BACKGROUNDThe enhanced removal of viruses in wastewater treatments plant is important due to concerns about public health. Bacteriophages (or phages) are often used to model the behavior of pathogenic human viruses as they are similar in size, structure and behavior. This study investigated the removal of phages MS-2 (25nm) and T4 (200nm) in an anaerobic membrane bioreactor (AnMBR) with a membrane pore size of 0.4 mu m. RESULTSThe membrane reactor without biomass was assessed and its log removal was 0.70.4 log for the MS-2 phage, and 2.3 +/- 0.2 log for the T4. When anaerobic biomass was added to the reactor the log removal for both phages increased, and this was thought to be due to a complex relationship with the biofilm on the membrane. CONCLUSIONSOverall MS-2 rejections ranged from 1.75 up to 5.5 log, with the highest rejections observed at the highest sparging rates after extensive fouling had occurred. For T4, removal in the AnMBR ranged from 5 log up to complete removal (>log 7). (c) 2014 Society of Chemical Industry