Comparative Performance of A²/O and a Novel Membrane‐Bioreactor‐Based Process for Biological Nitrogen and Phosphorus Removal

Abstract

The comparison between a novel membrane bioreactor (MBR) system and a conventional anaerobic-anoxic-aerobic (A 2 /O) system was conducted using synthetic wastewater (SWW) and municipal wastewater (MWW). Each system was operated at an overall hydraulic retention time of 8 hours and solids retention time of 10 days. The MBR exhibited better overall system performance than the A 2 /O system, in terms of phosphorus removal. Nitrogen removal efficiencies were close in the two systems at 73 to 74% in both runs, while phosphorus removal efficiencies were 96 and 74% (SWW run) and 80 and 75% (MWW run), for the MBR and A 2 /O, respectively. Effluent soluble chemical oxygen demand (COD) was less than 15 mg/L in the two systems during both runs. Phosphorus uptake by denitrifying phosphate-accumulating organisms accounted for 49% of the total uptake in the MBR compared with 33% in the A 2 /O during the SWW run. The dynamic test clearly showed that the MBR had better denitrification capacity than the A 2 /O system. The MWW run indicated that MBR ferments particulate COD better than A 2 / O. The effect of the intermediate clarifier on MBR phosphorus removal was significant, with phosphorus uptake of 0.16 g/d in the SWW run and phosphorus release of 0.08 g/d in the MWW run, thus enhancing the total phosphorus removal in both cases. Water Environ. Res., 82, 69 (2010).

Membrane Processes

“…The comparative study concluded that the MBR system outperforms the A 2 /O system in phosphorus removal (Kim and Nakhla, 2010a (Niewersch et al, 2010). For the use of pretreated The contribution of anoxic decay process to the overall denitrification potential was evaluated as 60%, substantially higher than the remaining 40% associated with the anoxic growth during the SNdN process.…”