土壤细菌胞外聚合产物对溶液中U(VI)的去除动力学研究

通过分离和扩培土壤细菌,提取其胞外聚合产物,进行在不同温度下对土壤细菌胞外聚合产物和土壤细菌产量的影响研究,同时进行反应时间对土壤细菌胞外聚合产物去除溶液中U(VI)的影响研究。采用准一级动力学方程和准二级动力学方程对其进行动力学进行分析,研究结果显示在303 K下培养土壤细菌并进行土壤细菌胞外聚合产物的提取较为合适。298 K、308 K和318 K的温度下,土壤细菌胞外聚合产物去除U(VI)在120 min左右达到反应平衡,平衡去除量分别为4. 97 mg/g,8. 75 mg/g,6. 96 mg/g。准二级动力学方程比准一级动力学方程能更好的描述反应进程,说明了土壤细菌胞外聚合产物去除U(VI)是一个以化学机制为主的反应。

Removal Kinetics of U(VI) in Aqueous Solution by Soil Bacterial Extracellular Polymeric Substances

Through isolating and expanding soil microorganisms,then extracting their extracellular secretions,the effects of different temperature on soil bacterial extracellular polymeric substances (SB-EPS) yield and soil bacterial yield were studied.Study on the effect of reaction time on U(VI) removal by SB-EPS in solution at different temperatures were performed.Dynamics are analyzed using pseudo first-order kinetic equations and pseudo second-order kinetic equations.The results showed that it was better to culture soil microorganisms and extract SB-EPS at 303 K.At temperatures of 298 K,308 K,and 318 K,the SB-EPS removed U(VI) reached a reaction equilibrium in about 120 minutes,and the equilibrium removal amounts were 4.97 mg/g,8.75 mg/g,and 6.96 mg/g.The pseudo-second-order kinetic equation can better describe the reaction process than the pseudo-first-order kinetic equation,which indicates that the removal of U(VI) by the extracellular polymeric products of soil bacteria is a chemical mechanism-based reaction.