Disposal of Hazardous Waste
There are a number of different ways to handle the disposal of hazardous waste whether it’s from general household rubbish or in a more regulated commercial setting. The good news is that there are a range of specialist companies nowadays that handle this kind of waste with processes that include highly specialised equipment and machinery to separate and desorption of harmful chemicals and materials.
In the first place, as with other waste, there should always be an attempt to recycle or reuse anything that has been classified as hazardous. New processes are being introduced all the time that can do just this. This, more sustainable approach, could include reusing components from electrical equipment or removing the most dangerous parts and recycling the rest and even blending hazardous chemicals such as solvents and reusing rather than disposing in landfill.
Across the whole of Europe and many other parts of the world, the handling of this kind of waste is covered by comprehensive hazardous waste legislation and failure to comply can lead to a fine of up to £5,000 or even, in extreme cases, imprisonment.
High and Low Temperature Thermal Desorption
Waste such as oil spills, contaminated soil and industrial sludge can undergo high temperature thermal desorption which is used to separate recyclable organic compounds from the waste. It is a process that was first developed in America in 1985 and can use a variety of ways to heat waste including rotary heating, microwave and infrared to remove volatile compounds leaving behind a cleaner residue. Low temperature thermal desorption which essentially depends on processes such as distillation to separate hazardous waste including solvents from products like paint and ink.
Centrifugation for Oil Sludge
The introduction of the landfill directive which basically meant that waste couldn’t go straight to traditional disposal sites but needed to be recovered or recycled as far as possible, led to the development of technologies such as using a centrifuge to separate solids from harmful substances in products like oil sludge. This process can help remove the less harmful components of the sludge which can then be safely disposed of either by recycling or for use in anaerobic digestion.
Physical and Chemical Treatment
There are also various physical and chemical processes that can be used to dispose of hazardous waste such as contaminated coolant water from reactors, machine oils and bleach to name just a few. This can include solvent blending, recycling and recovery all of which are designed to make substances less harmful.
Waste can also be treated by using processes such as anaerobic digestion where bacteria are used to break down by products of hazardous waste. This is becoming more common as we find ways to transform agricultural and industrial waste into heat and energy.
High Temperature Incineration
Another solution for this kind of waste, of course, is incineration which is used for substances such as solvent based adhesives, controlled drugs, sulphur contaminated waste and anything that cannot be reasonably treated in other ways including clinical waste.
Hazardous WEEE Waste
The majority of waste that we produce which is classed as hazardous is often only a small part of the items we throw away. Nowhere is this truer than with electronic and electrical waste. There are capacitors that have polychlorinated biphenyls and fridges and freezers which contain ozone depleting substances. Then you also have fluorescent lights that contain mercury and there are nickel-cadmium batteries which carry their own risks. These types of waste are often more challenging to deal with and disposal involves either repurposing or separating hazardous components and recycling the useful metal and plastic parts.
All categories of waste have their hazardous components. These are generally stipulated by the European Waste Catalogue (EWC) and you can check on the Government website for different classes of waste to see if your waste falls within this category. Examples with their EWC code include:
- For construction and demolition waste: Insulation containing asbestos, coded 17-06-01.
- For packaging and recyclable waste: Things like empty paint tins that contain residues of hazardous waste, coded 15-01-10.
- Waste electrical and electronic equipment: Such as television cathode ray tubes that contain hazardous substances under EWC code 20-01-35.
- Healthcare and related wastes: Substances such as cytotoxic and cytostatic waste, coded 18-01-08.
All these different kinds of waste have to be disposed of properly, particularly if they have hazardous components. This presents a major challenge for waste disposal over the next few decades with approaches ranging from full incineration to recycling and repurposing.
Find out more about the management of hazardous waste.