Abstract
This study evaluated the performance of an algal membrane bioreactor (A‐MBR) for secondary wastewater effluent polishing and determined the membrane fouling behavior and dominance of algae in the A‐MBR. The continuous flow A‐MBR (effective volume = 7.2 L) was operated with low biomass wastage for more than 180 days, resulting in an average algal mixed liquor suspended solid concentration of 4922 mg/L. At the influent concentrations of 43 mg/L COD, 1.6 mg/L total phosphorus (TP), and 11.8 mg/L total nitrogen (TN), the effluent COD, TP and TN concentrations were 26 ± 6 mg/L, 0.7 ± 0.3 mg/L, and 9.6 ± 1.2 mg/L, respectively. High‐density algae cultivation facilitated P adsorption and chemical precipitation. However, the TN removal efficiency was only 14% because of low biomass wastage. Although bacteria represented less than 2% of the total biomass in the A‐MBR, bacterial growth in the secondary wastewater effluent accelerated membrane fouling.