A special light-aerobic condition for photosynthetic bacteria-membrane bioreactor technology.

The combined photosynthetic bacteria (PSB) and membrane bioreactor (MBR) technology has the great advantage of simultaneously realizing wastewater purification and bio-resource recovery and has attracted increasing attention in recent years. Light-oxygen conditions are the most vital factor in wastewater treatment. The special light-aerobic condition was first applied to PSB-MBR wastewater treatment, and it was compared with three typical light-oxygen conditions. The results showed that the highest chemical oxygen demand (COD) removal efficiency (96.28%) and the highest biomass production (1.12 g/L/d) were simultaneously obtained under light-aerobic condition. This phenomenon overcame the limitations whereby optimal pollutant removal and bio-resource recovery could not be achieved at the same time. An analysis of the microbial community showed that different light-oxygen conditions caused large variations in the microbial community composition of PSB-MBR. The microbial diversity was lower when light and oxygen co-existed.