钝化剂对镉铅污染土壤修复效果研究

Study on Remediation Effect of Passivation Agent on Cd-Pb Polluted Soil

【目的】农田土壤重金属污染问题是农产品安全的隐患,以镉铅污染土壤为试验地,探究镉铅污染土壤上农产品安全利用的有效钝化措施,为镉铅污染土壤安全利用提供切实有效的方法。【方法】通过对镉铅污染土壤撒施碱性钝化剂石灰石粉,施用量为0.3 kg/m^(2),检测石灰石粉施用前后土壤pH值、重金属有效态,测定施用后采收的上海青茎叶的重金属含量,分析石灰石粉钝化措施效果。【结果】实施石灰石粉处理后,镉铅污染土壤的pH值升高0.2,有效镉含量降低0.04 mg/kg、有效铅含量降低1.38 mg/kg,产出的农产品可食用部位重金属含量均低于国家标准的污染限量值。【结论】0.3 kg/m^(2)石灰石粉钝化处理能够实现镉铅污染土壤的有效镉、有效铅钝化,处理后的土壤能够实现农产品安全生产。

【Objective】Heavy metal pollution in farmland is a hidden danger to the safety of agricultural products.Using Cd-Pb polluted soil as the experimental site,this study explores effective passivation measures for the safe utilization of agricultural products in Cd-Pb polluted soil,providing practical and effective methods for the safe utilization of Cd-Pb polluted soil.【Method】By spreading 0.3 kg/m^(2) limestone powder as alkaline passivation agent in Cd-Pb polluted soil,the soil pH value and available heavy metal status before and after the application of limestone powder were detected,and the heavy metal content in the stems and leaves of Brassica rapa leaves after application was measured to evaluate the effectiveness of limestone powder passivation measures.【Result】After the application of limestone powder,the pH value of Cd-Pb polluted soil increased by 0.2,the available Cd content decreased by 0.04 mg/kg,and the available Pb content decreased by 1.38 mg/kg.The heavy metal content in the edible parts of the produced agricultural products was lower than the pollution limit value of GB 2726-2022 standard.【Conclusion】Limestone powder passivation treatment can achieve available Cd and Pb passivation in Cd-Pb polluted soil,and the passivated soil can achieve safe production of agricultural products.