珠江三角洲海陆交互相沉积物中镉生物有效性与生态风险评价  

Bioavailability and Ecological Risk Assessment of Cadmium in the Sea-Land Interaction Sediments of the Pearl River Delta

作　　者：王芳婷 包科 陈植华[1] 黄长生[3] 张彩香[1] 赵信文[3] 刘学浩[3] WANG Fang-ting;BAO Ke;CHEN Zhi-hua;HUANG Chang-sheng;ZHANG Cai-xiang;ZHAO Xin-wen;LIU Xue-hao(School of Environmental Studies,China University of Geosciences,Wuhan 430074,China;Safety Center for River and Lake Protection,Construction and Operation,Changjiang Water Resources Commission of the Ministry of Water Resources,Wuhan 430015,China;Wuhan Geological Survey Center,China Geological Survey,Wuhan 430205,China)

机构地区：[1]中国地质大学(武汉)环境学院,武汉430074 [2]长江水利委员会河湖保护与建设运行安全中心,武汉430015 [3]中国地质调查局武汉地质调查中心,武汉430205

出　　处：《环境科学》2021年第2期653-662,共10页Environmental Science

基　　金：国家重点研发计划项目(2018YFC1800800);中国地质调查局武汉地质调查中心广州多要素城市地质调查项目(DD20190291)。

摘　　要：镉(Cd)污染对人类健康构成威胁,开展Cd生物有效性研究及生态风险评价,有助于防治和减轻Cd的危害.通过分析海陆交互相土壤中的Cd含量及形态,揭示了土壤Cd的富集特征及变化规律,通过累积指数法(I_(geo))、潜在生态危害指数法(Er)和风险评估编码法(RAC),对Cd的环境生态风险进行了评价.结果表明:①杂填土中Cd含量通常低于0.3mg·kg^(-1),素填土中Cd含量通常高于0.3mg·kg^(-1),海相沉积物Cd平均含量为0.36mg·kg^(-1),5 m以浅海相沉积物中Cd含量通常比5 m以深更高,陆相沉积物中Cd含量显著低于海相沉积物,Cd平均含量为0.10 mg·kg^(-1);②人工填土层(Q4ml)土壤Cd与CEC存在中度相关,相关系数为0.52(P<0.05),海相沉积物Cd含量与有机质含量存在低度相关,相关系数为0.49(P<0.05),镉全量及土壤理化性质均对土壤镉的形态分布的影响显著;③人工填土层和海相沉积物土壤地质累积指数以1<I_(geo)<2为主,均属于中度污染,人工填土层和海相沉积物土壤潜在生态危害指数以80<Er<160为主,存在较高潜在生态危害,各钻孔土壤酸可提取态Cd在总Cd中所占的比例均值均大于50%,普遍存在极高潜在生态风险.这些结果将为环境和农业决策提供良好的依据,为土壤污染调查和修复提供理论指导.Cadmium(Cd)pollution poses a threat to human health,and research on Cd bioavailability as well as its ecological risk assessment can help prevent and mitigate Cd hazards.The enrichment characteristics and variability of Cd were investigated in sea-land interaction soil fractions and the associated environmental and ecological risks were evaluated using the accumulation index(I_(geo)),potential ecological hazard index(Er),and risk assessment coding(RAC).The results showed that:①The Cd content of miscellaneous fill material was typically lower than 0.3 mg·kg^(-1) and that of plain full was higher than 0.3 mg·kg^(-1).The Cd content of marine sediment was significantly higher than that of continental sediments,averaging 0.36 and 0.10 mg·kg^(-1),respectively.The concentration of Cd in marine sediments buried at shallow depths(<5 m)was generally higher than at greater depths(>5 m).②There was a moderate correlation between Cd and CEC in artificial fill(Q4ml;correlation coefficient=0.52,P<0.05).There was a weak correlation between Cd and organic matter in the marine sediments(correlation coefficient=0.49,P<0.05).Total cadmium and the physical and chemical properties of soil had a significant influence on the fraction of soil cadmium.③The I_(geo) of artificially fill and marine sediment was dominated by the relationship 1<I_(geo)<2,which indicated a moderate level of pollution.The Er of artificial fill and marine sediment was mainly 80<Er<160,indicating a high potential ecological hazard.Soil acid-extractable Cd accounted for more than 50%of the total Cd in each drill hole,which generally indicated a very high potential ecological risk.These results provide a basis for environmental and agricultural decision-making and provide theoretical guidance for soil pollution investigations and remediation.

关 键 词：土壤镉 影响因素 CD形态 生态风险评价 广州南沙 

分 类 号：X171.5[环境科学与工程—环境科学]