Cultivation of Chlorella vulgaris on wastewater containing high levels of ammonia for biodiesel production

• Published in: Bioresource technology 2013-02, Vol.129, p.177-181
• Main Authors: He, P.J., Mao, B., Shen, C.M., Shao, L.M., Lee, D.J., Chang, J.S.
• Format: Article
• Language: English
• Subjects: Ammonia; Ammonia - isolation & purification; Ammonia - metabolism; Applied sciences; Biodiesel; Biodiesel production; Biofuel production; Biofuels - microbiology; Biological and medical sciences; Bioreactors - microbiology; Biotechnology; Chlorella vulgaris; Chlorella vulgaris - metabolism; Cultivation; Energy; Exact sciences and technology; Fatty acids; Feasibility; Feasibility Studies; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Lipids; Methane - isolation & purification; Methane - metabolism; Nitrogen - isolation & purification; Nitrogen - metabolism; Pollution; Waste water; Waste Water - chemistry; Waste Water - microbiology; Wastewater treatment; Wastewaters; Water Pollutants, Chemical - isolation & purification; Water Pollutants, Chemical - metabolism; Water Purification - methods; Water treatment and pollution
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2012.10.162

► Composition of microalgal cells depends on the composition of the wastewater feeds. ► FAME composition of the cultivated C. vulgaris is suitable for biodiesel production. ► Increasing NH4+-N yielded additional short-chain and saturated fatty acids. The feasibility of cultivating Chlorella vulgaris with wastewater containing high ammonia nitrogen concentrations was examined. The average specific growth rate of C. vulgaris was 0.92d−1 at 17mgL−1 NH4+-N, but declined to 0.33d−1 at NH4+-N concentrations of 39–143mgL−1. At 39mgL−1 NH4+-N, lipid productivity reached a maximum value (23.3mgL−1d−1) and dropped sharply at higher NH4+-N levels, which demonstrated NH4+-N should be controlled for biodiesel production. C16 and C18 fatty acids accounted for 80% of total fatty acids. Increasing NH4+-N from 17 to 207mgL−1 yielded additional short-chain and saturated fatty acids. Protein content was in positive correlation with NH4+-N content from 17mgL−1 (12%) to 207mgL−1 (42%). Carbohydrate in the dried algae cell was in the range of 14–45%, with a peak value occurring at 143mgL−1 NH4+-N. The results demonstrate that product quality can be manipulated by NH4+-N concentrations of the initial feeds.