn contents in ECS sediment were also measured to identify the major factors controlling THg and MeHg in ECS sediment.The results of Spearman correlation and multiplelinear regression analyses suggest thatLOI and the microorganisms in the sediment may be the major factors controlling MeHg in thesediment,while anthropogenic dischargeand total iron were identified to be the main controlling factor for THg.
引文
[1]Futsaeter G,Wilson S,The UNEP global mercury assessment:sources,emissions and transport[C].[s.l.]:E3S Web of Conferences,EDP Sciences,2013,1:36001.
[2]Huang M,Deng S,Dong H,et al.Impacts of atmospheric mercury deposition on human multimedia exposure:Projection from observations in the Pearl River Delta region,South China[J].Environmental Science&Technology,2016,50(19):10625-10634.
[3]Sakata M,Marumoto K,Narukawa M,et al.Mass balance and sources of mercury in Tokyo Bay[J].Journal of Oceanography,2006,62(6):767-775.
[4]Brett-Crowther M.Mercury in the environment:Pattern and process[M].California,USA:University of California Press,2012.
[5]孙阳昭,陈扬,刘俐媛,等.从水俣病事件透视日本汞污染防治管理的嬗变[J].环境保护,2013,41(9):35-37.Sun Y Z,Chen Y,Liu L Y,et al.Perspective from minamata disease events in Japan the change of the mercury pollution prevention management[J].The Environmental Protection,2013,41(9):35-37.
[6]覃东立,姜秋俚,付友生.全球汞污染回顾与分析[J].环境保护科学,2009,35(4):75-78.Tan D L,Jiang Q L,Fu Y S.The global mercury pollution review and analysis[J].Environmental Protectionscience,2009,35(4):75-78.
[7]Liu M,Chen L,Wang X,et al.Mercury export from mainland China to adjacent seas and its influence on the marine mercury balance[J].Environmental Science&Technology,2016,50(12):6224-6232.
[8]Wang C,Ci Z,Wang Z,et al.Air-sea exchange of gaseous mercury in the East China Sea[J].Environmental Pollution,2016,212:535-543.
[9]Buck C S,Hammerschmidt C R,Bowman K L,et al.Flux of total mercury and methylmercury to the Northern Gulf of Mexico from US Estuaries[J].Environmental Science&Technology,2015,49(24):13992-13999.
[10]Liu J P,Xu K H,Li A C,et al.Flux and fate of Yangtze River sediment delivered to the East China Sea[J].Geomorphology,2007,85(3-4):208-224.
[11]Schartup A T,Balcom P H,Mason R P.Sediment-porewater partitioning,total sulfur,and methylmercury production in estuaries[J].Environmental Science&Technology,2014,48(2):954-960.
[12]Warner K A,Roden E E,Bonzongo J C.Microbial mercury transformation in anoxic freshwater sediments under iron-reducing and other electron-accepting conditions[J].Environmental Science&Technology,2003,37(10):2159-2165.
[13]Xia C,Wu X,Lam J C W,et al.Methylmercury and trace elements in the marine fish from coasts of East China[J].Journal of Environmental Science and Health,Part A,2013,48(12):1491-1501.
[14]Huang Z,Pan X D,Han J L,et al.Determination of methylmercury in marine fish from coastal areas of Zhejiang,China[J].Food Additives and Contaminants:Part B,2012,5(3):182-187.
[15]Liu W,Hu L,Lin T,et al.Distribution and mass inventory of mercury in sediment from the Yangtze River estuarine-inner shelf of the East China Sea[J].Continental Shelf Research,2017,132:29-37.
[16]Meng M,Shi J,Yun Z,et al.Distribution of mercury in coastal marine sediments of China:Sources and transport[J].Marine Pollution Bulletin,2014,88(1-2):347-353.
[17]Fang T H,Chen R Y.Mercury contamination and accumulation in sediments of the East China Sea[J].Journal of Environmental Sciences,2010,22(8):1164-1170.
[18]Shi J B,Liang L N,Yuan C G,et al.Methylmercury and total mercury in sediments collected from the East China Sea[J].Bulletin of Environmental Contamination and Toxicology,2005,74(5):980-987.
[19]Duan L Q,Song J M,Yu Y,et al.Spatial variation,fractionation and sedimentary records of mercury in the East China Sea[J].Marine Pollution Bulletin,2015,101(1):434-441.
[20]Martin T D,Creed J T,Long S E.Sample Preparation Procedure for Spectrochimical Determination of Total Recoverable Elements[M].Methods for the Determination of Metals in Environmental Samples.Boca Raton:CK Smoley,1992:15-24.
