Enhancing the biomass production of microalgae by mixotrophic cultivation using virgin coconut oil mill effluent
Resti Nurmala Dewi, Mahreni, Muhamad Maulana Azimatun Nur, Al Ansor Siahaan, Arbayu Candra Ardhi
Abstract
Skim is a major by-product of the virgin coconut oil (VCO) industry consisting of nutrients and is currently discharged to the environment as waste. Hence, this research aimed to utilize skim as a medium for Botryococcus braunii and Chlorella vulgaris growth. The effect of organic carbon resourced from glucose and glycerol on biomass was also investigated at certain concentrations with intervals 100:0 to 0:100 (%). Results indicated that Botryococcus braunii and Chlorella vulgaris cultivated under 20% VCO mill effluent gave the highest biomass production, which accounts for 1.69 g/L and 5.34 g/L; 89.40% and 86.70% COD reduction efficiency. Whereas, mixotrophic condition showed a positive trend for Botryococcus braunii at 80:20 (glucose:glycerol) with 5.60 g/L biomass production and 97.64% COD removal efficiency. Vice versa, the addition of glucose:glycerol gave an inhibitory impact on Chlorella vulgaris as the biomass production was merely 1.66 g/L with COD efficiency 94.03%.