Adsorption and Desorption Performance of Dichloromethane over Activated Carbons Modified by Metal Ions

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• 作者：Hongyan Pan ; Min Tian ; Hui Zhang ; Yu Zhang ; Qian Lin
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2013
• 出版时间：September 12, 2013
• 年：2013
• 卷：58
• 期：9
• 页码：2449-2454
• 全文大小：354K
• 年卷期：v.58,no.9(September 12, 2013)
• ISSN：1520-5134

文摘

Activated carbons (ACs) were modified separately by impregnation with different types of metal ions, Al³⁺, Mg²⁺, Li⁺, Fe³⁺, and Ag⁺ in this work. Adsorption breakthrough experiments of dichloromethane (DCM) were carried out for measuring working adsorption capacities (Q_m) of modified ACs toward DCM, and temperature programmed desorption (TPD) experiments were conducted for estimating desorption activation energy (E_d) of DCM on these ACs. The effects of metal ions on the adsorption/desorption of DCM on the modified ACs were discussed with the help of hard and soft acid and base (HSAB) theory. Results showed that Q_m of DCM on these ACs followed the order: Q_Al(III)/AC > Q_Li(I)/AC > Q_Mg(II)/AC > Q_Fe(III)/AC > Q_AC > Q_Ag(I)/AC, and the E_d of DCM followed the same order. As compared to that of the original AC, the surface local acid hardness of the modified ACs was enhanced with the doping of hard acid metal ions such as Al³⁺, Li⁺, Mg²⁺, and Fe³⁺, and thus the interactions between DCM and Al(III)/AC, Li(I)/AC, Mg(II)/AC, and Fe(III)/AC surfaces were also enhanced due to the hard base characteristic of DCM. However, when the AC was doped with soft acid Ag⁺, its surface local acid hardness was decreased. As a result, the interaction between DCM and Ag(I)/AC was weakened.