[21]Pfeil D L,Stalvey D.Satisfying certification requirements of USEPA method 1631[J].American Laboratory,2004,36(12):11-16.
[22]Babu S H,Kumar K S,Suvardhan K,et al.Preconcentration technique for the determination of trace elements in natural water samples by ICP-AES[J].Environmental Monitoring and Assessment,2007,128(1-3):241-249.
[23]Li Y,Duan Z,Liu G,et al.Evaluation of the possible sources and controlling factors of toxic metals/metalloids in the Florida Everglades and their potential risk of exposure[J].Environmental Science&Technology,2015,49(16):9714-9723.
[24]刘育民,严蔚芸,窦贻俭,等.江苏沿海底质重金属背景值的调查[J].中国环境科学,1(2):60-67.Liu Y M,Yan W Y,Dou,D J,et al.Investigation on background value of heavy metals in coastal base of jiangsu province[J].China Environmental Science,1981(2):60-67.
[25]窦维伟.黄、东海沉积物中金属元素的地球化学组成及铝、钛的形态分布[D].青岛:中国海洋大学,2007.Dou W W,Biogeochemical Characteristics of Metal Elements and Speciation of Aluminum and Titanium in Sediments in the Yellow Sea and East China Sea[D].Qingdao:Ocean University of China,2007.
[26]Huh C A,Su C C.Sedimentation dynamics in the East China Sea elucidated from 210Pb,137Cs and 239,240Pu[J].Marine Geology,1999,160(1-2):183-196.
[27]Kim E,Noh S,Lee Y,et al.Mercury and methylmercury flux estimation and sediment distribution in an industrialized urban bay[J].Marine Chemistry,2014,158:59-68.
[28]Beldowski J,Miotk M,Pempkowiak J.Methylation index as means of quantification of the compliance of sedimentary mercury to be methylated[J].Environmental Monitoring and Assessment,2015,187(8):498.
[29]Zhu C,Xue B,Pan J,et al.The dispersal of sedimentary terrestrial organic matter in the East China Sea(ECS)as revealed by biomarkers and hydro-chemical characteristics[J].Organic Geochemistry,2008,39(8):952-957.
[30]Drevnick P E,Cooke C A,Barraza D,et al.Spatiotemporal patterns of mercury accumulation in lake sediments of western North America[J].Science of the Total Environment,2016,568:1157-1170.
[31]Amos H M,Jacob D J,Kocman D,et al.Global biogeochemical implications of mercury discharges from rivers and sediment burial[J].Environmental Science&Technology,2014,48(16):9514-9522.
[32]Fleck J A,Marvin-DiPasquale M,Eagles-Smith C A,et al.Mercury and methylmercury in aquatic sediment across western North America[J].Science of the Total Environment,2016,568:727-738.
[33]ivkovi'c I,Kotnik J,oli'c M,et al.The abundance,distribution and speciation of mercury in waters and sediments of the A-driatic Sea-a review[J].Acta Adriatica:International Journal of Marine Sciences,2017,58(1):165-186.
[34]Jin H,Liebezeit G,Ziehe D.Distribution of total mercury in surface sediments of the Western Jade Bay,Lower Saxonian Wadden Sea,Southern North Sea[J].Bulletin of Environmental Contamination and Toxicology,2012,88(4):597-604.
[35]Apeti D A,Lauenstein G G,Evans D W.Recent status of total mercury and methyl mercury in the coastal waters of the northern Gulf of Mexico using oysters and sediments from NOAA’s mussel watch program[J].Marine Pollution Bulletin,2012,64(11):2399-2408.
[36]Abi-Ghanem C,NakhléK,Khalaf G,et al.Mercury distribution and methylmercury mobility in the sediments of three sites on the Lebanese Coast,Eastern Mediterranean[J].Archives of Environmental Contamination and Toxicology,2011,60(3):394-405.
[37]Conaway C H,Watson E B,Flanders J R,et al.Mercury deposition in a tidal marsh of south San Francisco Bay downstream of the historic New Almaden mining district,California[J].Marine Chemistry,2004,90(1-4):175-184.
[38]Ouddane B,Mikac N,Cundy A B,et al.A comparative study of mercury distribution and methylation in mudflats from two macrotidal estuaries:The Seine(France)and the Medway(United Kingdom)[J].Applied Geochemistry,2008,23(4):618-631.
[39]Baldi F,Gallo M,Marchetto D,et al.Seasonal mercury transformation and surficial sediment detoxification by bacteria of Marano and Grado lagoons[J].Estuarine,Coastal and Shelf Science,2012,113:105-115.
[40]Ogrinc N,Monperrus M,Kotnik J,et al.Distribution of mercury and methylmercury in deep-sea surficial sediments of the Mediterranean Sea[J].Marine Chemistry,2007,107(1):31-48.
[41]Johannessen S C,Macdonald R W,Eek K M.Historical trends in mercury sedimentation and mixing in the Strait of Georgia,Canada[J].Environmental Science&Technology,2005,39(12):4361-4368.
[42]Sanders C J,Santos I R,Silva-Filho E V,et al.Mercury flux to estuarine sediments,derived from Pb-210and Cs-137geochronologies(Guaratuba Bay,Brazil)[J].Marine Pollution Bulletin,2006,52(9):1085-1089.
[43]祝惠,阎百兴,张丰松,等.松花江沉积物主要组分对汞吸附的贡献[J].环境化学,2010,29(5):865-869.Zhu H,Yan B X,Zhang F S,et al.Contribution of major sediment components in songhua river to mercury adsorption[J].Environmental Chemistry,2010,29(5):865-869.
[44]Asmund G,Nielsen S P.Mercury in dated Greenland marine sediments[J].Science of the Total Environment,2000,245(1-3):61-72.
[45]Hellal J,Guédron S,Huguet L,et al.Mercury mobilization and speciation linked to bacterial iron oxide and sulfate reduction:Acolumn study to mimic reactive transfer in an anoxic aquifer[J].Journal of Contaminant Hydrology,2015,180:56-68.
[46]Kerin E J,Gilmour C C,Roden E,et al.Mercury methylation by dissimilatory iron-reducing bacteria[J].Applied and Environmental Microbiology,2006,72(12):7919-7921.
[47]Ci Z,Zhang X,Yin Y,et al.Mercury redox chemistry in waters of the eastern Asian seas:from polluted coast to clean open ocean[J].Environmental Science&Technology,2016,50(5):2371-2380.
[48]Heiri O,Lotter A F,Lemcke G.Loss on ignition as a method for estimating organic and carbonate content in sediments:reproducibility and comparability of results[J].Journal of Paleolimnology,2001,25(1):101-110.
[49]Zhang R,Russell J,Xiao X,et al.Historical records,distributions and sources of mercury and zinc in sediments of East China sea:Implication from stable isotopic compositions[J].Chemosphere,2018,205:698-708.
[2]Huang M,Deng S,Dong H,et al.Impacts of atmospheric mercury deposition on human multimedia exposure:Projection from observations in the Pearl River Delta region,South China[J].Environmental Science&Technology,2016,50(19):10625-10634.
[3]Sakata M,Marumoto K,Narukawa M,et al.Mass balance and sources of mercury in Tokyo Bay[J].Journal of Oceanography,2006,62(6):767-775.
[4]Brett-Crowther M.Mercury in the environment:Pattern and process[M].California,USA:University of California Press,2012.
[5]孙阳昭,陈扬,刘俐媛,等.从水俣病事件透视日本汞污染防治管理的嬗变[J].环境保护,2013,41(9):35-37.Sun Y Z,Chen Y,Liu L Y,et al.Perspective from minamata disease events in Japan the change of the mercury pollution prevention management[J].The Environmental Protection,2013,41(9):35-37.
[6]覃东立,姜秋俚,付友生.全球汞污染回顾与分析[J].环境保护科学,2009,35(4):75-78.Tan D L,Jiang Q L,Fu Y S.The global mercury pollution review and analysis[J].Environmental Protectionscience,2009,35(4):75-78.
[7]Liu M,Chen L,Wang X,et al.Mercury export from mainland China to adjacent seas and its influence on the marine mercury balance[J].Environmental Science&Technology,2016,50(12):6224-6232.
[8]Wang C,Ci Z,Wang Z,et al.Air-sea exchange of gaseous mercury in the East China Sea[J].Environmental Pollution,2016,212:535-543.
[9]Buck C S,Hammerschmidt C R,Bowman K L,et al.Flux of total mercury and methylmercury to the Northern Gulf of Mexico from US Estuaries[J].Environmental Science&Technology,2015,49(24):13992-13999.
[10]Liu J P,Xu K H,Li A C,et al.Flux and fate of Yangtze River sediment delivered to the East China Sea[J].Geomorphology,2007,85(3-4):208-224.
