Integrated experimental investigation and mathematical modeling of a membrane bioelectrochemical reactor with an external membrane module

•An MBER is formed by linking an external membrane module to a tubular MFC.•Membrane module is installed under the MFC to take advantage of catholyte dripping.•The MBER could achieve energy neutral with a reduced anolyte recirculation rate.•The mathematical model could predict the influence of several key factors.

Membrane bioelectrochemical reactors (MBERs) integrate membrane filtration module into microbial fuel cells (MFCs) to achieve silmultaneous wastewater treatment, bioenergy production, and high-quality effluent. Previous MBERs usually have membrane modules as a part of the MFC reactors that creates challenges for membrane cleaning. In this study, an MBER with an external membrane module was investigated through both experiments and mathematical modeling. This MBER produced a current density of 7.1 ± 0.5 A m−3 with an anolyte recirculation of 90 mL min−1; reducing the anolyte recirculation rate had a negligible effect on MBER’s electrical performance but resulted in a positive energy balance of 0.003 ± 0.002 kWh m−3. Periodic backwashing (1 min-backwashing/15 min-operation) was demonstrated as an effective method for fouling control. A mathematical model was developed and validated using the experimental data. The model could predict the influence of key parameters such as influent organic concentration and anolyte flow rate on the current generation, and identify the maximum organic loading rate for current generation. Those results encourage further investigation and development of this MBER toward system scaling up.

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