Enhancing the performance of a microbial electrochemical system with carbon-based dynamic membrane as both anode electrode and filtration media†
Microbial electrochemical systems (MESs) can be incorporated with membrane filtration that assists the bioelectrochemical treatment. Herein, a dynamic membrane (DM) was created on the carbon cloth-based anode electrode in a dynamic membrane microbial electrochemical system (DMES) and evaluated for treating domestic wastewater. The advantage of this DMES was demonstrated via comparing to the one without DM filtration. It was found that DMES achieved a current density of 15.75 ± 0.86 A m−3 at 10 Ω, which is significantly higher than that of the control system with no DM filtration (6.60 ± 0.22 A m−3). Moreover, the DMES effluent had a turbidity of 11.1 ± 0.3–16.7 ± 0.5 NTU under the varied water fluxes, which is much lower than that from the control system (29.3 ± 0.8–34.8 ± 0.5 NTU). The use of a stainless-steel current collector as a part of DM could increase the current generation. However, adding one more layer of DM showed a limited improvement of the DMES performance at the expense of an additional capital cost. When fed with actual domestic wastewater for an extended operation for 30 days, DMES showed relatively stable treatment performance and was able to maintain turbidity lower than 5 NTU. This study has provided the initial results of employing the DM concept in the anode of an MES for enhanced treatment performance and electricity generation. Several challenges to be addressed were identified and discussed with further investigation.