【摘要】 采用0.05mol·L-1的EDTA作为解吸剂,对中低污染负荷土壤中Cd、Pb、Cu、Zn进行了振荡解吸研究,并运用一级动力学方程、Elovich方程和双常数方程进行模拟。结果表明,污染土壤中重金属Cd、Pb、Cu、Zn的解吸率随着解吸时间的延长而不断增加,中污染负荷土壤Cd、Pb、Cu、Zn解吸率高于低污染负荷土壤。反应720min后,EDTA对中污染和低污染土壤中Cd、Pb、Cu、Zn的解吸率分别为Cd45.16%、30.88%,Pb51.32%、26.45%,Cu17.86%、14.23%,Zn23.31%、19.63%。双常数方程是描述污染土壤中Cd、Pb、Cu、Zn解吸动力学过程的最佳方程,其次为Elovich方程,最差模型是一级动力学方程。Cd、Pb、Cu、Zn的解吸速率随解吸时间延长而不断降低,Cd、Pb、Cu、Zn在中污染土壤中的解吸速率大于其在低污染土壤中的解吸速率。更多还原

【Abstract】 EDTA(0.05 mol·L-1)was used as a solution to desorb Cd,Pb,Cu,and Zn in soils with medium and slight pollution loads.First-order dynamics equation,Elovich equation,and double-constant equation were employed to describe the dynamic process.Results showed that the desorption efficiencies of Cd,Pb,Cu and Zn increased with increasing action time.The desorption efficiencies of Cd,Pb,Cu and Zn in soil with medium pollution load were higher than those in soil with slight pollution load.After action 720 min,the desorption efficiencies of Cd,Pb,Cu and Zn were 45.16%,51.32%,17.86%,and 23.31% in soil with medium pollution load,30.88%,26.45%,14.23%,and 19.63% in soil with slight pollution load.Two-constant equation was the best model to describe the desorption kinetics of Cd,Pb,Cu,and Zn,Elovich equation was the second,and the worst was first-order dynamics equation.The desorption velocity of Cd,Pb,Cu,and Zn in the soils decreased with increasing duration of desorption.The desorption velocity of Cd,Pb,Cu and Zn in soil with medium pollution load were faster than those in soil with slight pollution load.更多还原