Start-up period investigation of pilot-scale submerged membrane electro-bioreactor (SMEBR) treating raw municipal wastewater

• SMEBR is a promising technology for wastewater treatment.
• Removal rates of NH3+-N, PO43--P, and COD were 99%, 99%, and 92%, respectively.
• No significant increase in the transmembrane pressure (0.02 kPa d−1) was reported.
• SMEBR required small treatment footprint.
• SMEBR, potentially, can reduce the overall sludge management related cost.

Submerged membrane electro-bioreactor (SMEBR) is a new hybrid technology for wastewater treatment employing electrical field and microfiltration in a nutrient-removing activated sludge process. A pilot SMEBR system was located at the wastewater treatment plant in the City of l’Assomption (Quebec, Canada) with the objective of investigating the start-up period performance under variable organic loadings and environmental conditions with respect to effluent quality, membrane fouling, and sludge properties. The pilot SMEBR facility was fed with the raw de-gritted municipal wastewater. At steady state operation, the removal efficiencies of ammonia (as NH3+-N), phosphorus (as PO43--P), and COD were 99%, 99%, and 92%, respectively. No substantial increase in the monitored transmembrane pressure as 0.02 kPa d−1 was reported. The time necessary to filter 100 mL of the sludge sample has decreased by 78% after treatment whilst the sludge volume index averaged 119 mL g−1. Energy requirements were in the range of 1.1–1.6 kW h m−3 of wastewater. It was concluded that the SMEBR is a very competitive technology when compared to conventional membrane systems as it can enhance treatment performance to an appreciable extent, remove phosphorus and reduce fouling.