Response surface methodology for optimization of phenol adsorption by activated carbon: Isotherm and kinetics study

Abstract

The effect of four different parameters such as pH, initial phenol concentration, adsorbent dose and temperature on the adsorptive removal of phenol from aqueous solution over commercial granular activated carbon (GAC) has been studied. Two-level full factorial design (FFD) combined with response surface methodology (RSM) have applied to find the best operating conditions. The optimum pH, initial phenol concentration, adsorbent dose and temperature have been found by applying desirability function (DF) to be 6, 1000 mg/L, 3 g and 28.75°C. The granular activated carbon has been characterized using different physicochemical methods. The experimental data best fits in Freundlich isotherm Equation and the removal follow pseudo-first-order kinetics. Thermodynamic parameter reveals that the removal process is feasible, exothermic and spontaneous in nature. The adsorbent is regenerated with 0.1 M NaOH solution for further reuse.