Removal of Cu2+ and Ni2+ from aqueous solution using SnO2 nanomaterial effect of: pH, time, temperature, interfering cations

Abstract Tin oxide, SnO 2 , nanomaterial was synthesized and tested for the removal of Cu 2+ and Ni 2+ ions from aqueous solutions. Various parameters for the binding were investigated in batch studied, which included pH, time, temperature, and interferences. In addition, isotherm studied was performed to determine the maximum binding capacity for both Cu 2+ and Ni 2+ ions. The optimal binding pH determined from the effects of pH were to be at pH 5 for both the Cu 2+ and Ni 2+ ions. The isotherm studies were performed at temperatures of 4 °C, 25 °C, and 45 °C for both the Cu 2+ and Ni 2+ ions and were found to follow the Langmuir isotherm model. The binding capacities for the Cu 2+ ions were 2.63 mg/g, 2.95 mg/g and 3.27 mg/g at the aforementioned temperatures, respectively. Whereas the binding capacities for Ni 2+ were 0.79 mg/g, 1.07 mg/g, and 1.46 mg/g at the respective temperatures. The determined thermodynamic parameters for the binding showed that the binding processes for the reactions were endothermic, as the ΔG was observed to decrease with decreasing temperatures. As well the ∆H was 28.73 kJ/mol for Cu 2+ (III) and 13.37 kJ/mol for Ni 2+ . The ∆S was observed to be 92.65 J/mol for Cu 2+ and 54.53 J/mol for Ni 2+ . The free energy of adsorption for the Cu 2+ was determined to be 13.99 kJ/mol and the activation energy for the binding of Ni 2+ was determined to be 8.09 kJ/mol. The activation energy data indicate that the reaction was occurring through chemisorption.