氯苯(CB)在粘土上的解吸特征

Desorption Characteristics of Chlorobenzene from Clay

为探索低浓度乙醇溶液中氯苯(Chlorobenzene,简称CB)在土壤中的迁移行为,以武汉市某化工厂受CB污染土壤为研究对象,设计正交试验,开展了淋洗条件筛选、最佳条件的验证和解吸动力学研究3组实验.优化出的最佳淋洗条件为常温、液土比(mL/g)为25∶1、淋洗液中乙醇体积浓度为10%、淋洗时间为2h;在最优淋洗条件下,CB的提取率为90%;且CB解吸规律符合Freundlich吸附模型.以低浓度乙醇为淋洗剂修复受CB污染土壤,不仅可实现污染土壤修复的目标,同时还能够保留土壤功能,避免造成二次污染.

The chlorobenzene （CB） desorption characteristics on clay matrix at room temperature condition were investigated to examine the CB＇s migration under a low concentration of ethanol. To find out if the CB polluted the soil （clay） of the Chemical Factory at Wuhan, Hubei Province, China, three series of experiments were performed in this study. The first is the best leac- hing filtering condition. The second is the verification of the result of the best leaching condition and the third is testing the de- sorption kinetics of CB on clay. The results show that the solution to soil ratio （mL/g） was 25 ~ 1 and ethanol concentration of 10% had the best leaching condition at 2 h at the room temperature. Moreover, the extraction rate of the chlorobenzene in soil was 90% under the best leaching condition. It was found that all desorption isotherm data of CB in clay could be best described with Freundlich equations. Using a low concentration of ethanol to restore the CB polluted clay is practicable. It can prevent secondary pollution while retaining the soil function as well.