Decolorisation of Biologically Treated Palm Oil Mill Effluent (POME) Using Adsorption Technique

An experimental study was conducted on the adsorption of color from biologically treated POME using palm kernel shell (PKS) and empty fruit bunches (EFB) as natural biosorbents, and activated carbon prepared from them by microwave and chemical activation with potassium hydroxide (KOH). BET surface area of all sorbents was determined and 1252 m 2 .g -1 was recorded for activated carbon prepared from PKS by chemical and microwave method (PKSCM). Adsorption performance was investigated as a function of contact time, adsorbent concentration, and pH. The adsorbents studied exhibit high efficiency for color adsorption. Adsorption increased with increasing contact time and the equilibrium states could be achieved in 12 hr. Optimum dose of adsorbents was found at 5g/100ml. The maximum uptake of color by all adsorbents occurred at pH of 2. A maximum percentage of color removal of 100% was obtained at the optimum conditions for PKSCM. Results were analyzed by the Langmuir and Freundlich isotherm models. Based on regression coefficient equilibrium, the data was found to fit well to the Langmuir equilibrium model. Pseudo-first order, pseudo-second order, and second order kinetic models were used to test the adsorption kinetics. Evaluation of experimental data indicated that the surface adsorption of color follows the pseudo-second order equation.