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

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 NH+3-N), phosphorus (as PO3―4-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.