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Bono N, Ponti F, Punta C, Candiani G. Effect of UV Irradiation and TiO 2-Photocatalysis on Airborne Bacteria and Viruses: An Overview. MATERIALS (BASEL, SWITZERLAND) 2021; 14:1075. [PMID: 33669103 PMCID: PMC7956276 DOI: 10.3390/ma14051075] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/07/2021] [Accepted: 02/19/2021] [Indexed: 12/20/2022]
Abstract
Current COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has put a spotlight on the spread of infectious diseases brought on by pathogenic airborne bacteria and viruses. In parallel with a relentless search for therapeutics and vaccines, considerable effort is being expended to develop ever more powerful technologies to restricting the spread of airborne microorganisms in indoor spaces through the minimization of health- and environment-related risks. In this context, UV-based and photocatalytic oxidation (PCO)-based technologies (i.e., the combined action of ultraviolet (UV) light and photocatalytic materials such as titanium dioxide (TiO2)) represent the most widely utilized approaches at present because they are cost-effective and ecofriendly. The virucidal and bactericidal effect relies on the synergy between the inherent ability of UV light to directly inactivate viral particles and bacteria through nucleic acid and protein damages, and the production of oxidative radicals generated through the irradiation of the TiO2 surface. In this literature survey, we draw attention to the most effective UV radiations and TiO2-based PCO technologies available and their underlying mechanisms of action on both bacteria and viral particles. Since the fine tuning of different parameters, namely the UV wavelength, the photocatalyst composition, and the UV dose (viz, the product of UV light intensity and the irradiation time), is required for the inactivation of microorganisms, we wrap up this review coming up with the most effective combination of them. Now more than ever, UV- and TiO2-based disinfection technologies may represent a valuable tool to mitigate the spread of airborne pathogens.
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Affiliation(s)
- Nina Bono
- GenT LΛB & µBioMI LΛB, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy; (N.B.); (F.P.)
| | - Federica Ponti
- GenT LΛB & µBioMI LΛB, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy; (N.B.); (F.P.)
- Laboratory for Biomaterials and Bioengineering, Canada Research Chair I in Biomaterials and Bioengineering for the Innovation in Surgery, Department Min-Met-Materials Engineering, Research Center of CHU de Quebec, Division of Regenerative Medicine, Laval University, Quebec City, QC G1V 0A6, Canada
| | - Carlo Punta
- OSCMLab, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy;
- Milano Politecnico Research Unit, National Interuniversity Consortium of Materials Science and Technology—INSTM, Via Mancinelli 7, 20131 Milan, Italy
| | - Gabriele Candiani
- GenT LΛB & µBioMI LΛB, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy; (N.B.); (F.P.)
- Milano Politecnico Research Unit, National Interuniversity Consortium of Materials Science and Technology—INSTM, Via Mancinelli 7, 20131 Milan, Italy
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Development of a photocatalytic filter to control indoor air quality. J Appl Biomater Funct Mater 2016; 14:e496-e501. [PMID: 27809331 DOI: 10.5301/jabfm.5000336] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The aim of this work was the development and characterization of a photocatalytic filter for the treatment of indoor air, characterized by a low pressure drop. METHODS The filter (photocatalytic filter) was based on a polyester substrate additivated with active carbon (Carbotex 150-6), treated with a sol of titanium dioxide (Sol 121-AB; NextMaterials Ltd.) and illuminated with UV LEDs to induce photocatalytic activity. RESULTS Tests showed that this filter, used in a suitable device for air circulation with a very low noise level, had the ability to block solid particulates, to photocatalytically oxidize a major fraction of volatile organic compounds (VOCs) and deactivate all of the bacteria blocked on the filter, in contrast to traditional commercial air filters on which the bacteria remain viable. CONCLUSIONS Activated charcoal filters treated with TiO2 and illuminated by UV LEDs were found to be extremely effective in killing bacteria and effective in decreasing VOC and total suspended particulates (TSP).
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