七道湾污水厂污泥重金属形态特征研究

摘要

The selective sequential extraction method developed by Tessier was used to analyze the chemical speciation of heavy metals（Cu,Zn,Pb,Cd,） in sludge of Qidaowan Wastewater Treatment Plant in Urumqi,and the bioavailability of heavy metals was studied.The results showed that the concentration sequence of heavy metals in sludge samples is ZnCuPbCd,Which were all in the range of farming standards.Zn,Cu,and Pb existed mainly in the form of residues and organic.Cd existed mainly residues,iron-manganese oxidation forms and carbonate forms.The proportions of unavailable forms of Zn and Cu were more than 60%,which was advantageous for agricultural use of the sludge.The proportions of available forms and potential available forms of Pb and Cd were more than 50%,which presented potential risk for agricultural use of the sludge.%采用Tessier连续提取法对乌鲁木齐七道湾污水厂夏季和冬季污泥中的Cu、Zn、Pb、Cd进行了含量和形态分析,研究了污泥中重金属的生物有效性。结果表明：该污水厂污泥中重金属含量Zn〉Cu〉Pb〉Cd,4种重金属含量均低于污泥农用污染物控制标准限值。Cu、Zn、Pb主要以残渣态和有机结合态形式存在,Cd主要以残渣态、铁锰氧化态和碳酸盐结合态形式存在。Zn、Cu的生物不可利用态含量高,所占比例在60%以上,对污泥农用有利,Pb、Cd两种元素的生物有效态和潜在有效态之和所占比例在50%以上,有较强的生物可利用性,在污泥农用时存在一定潜在风险。