镉锌复合污染土壤修复技术研究

Study on Remediation Technology of Cd-Zn Combined Contaminated Soil

摘要: 重金属元素进入土壤造成土壤污染，具有隐蔽性和难治理性，且影响了粮食安全生产，也是对整个生态系统安全的严重威胁。为此就需要开展土地资源风险管控，采用多种措施实现中轻度污染农田安全利用，保障农产品安全。本文针对XX区主要成弱碱性的Cd、Zn污染土壤，采用添加土壤调理剂降低重金属元素的生物活性、继而降低重金属元素在种植物中的积累，实现土地安全利用。结果表明，在试验大盆中添加调理剂6周左右，土壤中Cd的生物有效态含量趋于稳定；在大田试验中调理剂可使土壤中Cd的生物有效态含量降低10%~28%，稻米中Cd含量降低0.03 μg/g，符合食品卫生标准。合理添加土壤调理剂可以实现研究区污染土地安全利用。

Abstract: Heavy metal elements entering the soil cause soil pollution, which is hidden and difficult to control, and affect the food security production, is also a serious threat to the security of the entire ecosystem. Therefore, it is necessary to carry out risk management and control of land resources, adopt various measures to realize the safe utilization of moderately and lightly polluted farmland, and ensure the safety of agricultural products. Aiming at the weakly alkaline Cd and Zn polluted soil in XX District, this paper adopts adding soil conditioner to reduce the biological activity of heavy metals, and then reduce the accumulation of heavy metals in species of plants, so as to realize the safe use of land. The results showed that the bioavailable content of Cd in soil tended to be stable after adding conditioner in the test basin for about 6 weeks; in the field experiment, the conditioner can reduce the bioavailable content of Cd in soil by 10%~28%, and the content of Cd in Rice by 0.03 μG/g, meeting the food hygiene standard. Reasonable addition of soil conditioner can realize the safe use of polluted land in the study area.