Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
148675 | Chemical Engineering Journal | 2013 | 8 Pages |
•A novel material was found to remove radiocesium effectively.•Different adsorption behaviors between modified and raw clay were compared.•The adsorption mechanism was discussed through the chemical process.
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+.
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