The wastewater treatment and biomass settleability were enhanced
through the synergistic cooperation between wastewaterborn
algae and activated sludge. More than 91.2% of COD was removed
regardless of algae and sludge inoculation ratios. The reactor
with 5:1 (algae/sludge) culture reached the highest total
nitrogen and phosphorus removal efficiency (91.0 ± 7.0% and
93.5 ± 2.5%, respectively) within the shortest time (10 days). Biomass
uptake was identified as the main nitrogen and phosphorus
removal mechanism. Besides, the biomass settleability was improved
with proper inoculation ratio. Furthermore, different algae/
bacteria inoculation ratios lead to different bacterial
community compositions, which might contribute to the different
treatment performance.