四种土壤调理剂对镉、铅的吸附效果研究

采用等温吸附试验研究了主要原料为麦饭石(M)、蒙脱石(T)、牡蛎壳(O)和硅钙矿(S)4种土壤调理剂对溶液中镉和铅的吸附效果。结果表明,4种土壤调理剂对镉和铅的吸附均可用Langmuir方程进行描述;相比而言,4种土壤调理剂对镉吸附量的大小顺序为O调理剂>S调理剂>M调理剂>T调理剂,对铅吸附量的大小顺序为M调理剂>S调理剂>O调理剂>T调理剂;随溶液pH值的增大各调理剂的吸附量逐渐减小,尤其当Cd溶液pH值>8,Pb溶液pH值>6,各调理剂的吸附量迅速降低。

Adsorption of aqueous cadmium and lead on four different soil amendments

Adsorption of aqueous cadmium and lead on four different soil amendments were investigated in this study.Langmuir isotherm equations were employed to study the sorption constants under different pH value in solution.The result indicated that the adsorption of Cd and Pb by the soil amendments obeyed the Langmuir equation.The extent of Cd adsorption was the oyster shell soil amendment(O)>the silicate and calcium carbonate minerals soil amendment(S)>the medical stone soil amendment(M)>the montmorillonite soil amendment(T),and the extent of Pb adsorption was the medical stone soil amendment(M)>the silicate and calcium carbonate minerals soil amendment(S)>the oyster shell soil amendment(O)>the montmorillonite soil amendment(T).The adsorption amount of each amendment decreased with increasing pH in solution,especially,while at the pH value of Cd solution higher than 8 and the pH value of Pb solution higher than 6,the sorption capacity decreased rapidly.