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The plastic age
Suggest 10 items made of plastics.
What are they made of before the invention of plastics?
- used as daily products
- used as substitutes
- higher technological products
e.g. photocopying machine.
Advantages of plastics
Rot, chemical and corrosion resistance
Possess strength
Good heat and electrical insulation
Ease of colouring
Suitable for mass production
Lightweight (foam plastics)
Easily moulded
Clear
Types of plastics
- Thermo-plastics
- Thermo-setting plastics
Raw materials for making plastics
Do you think there will be any problems about meeting the increasing demand of plastics in the future?
It will be in shortage because it came from the petroleum
Throwing it away or not?
Hugh cost of collection and disposal ($685/ton, $24/person/month)
20% of the total waste of 8090 tonnes collected each day
No suitable dumping sites (all filled up by 2015)
Non-degradable (cannot be decomposed)
Produce dangerous and toxic fumes in incinerator (PVC, PU, PS and PE)
Any possible solutions?
4-R Principles
Replace
Reduce
Reuse
Recycle
Use degradable plastics:
• Biopolymers – polymers made by living organisms
• Synthetic plastics – can break down naturally
1. Photodegradable plastics
2. Synthetic biodegradable plastics
3. Plastics which dissolve in water
Any limitation? Why is it not so popular?
Replace
Read p. 8 – 9 ‘Paper or polystyrene Which is greenest?’
And p. 14 ‘A Burger to Go – Hold the Plastics’
Go back to paper?
An environmental analysis includes:
1. The environmental impact of obtaining raw materials.
2. The amount of raw material used
3. The energy used in processing / making / fabricating the material.
4. The energy involved in transporting and using the product.
5. The reuse or recycling of the product.
6. The costs and impact of disposal
Debate on the issue on the use of lunch boxes.
Reduce and Reuse
Using less
-Suggest problems.
-What prevent people for using less plastic bags?
-How can we persuade people to BYOB?
Read p. 13 ‘Breaking the Trash Habit’
Read p. 14 ‘The New Yorker’
Read p. 15 ‘ Charge for plastic bags instead’
Stringent new rules that make the manufacturing, retailing and packaging sectors responsible for recycling the wrapping and containers of everything they sell.
What about price reduction?
• Recycling include collection, processing, and procurement Recycling include collection, processing, and procurement
or reuse of the recovered materials. or reuse of the recovered materials.
Recycling is the act of recovering a waste material forRecycling is the act of recovering a waste material for
reuse and processing into another useful product.reuse and processing into another useful product.
• All three activities must be completed in order to make All three activities must be completed in order to make
recycling programs effective.recycling programs effective.
What make recycling difficult in H. K.?
How can we promote recycling of plastics? Discuss and present your findings.
Recycling in Hong Kong (read p. 5)
Collection and disposal of wastes
Propose policies on the problems of plastic wastes
You are placed in a higher Government position. Write an essay of a plan for dealing with the problems of plastic wastes.
There are some possible ways suggested by your classmates. However, you have to rank them according to their effectiveness and feasibility.
Incineration
Landfilling
Participation by industrial companies to take the initiative to adopt the plastic waste avoidance measures.
Promotion to use less packaging material of both the manufacturers and consumers (award scheme).
Symbol to distinguish - provide choices for consumers.
Raise the awareness and change the social attitude of throw away habit.
Do we really need an extra bag for purchasing goods at supermarket?
Government takes the first lead to reduce the use of plastics.
EPD drives the plastic waste reduction plan.
Legislative measures
Producers‘ responsibility scheme to manage the waste they created.
Polluter pays principle
Subsidization on promoting the use of “green bags”.
Design more beautiful and attractive plastic bags - keep and reuse.
Reuse and use more efficient.
Recycling - sorting by households, collecting by Government.
Wellcome and Park‘N - collect plastic bags in exchange of stamps.
Find substitutes
http://www.em.doe.gov/em30/wasttrea.html
http://www.soc.titech.ac.jp/uem/waste/waste.html
http://www.info.gov.hk/epd/index.htm
http://www.info.gov.hk/epd/E/ehk99/home/chinese/ccontnt7.htm
http://www.unep.or.jp/CTT_DATA/index_waste.html
http://www.greenpeace.org/
Environmental Protection 94
Environmental Science
The end