不同介质材料组合可渗透反应墙渗透性能试验研究

Permeability test of permeable reactive barrier of different medium and material combinations

渗透系数是可渗透反应墙(PRB)正常运行的关键参数之一,与PRB活性填充材料的选择密切相关。本试验采用常水头渗透系数测试法,首先选用斜发沸石、红辉沸石为作为PRB的活性介质材料,考察了沸石矿物的类型和粒径对PRB渗透系数的影响,试验结果显示,同一粒径的斜发沸石PRB和红辉沸石PRB渗透系数相差一个数量级;处于同一数量级渗透系数沸石PRB,斜发沸石的粒径大于红辉沸石的粒径。在此基础上,以膨润土作为掺和活性介质材料,讨论了渗透系数处于同一数量级沸石PRB,掺和比例对渗透系数的影响,结果表明,膨润土的掺和能导致沸石PRB渗透系数量级上的差异,与斜发沸石相比,红辉沸石更有利于实现沸石PRB系统渗透系数的可调性。

Perme ability coefficient is one of the key parameters for the normal operation of permeable reactive barrier (PRB)and it plays an important role in selecting different active medium filling material of PRB.The test conducted in this paper applied constant head permeability test method.Firstly,the author chose clinop-tilolite and stellerite as active medium filling material of PRB,and studied the effect of zeolite minerals of different types and particle sizes on the permeability coefficient of PRB.The test results indicated that the permeability coefficient of clinoptilolite PRB is one order of magnitude higher than that of stellerite PRB of the same particle size,and the particle size of clinoptilolite are larger than that of stellerite while the permea-bility coefficients of both have the same order of magnitude.Secondly,the author chose bentonite as blended active medium material,and studied the effect of blending proportion of bentonite on permeability coeffi-cients of zeolite PRBs which have permeability coefficients at the same order of magnitude.The results indi-cated that the blending of bentonite would result in different permeability coefficients of zeolite PRBs at different order of magnitude,and stellerite is more conducive to adjustability of permeability coefficient of zeolite PRB system than clinoptilolite does.