天然黄铁矿对铀污染地下水中U(Ⅵ)的吸附探究

Study on Adsorption of U(Ⅵ) by Natural Pyrite in Uranium-Contaminated Groundwater

为探究天然黄铁矿作为填充PRB的活性反应材料,修复U(Ⅵ)污染地下水的吸附机理,通过静态批试验研究了初始pH值、初始铀浓度和接触时间对天然黄铁矿吸附U(Ⅵ的影响,并分析了吸附过程中的吸附等温线和动力学行为。结果表明,黄铁矿对U(Ⅵ)的吸附与Langmuir和Freundlich吸附等温方程都能较好拟合,且符合准二级动力学模型;粒径越小的黄铁矿吸附效果越好;在试验范围内的pH值中,pH=7～8时,U(Ⅵ)的去除率最高,其吸附量与去除率呈相反趋势;根据SEM和XRD结果推测,黄铁矿对U(Ⅵ)的吸附主要为表面吸附。

In order to explore the mechanism of adsorption of U(VI)-contaminated groundwater by natural pyrite as an active PRB reaction material,peformed a series of batch tests to explore the effects of initial pH,initial concentration of U(VI)and contact time on the adsorption of U(VI)by natural pyrite.And analyzed the adsorption isotherms and kinetic behaviors during the adsorption process.The results shown that the adsorption fitted well to the Langmuir and Freundlich adsorption isotherms,and it was in accordance with the pseudo-second-order kinetic model;the smaller the particle size,the better the adsorption effect of pyrite;the range of pH in this experiment,when pH=7-8, the removal rate of U(VI)was the highest,and the curve about adsorption capacity is opposite to the removal rate.