皂素和柠檬酸复合淋洗土壤中的钍

采用振荡淋洗和土柱动态淋洗实验研究了皂素和柠檬酸复合对土壤中钍的淋洗性能。实验结果表明:将质量浓度为20 g/L的皂素与浓度为20 mmol/L的柠檬酸以体积比1∶10配制复合淋洗液对污染土壤中钍的去除效果最佳,淋洗3.0 h,钍去除率为84.98%;准一级动力学方程能更好地描述复合淋洗液对钍的淋洗动力学特征;动态淋洗实验中当复合淋洗液用量为1 600 mL时,钍的累积去除量为73.66 mg/kg;淋洗后土壤中钍的酸可提取态、氧化结合态和有机结合态含量分别减少了79.63%、38.13%和20.34%,残渣态含量变化不大;淋洗后土壤中钍的稳定性增加。

Leaching of thorium in contaminated soil by saponin and citric acid

The combination leaching effect of saponin and citric acid on the thorium-contaminated soil was studied by shaking leaching and dynamic column elution. The results showed that：the thorium removal rate of 84.98% was obtained under the optimum conditions of saponin mass concentration 20 g/L,citric acid concentration 20 mmol/L,volume ratio of saponin solution to citric acid solution 1∶10 and leaching time 3.0 h;The pseudo-first-order kinetic model could better describe the combined leaching process;The accumulative removal amount of thorium was 73.66 mg/kg when the leaching volume of combined leaching agent was 1 600 mL in the dynamic column elution experiment;The contents of acid extractable form,oxidation combined form and organic binding state of thorium in the soil were reduced 79.63%,38.13% and 20.34%,respectively,but the content of residue state thorium had slightly changed after leaching;The stability of thorium in the treated soil was improved.