Abstract
Chitosan, poly-β-(1,4)-2-acetamido-2-deoxy-Đ-glucose (N-deacetylated) was used as an adsorbent to adsorb the excess oil from oily wastewater. Chitosan is a biodegradable cationic biopolymer achieved by the extensive deacetylation of chitin obtained from prawn shell waste.
Palm oil mill effluent (POME) is one of the major problematic oily wastewaters in Malaysia. Preliminary analysis showed that POME contains ca. 2000 mg/l residue oil. A bench-scale study of the adsorption by chitosan of residue oil in POME was conducted using a jar-test apparatus. Effects of experimental parameters such as the dosage of chitosan in powder and flake form, contact time, mixing rate, settling time and pH were studied in order to obtain the optimum conditions for the adsorption of residue oil from POME.
The results obtained showed that chitosan powder, at a dosage of 0.5 g/l and employing a contact time of 15 min, a mixing rate of 100 rpm, sedimentation for 30 min and a pH value of 5.0, provided the most suitable conditions for the removal of residue oil from POME. The removal efficiencies obtained were ca. 97–99%. FT-IR spectra and SEM micrographs of chitosan before and after adsorption were presented to prove that the residue oil had been adsorbed by chitosan.