Statistical experimental design and bioreactor strategies were applied to enhance CO 2 fixation ability of microalga Scenedesmus obliquus CNW-N. Four operating parameters strongly influencing microalgal CO 2 fixation efficiency (namely, CO 2 concentration, CO 2 flow rate, magnesium concentration, and light intensity) were optimized with response surface methodology. The optimal range of parameters achieving the best overall performance of specific growth rate and CO 2 fixation rate was determined with overlay counter plot techniques. Optimal ranges of CO 2 concentration, CO 2 flow rate, magnesium concentration and light intensity were 2.0-2.5%, 0.3-0.5vvm, 1.7-2.7mM and 180-250μmolm -2s -1, respectively, achieving a specific growth rate of >1.22d -1 and CO 2 fixation rate of >800mgL -1d -1. Semi-batch operations further enhanced the biomass productivity, photosynthesis efficiency, and CO 2 fixation rate to 1030mgL -1d -1, 10.5%, and 1782mgL -1d -1, respectively. This performance is better than the results reported by most related studies.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal