Removal of nutrients from domestic wastewater by microalgae coupled to lipid augmentation for biodiesel production and influence of deoiled algal biomass as biofertilizer for Solanum lycopersicum cultivation

• Published in: Chemosphere (Oxford) Vol. 268; p. 129323
• Main Authors: Silambarasan, Sivagnanam, Logeswari, Peter, Sivaramakrishnan, Ramachandran, Incharoensakdi, Aran, Cornejo, Pablo, Kamaraj, Balu, Chi, Nguyen Thuy Lan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-04-2021
• Subjects: Biodiesel; Biofertilizer; Biofuels - analysis; Biomass; Chlorella; Domestic wastewater; Lipids; Lycopersicon esculentum; Microalgae; Microalgal consortium; Nitrogen; Nutrients; Nutrients removal; Waste Water; Biofertilizer; Nutrients removal; Microalgal consortium; Domestic wastewater; Biodiesel
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.129323

In this study, Chlorella sp., Scenedesmus sp., and their consortium were used for the biorefinery approach. The algal consortium (Chlorella sp. + Scenedesmus sp.) grown well in 75% diluted wastewater, and obtained the highest biomass (1.78 g L−1), chlorophyll (27.03 μg mL−1), protein (175 μg mL−1) and lipid content (34.83% dry cell weight). Algal consortium showed mainly 51.75% of palmitic acid and 35.45% of oleic acid in the lipids. The removal of nitrate, ammonium, phosphate, chemical oxygen demand, total organic carbon and total nitrogen in 75% diluted wastewater by algal consortium were 96%, 98%, 95%, 83%, 86% and 94%, respectively. Moreover, deoiled algal biomass (DAB) waste used as a biofertilizer combined with inorganic fertilizer resulted in the grater improvement of Solanum lycopersicum shoot length (44%), root length (89%), fresh weight (95%), dry weight (53%), macro and micro-nutrients (N 61%, P 179%, K 71%, Ca 38%, Mg 26% and Fe 11%), and tomato yield (174%) as compared to control treatment. Our results indicate that the use of consortium is not only a potential bioresource for wastewater treatment and biodiesel production but also the DAB waste is an effective biofertilizer for sustainable agriculture production.
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•Chlorella sp. + Scenedesmus sp. produced 1.78 g L−1 of biomass in 75% wastewater.•Algal consortium obtained 78–98% nutrients removal rates in 25–100% wastewater.•Algal consortium had higher amount of C16:0 and C18:1 fatty acids in the lipids.•Wastewater grown algal biomass as a potential feedstock for biodiesel production.•Application of 50% DAB3 + 50% NPK fertilizers were improved the tomato plants yield.