chapter 19: What’s the compostion of your domestic waste stream? IS THERE VALUE IN RECYCLING?
What’s the compostion of your domestic waste stream? IS THERE VALUE IN RECYCLING? Peter Silbemagl Director PD Naidoo and Associates Consulting Engineers (Pty) Ltd
INTRODUCTION
In order to answer the question “Is there value in recycling?” or “Is recycling worth it?” or “Can recycling be viable?” (presumably financially viable), you need to know what is in your waste stream. Gone are the bad old days where only very few waste managers cared about the composition of the waste stream, when the paradigm was ‘collect it all, transport it as efficiently as possible and dispose it all as cheaply as possible’. Today, in order to plan our recycling, treatment and recovery options (and our eventual disposal of the ever-shrinking remainder), we need to know the composition of our waste streams. If we look at the general domestic waste generated by households, this waste can broadly be classified (in terms of material types processing options) as: Recyclables: (Typically, but not only): Paper/cardboard Plastic Metal Glass Compostable: Garden greens Putrescible: food leftovers Inerts Remaining High Calorific: (items that have high energy value) fibreglass rubber combination plastics (not recyclable) Other remainder: Sand Broken crockery Alternatively, the domestic waste stream can be classified in terms of granolumetric sizes (ie percentage of waste stream falling through certain sieve sizes).
WASTE CHARACTERISATION
Experience in South Africa
It should be noted that in South Africa there is some experience in waste characterisation studies which have determined the composition of the waste based on material classification, eg paper, plastic, glass, metals, etc. It is not known whether any surveys (other than some unpublished data from Bloemfontein) have included a size categorisation to categorise the waste into sizes, eg below 60mm, 60 – 160mm and above 160mm, and then to determine the materials in each of the size categories. Adler et al reported at the 3rd International Symposium on MBT and MRF held in May 2009 the waste revolution HANDBOOK
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