大辽河水系表层沉积物中重金属的迁移特征及生物有效性研究  

Transport and Bioavailability of Cu,Pb,Zn and Ni in Surface Sediments of Daliao River Watersystem

作　　者：范英宏[1] 林春野[1] 何孟常[1] 杨志峰[1] 

机构地区：[1]北京师范大学环境学院、水环境模拟国家重点试验室、水沙科学教育部重点实验室,北京100875

出　　处：《环境科学》2008年第12期3469-3476,共8页Environmental Science

基　　金：国家重点基础研究发展规划(973)项目(2004CB418502);国家自然科学基金项目(40671002)

摘　　要：为了研究大辽河水系表层沉积物中重金属的迁移特征和生物有效性,采集了9个表层沉积物样品,测定了沉积物的理化性质、重金属Cu、Pb、Zn和Ni的总量及化学形态,并利用DGT方法和离心方法测定了沉积物孔隙水中Cu、Pb、Zn和Ni的浓度.结果表明,沉积物中Cu、Pb、Zn和Ni的总含量分别为16.8--49.2、12.9--55.8、38.7--152.8和18.1--39.0 mg/kg;DGT测定的孔隙水中重金属的浓度c（DGT）与离心方法测定的孔隙水中重金属浓度的比值低于0.5,表明沉积物中重金属从固相到液相的再补给能力和生物有效性比较低.相关分析表明,碳酸盐结合态Cu对DGT测定的Cu的浓度c（DGT）的贡献较大（r=0.633,p〈0.05）;对于Pb,可交换态含量对c（DGT）的贡献较大（r=0.617,p〈0.05）;而对于Ni,可交换态、锰氧化物结合态、有机质结合态和铁氧化物结合态对c（DGT）浓度的贡献都比较大（r〉0.650,p〈0.05）.此外,pH也是影响重金属元素从固相到液相的释放重要因素.To understand the transport and bioavailability of heavy metals in the surface sediment of Daliao River system, nine samples of surface sediment were collected. Clay content, pH, and Eh of these sediment samples were measured. Total contents and chemical speciation of Cu, Pb, Zn and Ni in the sediment were determined. In addition, the concentrations of Cu, Pb, Zn and Ni in the pore water of the sediment were determined separately by DGT （diffusive gradient in thin film） method and traditional centrifuge method. The total contents of Cu, Pb, Zn and Ni in the sediment were 16.8-49.2, 12.9-55.8, 38.7-152.8 and 18.1-39.0 mg/kg, respectively. The ratios of DGT measured concentrations c （DGT） to heavy metal concentrations in pore water were lower than 0.5, showing lower replenishment of these metals from solid to the liquid and lower bioavailability of the metals in the sediments. Correlation analysis showed that c （DGT） of Cu was significantly influenced by Cu in the carbonate ＇fraction （ r = 0. 633, p 〈 0.05）, while c （DGT） of Pb was influenced by Pb in the exchangeable fraction （ r = 0.617, p 〈 0.05）. Ni in the exchangeable, Mn oxides, organic matter （OM） and Fe oxides fractions may contribute to the c （DGT） of Ni （ r 〉 0.650, p 〈 0.05 ）. In addition, pH was also an important factor influencing the release of heavy metals from solid to liquid in sediments.

关 键 词：重金属 DGT 化学形态 生物有效性 沉积物 

分 类 号：X522[环境科学与工程—环境工程]