Simultaneous removal of phenol and cyanide from aqueous solution by adsorption onto surface modified activated carbon prepared from coconut shell

The present study is devoted to the elimination of phenol and cyanide from binary component aqueous solution by adsorption onto copper impregnated coconut shell activated carbon (Cu-CSAC). Effects of initial concentration, adsorbent dose, pH, temperature and contact time on phenol and cyanide elimination have been examined. At an optimum temperature 30 degrees C, pH 8, and the adsorbent dose of 40 g/L, 71.43% phenol and 86.8% cyanide were removed from binary aqueous solution comprising 300 mg/L of phenol and 30 mg/L of cyanide. The isotherm modeling study is carried out by accompanying batch experiments at range of initial concentration 100-1000 mg/L of phenol and 10-100 mg/L of cyanide. Three mono component isotherm model and six binary component isotherm models were considered. The model parameters were predicted by using non-linear regression analysis technique. It was observed that the experimental data indicate a better fit with an Extended Freundlich isotherm model for adsorption of phenol and cyanide in the binary component system. The adsorption efficiency of Cu-CSAC was observed to be 239.85 mg/g of phenol and 5.30 mg/g of cyanide. The mechanism of adsorption process was found chemisorption followed by Pseudo second order kinetics. Thermodynamic studies indicated the adsorption process onto Cu-CSAC as endothermic nature and reversible. (C) 2016 Elsevier Ltd. All rights reserved.