Copper oxide incorporated mesoporous alumina for defluoridation of drinking water

In the present study mesoporous alumina was modified by coating copper oxide to enhance the defluoridation of water. The copper oxide coated alumina (COCA) was synthesised by impregnating alumina with copper sulphate solution followed by calcination at 450 °C in presence of air. The COCA was thoroughly characterised using powder XRD, SEM and BET surface area analysis. It was observed that coating of copper oxide improves the adsorption capacity of unmodified alumina from 2.232 to 7.770 mg g−1. Various adsorption isotherm and kinetic parameters were computed using batch adsorption studies to determine the adsorption capacity and to understand the mechanism of adsorption. The results revealed that the adsorption follows Langmuir isotherm and pseudo-second-order kinetic models. The adsorption capacity obtained from Langmuir isotherm plots were 3.155 mg g−1. Assessment of the water quality before and after treatment with COCA also confirmed that the there is no leaching of copper and other parameters were also within permissible limits of Indian drinking water standard indicating that the COCA can be used for treatment of fluoride contaminated drinking water.