Chapter 16 Sustainability: How can we make
a difference?
16.1: How can we manage waste better?
1
In figure 16.4 on page 400 of Big Ideas Science 3 it is suggested that aluminium cans can take between
200-500 years to break down. In the information listed on the Keep Australia Beautiful website
(http://www.kab.org.au/files/kabweek/kab_week_2009_-key_statistics_(2).pdf), it is stated that this process
could take 80–200 years. What factors are likely to affect how long it takes for aluminium cans to break
down?
2
Does aluminium decompose by rusting, as iron does? (Hint: revisit Chapter 3 if you are unsure about this.)
3
Fossils of humans have been found that are thousands of years old but skeletons of animals that have died
out in the paddock become brittle and fragile after only 6 to 12 months exposure to the sun and rain. When
bodies are buried in coffins it can take more than 100 years for the bones to decompose. A human bone
would take about 8 years to break down in a area like Mexico, while it would take 80 years in a cold
environment like Canada. It depends on the contents of the bone and the environment it is in. How does
the temperature and the environment have an impact on the decomposition of bones?
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4
Over 80% of what we throw away can be reused or recycled. Make a list of ten objects and materials that
can be recycled in your community.
5
In Experiment 16.1 on page 401 of Big Ideas Science 3, you conduct an investigation into biodegradability.
Different materials are buried in the ground for two weeks and then dug up and studied to see whether
there are any signs of oxidation, decomposition or attack by animals. A better investigation would require
you to divide an area into plots and carefully label them with labels that will withstand the effects of
weather. You could then bury different types of materials and leave them for at least a year to see whether
there were any changes. What factors would you need to keep the same to ensure that this investigation
was a fair test?
6
Some materials decompose faster if they are not buried. If they could be exposed to the sun, the wind and
the rain they would break down much more quickly. Design a new method of storing waste materials so
that they are exposed to the sunshine and the weather.
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Try out the interactive game at the Waste Wise WA website and create your
own virtual compost then answer the following questions.
7
What kinds of materials are needed to make healthy, balanced compost?
8
How many days are required to make good compost?
9
Why does the compost need to be kept damp?
10 Why can’t you put meat scraps into the compost?
11 Oxygen is an essential ingredient for the production of good compost. What chemical reaction is likely to be
taking place in the compost bin?
12 As the compost is formed from the decomposing matter the compost bin becomes quite warm. Is this a
sign that the decomposition reaction is exothermic or endothermic?
Now try making a virtual worm farm. Make sure you read the instructions on
how to take care of a worm farm first.
13 What kind of environment do worms like to live in? More information can be found at this site:
http://barinya.com/australia/environment/Worm_Farms_Australia.htm
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14 What are worm castings?
Further activities
15 Use the templates and resources at the Towards Zero Waste WA website to help you create your own
poster or brochure promoting the use of worm farms and composting.
16 Worms farms cost around $110 each, and you can read about how to purchase one at the Worms to
Waste website. Given that local councils and state, territory and federal governments are trying to
encourage Australians to produce less waste and recycle or reuse what they can, do you think that they
should provide all Australian households with a worm farm? Write a letter to your local council, state or
federal minister for parliament suggesting some ideas to help people reduce waste.
17 Keep Australia Beautiful is an organisation that aims to literally keep Australia beautiful. Each year they run
Clean Up Australia Week where thousands of volunteers collect rubbish that has been dumped in the
environment. Keep Australia Beautiful carries out research twice a year at 975 sites to compile the National
Litter Index, and you can read the latest report here. Cigarette butts are the most common item found in
litter and plastic litter objects contributed the greatest volume to the litter that was collected.
Think about registering to run your own local litter count. You will find the details here.
18 In 2009, Keep Australia Beautiful ran the Trash my Ad competition in which students were invited to design
their own television ad to influence littering behaviour. You can see the winning ads here:
http://trashmyad.com.au/?id=301
In groups, discuss what sort of advertisement you would produce to try and reduce the littering behaviour
of students at your school. Create a storyboard of your ideas.
19 Play Catchment Detox to see if you can repair a damaged river catchment and create a sustainable and
thriving economy. This is an online game where you are in charge of the whole catchment area. You
decide which activities you undertake (planting crops, logging forests, building factories or setting up
national parks), and you see the consequences of your decisions as the game progresses. The aim is to fix
environmental problems and provide food and wealth for the population.
Oxford Big Ideas Science 3
ISBN 978 0 19 556453 2
© Oxford University Press Australia