Sunday, February 13, 2011

The New Waste Technologies: Recycling and Creating Energy From Waste

Many governments, towns and communities throughout the Western world are making new rules concerning the treatment of Municipal Solid waste (MSW). New concepts of waste management are needed in which the idea of recycling is of major importance.


Incineration will be used for the easily burnable fraction of what cannot be recycled, and for some kinds of hazardous wastes such as hospital waste, while the left over will be disposed of in sanitary MSW landfills.

The recycling of products is best done at source by the public when they put their waste out for collection and this is called source separation. However, if the waste is mixed up when collected it can still be separated again by mechanical separation plants or by hand picking using human labour and a conveyor.

The plants in which the separation of mixed wastes is carried out are usually called Mechanical Bioligical Treatment Plants, or MBTs. These plants cost a lot to build, are expensive to run. They also use a lot of power which reduces the value of recycling by expending non-renewable energy in the process.

The last decade has seen source separation introduced in many countries, especially in Scandinavia, Germany, the Netherlands, Switzerland, Austria and Canada. Now, more recently source separation is being implemented in the United Kingdom and the rest of Europe now that European Waste Regulations require so much of the MSW produced not to be landfilled.

The most important reasons to separate waste at the source are:

- The difficulty to find sites for new landfills and the negative attitude of the public towards landfilling and incinerating.

- Source separation improves the quality of the products which will have to be recycled. The fact that the organic fraction is separated from the inorganic fraction means that the organic fraction will have a low concentration of heavy metals and will be free of metals, glass and stones, while the inorganic fraction will be drier and less dirty.

The degree of recycling which can be achieved depends of the system used for source separation but it is the highest if the separated waste is picked up at the houses in separate containers.

A high percentage of recycling can only be achieved though by recycling the organic fraction of MSW whereby anaerobic techniques such as the anaerobic digestion process are very promising since they not only produce a humus-like residue, comparable to the compost produced in aerobic conversion techniques, but also a form of energy, biogas, which can be easily upgraded to several forms of valuable energy.

So, by source separating your waste you can make a difference - especially if there is an Anaerobic digestor in your area.

Why not find out more about waste technologies, and encourage your friends to recycle. Your children and later generations will benefit - don't they deserve the same opportunities you had?

Steve Last is a regular contributor of waste management related articles. Visit, the Waste Technology Web Site to find out more.

He also maintains a dog breed and many others at The Dog Breeds Compendium Tibetan Terrier page.

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