Removal of viruses and antibiotic resistance genes in bacteriophage fraction by conventional activated sludge (CAS) and membrane bioreactor treatment (MBR) systems

The study analyzed the presence and removal of viruses and antibiotic resistance genes in wastewater using conventional activated sludge (CAS) and membrane bioreactor (MBR) systems. 124 wastewater samples were collected from a Japanese wastewater treatment plant. The most abundant virus was pepper mild mottle virus (PMMoV), with a 100% detection rate before and after treatments. MBR was found to be more effective in removing tested viruses. However, some ARGs in bacteriophage fraction were detected before treatments but still present in treated wastewater, suggesting that CAS and MBR cannot completely remove these genes, potentially affecting transduction incidence.