复合矿物介质动态去除重金属多污染物实验研究

An experimental study on the dynamic removal of heavy metallic multi-pollutants using composite mineral media

本文针对广西某多金属矿山尾矿库渗滤液造成的地下水污染问题,以蛭石、十六烷基三甲基溴化铵(CTAB)改性蛭石及赤铁矿作为PRB复合介质材料,进行了动态去除水中多污染物Cu^(2+)、Zn^(2+)、Mn^(2+)、CrO_(4)^(2–)的实验,研究了三种介质材料的组装方式对多种污染物的去除行为。动态吸附实验表明,介质的不同组装方式会影响体系的p H值,及吸附柱对多污染物的去除效果。通过对反应前后矿物介质的物相、形貌等测试表征,讨论了矿物介质材料对污染物的去除机理。赤铁矿以表面吸附为主,蛭石、CTAB改性蛭石以离子交换为主,也存在表面吸附等过程。以上成果为复合矿物介质实际用于重金属污染地下水的原位修复奠定了重要基础。

Aiming at the in-situ remediation of groundwater pollution caused by the leachate from the tailings reservoir of a polymetallic mine in Guangxi Zhuang Autonomous Region,experiments of the dynamic adsorption of multi-pollutants Cu^(2+),Zn^(2+),Mn^(2+)and CrO_(4)^(2–)have been conducted by using composite PRB medium materials of vermiculite,CTABmodified vermiculite and hematite for investigating the removal behaviors of multi-pollutants by different assemblies of three mineral materials.The results of dynamic adsorption experiments show that different assembly methods of media have affected pH values of the systems and removal efficiencies of their multi-pollutants by the adsorption column.The pollutants removal mechanisms of composite mineral medium materials have been discussed based on the measurement and characterization of phases and morphologies of composite mineral media before and after the dynamic adsorption.The removal of pollutants by hematite is mainly in form of the surface adsorption,while removals of pollutants by vermiculite and the CTAB modified vermiculite are mainly in form of the ion exchange,and littlely in form of the surface adsorption.The above results have laid an important foundation for the practical application of these composite mineral media into the in-situ remediation of heavy metal polluted groundwater.