Illumination factors can affect growth of microalgae and HCO3− fixation. In order to optimize microalgae growth in culture system and HCO3− fixation from wastewater, the effects of light source, light interval on the growth of microalgae, Chlorella sp. and Scenedesmus obliquus sp., were studied in experiment culture system. The effects of light intensity and available illumination area on HCO3− fixation of microalgae were also considered. Microalgae were grown in a constant light incubator-shaking table experiment system (CLIST system) to assess biomass, pH, DO, and HCO3− concentration at 30°C cultivation temperature. The light interval evaluated were 15min, 1h, 4h, 8h and 12h, respectively. HCO3− fixation of microalgae was investigated at five different light intensities (1000, 2000, 3700, 6800 and 8200lux) and four available illumination areas (45, 80, 120, 200cm2) in CLIST system. Under the light interval of 12:12, light intensity of 6800lux and available illumination area of 200cm2, the removal rate of HCO3− in the water was found to be 65.7%, with a maximum biomass concentration above 1400mg/L. In this study, 0.953g HCO3− in per litre of wastewater would be captured by microalgae, in other word, producing 1.00g of microalgae biomass fixed 1.10g of HCO3−.
