大坦沙污水厂污泥重金属形态及其生物有效性的研究

Chemical Forms and Bioavailability of Heavy Metals in the Sludge of Datansha Wastewater Treatment Plant

采用Tessier连续提取法对大坦沙污水厂污泥中的Cu、Zn、Pb、Cd、Cr、Ni进行形态及总量分析,同时采用盆栽试验,研究了污泥中重金属的生物有效性。结果表明,污泥中Cu、Zn、Pb、Cd、Cr、Ni的含量均低于污泥农用控制标准值;Pb、Cd主要以残渣态和可交换态存在,Cu、Zn、Cr、Ni主要存在形式为有机结合态和残渣态;Zn、Pb、Cd、Cr的不可利用态所占比例均在50%以上,这对污泥农用是非常有利的。盆栽植物的根部对重金属的富集作用大于茎叶,其吸收的重金属不仅包括可交换态和碳酸盐结合态,还包括了在一定条件下释放出来的铁锰氧化态和有机结合态。

The selective sequential extraction procedures developed by Tcssier was used to study the chemical forms of heavy metals （Cu, Zn, Pb, Cd, Cr and Ni）in municipal sludge, and the bioavailability of heavy metals was studied by pot experiment. The experiment result showed the total contents of Cu, Zn, Pb, Cd, Cr and Ni were all in the range of farming standards. Pb and Cd mostly existed in residual and exchangeable forms. Cu, Zn, Cr and Ni existed mainly in the form of organometallic compounds and residues. The proportions of unavailable forms of Zn, Pb, Cd and Cr were more than 50%, which was very advantageous for agricultural use of the sludge. The root of potted plant can enrich more heavy metals than stem and leaf. The heavy metals absorbed by potted plant included not only exchangeable and carbonate forms, but also iron-manganese oxidation state and organic forms which can be released under certain conditions