铜和镉在淀山湖沉积物中的形态和传输研究  

Occurrence and Transportation of Copper and Cadmium in Dianshan Lake's Sediments

作　　者：石秀春[1] 庄云龙[1] 

机构地区：[1]上海大学环境与化学工程学院,上海200072

出　　处：《上海大学学报（自然科学版）》2002年第2期167-170,共4页Journal of Shanghai University:Natural Science Edition

摘　　要：根据 Tessier's连续化学提取法测定了淀山湖沉积物中微量金属铜和镉的赋存形态 ,研究了它们从水体向沉积物 /水体系静态柱传输特征 ,根据非稳态扩散模型 ,测量了两者的扩散速率常数 .研究表明 ,沉积物中铜和镉的含量都低于一般沉积物的质量基准 .镉主要以可交换态存在 ,但其总量较低 ,铜主要以残渣态存在 .在该湖条件下 ,沉积物中的重金属很难溶出 .Cu2 +和 Cd2 +在沉积物间隙水中浓度与深度的关系符合方程 C(x) =C+Ae Bx ,它们的扩散速率常数分别为 0 .0 7～ 30 .6 0、0 .6 2～ 9.81mg/ (m2· h) ,扩散系数分别为 4 .4 8× 10 - 6和 3.35× 10 - 6 cm2 /s: According to Tessier's sequential chemical extraction procedure, the occurrence of heavy metals(Cu and Cd) in the Dianshan Lake's sediments is determined. The static column transportation characteristics of heavy metals(Cu and Cd) from the overlying water into sediments/water system are studied. Their diffusion rate constants have been measured with an unstable state diffusion model. The research shows that concentrations of copper and cadmium are much less than the level of general sediments. Cadmium mainly exists in an exchangeable state. But the total amount of cadmium is much less. Copper mainly exists in a residual state. Under the lake condition, it is very difficult that the heavy metals in the sediments transport into overlying water. The relationship between the concentration C(x) and the depth x in the sediments accords with the model C(x)=C+A e Bx . Their diffusion rate constants range from 0.07 to 30.60 mg/(m 2·h) and from 0.62 to 9.81 mg/(m 2·h), respectively. Their diffusion coefficients are 4.48×10 -6 cm 2/s and 3.35×10 -6 cm 2/s, respectively.

关 键 词：铜 镉 淀山糊沉积物 重金属 传输特性 赋存形态 扩散速率常数 可交换态 残渣态 水体污染 

分 类 号：X131.2[环境科学与工程—环境科学]