Airborne microorganisms are important sources of infection and their effective removal is an important infection control measure. Furthermore, airborne diseases have been known as top ten causes of death by WHO. Several air disinfection technologies are currently available. However, they are energy-intensive and may pose potential health concerns due to ozone generation. High efficiency particulate air filters can effectively filter and capture airborne microorganism. This type of filter is mostly occupied in hospital air circulation system. However, these microorganisms can remain viable on the filter and pose risk of recontamination during operation. As these microorganisms will continue to aggregate and populate on the filter media and surface and eventually lead to filter de...[ Read more ]

Airborne microorganisms are important sources of infection and their effective removal is an important infection control measure. Furthermore, airborne diseases have been known as top ten causes of death by WHO. Several air disinfection technologies are currently available. However, they are energy-intensive and may pose potential health concerns due to ozone generation. High efficiency particulate air filters can effectively filter and capture airborne microorganism. This type of filter is mostly occupied in hospital air circulation system. However, these microorganisms can remain viable on the filter and pose risk of recontamination during operation. As these microorganisms will continue to aggregate and populate on the filter media and surface and eventually lead to filter degradation and penetration. This thesis report aims at presenting the performance of a multilevel antimicrobial systems for particulate air filters to inactivate and inhibit growth of microorganisms. Chlorine dioxide, the volatile biocide was encapsulated by polymer and surround by catalytic-dyad to achieve “release-killing”, “contact-killing” and “anti-adhesion” properties. The laboratory tests showed that antimicrobial system was able to last for 7.6 months on the filter and around 3.8 years on the glass surface. It was able to disinfect up to 90% of bacteria on both material surface for 10 minutes contact. A particulate air filter made of PP and PET was used in this project. The field testing showed that there was a significant difference in treatment and control group for an air filter that half spray coated with antimicrobial system. Weather, room size of location and human activity frequency around the air purifier were key factors that may affect the performance of antimicrobial system but positive reduction still can be achieved.