EFFICACY STUDIES

UV light has been shown to have a more deadly and efficient effect, comparatively on viruses, than common air filtration methods including HEPA. Learn what air treatment method is best for your environment and which are more effective in destroying viruses, as well as being economically viable. Read more here.

Disinfection of air is required in medical facilities, in production processes where biological contamination must be prevented, like food preparation areas in restaurants, also in residential or commercial buildings. Disinfection of air will kill the mold, mould (both of them fungi), pathogenic bacteria, viruses and other hazardous microbes indoor to improve indoor air environment greatly. Several attributes of Photocatalytic oxidation (PCO) make it a strong candidate for indoor disinfection applications. First, photocatalytic reactors may be integrated into new and existing heating, ventilation, and air conditioning (HVAC) systems due to their modular design, room temperature operation, and negligible pressure drop (Fig 5). Then can also be used as stand-alone air cleaners. PCO reactors feature low power consumption, potentially long service life, and low maintenance requirements. These attributes contribute to the potential of PCO technology to be an effective process for removing and destroying low level pollutants in indoor air, including bacteria, viruses and fungi.

The research work on PCO disinfection and bactericidal effect has established an effective way to remove and destroy a wide range of biological pollutants in water and indoor air. Cellular membrane can be an important target for the photocatalytic activity of TiO2 in cells, and reactive oxygen species including the hydroxyl radical can cause DNA damage. PCO technology can be applied for removing and destroying low level pollutants in indoor air, including bacteria, viruses and fungi, it also shows the antimicrobial effect on surfaces. Still a lot further research is necessary to improve the bactericidal efficiency of PCO effect and optimize the treatment conditions, consequently facilitate the wide application of PCO technology to disinfection of water and air environment.

Source: Wang Ying BS MS, Yang Xudong BS MS PhD MASHRAE, Wang Yunqiu BS MS PhD, Wang Yongbao BS MS PhD & Han Zhiyong BS MS PhD (2005) Disinfection and Bactericidal Effect Using Photocatalytic Oxidation, HKIE Transactions, 12:1, 39-43, DOI: 10.1080/1023697X.2005.10667992

A research study was completed, examining the airborne microbial killing efficiency of a unique photocatalytic reactor to eliminate fungal and bacterial pathogens. The study examined baseline bacterial and fungal cultures, commonly known as pathogens, collected at specific clinical sites. Samples of methicillin-resistant Staphylococcus aureus (MRSA) were studied in depth, identifying genus and species in varying culture media. The use of a biocide unit revealed up to a 300% reduction of airborne microbes. 

The study also examined baseline bacterial and fungal cultures collected at specific clinical sites both before and after the installation and use of a unique photo-catalytic reactor that kills many common hospital pathogens. Cultures were incubated, and separate culture counts (colony-formed units) for specific microbes were recorded for a given clinical area, with specific interest focused on particularly dangerous pathogens, such as methicillin resistant staphylococcus aureus. 

Source: Journal of Clinical Engineering: April-May-June 2004 – Volume 29 – Issue 2 – p 79-88

Titanium dioxide (TiO2) under ultraviolet (UV) light (used in PathoControl systems) have been tested and produce a strong oxidative effect which may be used as a photocatalytic disinfectant. Although many studies on the photocatalytic inactivation of bacteria have been reported, few studies have addressed virus inactivation. A study successfully demonstrated the inactivation of influenza virus via (these) elements.

The International Organization for Standardization (ISO) methodology for the evaluation of antibacterial activity of this photocatalysis could be applied to the evaluation of antiviral activity. The viral titers were dramatically reduced by this photocatalytic reaction. Even with a low intensity of UV-A, a viral reduction was observed within a short irradiation time. Results showed that ASIET’s photocatalytic process TiO2 photocatalysis could be used to inactivate the influenza virus. Furthermore, a minor modification of the ISO test method for anti-bacterial effects of TiO2 photocatalysis could be useful for the evaluation of antiviral activity. 

Source: Photochemical & Photobiological Sciences

Photocatalytic oxidation (PCO) with nanoscale titanium dioxide {Ti02) is considered one of the most promising technologies in the field of air disinfection and destruction of volatile organic compounds (VOCs) in air. When irradiated by ultraviolet (UV), Ti02 catalyst produces hydroxyl radicals, which can kill microorganisms and oxidize VOCs. Numerous studies have been conducted to develop more efficient PCO-Ti02 systems in air purification and to explore and expand their application in other areas and fields.

(For this study) a novel pilot-scale ultraviolet (UV) photocatalytic oxidation (PCO) scrubber has been developed for evaluation of its antimicrobial efficacy. Photocatalytic oxidation is a technology that produces hydroxyl radicals (•OH) and superoxide (O2-1) from reactions between water/oxygen and a semiconduc-tor (normally titanium oxide) under UV radiation. Both hydroxyl radicals and superoxide have antimicrobial capacity and have been proven to be capable of inactivating airborne Staphylococcus aureus (Vohra et al., 2006), Escherichia coli (Vohra et al., 2006; Pal et al., 2008), A,spergillus niger (Vohra et al., 2006), MS2 phage (Vohra et al., 2006), etc.

Source: Gilcrease, Patrick C., “Proceedings of the Thirty-fifth Annual Biochemical Engineering Symposium” (2006). Biochemical Engineering Symposium Proceedings. 28.

After the discovery of the 2019 novel coronavirus, the virus responsible for COVID-19 was renamed the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). CoVs, among the largest known RNA Viruses, includes 4 genera, including betacoronaviruses, which includes SARS and MERS. It has been found that transmission of this genus of viruses can be transmitted via blood products. Researchers found that Amotosalen with UV-A light, Riboflavin with UV-B light, and UV-C light can all inactivate the SARS and MERS virus in blood.

Source: February 2020, Sciencedirect.com

Have you ever wondered what is contaminating the air inside your home or office? This document explores airborne pathogens and pollutants in detail.

Photocatalytic oxidation systems are highly effective in killing pathogens and pollutants and are easy to use. Tap or click to read the PDF.