Optimization of bromate adsorption onto Fe-CNTs nanocomposite using response surface methodology

Abstract

This study was aimed at employing response surface methodology (RSM) for optimization of process variables and identifying optimal conditions for the adsorption of bromate (BrO₃-) from contaminated water using multi-walled carbon nanotubes, based on iron hydr(oxide), Fe-CNTs nanocomposite. Fifteen experimental runs were conducted in batch mode to study the effect of individual as well as interactive process variables,  i.e., pH, BrO₃− initial concentration, and adsorbent dose, on the removal of BrO₃− using Box–Behnken design (BBD) of RSM. The coefficient of determination (R²) at 98.34% indicated a good agreement between actual and predicted values. The main effect and contour plot were drawn to obtain the independent and interactive effect of operational variables on BrO₃− uptake. A process optimization curve was drawn to determine the optimum operating conditions that lead to a desirable response. The optimum conditions for BrO₃− adsorption using Fe-CNTs nanocomposite were found to be pH 2.0, initial BrO₃− concentration of 10.0 mg/L, and adsorbent dose of 0.010 g per 50 mL solution.