【摘要】 测定了3种水稻土胶体在不同Cd/Pb摩尔比的悬液体系中的Zeta电位,并与2种重金属离子在土壤中的吸附量和解吸量进行比较,当Cd/Pb摩尔比为1∶4时,Zeta电位数值最高;Cd/Pb摩尔比为1∶1时Zeta电位数值居中;Cd/Pb摩尔比为4∶1时Zeta电位数值最小,因此,Pb(Ⅱ)在三种土壤表面发生专性吸附的能力均大于Cd(Ⅱ),这与土壤中Pb(Ⅱ)和Cd(Ⅱ)的吸附量和解吸量的结果相一致.更多还原

【Abstract】 The zeta potential of the colloids of three paddy soils in suspensions containing Pb and Cd with various Cd/Pb molar ratios was determined and adsorption of Pb(Ⅱ) and Cd(Ⅱ) by the soils and desorption of the pre-adsorbed Pb(Ⅱ) and Cd(Ⅱ) were investigated with batch method. The results showed that the values of zeta potential in colloidal suspensions of paddy soils with various Cd/Pb molar ratios can be used to predict the relative strength of specific adsorption of heavy metals on soil surface. The value of zeta potential increased with the decrease in the molar ratio of Cd/Pb in colloid suspensions of three paddy soils,this suggested that the strength of specific adsorption of Pb(Ⅱ) on the soils was greater than that for Cd(Ⅱ). This prediction is also consistent with the results of the adsorption Pb(Ⅱ) and Cd(Ⅱ) on the soils and the desorption of pre-adsorbed Pb(Ⅱ) and Cd(Ⅱ) from the soils.更多还原