含水层介质对氯酚类污染物的吸附-解吸特性  

Characteristics of chlorophenols adsorption by natural sandy aquifer material

作　　者：杜连柱[1] 张兰英[1] 刘睿[2] 高松[1] 张玉玲[1] 

机构地区：[1]吉林大学环境与资源学院,吉林长春130026 [2]中国科学院沈阳应用生态研究所//中国科学院陆地生态过程重点实验室,辽宁沈阳110016

出　　处：《生态环境》2008年第1期23-27,共5页Ecology and Environmnet

基　　金：国家“973”项目(2004CB418505);吉林大学自然科学基金种子项目(419070402425)

摘　　要：为探讨含水层介质对氯酚类污染物的吸附规律,以吉林市含水层介质--砂土为实验材料,采用批量吸附实验方法分别研究了2,4-二氯酚、2,4,6-三氯酚及五氯酚单独存在和共存条件下在砂土上的吸附-解吸行为,并对pH、离子强度对吸附过程的影响进行了探讨。结果表明,砂土对三种氯酚的吸附-解吸符合Freundlieh等温模型,吸附常数Kd分别为5.659、2.507和2.104,解吸常数分别为22.642、8.222和4.488;吸附反应符合二级吸附速率动力学方程,吸附速率常数K分别为0.4851kg·mg-1·h-1、0.0299kg·mg-1·h-1和0.1225kg·mg-1·h-1。氯酚在砂土上的吸附机理以疏水分配和配位体交换为主。在实验范围值内,吸附量随pH增加而减小,增加离子强度可以明显加强氯酚在砂土上的吸附.Adsorption-desorption to natural sandy aquifer material was an underlying process affecting the transport, degradation, and biological activity of hydrophobic organic contaminants in the environment. In this study, batch experiments were carried out to elucidate the adsorption and desorption behavior of chlorophenols （2,4-DCP, 2,4,6-TCP and t＇CP） on sandy aquifer material in single and bisolute aqueous solutions and in the same time, the effect of pH and ion intensity on sorption was clarified. Adsorption-desorption isotherms were measured. The result showed that the process of chlorophenols adsorption by the sandy aquifer material was fitted to Freundlieh adsorption isotherm and the second-order kinetics. The adsorption constant of 2,4-DCP, 2,4,6-TCP and PCP in sandy material was 5.659, 2.507 and 2.104 and the desorption coefficient was 22.642, 8.222 and 4.488, the adsorption rate constant was 0.4851 kg·mg^-1·h^-1, 0.0299 kg·mg^-1·h^-1 and 0.1225 kg·mg^-1·h^-1 respectively, The mechanisms of the adsorption of CPs onto sandy aquifer material can be summarized as the corporate effect of hydrophobic separation, ligand exchange and electrostatic interaction. The adsorption increased with the increase of ion intensity and decreased with pH changing from 6 to 9.

关 键 词：氯酚 吸附-解吸 吸附等温线 吸附动力学 

分 类 号：X131[环境科学与工程—环境科学]