Application of Sterilization Process for Inactivation of Bacillus Stearothermophilus in Biomedical Waste and Associated Greenhouse Gas Emissions

Cevat Yaman

doi:10.3390/app10155056

Abstract

This study investigated the biomedical waste collection, transportation, and treatment activities in the city of Kocaeli, Turkey. As an alternative to incineration technology, a steam autoclave was used to sterilize the biomedical waste. Information regarding the collection, transportation, treatment and associated greenhouse gas emissions (GHG) were also investigated. Prior to sterilization, biological indicator vials containing Bacillus stearothermophilus were placed in the center of the load to ensure that the pathogens were destroyed. GHG emissions were calculated based on the fuel consumed by the biomedical waste collection vehicles and the electricity/natural gas used at the sterilization plant. Results of this work revealed that the total biomedical waste generated per year increased from 1362 tons in 2009 to 2375 tons in 2019. The amount of biomedical waste generated per hospital bed was determined as 1.19 kg.bed−1.day−1. Results show that for efficient sterilization of biomedical wastes, the steam treatment system process should be operated at a contact time of 45 min, a temperature of 150 °C, and at a steam pressure of 5 bar. Biological indicator tests showed that the number of living Bacillus stearothermophilus decreased significantly, with removal rates greater than 6log10. Finally, it was determined that the biomedical waste management activities generated a total of GHG emissions of 5573 ton CO2 equivalency (tCO2-e) from 2009 to 2019. Furthermore, the average global warming factor (GWF) was calculated to be 0.269 tCO2-e per ton of biomedical waste generated. This study showed that the sterilization process is very effective in destroying the pathogens and the management of biomedical waste generates considerable amounts of GHG emissions.

Highlights

The appropriate management of biomedical waste is extremely important due to its significant environmental and health hazards
It was observed during this study that the steam autoclave performed most effectively at a contact time of 45 min, a temperature of 150 ◦ C, and at a steam pressure of 5 bar, to inactivate Bacillus stearothermophilus
It was shown in this study that the biomedical waste collection, transport and sterilization processes generated a total of greenhouse gas (GHG) emissions of 5573 tCO2 -e from 2009 to 2019

Summary

Introduction

The appropriate management of biomedical waste is extremely important due to its significant environmental and health hazards. Biomedical waste poses a great risk of infection through the spread of pathogens from health institutions into the environment [1]. Medical devices are being manufactured for single use only, further increasing the amount of biomedical waste especially in developing countries. This will result in a rapid increase in biomedical waste amounts that should be disposed in a safe manner [2]. The terms infectious waste and biomedical waste are usually used for wastes that cannot be disposed of in a municipal solid waste landfill due to their pathogenic content. The safe disposal of biomedical wastes is of a great concern for the generators and the public.

Methods

Discussion

Conclusion