苄嘧磺隆和芘在土壤中的吸附解吸行为

Sorption-desorption Behavior of Bensulfuron-methyl and Pyrene in Soil

吸附是外源有机污染进入土壤后首先发生的最重要的过程,直接影响着有机物的生物可利用性。采用完全混合法研究了苄嘧磺隆和芘在土壤中的吸附-解吸动力学特征以及等温吸附解吸行为。结果表明,(1)苄嘧磺隆和芘在土壤中的吸附-解吸动力学过程存在两段行为,即初期快速反应阶段和经过一段时间后的慢速阶段,动力学特征表明供试有机物8h内能达到吸附-解吸平衡;(2)在试验浓度范围内,线性方程能很好地描述苄嘧磺隆和芘在土壤中的吸附解吸行为;(3)苄嘧磺隆和芘在土壤中存在解吸迟滞现象,解吸并不完全是吸附的可逆过程,土壤中存在不可逆吸附室是造成解吸滞后的主要原因。

Adsorption is the initial process when the exterior organic pollutants enter the soil, which influences directly the bioavailability of organics in soil The sorption-desorption behavior and its kinetics of Bensulfuron-methyl （ BSM ） and Pyrene （PYR） in soil as well as the isothermal sorption and desorption behavior were studied using completely mixing method. The results showed that ： （ 1 ） the sorption-desorption kinetics of BSM and PYR in soil included two phases, a speed reaction phase initially and a slow reaction phase followed. The kinetics showed that the testing organics could reach the sorption-desorption equilibrium in eight hours. （2） Within the testing concentration range, the linear equation described well the sorption-desorption behavior of BSM and PYR in soil （3） There was a phenomenon of desorption delaying for BSM and PYR in soil, the sorpfion is not a complete reversible process of desorption. The existence of irreversible sorption room in soil was the major cause of desorption delaying.