Cultivation of microalgae species in tertiary municipal wastewater supplemented with CO2 for nutrient removal and biomass production

This study demonstrates the potential for algae-based biofuel production by coupling advanced wastewater treatment with microalgae cultivation for low-cost lipid production. Three species (Chlorella vulgaris, Scenedesmus obliquus and Ourococcus multisporus) with higher biomass yield were selected and cultured in wastewater amended with 15% CO2. C. vulgaris, S. obliquus and O. multisporus showed optimal specific growth rates (μopt) of 1.37, 1.14 and 1.00 day−1, respectively, and almost complete removal (>99%) of nitrogen and phosphorus within 4 days. The highest specific lipid productivity was 0.164 g-lipids g-cell−1 day−1 and oleic acid was increased to 44% in C. vulgaris after 7 days of cultivation in the presence of CO2. It was concluded that C. vulgaris is a good potential source for the production of biodiesel coupled with nutrient removal from wastewater.