Bacteriophage MS-2 removal by submerged membrane bioreactor

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Microbiology

Background:

• Membrane bioreactors (MBRs) offer advanced wastewater treatment capabilities.
• High-quality sewage effluent production is a key goal in wastewater management.
• Pathogen removal is a critical aspect of wastewater disinfection.

Purpose of the Study:

• To investigate the pathogen removal performance of a submerged membrane bioreactor (MBR).
• To identify factors influencing virus removal in MBR systems.
• To evaluate the role of membrane filtration, biomass, and biofilm in pathogen removal.

Main Methods:

• Utilized a bench-scale submerged MBR with a 0.4-micrometer hollow-fiber membrane module.
• Employed bacteriophage MS-2 as an indicator organism for virus removal studies.
• Analyzed the impact of mixed liquor suspended solids (MLSS), sludge retention time (SRT), and food to mass (F/M) ratio.

Main Results:

• The membrane alone provided limited MS-2 phage removal (0.4+/-0.1 log).
• Substantial increases in virus removal were observed with the presence of suspended biomass and attached biofilm.
• Phage removal was found to be dependent on MLSS concentration, SRT, and F/M ratio.

Conclusions:

• MBRs can function as effective pre-disinfection or disinfection units for high-quality effluent.
• Both physical filtration by the membrane and biological removal by biomass/biofilm contribute to pathogen removal.
• Virus removal in MBRs is influenced by a complex interplay of biological and physical factors, including biomass properties and membrane integrity.