矿渣基改性剂对城市污泥重金属稳定化

以城市生活污泥为研究对象,采用矿渣基改性剂在不同投加量和养护时间条件下对其改性,并通过重金属的稳定效率及形态变化分析和评价污泥中Cr、Cu、Zn、Pb、As和Cd等重金属的固化效果.结果表明:随养护时间或投加量的增加,重金属稳定效率不断提升,在养护14 d后,改性剂的投加量为50％时达到最大,其中Cu最高为69.62％...

Stabilization of Heavy Metals in Municipal Sludge Using a Slag-Based Modifying Agent

Taking urban domestic sludge as the research object, a slag-based modifying agent was used to modify sludge under different dosages and curing times, and the solidification effect of six heavy metals in the sludge, namely Zn, Cr, Cu, Pb, As, and Cd, were evaluated by analyzing stability efficiency and morphological changes. The results showed that the stability efficiency improved as curing time and dosage increased, reaching the maximum when the curing time was 14 d and the dosage was 50%. Under these conditions, Cu reached the maximum of 69.62%, and the most rapid growth was observed when dosages were 5%-20%. Through the regression analysis of adding amount, maintenance time and stability efficiency, it was found that the fitting correlation coefficient Cu was the highest 0.97, with a strong degree of fitting and a strong interaction between adding amount and maintenance time, which had a significant influence on the stability efficiency. In addition, Pb and As were the residual state, Cu and Cr were oxidizable state and residue state, Zn and Cd were reducible and extractable state as the main forms in the sludge after modifying, respectively. With the increase of curing time or dosage, the residual state of each heavy metal increased by 7%-86%. The results showed that the slag-based modifying agent could effectively solidify heavy metals in sludge and reused solid wastes such as sludge.