添加方式对不同固化剂稳定土壤重金属的影响

Effects of different applications of soil remediation agents on heavy-metal stabilization in contaminated soil

以石灰、膨润土、沸石、骨粉、硫化钠、硫酸亚铁为固化材料,分别在最佳添加量下以不同添加方式(固-固、固-液和液-液)对重金属污染土壤进行稳定化修复,研究不同添加方式对固化剂稳定化修复土壤重金属的效果。结果表明:固化剂的添加方式会对土壤重金属的稳定化作用效果产生不同程度的影响,其中以液-液方式添加的石灰对潼关和凤县土壤中Cd稳定化效果最好,土壤中有效态Cd含量分别减少87.9%和70.8%;以固-液方式添加的膨润土对潼关和骨粉对凤县土壤中Pb的稳定化效果最好,重金属残渣态的比例分别增加了59.0%和56.3%;硫酸亚铁以固-液、液-液的添加方式分别对潼关和凤县土壤中Zn稳定化效果最优,有效态Zn含量减少87.2%和84.3%。

In this study,lime,bentonite,zeolite,bone powder,sodium sulfide,and ferrous sulfate were used to immobilize heavy metals in contaminated soil using different methods and at optimal application rates.The results revealed the following:lime had the greatest effect on Cd immobilization,bentonite and bone powder optimized Pb immobilization,and ferrous sulfate had the greatest effects on Zn immobilization in Tongguan and Feng County soils.However,the degrees of soil heavy metal immobilization differed according to the form of the remediation agents.Lime in liquid-liquid form had the greatest effect on Cd immobilization in both Tongguan and Feng County soils;the content of available Cd reduced by 87.9%and 70.8%,respectively.Bentonite and bone powder in a solid-liquid form had sound effects on Pb stabilization in both soils.Metals in the residual state increased by 59.0%and 56.3%for Tongguan and Feng County soils,respectively.Furthermore,the application of ferrous sulfate in the solid-liquid and liquid-liquid form optimized Zn immobilization in Tongguan and Feng County soils with the available Zn content reduced by 87.2%and 84.3%,respectively.