Microalgal consortia technology: A novel and sustainable approach of resource reutilization, waste management and lipid production

The present study was conducted to assess the efficiency of naturally growing competent microalgal consortia (Chlorella vulgaris, Chlorococcum humicola and Nannochloropsis sp.) in the waste remediation of sewage water and lipid production. Results showed that microalgal consortia during wastewater (WW) treatment efficiently utilized the inorganic nutrients (N and P) and exhibited higher growth, biomass and photosystem II activity (Fv/Fo, Fv/Fm, Mo, ETo/RC and Pi(Abs)) as compared to respective individual algal species. SEM data showed clumped morphology and 16.21% increases in the cell size treated with WW. The wastewater treated with microalgal consortia showed reduction in physicochemical parameters viz., conductivity (19.24%), NO3-1 (68.55%), PO4-3 (55.99%), TS (41.31%), TSS (35.48%), TDS (53.32%) and BOD (66.85%) after 15d of treatment. The FTIR spectra (4000-3400 cm(-1)) of algal biomass generated in BG-11 nutrient solution (NS) and wastewater showed higher absorption representing -OH compounds as compared to tap water. Further, the high IR spectral peak length ratio of L/C in microalgal consortia treated with WW exhibited greater lipid accumulation which could be used in the bioenergy production in sustainable way. Thus, species richness and complementary association of algae may be a better solution with multiple benefits of waste reutilization, phycoremediation and lipid yield. (C) 2021 Elsevier B.V. All rights reserved.