[目的]研究磷酸盐对重金属Pb、Cd、Zn的钝化作用.[方法]以磷酸盐作为钝化剂,添加量设为50 ~1 200 g/m2,考察Pb、Cd、Zn的有效态浓度随着钝化剂添加量的变化.[结果]随着磷酸盐添加量的增大,Pb、Cd、Zn有效态浓度均呈下降趋势,Pb从280 mg/kg下降到123 mg/kg,Zn从14.20 mg/kg下降到7.18 mg/kg,Cd从1.50 mg/kg下降到1.27 mg/kg,最终得到最佳添加量为500 g/m2,并且30 d后Pb、Cd、Zn有效态浓度达到稳定状态.添加磷酸盐后土壤pH从5.62增加到7.57.[结论]磷酸盐可使土壤中的Pb、Cd、Zn浓度明显降低,达到预期的土壤修复效果.%[Objective]To study the inactivation effect of Pb, Cd and Zn by heavy metal phosphate.[Method]The effective concentration of Pb, Cd and Zn was determined by using 50-1 200 g/m2 as a passivating agent.[Result]The results showed that effective concentrations of Pb, Cd and Zn decreased with the increase of the passivation dose, the Pb decreased from 280 mg/kg to 123 mg/kg, Zn decreased from 14.20 mg/kg to 7.18 mg/kg, the Cd decreased from 1.50 mg/kg to 1.27 mg/kg, and finally the optimal addition amount was 500 g/m2.After 30 days, the effective concentration of Pb, Cd, Zn reached a stable state.After adding the passivator, the pH of the soil was increased from 5.62 to 7.57.[Conclusion]The Pb, Cd and Zn concentrations in the soil can be reduced significantly by the phosphate passivation agent, which can achieve the desired effect of soil remediation.
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