Efficient adsorption of heavy metal ions onto diethylamine functionalized calix[4]arene based silica resin

Water might be contaminated by different metal ions, resulting in different waterborne diseases in human and aquatic life. This research study aimed at synthesizing the diethylamine functionalized calix[4]arene based silica (DFCS) resin for the effective removal of heavy metals such as Cd2+, Pb2+, and Hg2+ from water. The DFCS resin was characterized using the FTIR spectroscopy and SEM techniques. The efficiency of the DFCS resin for the removal of metal ions was evaluated by performing equilibrium studies under the optimized conditions. Moreover, the experimental data were subjected to isotherm models; however, the Freundlich model was bestfit one as compared to the Langmuir model. The energy calculated from the DR model was 10.3, 9.7 and 9.2 KJ/mol for Cd2+, Pb2+, and Hg2+,respectively, suggesting that the ion exchange process is involved. The thermodynamic values revealed that the reaction is spontaneous and exothermic, following the pseudo secondorder kinetic model equation.