The main process for disposing of clinical waste is thermal treatment – used to treat sharps and infectious waste. It utilises high temperatures to make the waste combustible and no longer harmful. Useful materials are resistant to thermal conditions and go through the process without getting damaged, while the waste material is burned down.
There are a few ways to perform thermal treatment including:
Autoclave procedure
This involves processing chemical waste by exposing it to high levels of heat, steam, and pressure in an autoclave machine. There are two systems of autoclave – batch or continuous flow process.
- Batch system – Waste is exposed to temperatures as high as 1600°C, pressures of 6 bar (gauge) and steam. Plastics melt, papers disintegrate, and labels are removed while bottles and metallic objects are cleaned.
- Continuous flow process – Waste such as stones, glass, and metals are removed from the initial waste before the automated autoclave process begins. This saves significant levels of energy while cutting down on labour and equipment costs.
Hybrid autoclave systems function similarly. However, they’re incorporated with other technologies so they can also function as washers and sterilisers.
Continuous steam treatment systems
This gets rid of the chemical and clinical waste while enhancing specific material properties – such as firmness and resistance to corrosive and abrasive forces.
Frictional heat treatment systems
Heat for waste combustion is generated through impact and friction. The residue is sterilised and later reduced into manageable volume through fine grinding and drying. This method can be used as an alternative to incineration. Studies show it has near-zero negative environmental impact and it significantly reduces the waste quantity.
Incineration
This involves exposing waste to heat to burn its organic components, converting them to ash, gas, and heat. The gas produced is commonly known as flue gas and is treated to rid it of pollutants before releasing it into the atmosphere. The heat can be utilised to generate electric power.