Waste generation would be even higher if not for waste prevention practices that keep materials out of the waste stream. Material recovery starts at home with activities such as back-yard composting of yard waste and using mowers that leave grass clippings on the lawn.
Amazingly large tonnages of waste are simply yard trimmings (garden waste). In 1998, Americans sent an enormous 27.7 million tons of yard trimmings into the waste stream, but at least this was down from 35.0 million tons in 1990.
There is clearly a lot that needs to be done to improve materials recovery and there are still big gains possible in waste prevention through this route.
Unfortunately, in Europe there are misguided regulations in force involving the expenditure of billions of Euros to define all discarded materials, including recyclables and compostables, as waste, and thus it can only to be collected by waste contractors. Once in their hands it cannot be sold on as a product because it is almost impossible to redefine materials once categorized as waste, as anything but waste.
So, in many ways material recovery is obstructed by the rules.
Material recovery is nevertheless taking place in some areas using some materials. Plastics is an example, materials recovery is by no means the only way to recycle plastics, but it is favored by the public and there are a growing number of good uses for recycled plastic materials. Other than recover the materials another popular option is to recover their thermal content, providing an alternative source of energy through the production of refuse derived fuel (RDF) for example.
Incineration is another option that also helps recover thermal content, providing an alternative source of energy usually through power generation.
Material recovery rates can be improved by designing products for recycling, and improvements are taking place in that field especially within the car manufacturers.
The existing global scrap recycling system works well for a number of commonly used metals. It is thought that interactions between different types of recyclables and different sections of the global market are gradually moving the market forward and translating into increased demand for a number of recovered materials.
Once the market matures and demand for recovered materials expands there is plenty of scope for increased plastics recovery from the waste stream. Plastic film and food containers have largely not been collected to date both because of the difficulties mentioned above and the high contamination by virtue of the materials contact with food and other products. However, with other uses developing for food wastes (eg in using them as a premium feedstock for Anaerobic Digestion).
Certainly, a reduction in plastics materials sent to landfill is slowly taking place. At the same time it will continue to be challenging to recover these materials, as plastic is one of the most difficult wastes to handle both in combustion technologies and even in tiny amounts when composting.
Steve D Evans is a leading waste management expert and has written a clear explanation of what are Materials Recovery Facilities along with many other terms used by the waste industry. Visiting this web site will solve your confusion the next time your Council sets out to gain Permission for a MRF, or a MBT plant, and even terms being increasingly used, like gasification, autoclaving and Mechanical Heat treatment are explained.
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