Optimization of aeration for biodiesel production by Scenedesmus obliquus grown in municipal wastewater
Despite the significant breakthroughs in research on microalgae as a feedstock for biodiesel, its production cost is still much higher than that of fossil diesel. One possible solution to overcome this problem is to optimize algal growth and lipid production in wastewater. The present study examines the optimization of pretreatment of municipal wastewater and aeration conditions in order to enhance the lipid productivity of Scenedesmus obliquus. Results showed that no significant differences were recorded in lipid productivity of S. obliquus grown in primary settled or sterilized municipal wastewater; however, ultrasound pretreatment of wastewater significantly decreased the lipid production. Whereas, aeration rates of 0.2 vvm significantly increased lipid content by 51 %, with respect to the non-aerated culture, which resulted in maximum lipid productivity (32.5 mg L−1 day−1). Furthermore, aeration enrichment by 2 % CO2 resulted in increase of lipid productivity by 46 % over the CO2 non-enriched aerated culture. Fatty acid profile showed that optimized aeration significantly enhanced monounsaturated fatty acid production, composed mainly of C18:1, by 1.8 times over the non-aerated S. obliquus culture with insignificant changes in polyunsaturated fatty acid proportion; suggesting better biodiesel characteristics for the optimized culture.
KeywordsBiodiesel Microalgae Optimization Scenedesmus obliquus Wastewater
We are grateful to the anonymous reviewers for suggesting insightful comments which led to a much improved manuscript. Financial support from Open Project of State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (Project number HCK201508) is highly appreciated.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
- 16.Folch J, Lees M, Sloane Stanley GH (1957) A simple method for the isolation and purification of total lipids from animal tissues. J Biol Chem 226(1):497–509Google Scholar
- 24.Zhang C, Zhang Y, Zhuang B, Zhou X (2014) Strategic enhancement of algal biomass, nutrient uptake and lipid through statistical optimization of nutrient supplementation in coupling Scenedesmus obliquus-like microalgae cultivation and municipal wastewater treatment. Bioresour Technol 171:71–79CrossRefGoogle Scholar
- 39.EN 14214:2008+A1 (2009) Automotive fuels. Fatty acid methyl esters (FAME) for diesel engines. Requirements and test methods. British Standards, ISBN 978 0 580 70781 0Google Scholar