화학공학소재연구정보센터
Chemical Engineering Journal, Vol.225, 237-244, 2013
Evaluation of Cs+ removal from aqueous solution by adsorption on ethylamine-modified montmorillonite
In this study, the adsorption performance of ethylamine-modified montmorillonite (Ethyl-Mt) and calcium-saturated montmorillonite (Ca-Mt) were evaluated by Cs+ adsorption experiments considering the influencing factors (initial solution pH, contact time, initial Cs+ concentration, temperature and ionic strength). FTIR, BET, SEM, EDS and Zeta potential analysis were used to characterize the surface properties of Ethyl-Mt and Ca-Mt. Experimental results demonstrated that the equilibrium uptake of Cs+ was highly pH-dependent. Pseudo-second-order model fitted well with the adsorption kinetic studies. The adsorption processes were described by Langmuir model with maximum adsorption capacity of 60.03 mg g(-1) and 80.27 mg g(-1) for Ca-Mt and Ethyl-Mt, respectively. Also, the thermodynamic studies showed that the adsorption of Cs+ was spontaneous and exothermic in nature. The presence of cations such as Na+, K+, Ca2+ astricted the adsorption of Cs+. The Cs+ removal on Ca-Mt was mainly ion exchange, while that on Ethyl-Mt would also involve coordination and surface complexation. On the basis of our results, Ethyl-Mt with high adsorption capacity and good surface characteristics is beneficial to be used for removal of Cs+. (c) 2013 Elsevier B.V. All rights reserved.