从动力学与热力学角度研究了膨润土浓度、吸附时间、温度对膨润土吸附Pb(Ⅱ)性能的影响.结果表明,膨润土对Pb(Ⅱ)具有较强的吸附性能.吸附速率k为0.09 g/(mg·h),服从假二级吸附动力学方程;吸附率随膨润土浓度、温度的升高而提高;膨润土对Pb(Ⅱ)的吸附符合Langmuir模型;该吸附是一个自发、吸热,物理表面吸附和化学离子交换吸附并存的吸附过程.
In view of the kinetic and thermodynamics mechanisms, this study discussed the effects of adsorption time , bentonite concentration,adsorption temperature on the adsorption of Pb (Ⅱ) by bentonite. The results showed that bentonite had high adsorption performance to Pb (Ⅱ). The adsorption rate,k,was 0.09 g/(mg·h),following the pseu﹣do﹣second﹣order kinetic equation. The adsorption rate increased with increasing bentonite concentration. Meanwhile , the adsorption rate increased with increasing temperature and fitted the Langmuir model well. The thermodynamic parameters calculated from the temperature﹣dependent adsorption isotherms suggested that the adsorption process of Pb(Ⅱ) was endothermic and spontaneous. The results indicated that the mechanism of Pb (Ⅱ) adsorption by bento﹣nite was based on physical surface adsorption and chemical cation exchange adsorption.