摘要
通过现场采样及室内分析,研究了江苏省43个城市污水处理厂污泥样品中6种重金属元素(Pb、Cd、Cr、Ni、Cu、Zn)的含量和形态。结果表明,不同污水处理厂的污泥样品中重金属元素的总量存在较大的差异,6种重金属元素平均含量的大小顺序为Zn>Cu>Cr>Ni>Pb>Cd;80%统计样本的Pb含量在120mg·kg-1以内,而Cd、Cr、Ni、Cu和Zn含量则分别在8.5、411、140、1410和1650mg·kg-1以内。对全省不同地区城市污泥重金属含量比较表明,苏南地区普遍高于苏中和苏北地区。用主成分分析法提取的3个主成分较好地反映了6个重金属指标的信息,累积贡献率为82.24%,第一主成分能解释接近50%的信息量,它主要反映了Cd、Ni、Cu的富集程度。连续提取方法对重金属分级表明,Pb和Cd主要以残余态为主,Cu和Cr主要以可氧化态和残余态形式存在,Ni和Zn的残余态含量较低而酸可提取态较高,有较大的释放潜力和生物有效性。
The total contents of heavy metals （Pb, Cd, Cr, Ni, Cu, Zn） and their fractions in sewage sludge that was collected from forty-three wastewater treatment plants in Jiangsu province were investigated by a sequential extraction. The results showed that the contents of heavy metals in sludge samples varied significantly. The average contents of heavy metals exhibited an order of Zn〉Cu〉Cr〉Ni〉Pb〉Cd. The concentrations of heavy metals in 80% of the statistical samples were found to be lower than 120 mg·kg^-1 for Pb, 8.5 mg·kg^-1 for Cd, 411 mg·kg^-1 for Cr, 140 mg·kg^-1 for Ni, 1 410 mg·kg^-1 for Cu, 1 650 mg·kg^-1 for Zn, respectively. As a whole, the heavy metal concentrations in sewage sludge in southern Jiangsu province were higher than that in central part and northern part. The extracted three principal components （PC1, PC2 and PC3, ranked by contribution） gave good expressions to the initial 6 variables. The cumulative proportion of the three principal components reached 82.24%. PC 1 represented nearly 50% information of initial variables and mainly accounted for the enrichment degree of Cd, Ni and Cu. The fractions obtained by the sequential extraction procedure indicated that Pb and Cd were dominantly associated with residual fraction. Cu and Cr were principally distributed in the oxidizable fraction and residual fraction. For Ni and Zn, the concentrations of acid extractable metals were high, indicating their relatively high bioavailability.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2007年第5期1982-1987,共6页
Journal of Agro-Environment Science
基金
江苏省建设厅科技重点项目(JS2004ZB05)
关键词
城市污泥
重金属
含量
主成分分析
形态分布
sewage sludge
heavy metal
concentration
principal component analysis
fraction
