Combination of UV radiation with 3D structure media filter for indoor air disinfection

Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China

^* Corresponding author: jjliu@tju.edu.cn

Abstract

The ongoing COVID-19 pandemic made us re-realize the importance of environmental disinfection in indoor areas. Several studies have documented that the air purification system combining UV light and high-efficiency particulate air (HEPA) filtration can successfully remove the virus from the air. However, UV light cannot penetrate deep into the HEPA, which causes the pathogens inside cannot be killed. In this study, we analyzed the potential of three-dimensional(3D) filter media combining with UV sterilization for the treatment of pathogen aerosols. Through geometric ray analysis, it is concluded that the transmittance attenuation of 3D filter material is linear, while that of ordinary fabric filter material is abrupt, which means UV light combining with common fabric filter can only kill the microorganisms on the surface. In order to prove that 3D filter with UV irradiation can eliminate microorganisms inside the 3D filter, we carried out an experimental verification. The results of the experiment shows that the bactericidal rate increased with UV dose and the k value is 3.75*10-4, much smaller than that in air UV disinfection. This indicates that although it is more difficult to kill pathogens on the surface of fibers than in air, 3D filter material with UV can kill the pathogens inside.