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.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal