Research progress on the cleaning and regeneration of PM2.5 filter media

Reusable PM2.5 filter media and their regeneration techniques have attracted widespread attention and shown significant prospect for application in air purification. In this study, we reviewed the recent research progress on the cleaning and regeneration of indoor PM2.5 filters considering two methods, namely, dry and wet cleaning. The principles, application status, and limitations of air back-blow and air pulse-jet dry-cleaning techniques were analyzed. The wet-cleaning characteristics and regeneration performance of novel washable PM2.5 filters, including superhydrophobic, electrostatically enhanced, metal–organic framework composite, and microchannel monolith filters, were evaluated and summarized. Maintaining the structural stability and chemical resistance of the filter media during the cleaning process was determined to be key to filter regeneration. Therefore, cleaning and regeneration characteristics should be integrated into the design of high-efficiency and low-resistance filter materials to develop more practical reusable PM2.5 filter media.