Incorporation of Copper/Melamine Complexes in Silica Surface Andtheir Sorption Activity of Organic Dye

Abstract

The efficiency and performance of supported melamine/ copper complexes, S/[CuCl2(Mel)2].2MeOH, as a new adsorbent, for the adsorptive removal of Indigo Carmine (IC) from aqueous solutions, has been evaluated with respect to several experimental conditions including contact time, initial IC concentration, temperature and adsorbent dosage. The maximum removal percentage (approximately 84%) was observed when used 0.05 g/L of S/[CuCl2(Mel)2].2MeOH, 1.5 x 10-5mol/L of initial IC concentration and contact time of 15min. The experimental data were analyzed by the Langmuir, Freundlich, and Tempkin isotherm models. The monolayer adsorption capacity of S/[CuCl2(Mel)2].2MeOHwas found to be 16.8 x 10-3mol/g by using Langmuir isotherm model. The calculation of the thermodynamic parameters such as Gibbs free energy, entropy and enthalpy changes of the ongoing adsorption process indicated the feasibility and endothermic nature of IC adsorption. The kinetics study suggested that the adsorption of IC onto S/[CuCl2(Mel)2].2MeOH proceeds according to the pseudo-second-order model.