Performance of anaerobic forward osmosis membrane bioreactor coupled with microbial electrolysis cell (AnOMEBR) for energy recovery and membrane fouling alleviation

- A combined system of AnOMBR and MEC was proposed in this study.
- Salt accumulation was low in this combined system.
- Enhanced methane yield was achieved by applying MEC in AnOMBR.
- Membrane fouling was mitigated with the application of electric field.

Anaerobic forward osmosis membrane bioreactor coupled with microbial electrolysis cell (AnOMEBR) was designed for the treatment of synthetic wastewater while magnesium acetate was used as the draw solution. Then the effect of electric field in AnOMEBR was assessed in terms of the reverse osmosis of draw solute, the mitigation of membrane fouling and energy recovery. Results showed that the conductivity increasing rate was about 0.08 ms/(cm·d) in AnOMEBR which was lower than that in AnOMBR without electric field (0.11 ms/(cm·d)). Lower membrane fouling propensity was obtained in AnOMEBR, and its membrane operation cycle was about 1.27 times as long as that in AnOMBR. The methane yield of AnOMEBR was about 0.281 L/g COD, and it almost increased by 11.07% compared with AnOMBR. Besides, the increasing methane yield could compensate for the extra power consumption in AnOMEBR, and about 0.537 kJ per day positive energy gain could be obtained.