利用Pb²⁺含量为8.02 mg/kg的土壤作为实验原土，以50~400 mg/L Pb （NO₃）₂分别对原土和投加K₂FeO₄的土壤进行吸附实验，考察了不同条件下两种土壤对Pb²⁺的吸附影响规律，并进行了动力学分析。在此基础上利用模拟酸性雨水，采用静态溶浸实验和连续浸提实验，从浸出浓度和土壤对Pb²⁺吸附态的影响两方面综合考查K₂FeO₄对土壤强化吸附固定Pb²⁺的效果。结果表明，实验土壤对于初始浓度为350 mg/L的Pb²⁺仍具有良好的吸附作用，当Fe⁶⁺/Pb²⁺质量比为5、吸附时间为8 h时吸附量高达486 mg/kg；而加入K₂FeO₄后使土壤对Pb²⁺的吸附等温线由Langmuir变为Freundlich，且整个反应过程符合准二级动力学模型，吸附趋于稳定形态，Pb²⁺的浸出大幅度降低，强化吸附固定效果显著。此外，吸附过程对pH和温度不敏感，这对于Pb²⁺污染土壤的原位修复具有重要的实际应用价值。

The soil with a Pb²⁺ content of 8.02 mg·kg^-1 is used as experimental soil,and the adsorption experiments of Pb(NO₃)₂ with a concentration of 50-400 mg·L^-1 are respectively performed by the experimental soil and the soil added K₂FeO₄.The adsorption rules of Pb²⁺ by two kinds of soil are explored under different conditions and the kinetic analysis are done.Besides,static leaching experiments and continuous extraction experiments are also carried out by using the simulated acidic rainwater,and the effect of K₂FeO₄ on the strengthening adsorption and fixation of Pb²⁺ by soil is investigated from leaching concentration and the effect of soil on adsorption state of Pb²⁺.The results show that the experimental soil still has good adsorption capacity against Pb²⁺ with an initial concentration of 350 mg·L^-1,and the adsorption capacity reaches as high as 486 mg·kg^-1 when the mass ratio of Fe/Pb is 5 and the adsorption time is 8 h.After the addition of K₂FeO₄,the adsorption isotherm of Pb²⁺ by soil changes from Langmuir isotherm to Freundlich isotherm,and the reaction accords with the quasi-second-order kinetic model.The adsorption tends to be stable,and the leaching behavior of Pb²⁺ drops greatly,which enhances the adsorption fixation effect significantly.In addition,the adsorption process is insensitive to pH and temperature,which has important practical application value for in-situ remediation of Pb²⁺ contaminated soil.

刘紫云(1993-),女,硕士生,研究方向为环境污染控制与修复,932115440@qq.com