Carbon-neutral treatment of N, N-dimethylformamide-containing industrial wastewater by anaerobic membrane bioreactor (AnMBR): Bio-energy recovery and CO2 emission reduction

High-strength industrial wastewater containing approximately 2000 mg/L of N, N-dimethylformamide (DMF) was treated by the anaerobic membrane bioreactor (AnMBR) during a long-term operation with the concept of carbon neutrality in this study. Bio-methane was recovered as bio-energy or bio-resource from DMF-containing wastewater along with the CO2 emission reduction. The results are clear evidence of the feasibility of carbon-neutral treatment of DMF-containing wastewater by the AnMBR. With an effective degradation under the organic loading rate of 6.53 COD kg/m3/d at the HRT of 12 h, the AnMBR completely covered the energy consumption during long-term operation by saving electricity of 4.16 kWh/m3 compared with the conventional activated sludge process. The CO2 emission of the AnMBR was just 1.06 kg/m3, remarkably reducing 1.45 kg/m3 of CO2. The treatment of DMF-containing wastewater by the AnMBR perfectly realized the goal of carbon neutrality, and was considered as an alternative to the conventional activated sludge process.