Performance evaluation of submerged membrane electro-bioreactor (SMEBR) system with anaerobic pretreatment receptacle anode electrode in municipal wastewater treatment

Abstract

Introduction: The main objective of this research was design and evaluation of Submerged Membrane Electro-bioreactor for achieves high quality of effluent in municipal wastewater treatment. SMEBR combined three operational processes; biological treatment, membrane filtration, and electrokinetics which lead to minimizing membrane fouling. The new design idea of SMEBR was based on applications of direct current (DC) on the cathode electrodes and the anode electrode. Materials and methods: The experimental setup of this study was made of Plexiglas and divided to two stages and operated continuously for 48 days. In Stage I, membrane bioreactor with total volume 3.74 L was operated for first 24 days without application of electrodes. In Stage II, membrane electro-bioreactor with total volume 5.39 L was operated continuously for lasted 24 days with application of electric field on anode and cathode electrodes. Membrane fouling behavior was determined by measuring the permeate flux at any time to its initial permeate flux during the first minute in each process. The main objective of this research were evaluating of membrane fouling and removals of〖 NH〗_3 N, PO_4^(3-)  P and COD parameters. Results and discussion: The results showed that membrane electro-bioreactor comparison to membrane bioreactor increased significantly removal efficiency of〖 NH〗_3 N, PO_4^(3-)  P and COD which were 7%, 15% and 2%, respectively. Membrane fouling rate around 22% decreased significantly. This significantly improvement (P-Value = 0.049) is probably due to the application of intermittent electric field and pre-anaerobic reactor. Also, may be colloids and negatively charged tiny particles such as Extracellular Polymeric Substances combined by positive ions that produced through aluminum anode electrode which cause electrocoagulation and flocculation of tiny particles and generated large size particles in pre-anaerobic reactor. So, their contributions in membrane fouling were decreased. Conclusions: The present study showed that application of an electric field at the membrane bioreactor lead to increasing quality of effluent and decline of membrane fouling. Consequently, membrane electro-bioreactor can be considered as a promising alternative technology for the conventional membrane bioreactor.