Feasibility study of ozone application for disinfection of infectious hospital wastes

Abstract

Introduction: Hospital waste disposal methods should be selected using the best available methods to minimize the health problems and environmental pollution of wastes. Therefore, the aim of this study was to evaluate the application of ozone in disinfection of hospital infectious wastes. Materials and Methods: The present study was carried out on infectious and sharp wastes of the hospital. Bacillus atrophaeus spores were cultured in plates containing TSA medium As an indicator in the bags containing infectious and sharp wastes in the worst possible conditions of ozone penetration. The ozone generator was equipped with a constant dose of 5 grams per liter, with a discharge of 1 and 3 liters per minute, and a contact time of 10 to 120 minutes To 3 (dry conditions, separate infusion with water vapor into the contact tank and injection into a glass column containing water and then transfer of ozone-containing bubbles to the contact tank). Then the ozone exposure indicators were incubated for 24 - 48 h at 36 ± 1 °C and, finally, the absence of colony growth in the culture medium was considered as the success of ozone in disinfection of infectious wastes. In this study, the process of wet and dry disinfection was performed with 4 replications Also, the effect of parameters such as volumetric, dense or non-dense waste was investigated on the efficiency of the extinction. The results were analyzed using descriptive and analytical statistics. Results: The results showed that the inactivation efficiency of Bacillus atrophaeus was 100% determined by dry gaseous ozonation at 80 min with a rate of one liter per minute in both types of infectious and sharp As the dose of ozone increased to 3 liters per minute, the deactivation time decreased, so that at the time of contact, the elimination efficiency was reduced to 100% at 15 minutes. The deactivation efficiency is 100% by the process of wet ozone injection (by glass column) for 30 minutes and 100% by wet injection of ozone (separate injection of water vapor into the contact tank) for 50 minutes. Conclusion: Based on the results of this study, the best conditions for risk-free infectious and sharp-wrapped wastes were obtained in conditions of dry ozone depletion. Therefore, this process can be used as a practical and acceptable method for the risk-free disposal of hospital wastes.