腐植酸对阿特拉津的吸附特性研究

Adsorption Characteristics of Humic Acid on Atrazine

采用批量平衡震荡法研究了腐植酸对不同浓度阿特拉津的吸附量随时间变化的规律,并利用傅里叶红外光谱(FTIR)和电子顺磁共振波谱(ESR)2种方法探讨其吸附机理。结果表明,腐植酸对阿特拉津的吸附量与吸附时间符合对数和双曲线函数关系,吸附初始阶段是一个快速过程,随着时间的增加,吸附速率逐渐减慢,最后趋于平衡。阿特拉津初始浓度分别为0.986mg/L、3.14mg/L、6.08mg/L、11.4mg/L、12.7mg/L和20.6mg/L,最终吸附量分别为0.235μg/kg、0.490μg/kg、1.32μg/kg、2.41μg/kg、2.06μg/kg和3.36μg/kg。阿特拉津在腐植酸颗粒和吸附溶液中量的分布符合一定的线性函数关系,可用Freundlich方程描述。FTIR分析表明,腐植酸与阿特拉津之间存在氢键、范德华力、质子转移和电荷转移等弱作用力;ESR检测证实,腐植酸对阿特拉津的吸附过程中发生了电荷转移。

Using batch equilibrium techniques, this paper mainly studied the effects of reaction time on atrazine amount adsorbed by different concentration of humic acid, and explained the functional mechanism between atrazine and humic acid using FTIR and ESR spectral analysis methods. The results indicated that the relationship between adsorption amount of atrazine and reaction time was fitted for Logarithmic and Hyperbolic equations. The adsorption rate of humic acid on atazine was very fast at the beginning, then went down slowly and finally reached equilibrium. The adsorption capacity of atrazine were 0.235 μg/kg, 0.490 μg/kg, 1.32 μg/kg, 2.41 μg/kg, 2.06 μg/kg and 3.361 μg/kg under the different initial concentration of atrazine with 0.986 mg/L, 3.14 mg/L, 6.08 mg/L, 11.4 mg/L, 12.7 mg/Land 20.6 mg/L, resceptively. The distribution relationships of atrazine between humic acid particles and solution could be described by Freundlich equation. The interactions between humic acid and atrazine were mainly weak forces, such as H-bond, Proton transfer, charge transfer, van der Waals force and so on. In addition, ESR analysis proved that charged transfer existed between humic acid and atrazine in the adsorption process.