Experimental evaluation on microwave radiation disinfection efficacy of the bacterial aerosols attached to a SiC composite filter

Abstract

In the air-conditioning system, it is important to disinfect bacteria attached on the filter. In the present work, disinfection experiments of Staphylococcus aureus with the microwave radiation method is implemented on the filter coating with SiC, i.e., SiC composite filter. The disinfection rate and temperature characteristics of the SiC composite filter under different disinfection power and operating time were measured and finally the disinfection mechanism was briefly analysed. Results show that the SiC can absorb the microwave and so heat the proposed SiC composite filter well. The Staphylococcus aureus attached on the SiC composite filter can be efficiently and rapidly disinfected under an appropriate condition. Results revealed that the system can achieve up to about 100% disinfection rate for a disinfection power of 600 W and operating time of 10 min. In addition, the temperature and disinfection rate on the SiC composite filter both increase gradually with disinfection power and operating time. And the effect of disinfection power is greater. Both of the thermal and non-thermal effects contribute to the disinfection of the microwave radiation method. The thermal effect is prevailing in disinfection process, while the non-thermal effect plays an auxiliary role. Quantitatively, the non-thermal effect contributes 42% and the thermal effect contributes 58% to disinfection rate under the condition of the disinfection power being 600 W and the operating time being 10 min. Finally, a correlation is made to accurately estimate disinfection rate of the microwave radiation disinfection at various disinfection power and operating time.