零价铁吸附还原溶液中U（VI）的实验研究

摘要

研究零价铁（Zero valent iron ， ZVI）去除溶液中的 U （VI），分析了 pH 值、反应时间、 ZVI 投加量、铀溶液初始浓度、其它离子（Mg2＋、 Mn2＋、 Cl －、 NO －3、 CO2－3和 Cu2＋）等条件因素对 U （VI）去除效果的影响，并讨论其去除机理。结果表明： ZVI 对溶液中 U （VI）有较好的去除作用，在 pH ＝4，振荡时间为120 min ，ZVI 投加量为1.6 g／L ，铀溶液初始浓度为10 mg／L ，铀去除量为4 mg ／g 时， U （VI）的去除率可达到63.7％。其它离子实验结果表明： Mg2＋、 Mn2＋、 Cl －、NO －3对 ZVI 去除 U （VI）影响不超过3％， CO2－3和 Cu2＋影响相对较大。 ZVI 去除溶液中 U （VI）以还原沉淀和吸附作用为主，吸附还原反应遵循一级化学反应动力学方程。%The removing effect of U (VI) in aqueous solutions by zero valent iron (ZVI) was stud‐ied. The effects of the dosage of ZVI , pH value of solution , shaking time and initial concentrations of U (VI) on treatment effect were investigated. The results shew that ZVI has very good removal effect on U (VI) , when pH value of solution is 4 and the shaking time is 120 min , the initial concentration of U (VI) is 5 mg/L , the dosage of ZVI is 1.0 g/L , the removal rate and capacity reached 63.7% and 4 mg ・ g- 1 respectively. The ions Mg 2 + , Mn 2 + , Cl- and NO 3 have no evident influence on U ( Ⅵ ) re‐-moval rate , but CO 2 -3 and Cu 2 + do have. The removal process contains reduction precipitation and sorp‐tion. The adsorption reduction process follows the pseudo first order reduction kinetics model.