重金属Cu2+污染土渗透特性试验研究

his paper mainly concentrates on the effect of Cu2+ erosion to the permeability properties of soil. In this paper, the leachate was chosen by artificial CuCl2 solution, and a serious of experiment were conducted to study permeability properties of contaminated soil under two different conditions using the triple-type flexible wall permeameter, through which the influence of confining pressure and polluted concentration of penetrating fluid on the soil permeability properties was analyzed. The experimental results have showed that when CuCl2 solution concentration was kept constant, regardless of penetrating fluid was pure water or CuCl2 solution, permeability coefficient of clay decreased with the increase of confining pressure, but under the same confining pressure the permeability coefficient of CuCl2 solution as leachate was less than that of the pure water as leachate, and with the increase of confining pressure, the reduction of permeability coefficient was gradually decreased until properties of fluid have little impact on the permeability of soil when the confining pressure was more than 600kPa. When confining pressure was kept constant but polluted concentration of penetrating fluid was different, the permeability coefficient of clay decreased rapidly at first and then gradually increased with the increased of CuCl2 solution concentration. The results of Micro-structure analysis have showed that the permeability coefficient of clay was different when the penetrating liquid was pure water or CuCl2 solution, the reason was that Cu2+ erosion could change the structure of the clay and has influence on the pore size in the soil samples, thus resulting in the differences in the macroscopic permeability.