Autoclave for healthcare waste treatment

Treatment of medical solid wastes by the application of autoclave sterilizer-shredder Triwira AS300 Made in Indonesia Introduction Hospitals are important sources of pollutants resulted from diagnostic, laboratory and research activities as well as medicine excretion by patients, which include active component of drugs and metabolite, chemicals, residues of pharmaceuticals, radioactive markers, iodinated contrast media, etc. (Verlicchi et al., 2010). In addition, it is estimated that 75% of the wastes produced by hospitals are general health care wastes, while the remaining 25% are regarded as hazardous infectious wastes (Prüss et al., 1999; Taghipour et al., 2014). Improper disposal of infectious hospital wastes and wastewater could cause serious risks to public health and environment. The discharge of hospital wastes and wastewater, especially those without appropriate treatment would expose the public in danger of infection. In particular, under the COVID-19 pandemic worldwide, it is of great significance to reduce the health risks to the public and environment. Thus, it is necessary to appropriately sterilize, disinfect and dispose of the hospital wastes before being transported or discharged. This short review will concentrate on disinfection technology for treatment of hospital solid wastes, and provide suggestions for hospital wastes treatment using Triwira AS300 autoclave-sterilizer-shredder that has been designed and manufactured in Indonesia since 1986. Medical solid wastes are usually classified before disinfection as shown in Fig. 4 (Blenkharn, 2007). The typical composition of healthcare waste is approximately 85% general non-infectious, 10% infectious/hazardous, and 5% chemical/radioactive (WHO, 2014). This section first summarizes major types of hospital waste disinfection technologies, including incineration, chemical disinfection and physical disinfection, and then illustrates the proper disinfection technologies used in different situations. Steps in healthcare waste management Steps in medical solid wastes management typically comprise basic processes and go through the following sequences: • Waste classification • Waste segregation • Waste minimization • Handling and collection • On-site transport and storage • Treatment and disposal Basic principles Principles of waste treatment, according to the international health organizations, should be centered on the following attributes (UNDP-WHO, 2020): • The main purpose is to reduce potential hazard posed by healthcare waste in order to protect public health and the environment • Treatment should be viewed in the context of waste management hierarchy • Measures should first be taken to minimize waste, segregate and reuse non-infectious waste items wherever possible • After minimization, the remaining waste materials should be treated to reduce health and environmental hazards, and the residues should be properly disposed of Approaches Treatment approaches are implemented in line with the waste management hierarchy • On-site treatment: Healthcare facility or small-scale hospital treats its own waste • Cluster treatment: Major hospital treats its waste plus waste from other healthcare facility in a small area • Central treatment: Dedicated treatment plant collects and treats waste from several healthcare facilities in an urban center or region Processes used in the treatment of healthcare waste Five basic processes are used in the treatment of hazardous healthcare wastes particularly sharps, infectious and pathological waste • Thermal • Chemical • Irradiation • Biological • Mechanical (used to supplement the other processes) Thermal treatment process • Rely on heat to destroy pathogens • Divided into two types: o Low-heat thermal systems Also called non-burn or non-incineration treatment technologies o High-heat thermal systems Which involves combustion and/or pyrolysis of healthcare waste Low-heat thermal process Uses thermal energy at elevated temperature high enough to destroy pathogens, but not sufficient to cause combustion or pyrolysis of waste • Generally operates between 100◦C to 180◦C • Takes place in moist or dry environment • Often involves shredding, grinding or mixing to increase exposure of waste to heat, therefore boost efficacy • Low-heat process results in sterilization of hazardous infectious and pathogen wastes Our healthcare waste treatment machine, Autoclave-sterilizer-shredder Triwira AS300, satisfies the requirements in accordance with the above-mentioned international standards and has been deployed in Indonesia since 1986. In the context of waste management hierarchy, our autoclave is suitable for use for on-site treatment at a single healthcare facility as well as cluster treatment at major hospital by deployment of several units depending on the volume of waste to be treated. Researches and worldwide application of low-heat, steam sterilization using autoclave proves that this type of technology provides a safe, efficient and effective approach to healthcare waste processing. Operating procedures: 1. Loading 2. Heating 3. Sterilizing 4. Cooling 5. Shredding 6. Draining 7. Unloading Specifications of Triwira AS 300 medical waste Autoclave-sterilizer-shredder: General characteristics Dimension L x W x H 270 x 210 x 330 m Shipping Weight Autoclave 3,500 Kg Diagram: Steam boiler 700 Kg Shredder 800 kg Max weight for hydraulic test 3,700 Kg Stress 2 Kg/cm2 Steam Pressure 3-4 Bar Max Steam Flow 170 Kg/h Compressed Air 6 Bar Electricity 380V /3-Phase 45 kW Operating characteristics Average Cycle Time 30 minutes Process Volume Capacity 350 liters Average Waste Density 100 – 150 Kg/m3 Average Process Weight Capacity 35 - 53 Kg/cycle Microbial Inactivation 108 Waste Volume Reduction 70-80% Consumption per cycle Electricity 1.7 kWh Steam 15 Kg/30 liters Water 25 liters Autoclave side-view Steam Boiler Shredder Operating procedures Our autoclave Triwira AS300 process is designed to shred and sterilize infectious waste to reduce its volume, and render its components unrecognizable all in one fully enclosed and automated, stainless steel, system stainless steel, system. It combines shredding, direct steam and high pressure to treat infectious materials. Unprocessed, that falls into the category of regulated waste materials are loaded into the upper chamber using overhead crane, and then undergoing sterilizing process in the autoclave where every particle is steam-heated to 136°C (276.8ºF) and pressurized to 3,5 bar (51 psi) for 10 minutes. The operating and treatment conditions are continuously monitored and validated to achieve complete sterilization in which microbial inactivation reaches 108. After the cooling process, overhead crane transfer waste into a shredding process and the final product is volume-reduced by up to 80%, rendered unrecognizable and safe to recycle or to dispose of as ordinary municipal waste. The disinfected and reduced-in-volume waste then packed into fresh plastic bags for delivery to final disposal sites. The 30-minute duration of an average cycle process is carefully monitored and entirely recorded. A trained operator monitors the process and carefully records a batch report at the end of each cycle and compares it with the essential sterilizing parameters for accurate record keeping. Between each cycle, The approved parameters are programmed into the standard operating procedures. Between each cycle, the operator confirms that each cycle runs properly and records this information in a daily log. References: Blenkharn J.I. 2007. Classification and management of clinical wastes. J. Hosp. Infect. Pp. 65:177–178. [Google Scholar] Prüss A., Giroult E., Rushbrook P. 1999. World Health Organization. Safe Management of Waste from Health Care Activities. [Google Scholar] UNDP. 2020. Module 15: Non-Incineration Treatment and Disposal of Healthcare Waste. Global Healthcare Waste Project. Verlicchi P., Galletti A., Petrovic M., Barceló D. 2010. Hospital effluents as a source of emerging pollutants: an overview of micropollutants and sustainable treatment options. J. Hydrol. Pp. 389:416–428. [Google Scholar] Taghipour H., Mohammadyarei T., Asghari Jafarabadi M., Asl Hashemi A. On-site or off-site treatment of medical waste: a challenge. J. Environ. Health Sci. Eng. 2014. Pp. 12:68. [PMC free article] [PubMed] [Google Scholar] For more information, please contact: Sutrisno Jono, Email: sutrisno.jono38@gmail.com Suhardiyoto Haryadi, Email: suhardiyoto@gmail.com