某铀尾矿场附近稻田土壤对铀的吸附性能试验研究

Adsorption Performance of Paddy Soil Near Uranium Tailing Pond on Uranium

研究了某铀尾矿场附近的稻田土壤对U(Ⅵ)的吸附性能,借助X射线衍射仪(XRD)对稻田土壤进行表征,考察了初始U(Ⅵ)质量浓度、固液质量体积比、溶液pH、吸附时间和温度等对稻田土壤吸附U(Ⅵ)的影响,分析了吸附反应动力学和热力学。结果表明:在溶液初始U(Ⅵ)质量浓度10 mg/L、固液质量体积比0.8 g/L、溶液pH=5.5、吸附时间120 min条件下,稻田土壤对U(Ⅵ)的吸附效果最佳,吸附量为8.3 mg/g;稻田土壤对U(Ⅵ)的吸附过程符合Langmuir等温吸附模型,为单分子层化学吸附,吸附反应自发吸热,为不可逆熵增反应;吸附动力学更符合准二级动力学模型。

The adsorption performance of paddy soil near a uranium tailing pond on U(Ⅵ)was researched.X-ray diffraction(XRD)was used to characterize the paddy soil.The factors affecting adsorption performance of paddy soil to U(Ⅵ)such as initial U(Ⅵ)mass concentration,solid mass-to-liquid volume ratio,solution pH,adsorption time and temperature were examined.The adsorption process thermodynamics and kinetics were analyzed.The results show that under the conditions of initial U(Ⅵ)mass concentration of 10 mg/L,solid mass-to-liquid volume ratio of 0.8 g/L,solution pH of 5.5 and adsorption time of 120 min,the adsorption capacity of paddy soil for U(Ⅵ)is 8.3 mg/g.The adsorption process is monolayer adsorption,in accordance with Langmuir model.Also,the adsorption reaction is spontaneous endothermic,which belongs to irreversible entropy increase reaction,and the adsorption kinetics is in line with the quasi second-order kinetic model.