Entrapped-cells-based anaerobic forward osmosis membrane bioreactor treating medium-strength domestic wastewater: Fouling characterization and performance evaluation.

A novel entrapped cells-based-anaerobic forward osmosis membrane bioreactor (E-FOMBR) was developed. Its performance and fouling were investigated in comparison with suspended cells-based-anaerobic forward osmosis membrane bioreactor (S-FOMBR). E-FOMBR and S-FOMBR were operated under the same conditions with two widely used draw solutions (NaCl and (NH)SO). The membrane fouling especially irreversible fouling in S-FOMBR was more severe than that in E-FOMBR regardless of the type of draw solution. The permeate flux of E-FOMBR were 1.79 and 1.85 LMH while those of S-FOMBR were 1.49 and 1.14 LMH with NaCl and (NH)SO as draw solutions, respectively. More deterioration of biological activity (suggested by lower organic removal) due to accumulation of salt was observed in S-FOMBR compared to E-FOMBR. Proteobacteria dominated in both FOMBRs but was more abundant in E-FOMBR than S-FOMBR. The superiority of E-FOMBR over S-FOMBR included higher and stable system performance, higher flux, and longer operation time.