Research on air purification technology (3): Antimicrobial and antiviral air filters

Air filters can effectively remove bacteria and viruses from the indoor environment, but they cannot kill or inactivate them, which makes the filters potentially become a secondary pollution source for the proliferation and spread of microorganisms. This paper focuses on the research and development of antimicrobial and antiviral air filters. Firstly, it reviews the common types of bacteria (such as Mycobacterium tuberculosis, Staphylococcus aureus), fungi (such as Aspergillus, Penicillium), and viruses (such as SARS-CoV-2, influenza virus) found in air-conditioned rooms and their hazards. Subsequently, it systematically analyses the antimicrobial mechanisms, advantages and disadvantages, and application status of three types of antimicrobial and antiviral materials that can be used in air filters: organic materials (such as quaternary ammonium salts, chlorine-containing disinfectants), inorganic materials (such as nano-silver, copper oxide, graphene), and bio-based materials (such as chitosan, ε-polylysine). Among them, metal nanoparticles (such as AgNP, CuONP) and metal-organic framework (MOF) compounds in inorganic materials have attracted much attention due to their high-efficiency and broad-spectrum antimicrobial and antiviral properties, but they have issues of toxicity and cost, and bio-based materials have high safety but insufficient durability. Finally, this paper presents two compound disinfectants (CC01 and CC02) developed by the author, which have broad-spectrum antimicrobial properties (the killing rate of Staphylococcus aureus is large than 99.99%), high antiviral efficiency, and inactivation rates of 99.99% for influenza virus (H1N1) and SARS-CoV-2. They are non-toxic and have a mild fragrance. These disinfectants are applied through spraying technology to air filters without affecting the filtration efficiency and resistance. The research shows that the development of antimicrobial and antiviral air filters holds significant social and environmental importance for improving indoor air quality and preventing the spread of microorganisms.