Kinetics, equilibrium and thermodynamic studies of adsorption of oil from oil-in-water emulsion by activated charcoal

Studies have been made on the effectiveness of powdered activated charcoal (PAC) for separating oil from oil-in-water emulsion. The present paper deals with the characterisation of oil-in-water emulsion and PAC before and after adsorption. From the BET surface area analysis it was found that the pore volume of activated charcoal after adsorption of oil decreased from 0.573 cc/g to 0.109 cc/g and surface area decreased from 383.016 m(2)/g to 73.072 m2/g. A maximum 98.8% separation of oil was obtained by adsorption of emulsion onto PAC at optimum condition. From the study of different adsorption isotherm it was found that Freundlich isotherm is the best way to describe the adsorption of oil from oil-water emulsion by PAC. Adsorption of emulsion on PAC follows both pseudo-first order and pseudo-second order kinetic model. Thermodynamic studies indicate that adsorption is feasible, spontaneous and exothermic in nature.