Virus rejection with two model human enteric viruses in membrane bioreactor system

Area of Science:

• Environmental Microbiology
• Water Treatment Technologies
• Virology

Background:

• Human enteric viruses pose significant public health risks.
• Conventional wastewater treatment methods show variable virus removal efficiency.
• Membrane bioreactors (MBRs) offer a potential solution for enhanced virus removal.

Purpose of the Study:

• To evaluate the virus rejection capabilities of a membrane bioreactor (MBR) using coliphage surrogates.
• To compare virus removal by Polyvinylidene fluoride (PVDF) and Polypropylene (PP) membranes.
• To elucidate the primary mechanisms of virus removal in MBR systems.

Main Methods:

• Testing PVDF (0.22 μm) and PP (0.1 μm) membrane modules for virus rejection.
• Utilizing T4 and f2 coliphages as surrogates for human enteric viruses.
• Comparing MBR performance against a conventional activated sludge system.

Main Results:

• MBRs achieved high log rejection values for T4 (>5.5 log) and f2 (>3.0 log) coliphages.
• In tap water, PP membranes showed complete T4 rejection, while PVDF achieved 2.1 log rejection.
• In wastewater, membrane fouling altered cut-off sizes, leading to similar rejection for both membrane types; virus inactivation was the dominant removal mechanism.

Conclusions:

• MBRs demonstrate superior virus removal compared to conventional activated sludge systems.
• Virus inactivation by microbial activity is the major removal mechanism in MBRs, surpassing sludge adsorption.
• MBR technology shows promise for effective enteric virus control in water treatment.