[11]Schartup A T,Balcom P H,Mason R P.Sediment-porewater partitioning,total sulfur,and methylmercury production in estuaries[J].Environmental Science&Technology,2014,48(2):954-960.
[12]Warner K A,Roden E E,Bonzongo J C.Microbial mercury transformation in anoxic freshwater sediments under iron-reducing and other electron-accepting conditions[J].Environmental Science&Technology,2003,37(10):2159-2165.
[13]Xia C,Wu X,Lam J C W,et al.Methylmercury and trace elements in the marine fish from coasts of East China[J].Journal of Environmental Science and Health,Part A,2013,48(12):1491-1501.
[14]Huang Z,Pan X D,Han J L,et al.Determination of methylmercury in marine fish from coastal areas of Zhejiang,China[J].Food Additives and Contaminants:Part B,2012,5(3):182-187.
[15]Liu W,Hu L,Lin T,et al.Distribution and mass inventory of mercury in sediment from the Yangtze River estuarine-inner shelf of the East China Sea[J].Continental Shelf Research,2017,132:29-37.
[16]Meng M,Shi J,Yun Z,et al.Distribution of mercury in coastal marine sediments of China:Sources and transport[J].Marine Pollution Bulletin,2014,88(1-2):347-353.
[17]Fang T H,Chen R Y.Mercury contamination and accumulation in sediments of the East China Sea[J].Journal of Environmental Sciences,2010,22(8):1164-1170.
[18]Shi J B,Liang L N,Yuan C G,et al.Methylmercury and total mercury in sediments collected from the East China Sea[J].Bulletin of Environmental Contamination and Toxicology,2005,74(5):980-987.
[19]Duan L Q,Song J M,Yu Y,et al.Spatial variation,fractionation and sedimentary records of mercury in the East China Sea[J].Marine Pollution Bulletin,2015,101(1):434-441.
[20]Martin T D,Creed J T,Long S E.Sample Preparation Procedure for Spectrochimical Determination of Total Recoverable Elements[M].Methods for the Determination of Metals in Environmental Samples.Boca Raton:CK Smoley,1992:15-24.
[21]Pfeil D L,Stalvey D.Satisfying certification requirements of USEPA method 1631[J].American Laboratory,2004,36(12):11-16.
[22]Babu S H,Kumar K S,Suvardhan K,et al.Preconcentration technique for the determination of trace elements in natural water samples by ICP-AES[J].Environmental Monitoring and Assessment,2007,128(1-3):241-249.
[23]Li Y,Duan Z,Liu G,et al.Evaluation of the possible sources and controlling factors of toxic metals/metalloids in the Florida Everglades and their potential risk of exposure[J].Environmental Science&Technology,2015,49(16):9714-9723.
[24]刘育民,严蔚芸,窦贻俭,等.江苏沿海底质重金属背景值的调查[J].中国环境科学,1(2):60-67.Liu Y M,Yan W Y,Dou,D J,et al.Investigation on background value of heavy metals in coastal base of jiangsu province[J].China Environmental Science,1981(2):60-67.
[25]窦维伟.黄、东海沉积物中金属元素的地球化学组成及铝、钛的形态分布[D].青岛:中国海洋大学,2007.Dou W W,Biogeochemical Characteristics of Metal Elements and Speciation of Aluminum and Titanium in Sediments in the Yellow Sea and East China Sea[D].Qingdao:Ocean University of China,2007.
[26]Huh C A,Su C C.Sedimentation dynamics in the East China Sea elucidated from 210Pb,137Cs and 239,240Pu[J].Marine Geology,1999,160(1-2):183-196.
[27]Kim E,Noh S,Lee Y,et al.Mercury and methylmercury flux estimation and sediment distribution in an industrialized urban bay[J].Marine Chemistry,2014,158:59-68.
[28]Beldowski J,Miotk M,Pempkowiak J.Methylation index as means of quantification of the compliance of sedimentary mercury to be methylated[J].Environmental Monitoring and Assessment,2015,187(8):498.
[29]Zhu C,Xue B,Pan J,et al.The dispersal of sedimentary terrestrial organic matter in the East China Sea(ECS)as revealed by biomarkers and hydro-chemical characteristics[J].Organic Geochemistry,2008,39(8):952-957.
[30]Drevnick P E,Cooke C A,Barraza D,et al.Spatiotemporal patterns of mercury accumulation in lake sediments of western North America[J].Science of the Total Environment,2016,568:1157-1170.
