Removal of Toluene from Aqueous Solutions Using Oil Palm Shell Based Activated Carbon: Equilibrium and Kinetics Study

This study is an attempt to investigate the adsorption of petroleum hydrocarbon (toluene) from aqueous solutions using granular activated carbon (GAC) synthesized from oil palm shell (OPS) (referred as OPS-based GAC). This study involved a series of batch experiments to determine the adsorption equilibrium and kinetics. The batch experiments were conducted by shaking 200 mL toluene solution containing 0.4 g GAC (initial concentrations of 5, 15, 25 and 30 mg/L) at 180 rpm at 30 degrees C. The OPS-based GAC achieved more than 80% toluene removal in all the experiments. The adsorption capacity of the OPS-based GAC estimated using Freundlich isotherm was 6.039 mg/g (L/mg)(1/n). The adsorption kinetic study showed that the adsorption of toluene was of chemisorption as the experimental data fitted better to the pseudo-second-order kinetic model than the pseudo-first-order kinetic model.