Biomass Fuel Production through Cultivation of Microalgae Coccomyxa dispar and Scenedesmus parvus in Palm Oil Mill Effluent and Simultaneous Phycoremediation

Abstract

Palm oil mill effluent (POME) is a potential alternative sources of biomass fuel upon phycoremediation treatment using microorganisms. In this study, Coccomyxa dispar and Scenedesmus parvus, as acidophilic microalgae, were used to investigate growth and the production of biomass fuel from the cultivation of POME, as well the effectiveness of removing contaminants from POME. Individual cultivation was conducted at 26 ± 3 °C for 14 days under three growth modes (mixotrophic, heterotrophic, and autotrophic). To elucidate the potential phycoremediation properties, the characteristics of treated POME were compared, such as optical density (OD), cell dry weight (CDW), calorific energy values (CEV), chemical oxygen demand (COD), biochemical oxygen demand (BOD), carbon, hydrogen, and nitrogen (CHN) elemental analysis, including oil and grease content. S. parvus exhibits an outstanding growth profile for all growth modes compared to C. dispar, with measurements of 228.8, 37.08, and 118.2 mg/L observed at day 14 of cultivation. The highest CEV is 32.30 MJ/kg, which was obtained from S. parvus in the mixotrophic mode. Maximum removal efficiency for COD and BOD was 81% and 19% in the mixotrophic growth mode with S. parvus. These results pinpoint that S. parvus has the potential to be utilized for biomass fuel production with high CEV and effective POME phycoremediation.