Cultivation of newly isolated microalgae Coelastrum sp. in wastewater for simultaneous CO2 fixation, lipid production and wastewater treatment

• Published in: Bioprocess and biosystems engineering 2018-04, Vol.41 (4), p.519-530
• Main Authors: Mousavi, Shokouh, Najafpour, Ghasem D., Mohammadi, Maedeh, Seifi, Mohammad Hasan
• Format: Article
• Language: English
• Subjects: Algae; Animal wastes; Batch culture; Biomass; Biotechnology; Carbon dioxide; Carbon dioxide fixation; Carbon sequestration; Cattle manure; Chemistry; Chemistry and Materials Science; Coelastrum; Consumption; Cultivation; Environmental Engineering/Biotechnology; Food Science; Gas flow; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Leachates; Light; Light intensity; Lipids; Luminous intensity; Microalgae; Nutrient removal; Productivity; Research Paper; Wastewater treatment
• ISSN: 1615-7591; 1615-7605
• DOI: 10.1007/s00449-017-1887-7

Cultivation of microalgae in wastewater is a promising and cost-effective approach for both CO 2 biofixation and wastewater remediation. In this study, a new strain of Coelastrum sp. was isolated from cattle manure leachate. The isolated microalgae were then cultivated in wastewater. Effects of different sCOD concentrations (600, 750, 900, 1050 mg L −1 ) and light intensities (1000, 2300, 4600, 6900 and 10000 Lux) on biomass production, CO 2 consumption rate and nutrient removal from wastewater were investigated. The results showed that maximum cell growth and CO 2 consumption rate were 2.71 g L −1 and 53.12 mg L −1 day −1 , respectively, which were obtained in the wastewater with 750 mg L −1 sCOD and under the light intensity of 6900 Lux. The microalgae were able to completely consume all CO 2 after incubation period of 4 days. The highest sCOD, total Kjeldahl nitrogen (TKN), nitrate and total phosphorous (TP) removal at such conditions were 53.45, 91.18, 87.51 and 100%, respectively. The lipid content of microalgal biomass was also measured under different light intensities; maximum amount of lipid was determined to be 50.77% under illumination of 2300 Lux. Finally, the CO 2 consumption rate and biomass productivity of microalgae in semi-batch culture with continuous gas flow (CO 2 6%:N 2 94%) were investigated. The rate of CO 2 consumption and biomass productivity were 0.528 and 0.281 g L −1 day −1 , respectively. The TKN, nitrate, TP and sCOD removal rate of microalgae were 83.51, 80.91, 100, 41.4%, respectively.