Optimization of sugarcane bagasse activation to achieve adsorbent with high affinity towards phenol

Abstract

Sugarcane bagasse as an agricultural/industrial biomass was converted into a low-cost activated carbon via anacid activation procedure under optimized conditions. Phosphoric acid was applied as a cost-effective and environmentallyfriendly chemical activator. The optimized activated carbon produced under temperature of 550 °C and impregnationratio of 1.5 showed a micromesoporous structure with specific surface area and pore volume of 972.5 m2/g and 0.43cm3/g, respectively. The adsorption capacity of the produced AC towards phenol was measured and, after only 30 min,the removal percentage reached over 95%. The greatest affinity towards phenol was obtained at pH of 4 justified by thepHpzc of the sorbent and speciation of phenol in solution. Under the intermediate concentration range, the Dubinin–Radushkevich isotherm was the best-fit model for describing the equilibrium data. The apparent adsorption energy wasequal to 10.94 kJ/mol. All the evidence showed that the mechanisms involved in phenol adsorption were ion-exchange,electrostatic, and physical adsorption.