复合电解液强化改良装置修复铀污染土壤研究

Research on the remediation of uranium-contaminated soil by composite electrolyte enhancement and improvement device

通过对照实验､单因素实验及正交实验对铀污染土壤进行了电动优化修复研究.结果表明:0.20mol/L酒石酸与0.05mol/L氯化铁复合电解液应用于改良装置修复后铀去除率提升至55.73%,铀平均浸出毒性浓度仅为0.07mol/L,且能量利用率增大至306.21.Visual MINTEQ软件模拟结果表明铀主要以带正电铀酰离子(UO_(2)^(2+))及少量中性铀-酒石酸络合物形式存在,因此,由于电迁移及正向电渗析的协同作用,铀的迁移方向为阳极到阴极.最后通过正交实验得出本实验最佳去除率的实验参数为0.15mol/L酒石酸和0.08mol/L氯化铁及1.5V/cm电压梯度.改良装置可通过提高土壤导电性、zeta电位、降低土壤pH值以提高修复效率,且酒石酸与氯化铁复合液作为电解液应用于改良装置修复铀污染土壤时能量利用率和去除率高,铀浸出毒性低.因此,酒石酸与氯化铁复合液应用于改良电动装置为铀污染土壤提供一种高效､绿色的原位修复技术.

Controlled experiment,single factor experiment and orthogonal experiment were used to study the electrokinetic optimization of uranium contaminated soil.The uranium removal efficiency increased to 55.73%,with an average leaching toxic concentration of uranium of only 0.07mol/L.After applying a composite electrolyte of 0.20mol/L tartaric acid and 0.05mol/L ferric chloride to the optimized device,the energy utilization efficiency increased to 306.21.Meanwhile,uranium mainly exists in the form of positively charged uranyl ion(UO_(2)^(2+))and a minor amount of neutral uranium-tartrate complex by using Visual MINTEQ software,therefore,due to the synergy of electromigration and forward electrodialysis,the migration direction of uranium is from anode to cathode.Subsequently,the experimental parameters yielding the best removal efficiency in this study were determined to be 0.15mol/L of tartaric acid,0.08mol/L of ferric chloride,and 1.5V/cm of voltage gradient via orthogonal experiment.In addition,the modified device has the potential to improve the effect of soil remediation by ameliorating soil conductivity,zeta potential and pH levels.Moreover,when utilizing the composite liquid made up of tartaric acid and ferric chloride as the electrolyte in the modified device for repairing soil contaminated with uranium,the energy utilization and removal efficiency were elevated,and the toxicity associated with uranium leaching was substantially reduced.Therefore,an efficient and sustainable in-situ remediation technology for uranium-contaminated soil is provided.