UNESCO resource kit - science and technology educa...

UNESCOModule 17: Sorting out waste -----........-----------------
Encouraging better waste management
Page 4
Most people understand that it is a good idea to dispose of waste materials carefully,
to re-cycle some, compost others and so on. But they need to be encouraged
to do this. Here are some more ideas for making good use of waste materials:
• Glass bottles may be melted down and added to new glass, to make new bottles.
• Combustible wastes may be burned to release useful energy, but undesirable
fumes and gases may also be produced.
• Animal and plant wastes may be degraded under suitable conditions
(absence of oxygen, temperature between 20°C and 35°C, presence of microorganisms)
to produce biogas. The residual slurry, rich in compounds of
nitrogen and phosphorus, is used as fertiliser.
• Alternatively, these organic wastes may be rotted down in a covered pit
to produce compost, a natural fertiliser.
• Old car tyres are often recycled for repairing shoes.
By now, you.should.be able to identify some waste materials which could be put
to better use. But how can you encourage people to sort their rubbish, so that
useful materials aren't wasted? Here are some suggestions:
• Design and make a waste bin for a particular type of recyclable waste
material. In one school, pupils designed waste bins shaped like pineapples
to collect organic materials which could be rotted down to make compost.
• Design and make a biogas digester. Fill it with rottable material. Find a way
of collecting any methane gas it produces.
• Identify suitable places in your neighbourhood where recycling bins could be
sited.
• Look around your neighbourhood to identify suitable sites for waste dumps.
Where will a dump have the minimum adverse effect on people, other
animals, and plants? Will water supplies be affected?
• Set up a Waste Disposal Task Force in your school. Can you find ways of
reducing the total amount of waste which your school produces? Could
more waste materials be sent for recycling?
• Site suitable waste bins around your school. Arrange a schedule of members
of your task force to empty them regularly, disposing of the contents in the
best possible ways.
• Run a competition in your school or community to devise posters or slogans
which encourage wise use of waste materials.