Background and Aim : Nowadays, high production of waste has become a global concern.Among different types of waste, infectious waste is one of the most hazardous types requiringcomplete decontamination with a high safety factor before disposal. The high volume of wasteproduced by healthcare centers in Tehran has reached ۸۰ to ۱۱۰ tons per day. Also, the emergenceof Covid-۱۹ has increased this amount significantly. The lack of administration of adequate andcutting-edge technologies for complete and safe decontamination and sanitary disposal ofinfectious waste could pose a serious threat to public health as well as the environment. Theadministration of novel and environmental-friendly methods such as advanced-oxidationprocesses can treat infectious waste and prevent the occurrence of hospital-acquired infectionssignificantly. The current study aims to evaluate the efficacy of administration of ozonation andUV radiation in the decontamination of solid wastes contaminated with Bacillus subtilisATCC۶۶۳۳, Pseudomonas aeruginosa ATCC۲۷۸۵۳, and Staphylococcus aureus ATCC۲۵۹۲۳Methods : An insulated apparatus capable of emission of different volumes of
ozone and
UV wasdesigned and produced for the current research. Artificial solid wastes were prepared using ۱۰۰grams of sterile cotton as a solid waste model. Then, different portions were contaminatedseparately with bacterial suspensions (adjusted with ۰.۵ McFarland turbidity standard in ۱۰۰ml),including B. subtilis, S. aureus, and P. aeruginosa. The wastes were treated using UV, ozonation(۵۰۰۰, ۱۰۰۰۰, and ۱۵۰۰۰ ppm), and UV+ozonation at different times, including ۱, ۳, ۵,۱۰, ۲۰, ۳۰,۶۰, ۱۲۰, and ۱۸۰ mins. For contamination evaluation, ۱۰ grams of wastes were added to ۹۰ ml ofsterile normal saline, and serial dilutions were prepared. The samples were cultured on Trypticasesoy agar and after ۴۸ hours incubating(۳۷c°) a colony count was performed.Results : The optimum elimination (zero counts) of each bacterium was observed as follows: A)۱۵۰۰۰ ppm ozonation+UV in ۳ mins for B. subtilis. B) ۵۰۰۰ pmm ozonation+UV in ۳۰ mins forP. aeruginosa. C) ۵۰۰۰ pmm ozonation in ۱۸۰ mins for B. subtilisConclusion : Our results represent the practicability of the designed apparatus in thedecontamination of infectious wastes as an cost-effective apparatus.