Comparative study of anaerobic dynamic membrane bioreactor and anaerobic electro-dynamic membrane bioreactor systems for high-strength wastewater treatment

Abstract

The objective of this study was to conduct a comparative analysis of anaerobic dynamic membrane bioreactor (AnDMBR) and anaerobic electro-dynamic membrane bioreactor (AnEDMBR) systems. The AnEDMBR systems were operated at two distinct electric field strengths, 0.8 V and 1.2 V. A hydraulic retention time of 5 days was maintained in both systems. A bench-scale continuous flow reactor equipped with a submerged membrane module utilizing activated carbon fabric as the dynamic membrane was employed. Synthetic wastewater with a high chemical oxygen demand (COD) concentration of 11.4 +/- 1.0 g/L was used as feed. The AnEDMBR system was equipped with an iron anode and the activated carbon fabric serving as a cathode which used as a dynamic membrane. The results showed that both systems achieved high COD removal efficiency exceeding 98%. Membranes exposed to an electric field of 1.2 V in the AnEDMBR system exhibited better resistance to fouling compared to those exposed to 0.8 V. Scanning electron microscopy (SEM) images of membrane surfaces indicated a positive effect between extracellular polymeric substances (EPS) and the cathodic membrane due to electrostatic repulsion for the applied voltages. This study provides a significant information for the application of AnEDMBR technology in treating of high-COD content wastewater.