Effect of current density value and current application period on the wastewater treatment performance of Electrochemically Enhanced Self-Forming Dynamic Membrane Bioreactors (e-SFDMBRs)
The use of membrane reactor in wastewater treatment gained interest for the past years due to its high-quality effluent. However, expensive membranes and high operational costs due to membrane fouling limit the wide application of this process. Research on fouling control by combining membrane use with different techniques have been studied to address this challenge. This study particularly uses electrochemically-enhanced self-forming dynamic membrane bioreactor (e-SFDMBR). The main feature of the SFDMBR technology is that the biological filtering layer self-forms on a support of cheaper, inert coarse-pore membrane. This work focuses on describing the treatment performance of the bioreactor and the effect of lowering the current density and application period of electric current on the effluent quality and membrane fouling. Two systems of e-SFDMBR were operated and compared in terms of ammonium-nitrogen and orthophosphate removal and concentration of fouling precursors. The lower application period system (0.5 mA/cm2, 3 min ON/27 min OFF) posted 99.71% ammonium-nitrogen removal while the lower current density system (0.3 mA/cm2, 5 min ON/20 min OFF) achieved 99.68% removal. Both systems were able to completely remove phosphate and produce low concentration values of known fouling precursors.