Long-term operation of a novel electrically-enhanced biomass concentrator reactor for wastewater treatment

Membrane biological reactors (MBRs) are a key technology in wastewater treatment nowadays. However, due to their high construction cost and energetic requirements, alternatives based on the same principle of biomass retention have been designed and operated. Amongst these, biomass concentrator reactors (BCRs), using a coarser filter medium instead of a membrane, have shown to be able to remove a wide range of contaminants from wastewater and groundwater. A new BCR-derived technology enhanced with an electric field, called the electrically-enhanced biomass concentrator reactor (E₂BCR), was designed and tested for urban wastewater treatment at different organic loads for a period of 180 days. The electrically-enhanced reactor showed better chemical oxygen demand (COD) removal performances than a non-enhanced control reactor (92.4% and 83.6% respectively) thanks also to electrocoagulation effects, and a lower fouling tendency, and proved to be more energy efficient in comparison with the control reactor in terms of energy consumption per mass of COD removed.