Optimization of copper ion removal from aqueous solution using corncob activated carbon supported with nano zero-valent iron adsorbent

Abstract

The removal of Copper ions from aqueous solution using corncob activated carbon supported with nano zero-valent iron (CAC-nZVI) as an adsorbent was studied. Response surface methodology (RSM) based on Box-Behnken Design (BBD) was used to examine the effects of the component variables (initial concentration, pH, adsorbent dosage) and their interactions effect on the adsorption of copper ions. The optimised values of the variables were 58.98mg/L, 0.483g and 7.69 for the initial concentration, adsorbent dosage and pH respectively. The copper ion removal mechanism was studied by fitting experimental data to Langmuir, Freundlich and Temkin isotherms. The results showed that the Freundlich isotherm provided the greatest fit for the adsorption and the reaction proceed according to pseudo-second-order kinetics. The values of thermodynamic parameters were indicative of a spontaneous and endothermic adsorption process.  Hence, corncob activated carbon from agricultural waste supported with nZVI could be used as a viable adsorbent for the treatment of wastewater containing copper.