Anaerobic membrane bioreactors for treating high organic content wastewater and reducing fugitive greenhouse gas emission

Abstract

This review aims to critically evaluate the role of anaerobic membrane bioreactors (AnMBRs) in wastewater treatment and their potential to reduce greenhouse gas (GHG) emissions. Data corroborated in this review show that AnMBRs are particularly suited for treating high-strength wastewater with elevated organic content, achieving chemical oxygen demand (COD) removal efficiency of 87–99%. Furthermore, GHG emissions from AnMBRs are in the range of 0.142–0.406 kg CO₂ eq. per m³ of treated water, significantly lower than aerobic processes and conventional anaerobic treatment. Nevertheless, full-scale AnMBR applications are limited and restricted to high strength wastewater from just a few industries. This is despite of the falling membrane cost, notable progress in membrane cleaning and fouling mitigation, and the maturity of associated technologies for biogas utilisation. Information obtained from this review suggests that system complexity, large space requirement, and lack of industrial operational experience are major hurdles to widespread applications of AnMBRs for wastewater treatment. This review contributes to a roadmap for further research work to address these challenges. With the urgent need to reduce GHG emissions, AnMBRs are expected to play a greater role in treating high strength industrial wastewater.