Study of ozone misting for sanitization of hospital facilities: A CFD approach

ABSTRACT The COVID-19 pandemic has demonstrated the demand for more effective procedures for sanitizing environments, especially high-risk ones, such as hospitals. Several products are used as disinfectants, with ozone being one of the strongest oxidants known. High relative humidity helps reduce the contact time required for viruses and bacteria inactivation with ozone. Thus, this work aimed to analyze the dispersion of an ozonized mist by CFD simulation to sanitize a hospital operating room. To our best knowledge, for the first time, the dispersion of an ozonized mist was investigated by CFD. The mathematical and numerical models were validated with results from the literature. The decay kinetics of the ozonized mist was obtained experimentally, resulting in a first order reaction with a kinetic constant of 2.66 × 10−4 s−1. The numerical results of concentration on the surfaces were analyzed qualitatively and quantitatively, providing relevant information about the fluid dynamics of the sanitizing process. Ozone mist concentrations were higher on the walls close to the generator and lower on the furthest walls and the ceiling. The ozone mist concentration in the room reached an average of 11 mg/L. Five minutes of ozone mist generation and another five minutes of decay by air circulation were sufficient to provide an increase in ozone mist to concentrations above 4 mg/L, considered satisfactory for the sanitization of the operating room surfaces.