Comparative study on structural modification of Ceiba pentandra for oil sorption and palm oil mill effluent treatment

Abstract: The performance of raw Ceiba pentandra (L.) Gaertn (raw kapok fibers (RKF)) for oil sorption and palm oil mill effluent (POME) treatment was compared with structurally modified kapok (NaOH-treated (SKF) and surface-modified kapok fiber (SMKF)) and bentonite clay. Based on FTIR, kapok wax functional group at 1726/cm was not detected in SKF rendering higher hydrophilicity. The reduction in peak intensity at 473 and 523/cm upon HCl treatment of bentonite, suggests the cleavage of Si�O�Al bond layer and Si�O�Mg (Fe) bonds. For filtration under gravity at 0.08 g/cm3, SKF showed high POME sorption of 82 g/g, but lower diesel sorption of 23 g/g. With HCl-treated bentonite, POME sorption at 69 g/g was only slightly higher than diesel sorption of 60 g/g. However, RKF and raw bentonite achieved higher removal efficiency of biological oxygen demand, chemical oxygen demand (COD), total organic carbon, and total nitrogen at 74�98 and 72�94, respectively, than with SKF at 66�80, and HCl-treated bentonite at 64�80. In batch mode, SMKF at 0.08 g/cm3 showed the highest oil sorption capacity of 56.7 g/g for Crude Palm Oil (CPO) and 33.7 g/g for diesel. Under continuous mode with 4000 mg/l CPO in water, 99 of COD removal was achieved at all packing densities and flow rates, regardless of kapok packing material. The dynamic oil retention was 96�99 for CPO and 99�100 for diesel at all packing densities. RKF and SMKF can both be suitable sorbent materials for CPO and diesel sorption, and for POME treatment. © 2014 Balaban Desalination Publications. All rights reserved.