[31]Amos H M,Jacob D J,Kocman D,et al.Global biogeochemical implications of mercury discharges from rivers and sediment burial[J].Environmental Science&Technology,2014,48(16):9514-9522.
[32]Fleck J A,Marvin-DiPasquale M,Eagles-Smith C A,et al.Mercury and methylmercury in aquatic sediment across western North America[J].Science of the Total Environment,2016,568:727-738.
[33]ivkovi'c I,Kotnik J,oli'c M,et al.The abundance,distribution and speciation of mercury in waters and sediments of the A-driatic Sea-a review[J].Acta Adriatica:International Journal of Marine Sciences,2017,58(1):165-186.
[34]Jin H,Liebezeit G,Ziehe D.Distribution of total mercury in surface sediments of the Western Jade Bay,Lower Saxonian Wadden Sea,Southern North Sea[J].Bulletin of Environmental Contamination and Toxicology,2012,88(4):597-604.
[35]Apeti D A,Lauenstein G G,Evans D W.Recent status of total mercury and methyl mercury in the coastal waters of the northern Gulf of Mexico using oysters and sediments from NOAA’s mussel watch program[J].Marine Pollution Bulletin,2012,64(11):2399-2408.
[36]Abi-Ghanem C,NakhléK,Khalaf G,et al.Mercury distribution and methylmercury mobility in the sediments of three sites on the Lebanese Coast,Eastern Mediterranean[J].Archives of Environmental Contamination and Toxicology,2011,60(3):394-405.
[37]Conaway C H,Watson E B,Flanders J R,et al.Mercury deposition in a tidal marsh of south San Francisco Bay downstream of the historic New Almaden mining district,California[J].Marine Chemistry,2004,90(1-4):175-184.
[38]Ouddane B,Mikac N,Cundy A B,et al.A comparative study of mercury distribution and methylation in mudflats from two macrotidal estuaries:The Seine(France)and the Medway(United Kingdom)[J].Applied Geochemistry,2008,23(4):618-631.
[39]Baldi F,Gallo M,Marchetto D,et al.Seasonal mercury transformation and surficial sediment detoxification by bacteria of Marano and Grado lagoons[J].Estuarine,Coastal and Shelf Science,2012,113:105-115.
[40]Ogrinc N,Monperrus M,Kotnik J,et al.Distribution of mercury and methylmercury in deep-sea surficial sediments of the Mediterranean Sea[J].Marine Chemistry,2007,107(1):31-48.
[41]Johannessen S C,Macdonald R W,Eek K M.Historical trends in mercury sedimentation and mixing in the Strait of Georgia,Canada[J].Environmental Science&Technology,2005,39(12):4361-4368.
[42]Sanders C J,Santos I R,Silva-Filho E V,et al.Mercury flux to estuarine sediments,derived from Pb-210and Cs-137geochronologies(Guaratuba Bay,Brazil)[J].Marine Pollution Bulletin,2006,52(9):1085-1089.
[43]祝惠,阎百兴,张丰松,等.松花江沉积物主要组分对汞吸附的贡献[J].环境化学,2010,29(5):865-869.Zhu H,Yan B X,Zhang F S,et al.Contribution of major sediment components in songhua river to mercury adsorption[J].Environmental Chemistry,2010,29(5):865-869.
[44]Asmund G,Nielsen S P.Mercury in dated Greenland marine sediments[J].Science of the Total Environment,2000,245(1-3):61-72.
[45]Hellal J,Guédron S,Huguet L,et al.Mercury mobilization and speciation linked to bacterial iron oxide and sulfate reduction:Acolumn study to mimic reactive transfer in an anoxic aquifer[J].Journal of Contaminant Hydrology,2015,180:56-68.
[46]Kerin E J,Gilmour C C,Roden E,et al.Mercury methylation by dissimilatory iron-reducing bacteria[J].Applied and Environmental Microbiology,2006,72(12):7919-7921.
[47]Ci Z,Zhang X,Yin Y,et al.Mercury redox chemistry in waters of the eastern Asian seas:from polluted coast to clean open ocean[J].Environmental Science&Technology,2016,50(5):2371-2380.
[48]Heiri O,Lotter A F,Lemcke G.Loss on ignition as a method for estimating organic and carbonate content in sediments:reproducibility and comparability of results[J].Journal of Paleolimnology,2001,25(1):101-110.
[49]Zhang R,Russell J,Xiao X,et al.Historical records,distributions and sources of mercury and zinc in sediments of East China sea:Implication from stable isotopic compositions[J].Chemosphere,2018,205:698-708.