白云石和硫酸亚铁复配对城市污泥中重金属形态分布及生物有效性的影响  

Effect of dolomite-ferrous sulfate complex on speciation distribution and bioavailability of heavy metals in municipal sludge

作　　者：陶祥运 李磊明 刘小红 司友斌 

机构地区：[1]安徽农业大学资源与环境学院,农田生态保育与污染防控安徽省重点实验室,合肥230036

出　　处：《环境工程学报》2018年第2期654-662,共9页Chinese Journal of Environmental Engineering

基　　金：公益性行业(农业)科研专项(201303101-06); 国家科技支撑计划项目(2015BAD05B04-02)

摘　　要：以合肥市某污水处理厂污泥为研究对象,研究白云石、硫酸亚铁以及白云石和硫酸亚铁复合物作为改良剂对污泥重金属形态和生物有效性的影响,并对其钝化机理进行了初步研究。结果表明:白云石可以提高污泥pH,硫酸亚铁则降低污泥的pH,白云石和硫酸亚铁复配添加时,污泥pH变化并不显著。白云石对污泥中Cu和Cd有较好钝化作用,硫酸亚铁对污泥中As具有显著钝化作用,白云石和铁盐复配对污泥中重金属Cu、Zn、Cd和As均有显著钝化作用。白云石和硫酸亚铁处理可显著降低污泥中重金属有效态含量,其中以5%白云石和5%硫酸亚铁复配处理的效果最好,与对照相比,污泥中的有效Cu、Zn、Cd和As分别减少了59.58%、42.26%、40.93%和55.68%。SEM-EDS和Visual MINTEQ模拟结果显示,白云石中的碳酸根离子能够与重金属发生沉淀反应。盆栽实验结果显示,污泥中加入白云石和硫酸亚铁后,青菜地上部和根部重金属含量降低,地上部Cu、Zn、Cd和As最大降低程度分别为53.56%、34.51%、57.29和77.04%。The treatment methods for the sludge from Hefei municipal wastewater treatment plant were studied,and the effects of three amendments dolomite,ferrous sulfate and dolomite-ferrous sulfate complex on the speciation distribution and bioavailability of heavy metals in the sludge were investigated,besides,a preliminary study on the mechanism of passivation were also investigated.The results showed that the addition of dolomite could raise the p H value of sludge,however,ferrous sulfate could reduce the sludge p H.When the dolomite-ferrous sulfate complex were added,the change of sludge p H was not significant.Dolomite has a better passivation effect on Cu and Cd in sludge,however,ferrous sulfate has a significant passivation effect on As in sludge.Dolomiteferrous sulfate complex had the significant passivation effect on heavy metals of Cu,Zn,Cd and As in the sludge.Dolomite-ferrous sulfate complex could significantly reduce the available state content of heavy metals in the sludge,5% dolomite and 5% ferrous sulfate complex treatment gave the best result.Compared with the control,the available contents of Cu,Zn and As decreased 59.58%,42.26%,40.93% and 55.68%,respectively.SEM-EDS and Visual MINTEQ simulation results showed that the carbonate ions in the dolomite can react with the heavy metal to form a precipitate.The results of pot experiments showed that the accumulation of heavy metals in the upper part and the roots of Brassica chinensis L.was greatly reduced by dolomite and ferrous sulfate amendments to the sludge.The contents of Cu,Zn,Cd and As in the upper part had the maximum reduction rates of 53.56%,34.51%,57.29,77.04%,respectively.

关 键 词：城市污泥 白云石 硫酸亚铁 重金属形态 生物有效性 

分 类 号：X703[环境科学与工程—环境工程]