Thermal and non-thermal germicidal effects of microwave radiation on microbial agents

To assess possible applications of evaporative humidifier elements of air-conditioning systems, the germicidal effect of microwave irradiation on fungal spores (e.g. Cladosporium herbarum and Fusarium solani), vegetative bacteria and bacterial spores (e.g., Bacillus subtilis) was investigated by this study. A general purpose microwave oven and a specifically assembled microwave source placed in a 2.45 GHz magnetron were used. Initially, the optimal radiation output power and exposure time were determined to achieve the desired germicidal effects using both wet and dry sample filters. The study also investigated whether the germicidal effect could be a direct result of the microwave irradiation or rather a result of the radiation-induced heat. The results of our study have indicated that microbial degradation could be dependent on the fungal strain type, microwave output power, exposure time and sample moisture. Our results have also illustrated that the germicidal effect shown in the experiments could be attributed to the associated rise in temperature particularly above 60℃ during the microwave irradiation of the fungal buffer solutions.
Source: Indoor and Built Environment - Category: Occupational Health Authors: Tags: Original Papers Source Type: research