Virus removal during sewage treatment by anaerobic membrane bioreactor (AnMBR): The role of membrane fouling

•Virus removal efficiency by AnMBR treating sewage was up to 3.6 logs.•Membrane fouling was the key factor in the virus removal by AnMBR.•Mechanisms of virus rejection by membrane were related with membrane fouling state.•The greatest resistance-specific virus rejection was organic pore blocking.•Strategy was provided to balance enhanced virus removal and high permeate flux. Anaerobic membrane bioreactor (AnMBR) is a low-energy and promising solution for sewage treatment. During the treatment, the fouled membrane of AnMBR is recognized as an important barrier against pathogenic viruses. Here, the role of membrane fouling of an AnMBR at room temperature in the virus removal was investigated using MS2 bacteriophage as a virus surrogate. Results revealed that the virus removal efficiency of AnMBR was in the range of 0.2 to 3.6 logs, gradually increasing with the course of AnMBR operation. Virus removal efficiency was found to be significantly correlated with transmembrane pressure (R2=0.92, p