环丙氨嗪在Aldrich胡敏酸中吸附-解吸特征的研究  

Adsorption and desorption characteristics of cyromazine on Aldrich humic acid

作　　者：袁敏[1,2,3] 林志荣[1,3] 徐仁扣[1] 

机构地区：[1]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,江苏南京210008 [2]江苏出入境检验检疫局,江苏南京210001 [3]中国科学院研究生院,北京100049

出　　处：《生态环境学报》2012年第7期1319-1324,共6页Ecology and Environmental Sciences

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-EW-405)

摘　　要：采用批平衡法,研究了不同温度下环丙氨嗪在Aldrich胡敏酸中的吸附与解吸特征。结果表明:环丙氨嗪吸附和解吸过程都包含极快速、快速和缓慢阶段。伪二级动力学方程能较好地描述不同温度下环丙氨嗪的吸附动力学特性,表明吸附速率决定于胡敏酸表面吸附位点的可用度,而不是溶液中环丙氨嗪的浓度。环丙氨嗪在极快速吸附阶段的吸附速率随温度的升高而增大,但平衡时的吸附量却随温度的增加而降低。吸附等温线和解吸曲线符合Langmuir方程和Freundlich方程。环丙氨嗪在胡敏酸上的解吸速率小于吸附速率,表明存在滞后效应。吸附焓变、熵变和自由能都为负值,表明环丙氨嗪在胡敏酸上的吸附是一个自发、熵减小的放热过程。-Go<40 kJ.mol-1表明环丙氨嗪在胡敏酸表面以物理吸附为主。Batch equilibrium experiments were conducted to investigate adsorption and desorption characteristics of cyromazine（CYR） on and from Aldrich humic acid（HA）.Results show that the adsorption and desorption of CYR on and from HA consisted of a rapid,a medium rapid and a slow processes.Adsorption kinetics curves at different temperatures were well fitted with a pseudo second-order kinetic model,suggesting that the adsorption was determined by the availability of sorption sites on the HA surfaces rather than the CYR concentration in the bulk solution.The adsorption rate of CYR in the rapid process increased with rise in temperature,but the adsorption amount at sorption equilibrium decreased with rise in temperature.Adsorption and desorption isotherms fitted Freudlich and Langmuir models well.The desorption rate of CYR from humic acid was lower than the sorption rate,implying a hysteresis occurred during the desorption of CYR from humic acid.The negative values of Ho,Soand Go before and after the adsorption revealed that the CYR adsorption on humic acid was a spontaneous,entropy decrease and exothermic processes.The absolute value of Go was less than 40 kJ.mol-1,indicating physical sorption predominated in the adsorption of CYR on humic acid.

关 键 词：环丙氨嗪 Aldrich胡敏酸 吸附 解吸 

分 类 号：X132[环境科学与工程—环境科学]