Advanced strategies for mitigation of membrane fouling in anaerobic membrane bioreactors for sustainable wastewater treatment

Municipal and industrial wastewater treatment plants (WWTPs) are recognized as significant energy consumers and greenhouse gases (GHGs) emitters in many countries. The direct and indirect GHG emissions from WWTPs primarily arise from biological activities involved in the oxidation of organic matter and nitrogen compounds under aerobic conditions. Developing viable biological processes that result in lower energy consumption and GHG emissions could be a future direction for the wastewater industry. According to the literature, anaerobic membrane bioreactors (AnMBRs) present a competitive alternative to aerobic wastewater treatment processes, offering several advantages such as reduced energy consumption and carbon footprint, lower nutrient requirements, decreased production and handling of excess sludge, and cost savings through the production of biogas. The collection and use of biogas as an energy source inside WWTPs indirectly contributes to the reduction of GHG emissions. However, the wider adoption of AnMBRs is hindered by severe membrane fouling issues. Hence, it is crucial to develop and implement strategies to mitigate fouling and ensure the sustainable operation of AnMBRs. This review evaluates and compares various advanced strategies for mitigating membrane biofouling in AnMBRs, considering their effectiveness in reducing the increase in trans-membrane pressure, maintaining membrane permeate flux, achieving high removal efficiency of organic matter, enhancing treatment capacity, and optimizing hydraulic retention time. Additionally, future perspectives and directions for further research and development in AnMBR fouling control strategies are envisioned. By providing a comprehensive overview of fouling control strategies and their potential benefits, this article aims to contribute to the advancement of sustainable and efficient AnMBR technology.