Lignin black liquor degradation on oil palm empty fruit bunches using ilmenite (FeO.TiO2) and its activity as antibacterial

Abstract

Lignin from oil palm empty fruit bunches (OPEFB) has been degraded using ilmenite mineral (FeO.TiO2). The FeO.TiO2 was examined for antibacterial activity against E. coli, S. aureus, S. typhi, and X. oryzae. It was extracted from iron sands by a magnetic separator and pre-oxidized at 800°C for 5 hours. Meanwhile, OPEFB was prepared with a pretreatment process using 10% NaOH solution to damage ester bonds between lignin, hemicellulose, and cellulose. Furthermore, the lignin was degraded by using FeO.TiO2 catalyst with the study of catalyst mass, degradation time, and lignin concentration variation. Based on XRF and XRD data indicated that the pre-oxidation result of iron sand was contained Fe2O3 (hematite) and FeO.TiO2 minerals with the highest dominant of Fe content in the sample. The result of lignin photodegradation using FeO.TiO2 catalyst showed that the lignin-derived compound obtained was Coniveryl Alcohol (C10H12O3). Antibacterial activity test against 4 bacterial samples i.e E. coli, S. aureus, S. typhi, and X. oryzae showed that each test has good activity in inhibiting bacteria with a range of inhibiting diameter zone between ±20 nm. Based on this study provides that lignin-derived compounds from OPEFB can be used as a natural antibacterial.