Development of scalable cultivation strategy for microalgal biomass generation using wastewater and integrated biorefinery approach for biofuel production

Microalgal biomass production using wastewater (WW) is a sustainable approach for economically viable biorefinery. The present study aims to develop a scalable cultivation strategy using novel microalgae strain Marvania coccoides for biofuels production. The cultivation strategy based on nutrient supplementation is developed at lab-scale (1 L) and validated at open-raceway pond system (200 L). Nutrient-supplemented wastewater (OWW) showed higher biomass productivity at both lab-scale (87.36 mg.L−1.d−1) and open pond system (133.89 mg.L−1.d−1) as compared to synthetic media. Biodiesel yield of 92.30 % was achieved upon transesterification of lipids from OWW (200 L) medium. Moreover, the residual biomass, i.e., lipid-extracted microalgal (LEM) biomass, yielded in 26.65 % of bio-oil and 56.94 % of biochar upon non-catalytic pyrolysis. Bio-oil and biochar produced were analyzed using element analyzer, gas chromatography-mass spectrometry (GC-MS), and fourier-transform infrared spectroscopy (FTIR). This scalable cultivation strategy for microalgae and biorefinery approach for production of biodiesel, bio-oil and biochar is sustainable solution for managing wastes and generation of biofuels. [Display omitted] •Novel microalgae Marvania coccoides was cultivated in domestic wastewater (WW).•Nutrient supplementation in WW enhanced biomass and lipid productivity.•Scaling-up microalgae cultivation showed 1.5-fold increase in biomass productivity.•Biodiesel yield of 92.30 % was observed from conversion of microalgal lipids.•Lipid-extracted microalgae (LEM) showed 26.65 % bio-oil and 56.94 % biochar yield.