Nitrogen removal in photo sequence batch reactor using algae-bacteria consortium

In this study, photo-sequencing batch reactors (PSBR) were setup to evaluate the effect of photoperiod (i.e. 24 h' illumination and 16 h/8 hlight-dark cycle) on NH4+-N removal performance of algae-bacteria consortium under long-term low-light intensity condition. It was observed that constant NH4+-N removal rate of 60 mg N/L/d was achieved in both photoperiods at low light intensity (LI) of 1000 lx. Longer photoperiod favored higher production of biomass. The photoperiod of 16 h/8 h light-dark cycle condition produced less biomass but exhibited same nitrification rate and slightly higher denitrification efficiency (30 mg/L) than the reactor that was operated at 24 h illumination. The results of this study demonstrated that using algae-bacteria consortia could be a sustainable and cost-effective method to treat NH4+-N-loaded wastewater.