Identification of Indoor Airborne Microorganisms and Their Disinfection with Combined Nano-Ag/TiO2Photocatalyst and Ultraviolet Light

Abstract

Deterioration of indoor air quality due to the airborne bacterial consortia is a widespread environmental problem. The main objectives of this study were to (1) determine dominant bacteria using real-time polymerase chain reaction in the indoor air of a medical nursing institute; (2) evaluate the feasibility of applying the synergetic effect of combining nano-Ag/TiO2 as photocatalyst and ultraviolet light irradiation to enhance the disinfecting capability of a full-scale bacterial treatment equipment. The predominant bacteria existing in the air of a Taiwanese nursing institution were identified as Acinetobacter baumannii, Burkholderia cepacia, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Thus, using an air purification device such as the nano-Ag/TiO2+ultraviolet light irradiation system to maintain the air quality is of great importance to reduce infectious diseases in the nursing institution. The average bacterial restraining rate for the five sampling points is 57.3%, indicating that the proposed equipment can restrain or disinfect bacteria effectively under the operational conditions for carrying out the study. The efficiency of the proposed equipment to disinfect air has been demonstrated on-site in the medical nursing institution. Results will provide valuable information to be referenced by planners and engineers for designing a full-scale commercialized device to implement the proposed indoor air quality control system in the future.