CO2 bio-fixation and biofuel production in an airlift photobioreactor by an isolated strain of microalgae Coelastrum sp. SM under high CO2 concentrations

• Published in: Environmental science and pollution research international 2018-10, Vol.25 (30), p.30139-30150
• Main Authors: Mousavi, Shokouh, Najafpour, Ghasem D., Mohammadi, Maedeh
• Format: Article
• Language: English
• Subjects: Algae; Aquatic microorganisms; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Biodiesel fuels; Biofuels; Carbohydrates; Carbon dioxide; Carbon dioxide fixation; Carbon sequestration; Coelastrum; Cultivation; Diesel; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fatty acids; Lipids; Microalgae; Nutrient removal; Photosynthesis; Research Article; Waste Water Technology; Wastewater; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-018-3037-4

Microalgae cultivation is a promising approach to remove ambient CO 2 via photosynthesis process. This paper investigates the impact of high CO 2 concentrations (6, 12, and 16%) on algae growth, CO 2 biofixation, lipid and carbohydrate contents, and nutrient removal of newly isolated microalgae, Coelastrum sp. SM. In addition, the ability of microalgae to produce biodiesel at optimal condition was studied. The microalgae were cultivated in wastewater using an airlift photobioreactor. Under 12% CO 2 , the maximum biomass productivity and CO 2 fixation rate were 0.267 g L −1  day −1 and 0.302 g L −1  h −1 , respectively. Total Kjeldahl nitrogen (TKN), total phosphorous (TP), nitrate, and sCOD removal efficiency were 84.01, 100, 86.811, and 73.084%, respectively. Under 12% CO 2 and at the same condition for cell growth, the highest lipid and carbohydrate contents were 3 7.91 and 58.45%, respectively. The composition of fatty acids methyl ester (FAME) of the microalga lipid was defined. Based on the obtained results and FAME profile, Coelastrum sp. SM was a suitable feedstock for biodiesel production and also, the organism had a great potential for CO 2 biofixation, which is also more suitable than any other reported strains in other related studies.