6种固化剂对土壤Pb Cd Cu Zn的固化效果

通过在重金属污染土壤中分别施加沸石、石灰石、硅藻土、羟基磷灰石、膨润土和海泡石6种固化剂,研究了这6种固化剂对土壤中Pb、Cd、Cu、Zn的固化效果,筛选出几种效果较好的固化剂。实验结果表明：沸石、石灰石和羟基磷灰石均能够有效地降低土壤中交换态Pb、Cd的含量,并且明显减少了土壤中Pb、Cd的毒性浸出量,其中沸石最多降低土壤中交换态Pb、Cd含量分别达到48.7%和56.2%,减少土壤中Pb、Cd的毒性浸出量达到37.1%和30.1%;沸石、石灰石均能够有效降低土壤中交换态Cu的含量,降低量分别高达68.1%和85.2%,膨润土能有效减少土壤中Cu的毒性浸出量,减少量最高达到66.51%;石灰石对土壤中Zn有着良好的固化效果。

Effects of Six Kinds of Curing Agents on Lead, Cadmium, Copper, Zinc Stabilization in the Tested Soil

The stabilization of Pb, Cd, Cu, Zn in heavy metals contaminated soil was studied by using six kinds of curing agents, namely, zeo- lite, limestone, diatomite, hydroxyl-apatite, bentonite and sepiolite, and some effective curing agents were picked out. The main results of the experiments were as follows：zeolite, limestone, hydroxyl-apatite could effectively reduce exchangeable contents and leaching solution con- tents of Pb and Cd in the soil. Zeolite showed the best effects on reducing exchangeable soil Pb and Cd by 48.7% and 56.2%, and on reducing leaching solution contents of Pb and Cd by 37.1% and 30.1%, respectively. Among six kinds of curing agents, zeolite had the best effects on Pb stabilization, limestone had the best effects on Cd stabilization in the soil. Zeolite and limestone could reduce exchangeable Cu effectively in the soil, and the reduction reached 68.1% and 85.2%. Bentonite could reduce leaching solution contents of Cu effectively and the reduc- tion reached 66.5%. Using limestone and bentonite at the same time would be more effective on Cu stabilization than using one of them. Limestone had the best effects on Zn stabilization in the soil, the reduction of exchangeable contents and leaching solution contents reached 90.9% and 60.1%.