可渗透反应墙对重金属离子Pb^(2+)、Cd^(2+)吸附效果的试验研究

An experimental study on the absorption effect of permeable reactive barrier on heavy metal ions Pb^(2+) and Cd^(2+)

以受尾矿库渗滤液重金属离子Pb2+、Cd2+污染的地下水为研究对象,用天然矿物材料红辉沸石与膨润土作为反应渗透墙(PRB)的活性介质填充材料,试验结果表明,膨润土∶红辉沸石=1∶7,PRB渗透系数处于10-4cm/s数量级且随时间下降最为缓慢;PRB对单一组分Pb2+和单一组分Cd2+去除率分别达99.95%和99.995%;但在双组分PRB体系中,重金属离子Pb2+的存在显著地抑制了PRB对Cd2+的吸附作用,优先选择性吸附顺序是Pb2+>Cd2+。

This paper focused on the ground water which was contaminated by heavy metal ions like Pb^2＋ and Cd^2＋ of leachate from tailings pond, and utilized natural mineral materials such as stellerite and bentonite as active medium filling materials of permeable reactive barrier （PRB）. The test results indicated that as bentonite and stellerite was mixed at the ratio of 1 ： 7, the order of magnitude of permeability coefficient is 10 4cm/s and the declining rate over time was the lowest. The removal rates of the single component Pb^2＋ and Cd^2＋ by PRB were 99. 95% and 99. 995% respectively. In the hi-component system of PRB, the absorption effect of PRB on Cd^2＋ was significantly suppressed by the existence of Pb^2＋. The priority order of pre ferential adsorption sequence is Pb^2＋ 〉Cd^2＋ .