硝基苯和西维因在活性炭上的吸附效果及动力学研究

Sorption and sorption kinetics of nitrobenzene and sevin on activated carbon

测定分析了活性炭的孔隙结构、表面性质及化学组成,研究了硝基苯和西维因在活性炭上吸附的等温线及动力学特征,结果表明Polanyi-Manes模型和二级动力学方程具有较高的拟合相关系数,说明吸附可能是以色散力为主的多过程复杂反应,活性炭对西维因的吸附容量及吸附速率略小于硝基苯,快速吸附过程与慢速吸附过程的差距较为明显,说明吸附质分子大小和吸附剂孔隙结构是影响吸附的重要因素;溶液Na+浓度对吸附的影响很小,可能由于介质离子强度对分子间色散力的影响较小.

Pore structure, surface property and chemical constitution of activated carbon were determined and analyzed. The sorption isotherms and kinetics of nitrobenzene and sevin on activated carbon were examined, respectively. The data demonstrate that Polanyi-Manes model and two-stape dynamics equation fit best with the highest regression coefficients （R2）, implying that sorption may be a multi-process reaction with dominating dynamic of dispersion force. The sorption capacity and rate of sevin onto activated carbon are lower than those of nitrobenzene, and the difference between fast and slow sorption stage is more obvious, indicate that adsorbate molecular size and adsorbent pore structure significantly influence the adsorption. The effect of Na＋ concentration on sorption is slight, possible due to little effect of medium ionic strength on dispersion force among moleculars.