Performance of a novel osmotic membrane bioreactor (OMBR) system: Flux stability and removal of trace organics

Results reported here highlight the potential and several challenges in the development of a novel osmotic membrane bioreactor (OMBR) process for the treatment of municipal wastewater. Following the initial gradual decline, a stable permeate flux value was obtained after approximately four days of continuous operation. There was evidence of continuous deterioration of biological activity of the OMBR system, possibly due to the build-up of salinity in the reactor. The removal of 25 out of 27 trace organic compounds with molecular weight higher than 266 g/mol was above 80% and was possibly governed by the interplay between physical separation of the FO membrane and biodegradation. In contrast, the removal efficiency values of the other 23 trace organic compounds with molecular weight less than 266 g/mol were very scattered. The removal efficiency of these low molecular weight compounds by OMBR treatment appears to depend mostly on biological degradation.

► The removal of 50 trace organic compounds by a novel OMBR system was evaluated.
► Both physical separation and biodegradation govern the removal of trace organics.
► High molecular weight compounds (>266 g/mol) were well removed.
► The removal of low molecular weight compounds (<266 g/mol) varied significantly.
► Deterioration of biological activity needs further investigation.