With the advent of the COVID-19 pandemic, there has been
a global
incentive for applying environmentally sustainable and rapid sterilization
methods, such as ultraviolet-C radiation (UVC) and ozonation. Material
sterilization is a requirement for a variety of industries, including
food, water treatment, clothing, healthcare, medical equipment, and
pharmaceuticals. It becomes inevitable when devices and items like
protective equipment are to be reused on/by different persons. This
study presents novel findings on the performance of these sterilization
methods using four microorganisms (Escherichia coli
,
Staphylococcus aureus
,
Candida albicans
, and Aspergillus fumigatus) and six material substrates (stainless steel, polymethyl methacrylate,
copper, surgical facemask, denim, and a cotton-polyester fabric).
The combination of both ozone and UVC generally yields improved performance
compared to their respective applications for the range of materials
and microorganisms considered. Furthermore, the effectiveness of both
UVC and ozone was higher when the fungi utilized were smeared onto
the nonabsorbent materials than when 10 μL droplets were placed
on the material surfaces. This dependence on the contaminating liquid
surface area was not exhibited by the bacteria. This study highlights
the necessity of adequate UVC and ozone dosage control as well as
their synergistic and multifunctional attributes when sterilizing
different materials contaminated with a wide range of microorganisms.