氨基膨润土对铜镍镉污染土壤的钝化修复研究

采集土壤,加入铜、镍和镉制成重金属污染土壤。以四乙烯五胺改性膨润土和膨润土原土作为修复剂,通过模拟酸雨和混合提取剂提取有效态重金属,评价膨润土和氨基膨润土对土壤中铜、镍、镉的钝化效果。结果表明:p H=3. 5的模拟酸雨对各污染土壤中重金属离子的提取率均在0. 1%以下。混合提取剂对污染土壤中有效态金属的提取能力比模拟酸雨强很多。添加膨润土原土和氨基膨润土均能钝化土壤中的铜、镍和镉,氨基膨润土上嫁接的氨基对金属有络合作用,因而比膨润土原土对铜、镍和镉具有更强的钝化能力。综合评价表明氨基膨润土是一种对铜、镍和镉污染土壤具有应用前景的钝化修复材料。

A study of passivation for copper, nickel and cadmium in soil by amino-bentonite

In this study, the heavy metal contaminated soils were prepared by adding a certain amount of copper, nickel and cadmium salts. The bentonite and tetraethylenepentamine modified bentonite (amino-bentonite) were added to the prepared soils as repair agents, and then available heavy metals were extracted by simulated acid rain and mixed extractant. The extraction rate of heavy metals in each contaminated soil was below 0.1% by simulated acid rain with pH of 3.5. The extraction capability of the mixed extractant for the available heavy metals in the contaminated soil was much stronger than that of the simulated acid rain. Adding bentonite and amino-bentonite could passivate copper, nickel and cadmium in soils. The amino-bentonite had stronger passivation capability for copper, nickel and cadmium than bentonite, because there was complexation between the grafted amino group on the amino-bentonite and the metals. The comprehensive evaluation shows that amino-bentonite is a passivation material with application prospects for copper, nickel and cadmium contaminated soils.