EFFLUENT MANAGEMENT OF PALM OIL FACTORY WITH OZONE TREATMENT BEFORE BIOGAS PRODUCTION

Abstract

Most of the effluent from palm oil factories is used to produce biogas, but the amount of gas obtained has not been very high, since there is a high content of palm sludge in the wastewater. At the end of fermentation, the resulting wastewater and sediment may be released into the water sources, causing environmental problems. This research aims to use ozone to treat palm oil wastewater before they are used to produce biogas. Wastewater used in this study was from a Palm oil extraction plant and had 70-80 per cent of decanter sludge. Ozone producing machine generates ozone at 1 g/h, 2 g/h, 3 g/h and 4 g/h was used for pre-treatment the decanter sludge for 0, 10, 20, 30, 40, 50, and 60 minutes. When pre-treatments of the waste with different ozone concentrations and exposure times, it was found that the optimal condition was ozone 2 g/h for 30 min. This could increase BOD from 49.98±0.90 g/l to be 69.60±1.02 g/l and Reducing sugar from 4.41±0.09 g/l to be 5.48±0.03 g/l. The TS was decreased from 74.20±1.96 to 52.05±0.10 and COD from 90.40±0.80 g/l to be 51.20±0.07 g/l. Biogas production from ozone pretreated wastewater gave significantly higher amount of biogas than from untreated wastewater (p<0.05). The biogas from the pretreated waste had better quality than the untreated waste for having significantly more methane (p<0.05).