湛江东海岛红树林湿地表层土壤重金属空间分布特征及生态风险评价
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摘要
近年来随着沿海地区工农业的迅速发展,大量污染物汇集于河口与海湾区,使得红树林湿地重金属污染也日趋严重。为探究东海岛红树林湿地表层(0~15 cm)土壤重金属污染现状,于2017年6月沿东海岛海岸线典型红树林分布区布设了7个站位(由东南向西北方向依次为YC、SYC、JJC、XWC、TMHHK、DCMT和DTSD)进行采样,测定样品中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn 8种重金属元素质量分数并分析其空间分布特征,采用潜在生态危害指数进行污染及潜在生态风险评价,结合相关性分析和主成分分析方法探讨其重金属来源。结果表明,(1)东海岛红树林湿地表层土壤8种重金属的质量分数平均值均超过雷州半岛土壤环境背景值,但未超过国家土壤环境质量一级标准限值。(2)单因子污染指数显示,东海岛红树林湿地表层土壤各重金属元素总体上到达中等污染程度。(3)潜在生态风险评价结果显示,东海岛红树林湿地表层土壤重金属污染总体上属于中等潜在生态风险;其中Hg潜在生态风险参数最高,平均值为105.524,属于强潜在生态风险,其余7种重金属元素均属于轻微潜在生态风险。(4)从潜在生态风险空间分布特征看,东海岛红树林表层土壤重金属空间差异较明显,其中XWC站位的潜在生态风险指数为351.690,为强潜在生态风险(主要来自Hg、Cd和As污染),YC、TMHHK、DCMT和DTSD 4个站位为中等潜在生态风险,SYC和JJC表现为轻微潜在生态风险。(5)统计分析结果表明,东海岛红树林湿地表层土壤中As、Cr、Cu、Ni、Pb和Zn这6种重金属元素之间具有强相关性,结合实地调查结果推测其来源主要与水产养殖排污及农业面源污染有关;而Cd和Hg之间的相关性不明显,推测其来源分别与船舶污染和生活排污有关。
With the rapid development of agriculture and industry in coastal areas in recent years, heavy metal pollution of mangrove wetlands is becoming more serious due to the large amount of pollutants collected in estuaries and bay areas. In order to research the pollution features of heavy metals in the surface soil(0~15 cm) of the mangrove wetland in Donghai Island, 7 stations(YC, SYC, JJC, XWC, TMHHK, DCMT and DTSD in turn, from Southeast to Northwest) were designed along the island coastline in typical mangrove areas and soils samples were collected in June 2017. The mass fraction of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn was determined, and their spatial distribution characteristics were analyzed. The potential ecological risk index was used for pollution assessment, and the sources of heavy metals were discussed by the correlation analysis and principal component analysis. The results were as follows:(1) The average mass fraction of 8 heavy metals in the surface soil of Donghai Island exceeded the environment background value, but did not exceed the first level of National Soil Environment Quality Standard.(2) The single factor pollution index showed that the heavy metal elements of the surface soil of the mangrove wetlands in the Donghai Island were generally moderately polluted.(3) The potential ecological risk assessment indicated that heavy metals pollution in the surface soil of the mangrove wetland in Donghai Island reached medium level in general. Among them, Hg owned the highest value of potential ecological risk with an average of 105.524, reaching strong potential ecological risk, while slight potential ecological risk for the others.(4) The spatial distribution characteristics of potential ecological risk assessment suggested obviously spatial differentiation of heavy metals in the surface soil of the mangrove wetland in Donghai Island. The potential ecological risk index of the XWC station was 351.690, which was a strong potential ecological risk(mainly from Hg, Cd and As pollution). The 4 stations of YC, TMHHK, DCMT and DTSD were medium potential ecological risk, while the SYC and JJC stations were slight.(5) The statistical analysis results showed that there were strong correlations among heavy metals such as As, Cr, Cu, Ni, Pb and Zn in the surface soil of Donghai island mangrove wetland. Combined with the results of field survey, it was concluded that the source of the heavy metals was mainly related to the pollutant from aquaculture industry and agricultural non-point source pollution. While the correlation between Cd and Hg and other elements was not obvious, it was speculated that their sources were in turn related to vessel pollution and domestic waste discharge.
