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用液流法研究了重金属离子铜与镉的在褐土中的竞争吸附动力学特性 ,用 L J吸附动力学方程结合竞争系数对铜与镉的竞争吸附动力学过程进行了描述。竞争性弱的镉离子吸附曲线出现“过饱和点”,镉在开始时占据的吸附位量的一部分 ,随着吸附过程的延续被铜逐渐交换占据 ,镉的吸附量由“过饱和点”逐渐下降 ,最后趋于竞争平衡 ;在试验温度区间内 ,单一离子及竞争离子在褐土中的吸附量均随温度的升高而增大 ;吸附速率随温度的升高而减小 ,阿仑尼乌斯经验方程不能符合本试验结果 ,显示出铜及镉在供试褐土中的吸附动力学有其特殊性。温度和 p H值的升高对镉的竞争有利 ,但镉在褐土中的吸附竞争能力远小于铜
The competitive adsorption kinetics of heavy metal ions of copper and cadmium in cinnamon soil was studied by liquid-flow method. The competitive adsorption kinetics of copper and cadmium was described by using L-adsorption kinetics equation and competition coefficient. Weakly competitive cadmium ion adsorption curves show a “supersaturation point”. Part of the adsorption sites occupied by cadmium at the beginning of the adsorption process are gradually replaced by copper and the amount of cadmium adsorbed gradually increases from “supersaturated point” Decreased, and finally tended to be competitive. In the experimental temperature range, the adsorption capacity of single ions and competing ions in the cinnamon soil increased with the increase of temperature. The adsorption rate decreased with the increase of temperature. Ux empirical equation can not meet the test results, showing that the adsorption kinetics of copper and cadmium in the test cinnamon has its own particularity. The increase of temperature and p H value is favorable for the competition of cadmium, but the adsorption ability of cadmium in cinnamon soil is far less than that of copper