Low-Carbon Operation Strategies for Membrane-Aerated Biofilm Reactor Through Process Simulation and Multi-Objective Optimization

As an emerging wastewater treatment technology, the membrane-aerated biofilm reactor (MABR) process is increasingly being coupled with anaerobic anoxic aerobic (AAO) process. However, there is currently a lack of systematic research and clear consensus on which of these two arrangements is more significant in improving overall process efficiency in practical applications. This study established GPS-X models of the conventional AAO process and two AAO-MABRs (anoxic or aerobic) under different concentrations of influent and effluent water quality conditions, and systematically compared their effluent quality, operation cost and greenhouse gas emissions. The results indicate that, compared with the conventional AAO process, the AAO-MABR coupled process improved the denitrification rate by 37.46%~47.71% (Anoxic), reduced energy consumption by an average of 0.11 kWh/m3, and lowered the operating cost by 0.036 USD/m3. In terms of carbon emission intensity, the AAO-MABR process achieved an average reduction of 0.67 kgCO2eq/m3. Notably, the AAO-MABR (Anoxic) configuration exhibited superior robustness under varying influent and effluent conditions, yielding the lowest average operational cost (0.047 USD/m3) and carbon intensity (0.61 kgCO2eq/m3). This study provides a reference for the practical application of MABR process, especially for the upgrading of traditional AAO processes.