With the rapid development of agriculture and industry in coastal areas in recent years, heavy metal pollution of mangrove wetlands is becoming more serious due to the large amount of pollutants collected in estuaries and bay areas. In order to research the pollution features of heavy metals in the surface soil(0~15 cm) of the mangrove wetland in Donghai Island, 7 stations(YC, SYC, JJC, XWC, TMHHK, DCMT and DTSD in turn, from Southeast to Northwest) were designed along the island coastline in typical mangrove areas and soils samples were collected in June 2017. The mass fraction of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn was determined, and their spatial distribution characteristics were analyzed. The potential ecological risk index was used for pollution assessment, and the sources of heavy metals were discussed by the correlation analysis and principal component analysis. The results were as follows:(1) The average mass fraction of 8 heavy metals in the surface soil of Donghai Island exceeded the environment background value, but did not exceed the first level of National Soil Environment Quality Standard.(2) The single factor pollution index showed that the heavy metal elements of the surface soil of the mangrove wetlands in the Donghai Island were generally moderately polluted.(3) The potential ecological risk assessment indicated that heavy metals pollution in the surface soil of the mangrove wetland in Donghai Island reached medium level in general. Among them, Hg owned the highest value of potential ecological risk with an average of 105.524, reaching strong potential ecological risk, while slight potential ecological risk for the others.(4) The spatial distribution characteristics of potential ecological risk assessment suggested obviously spatial differentiation of heavy metals in the surface soil of the mangrove wetland in Donghai Island. The potential ecological risk index of the XWC station was 351.690, which was a strong potential ecological risk(mainly from Hg, Cd and As pollution). The 4 stations of YC, TMHHK, DCMT and DTSD were medium potential ecological risk, while the SYC and JJC stations were slight.(5) The statistical analysis results showed that there were strong correlations among heavy metals such as As, Cr, Cu, Ni, Pb and Zn in the surface soil of Donghai island mangrove wetland. Combined with the results of field survey, it was concluded that the source of the heavy metals was mainly related to the pollutant from aquaculture industry and agricultural non-point source pollution. While the correlation between Cd and Hg and other elements was not obvious, it was speculated that their sources were in turn related to vessel pollution and domestic waste discharge.
引文
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陈碧珊,苏文华,罗松英,等.2017.湛江特呈岛红树林湿地土壤重金属含量特征及污染评价[J].生态环境学报,26(1):159-165.
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李晓敏.2008.东海岛土地利用变化及影响因素分析[D].呼和浩特:内蒙古师范大学:2.
李玉,俞志明,宋秀贤.2006.运用主成分分析(PCA)评价海洋沉积物中重金属污染来源[J].环境科学,27(1):137-141.
刘芳文,颜文,苗莉.2015.湛江港海域海水和表层沉积物重金属分布特征及其污染评价[J].海洋技术学报,34(2):74-82.
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刘景春.2006.福建红树林湿地沉积物重金属的环境地球化学研究[D].厦门:厦门大学.
冉延平.2012.城市表层土壤重金属污染多元统计分析和污染评价[J].安徽农业科学,40(9):5454-5458.
邵学新,吴明,蒋科毅.2007.土壤重金属污染来及其解析研究进展[J].广东微量元素科学,14(4):1-6.
孙钦帮,张冲,乌立国,等.2017.广东红海湾表层沉积物重金属含量的空间分布特征与污染状况评价[J].生态环境学报,26(5):843-849.
王中丙.2013.湛江年鉴[M].广东:南方出版传媒广东人民出版社.
徐争启,倪师军,庹先国,等.2008.潜在生态危害指数法评价中重金属毒性系数计算[J].环境科学与技术,31(2):112-115.
许炼烽,刘腾辉.1996.广东土壤环境背景值和临界含量的地带性分异[J].华南农业大学学报,17(4):58-62.
姚晓飞,周岩梅,于晓华,等.2011.南沙河表层沉积物重金属污染评价及来源解析[J].环境科学与技术,34(12):197-200.
银燕春,王莉淋,肖鸿,等.2015.成都市区、城郊和农村生活垃圾重金属污染特性及来源[J].环境工程学报,9(1):392-400.
赵秀峰,王强盛,石宁宁,等.2010.石化园区周边农田土壤重金属污染分析与评价[J].环境科学学报,30(1):133-141.
朱小丹.2016.广东年鉴[M].广东:广东年鉴社:27.
LI R G,LI R L,CHAI M W.2015.Heavy metal contamination and ecological risk in Futian mangrove forest sediment in Shenzhen Bay,South China[J].Marine Pollution Bulletin,101(1):448-456.
LIU J J,WU H,FENG J X,et al.2014.Heavy metal contamination and ecological risk assessments in the sediments and zoobenthos of selected mangrove ecosystems,South China[J].Catena,119:136-142.
MIOLA B,MORAIS J O,PINHEIRO L S.2016.Trace metal concentrations in tropical mangrove sediments,NE Brazil[J].Marine Pollution Bulletin,102(1):206-209.
