Sorting/Processing of waste
Depending on the nature of the source material, there are a plethora of sorting and processing activities utilised that range from labour intensive hand picking operations through to highly mechanised or technically complex processes. The chosen method of sorting will depend on many factors such as the nature of the waste, the ease of segregation and the yield and quality of the resultant recyclates.
Municipal (household) kerbside sorted recyclables
A proportion of waste is sorted into its fractions (typically glass, plastics and paper) at the kerbside. These pre-sorted materials are forward to transfer stations for bulking up and compacting prior to transportation onto processing facilities, or in some cases export. The process can involve manual picking lines for removal of erroneous materials and the use of compacting machinery.
Municipal (household) and commercial mixed recyclable waste
If not sorted at the kerbside, municipal recyclates may be taken to centralised premises, such as transfer stations or materials recycling facilities (MRFs) for sorting and or processing. The waste stream can be sorted into various constituent components (eg paper, plastics, glass, metals, WEEE etc and the residual material) depending on the set-up at each particular MRF. Commercially derived waste is treated in much the same manner. Irrespective of the complexity of the MRF there are usually manual picking lines incorporated at various stages of the process to remove unwanted or rogue materials.
Industrial or builders waste
Generally this type of waste is collected by skip and delivered to waste transfer stations where the material (primarily construction based) is sorted into its component parts prior to processing or disposal. Again, these sites can incorporate a mixture of manual and mechanical operations, to include the use of MRFs,
There are a number of significant hazards associated with all sorting operations:
The recyclates that result from the sorting operation (or from other sources such as Civic Amenity/HWRC/Bring Sites) may be processed on the same site that the sorting took place or forwarded on to more specialised facilities for treatment.
Further processing of recyclables and other waste materials can involve a number of discrete sub-industries of the waste management and recycling sector:
Some of the above processes give rise to specific occupational health issues, such as:
- wood dust
- exposure to lead and mercury in WEEE recycling.
For sorting and processing operations there is a useful self audit check list that can be used for activities where hand sorting of materials plays a part.