D‐Galactose based hydrophobic ionic liquid: A new adsorbent for the removal of Cd2+ ions from aqueous solution.

The present study reports the synthesis of D‐galactose based hydrophobic ionic liquid (IL) and its potential application in the removal of Cd2+ ions from aqueous solution. The synthesized D‐galactose based hydrophobic ionic liquid is insoluble in water and stable at room temperature as a solid. Batch adsorption studies were carried out to investigate the sorption capacity of IL toward Cd2+ ions. The experimental data was analyzed with various isotherm and kinetic models to understand the adsorption process. The Arrhenius activation energy was found to be 12.7 and 22.5 kJ/mol, respectively, for 10 and 30 mg/L of initial metal ion concentration suggesting physisorption of Cd2+ ions on to IL. The thermodynamic parameters suggest that the present process is spontaneous and exothermic in nature. The present IL exhibited superior adsorption capacity toward Cd2+ ions in presence of other co‐cations in aqueous solution. These results suggest that, the synthesized IL can be a superior adsorbent for the removal of Cd2+ ions from aqueous solution. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S139–S145, 2019 [ABSTRACT FROM AUTHOR]