NATH B,BIRCH G,CHAUDHURI P.2013.Trace metal biogeochemistry in mangrove ecosystems:a comparative assessment of acidified(by acid sulfate soils)and non-acidified sites[J].Science of the Total Environment,463-464:667-674.
SANDILYAN S,KATHIRESAN K.2014.Decline of mangroves--a threat of heavy metal poisoning in Asia[J].Ocean Coast.Manag,102(Part A):161-168.
蔡龙炎.2010.基于主成分分析法的泉州湾表层沉积物中重金属污染可能来源分析[J].台湾海峡,29(3):325-329.
陈碧珊,苏文华,罗松英,等.2017.湛江特呈岛红树林湿地土壤重金属含量特征及污染评价[J].生态环境学报,26(1):159-165.
陈守莉,王平祖,秦明周,等.2007.太湖流域典型湖泊沉积物中重金属污染的分布特征[J].江苏农业学报,23(2):124-130.
陈则实.1999.中国海湾志第十分册(广东省西部海湾)[M].北京:海洋出版社.
程皓,陈桂珠,叶志鸿.2009.红树林重金属污染生态学研究进展[J].生态学报,29(7):3893-3899.
戴纪翠,倪晋仁.2009.红树林湿地环境污染地球化学的研究评述[J].海洋环境科学,28(6):779-784.
邓利,张慧敏,劳大荣,等.2014.福田红树林自然保护区沉积物重金属污染现状及生态风险评价[J].海洋环境科学,33(6):948-953.
郭菊兰,朱耀军,武高洁.2013.海南清澜港红树林湿地沉积物环境质量评价[J].林业资源管理,41(6):121-126.
韩卓汝,赵志忠,袁建平,等.2013.海南岛北部红树林湿地表层沉积物重金属元素分布相关性特征及其污染源分析[J].海南师范大学学报(自然科学版),26(1):66-70.
黄建国.2007.福建主要滨海湿地生态系统重金属污染特征及评价[D].福州:福州农林大学:4.
雷凌明,喻大松,陈玉鹏,等.2014.陕西泾惠渠灌区土壤重金属空间分布特征及来源[J].农业工程学报,30(6):88-96.
李柳强,丁振华,刘金玲,等.2008.中国主要红树林表层沉积物中重金属的分布特征及其影响因素[J].海洋学报,30(5):159-164.
李瑞利,柴民伟,邱国玉,等.2012.近50年来深圳湾红树林湿地Hg、Cu累积及其生态危害评价[J].环境科学,33(12):4276-4283.
李晓敏.2008.东海岛土地利用变化及影响因素分析[D].呼和浩特:内蒙古师范大学:2.
李玉,俞志明,宋秀贤.2006.运用主成分分析(PCA)评价海洋沉积物中重金属污染来源[J].环境科学,27(1):137-141.
刘芳文,颜文,苗莉.2015.湛江港海域海水和表层沉积物重金属分布特征及其污染评价[J].海洋技术学报,34(2):74-82.
刘加飞.2013.东海岛潮间带表层沉积物重金属含量、形态分布及其潜在生态风险评价[D].湛江:广东海洋大学.
刘景春.2006.福建红树林湿地沉积物重金属的环境地球化学研究[D].厦门:厦门大学.
冉延平.2012.城市表层土壤重金属污染多元统计分析和污染评价[J].安徽农业科学,40(9):5454-5458.
邵学新,吴明,蒋科毅.2007.土壤重金属污染来及其解析研究进展[J].广东微量元素科学,14(4):1-6.
孙钦帮,张冲,乌立国,等.2017.广东红海湾表层沉积物重金属含量的空间分布特征与污染状况评价[J].生态环境学报,26(5):843-849.
王中丙.2013.湛江年鉴[M].广东:南方出版传媒广东人民出版社.
徐争启,倪师军,庹先国,等.2008.潜在生态危害指数法评价中重金属毒性系数计算[J].环境科学与技术,31(2):112-115.
许炼烽,刘腾辉.1996.广东土壤环境背景值和临界含量的地带性分异[J].华南农业大学学报,17(4):58-62.
姚晓飞,周岩梅,于晓华,等.2011.南沙河表层沉积物重金属污染评价及来源解析[J].环境科学与技术,34(12):197-200.
银燕春,王莉淋,肖鸿,等.2015.成都市区、城郊和农村生活垃圾重金属污染特性及来源[J].环境工程学报,9(1):392-400.
赵秀峰,王强盛,石宁宁,等.2010.石化园区周边农田土壤重金属污染分析与评价[J].环境科学学报,30(1):133-141.
朱小丹.2016.广东年鉴[M].广东:广东年鉴社:27.