[Simultaneous carbon and nitrogen removal by gas-water alternative membrane bioreactor].

A bench-scale comparative study between gas-water alternative membrane bioreactor (AMBR) and traditional submerged membrane bioreactor (SMBR) treating synthetic municipal wastewater was conducted with respect to the effects of carbon and nitrogen removal and membrane fouling. The results showed that both the AMBR and the SMBR had very good removal in COD and NH4+ -N of more than 96%. In SMBR, carbon and nitrogen removal was enabled by biomass in bulk liquid, while in AMBR, it was supposed to be functioned mainly by the biofilm attached to the surface of hollow fiber membrane since little sludge was found in the bulk liquid. However, TN removal was 76.94% in AMBR and 52.41% in SMBR, showing a more effective denitrification in AMBR compared to SMBR. Also, AMBR was found to be more effective in membrane fouling alleviation than SMBR through long time investigation of trans-membrane pressure.