采用添加量为100 kg/m3的固化剂对遭受重金属污染的淤泥进行固化试验,根据试验结果研究了原泥中重金属Cd,Cr,Cu,Ni,Pb和Zn的含量及固化处理前后重金属的赋存形态分布,并对原泥和固化淤泥进行了浸出毒性试验.试验结果表明:在淤泥固化处理过程中,重金属的赋存形态发生了改变,稳定态质量分数有了不同程度的增加;Cd,Cr,Cu,Ni和Zn得到很好的稳定化处理,5种重金属的浸出量、浸出率均有明显降低而且达到标准要求;固化剂对重金属的稳定化作用,除了通过改变重金属的赋存形态,促进重金属非稳定态向稳定态转变来实现外,还可以通过其他方式来实现.
The solidification tests on the sludge polluted by heavy metals were performed by adding curing agent of 100 kg/m3.On such a basis,the contents of heavy metals of Cd,Cr,Cu,Ni,Pb and Zn in the original sludge as well as their form distributions before and after solidification were studied.The hazardness leaching tests on the original sludge and the solidified sludge were carried out.The test results show that the forms of heavy metals change during the solidification of the sludge,and the stable mass percentages increase to some extent.The heavy metals of Cd,Cr,Cu,Ni and Zn are well stabilized,and their leaching amount and leaching ratio obviously decrease and meet the requirements.The stabilization effect of the curing agent on the heavy metals is realized by changing the form distribution of the heavy metals and further improving their transformation of unstable state into stable one,and it may be also realized by other ways.