Cd^(2+)、Zn^(2+)在不同介质中的等温吸附及迁移特性

The Isothermal Adsorption and Transport of Cadmium、Zinc in Different Texture

采用等温吸附实验和土柱实验,探讨了重金属镉、锌在青岛地区三种主要土壤(棕壤、潮土和砂浆黑土)中的静态吸附特征和在石英砂、石英粉中的动态迁移特性。在静态等温吸附实验中,棕壤和潮土对Cd2+、Zn2+的吸附量相近,而黑土对Cd2+、Zn2+的吸附量明显高于棕壤和潮土。Cd2+、Zn2+的吸附比率随着加入浓度的增加而减少。在动态迁移实验中,Cd2+、Zn2+的迁移特性受介质质地、加入浓度、背景浓度和pH值的影响。由实验可知:Zn2+的迁移性比Cd2+强;随着pH的升高,介质对重金属的吸附容量和固持力增加。

The adsorption qualities of cadmium, zinc in brown soil, alluvial meadow soil and indicotic black soil and the transport qualities of cadmium.zinc in quartz were determined in an isothermal adsorption and column experiment. In the isothermal static equilibrium adsorption experiment, it was found that the amount of cadmium ,zinc adsorptions in brown soil and alluvial meadow soil were similar, while lower than that in indicotic black soil. The rate of adsorption decreased as the concentration of added heavy metal increased. In the column experiment, the quality of different texture, concentration and pH of added heavy metal can strongly effect the transport of cadmium,zinc. It can be concluded that the transport of zinc was faster than that of cadmium in different texture. The amount of adsorptions increased as the increase of pH.