Experimental and CFD evaluation of ozone efficacy against coronavirus and enteric virus contamination on public transport surfaces

Abstract

The limited information about the routes of the transmission of SARS-CoV-2 within the ongoing pandemic scenario mobilized the administration, industry and academy to develop sanitation and disinfection systems for public and private spaces. Ozone has been proposed as an effective disinfection method against enveloped and non-enveloped viruses, including viruses with similar morphology to SARS-CoV-2. Due to this efficacy, numerous gaseous and aqueous phase ozone applications have emerged potentially to inhibit virus persistence in aerosols, surfaces, and water. In this work, a numerical model, a RANS CFD model for ozone dispersion inside tram and underground coach has been developed including the chemical self-decomposition and surface reactions of the ozone. The CFD model has been developed for a real tram coach of 28.6 ×2.4 ×2.2 m (L x W x H) using 1.76 million nodes and the Menter’s shear stress transport turbulence model. The model predicts the O 3 concentration needed to meet disinfection criteria and the fluid dynamics inside the public transport coach. The effectiveness of the system against disinfection and virus inactivation has been validated with laboratory and field tests in real full-scale coach against the inactivation of cytopathogenic porcine epidemic diarrhea virus (PEDV) and murine norovirus (MNV-1) as SARS-CoV-2 virus surrogates. Lab-scale experiments on plastic surfaces demonstrated O 3 disinfection inactivate >99.8% murine norovirus (MNV-1) and porcine epidemic diarrhea virus (PEDV) used as enteric virus and SARS-CoV-2 surrogates, respectively. Additionally, field tests in real full-scale coach gives virus inactivation as >98.6% of infectious MNV-1 and >96.3% PEDV were inactivated.

A systematic review of COVID-19 transport policies and mitigation strategies around the globe

“…To a certain extent, studies have found evidence of disinfection having a positive effect in reducing virus transmission, yet more research is needed to establish conclusive evidence. The use of ozone as a disinfectant is studied by Falcó et al (2021) , who find that ozone concentrations must be monitored and kept at specific levels required to eliminate viral infectivity. Moreover, the literature proposes innovative alternatives such as relying on UV-C LEDs and continuous sanitation air systems (CSAs) based on ionizers ( Baldelli et al, 2022 ).…”