Applying Ozone in Cattle Wastewater to Maximize Lipid Production in Microalgae Biomass

• Published in: Bioenergy research 2023-12, Vol.16 (4), p.2489-2501
• Main Authors: Lomeu, Alice Azevedo, de Oliveira Moreira, Olívia Brito, de Oliveira, Marcone Augusto Leal, de Mendonça, Henrique Vieira
• Format: Article
• Language: English
• Subjects: Air pollution; Algae; Ammonia; Animal wastes; Aquatic microorganisms; Biodiesel fuels; Biofuels; Biomass; Biomass energy; Biomedical and Life Sciences; Bioremediation; Carbon dioxide; Carbon dioxide fixation; Cattle; Consortia; Deposits; Energy consumption; Energy minerals; Farms; Fossil fuels; Life Sciences; Lipids; Microalgae; Oil exploration; Ozone; Photobioreactors; Plant Breeding/Biotechnology; Plant Ecology; Plant Genetics and Genomics; Plant Sciences; Wastewater; Wood Science & Technology
• ISSN: 1939-1234; 1939-1242
• DOI: 10.1007/s12155-023-10564-z

The increased demand for energy results in an increase in fossil fuel consumption. However, the planet’s oil deposits will soon reach unsustainable levels, presenting an opportunity for biofuels. In this study, cattle wastewater (CWW) was used to cultivate a microalgae consortium in photobioreactors. Seven rounds of experiments were carried out with the addition of CO 2 (ControlCO 2 ), ozone application for 10, 20, and 30 min (O 3 T10, O 3 T20, and O 3 T30), and a combination of CO 2 and ozone (O 3 T10CO 2 and O 3 T20CO 2 ). Maximum dry biomass (18.63 g/L) and CO 2 biofixation (8047.79 mg/L/d) were obtained in O 3 T20CO 2 . A total of 48% of lipid was registered in O 3 T30 and O 3 T20, indicating that microalgae were stressed when exposed to ozonized wastewater. C16:0 was detected in higher concentrations in all experiments. O 3 T30, O 3 T10CO 2 , and O 3 T20CO 2 had values for C18:3 in accordance with the requirements of EN 14,214. Projections show that a farm with 2000 animals could produce 430 g of biofuels per kg of biomass and fixed 2.67 tCO 2 /y. Removals of up to 100% for NH 3 –N, 99.6% for P, and 91.7% for COD were recorded. The data indicates a possibility for CWW bioremediation and biofuel production in significant quantity and quality in comparison to the current scenario of microalgae cultivation.