中文摘要：

城市污泥中重金属污染日益得到关注,而重金属毒性/有效性的评价方法还没有统一的标准.本实验以南京市四个采用不同处理工艺的生活污水处理厂的脱水污泥为研究对象,利用梯度扩散薄膜技术（DGT）和化学连续提取法测定重金属（Ni、Cu、Zn、Cd、Pb、V、As、Mo、Sb和W）的含量,并分析两者所测浓度之间的相关性,探讨脱水污泥中重金属的有效性.实验结果表明,部分脱水污泥中Ni、As和Cd总量浓度超出农用泥质的行业标准,阴离子型重金属元素的生物可利用态（非专性吸附态NS1,专性吸附态SS2）所占比例普遍高于阳离子型重金属（可交换态EX1,碳酸盐结合态CB2）;Ni和Cu的EX1和EX1＋CB2、As的NS1和NS1＋SS2、Mo和Sb的SS2与相对应元素的DGT浓度具有显著的相关性.DGT技术有望应用于污泥中重金属的原位测定.

英文摘要：

Heavy metal contamination in municipal sewage sludge has attracted more and more attention,but no unified standard method exists to evaluate the toxicity/availability of heavy metals.In this study,diffusive gradients in thin-films technique（DGT）and sequential extraction procedure were applied to assess heavy metal（Ni,Cu,Zn,Cd,Pb,V,As,Mo,Sb and W）bioavailability in dewatered sewage sludge from four domestic sewage treatment plants in Nanjing,China.The results showed that the contents of Ni,As and Cd in some samples exceeded the allowed threshold values set by national/industrial standards for land use of sewage sludge.Results from the sequential extraction revealed that the bioavailable fraction of anionic metals（NS1＋SS2）were higher than that of cationic metals（EX1＋CB2）.Linear regression analysis be-tween DGT measured concentrations and fractions defined by sequential extractions indicated that the fraction of EX1 and EX1＋CB2for Ni and Cu,the fraction of NS1 and NS1＋SS2for As and the fraction of SS2 for Mo and Sb had a significant relationship with their concentrations measured by DGT.