The World's Waste

There are three main types of waste in todays society, municipal waste and industrial waste.

Municipal Waste : This is waste created by the population of an area, from houses etc.

Industrial Waste :  This is waste created by industrial factories and other such places.

Hazardous Waste: Hazardous waste is a mixture of many different types of substances but approximately 50% of them are chemicals.  Hazardous waste comes from many different sources including research laboratories, farmers and even households.  At present the governments of developed countries have no idea of  how much, what type and the destination of hazardous materials.  This makes it practically impossible to keep track of and manage these materials, let alone dispose of them safely.  

Below is a waste generation table showing the amount of waste created per person per day in different cities of different countries.

Waste is a common bi-product of  life in todays modern civilization. This has led some governments to introduce a waste management list.  The list  below shows ways to reduce the amount of pollution entering our planets ecosystem. 

1. Avoid the creation of waste if possible.

2. Re-use unavoidable waste.

3. If re-use is not possible, recycle.

4. If re-use, recycling are not practical use waste for fuel.

5. If all the above are not possible, choose solution that causes least environmental damage.

Solutions for waste disposal

Landfill

Possibly the oldest way of disposing of waste is to dump it under ground, the main problem with this is the lack of unused landfill sites.  Although it was a practical solution many years ago, it has now come to the governments attention that many hazardous materials were dumped in these landfill sites and now require disposing of in a more practical way.  Another problem with landfill sites is the methane gas released by decomposing waste, if this is not checked and controlled the build up could cause a risk to local populations.  Many new landfill sites are being equipped with gas pipes that channel the methane gas into useful areas (i.e. Industrial areas).

Combustion

Many OECD countries are now burning waste to save space in land fill sites.  The weight of rubbish can be reduced by as much as 75% and volume as much as 90%.  This solution on first appearance seems practical , until we consider the difficulties in trying to dispose of chemicals. Although burning toxic chemicals makes most of them harmless they produce toxic gases which are even more harmful to the planet (i.e.  Sulphur oxides, carbon monoxide).  It is calculated that the burning of an average kg of rubbish can produce 10.8MJ of energy.  This means that just 2.6 tonnes of municipal solid waste can replace 1 tonne of coal if burnt at equal efficiencies.

Recycling

Many countries employ a recycling project for most types of household refuse.  Recycling however is only beneficial to the country if it costs less to recycle than it does to purchase new resources,  that is the main reason that many third world countries do not have a recycling project.

Clean Technology

At the moment this is not very widely accepted as it has yet to be seen whether the future can produce a clean way of creating and disposing of, hazardous waste.

Clean production is defined as industrial systems which avoid, or eliminate hazardous waste and hazardous products, and use a minimal amount of raw materials, water and energy.

An experiment at the university of Lund in Landskrona, Sweden helped a local lighting company decrease the amount of pollution it created. The results of the experiment was a reduction in the amount of trichloroethylene pollutants entering the atmosphere and a massive reduction in labour costs.

Contributed by SATIS  A/S Student 1999

Webworld 3 : Special Issue