1. Waste Treatment
Waste treatment techniques are used to change the physical, chemical or biological character of the waste, to reduce its volume and/or toxicity and to make the waste safer for disposal.

2. How is waste being generated?
Raw Material Acquisition
Material Processing
Product Manufacture
Product Use or Consumption
Disposal
Waste
Waste
Waste
Waste
Waste generated in the life cycle of a product

3. Type of waste Domestic Waste Construction Waste Commercial Waste
Industrial Waste

4. Waste load in HK [1] Waste Classification in HK Municipal solid waste
Domestic waste
Commercial waste
Industrial waste
Construction & demolition (C&D) waste
Chemical waste
Special waste (e.g. clinical waste, radioactive waste)
Other solid wastes

5. Waste load in HK [2] Quantity of waste
The quantities of major types of solid waste disposed of in Hong Kong ( )

6. Waste load in HK [3] Composition of waste
Major components of domestic waste disposed of in Hong Kong

7. Reasons for waste reduction
Landfill capacity
Cost of waste managements
Costs of waste facilities
Costs of landfill restoration
Social costs
Environmental cost
Economic value of the waste itself
Economic development

8. Treatment of Solid Waste
Disposing in the landfills
Burning in the incinerator
Composting
Recycling of recyclable waste
Why do we need treatment of waste ?
Because managing the waste properly
helps to avoid adverse environmental
and public health consequence.
Ocean dumping

9. In Incinerators of conventional design, refuse is burned on moving grates in refractory-lined chambers;
Combustible gases and the solids they carry are burned
in secondary chambers.
Combustion is 85 to 90 % complete for the combustible
materials.
In addition to heat, the products of incineration include
the normal primary products of combustion:
- carbon dioxide and water-as well as oxides of
sulphur and nitrogen and other gaseous pollutants;
- nongaseous products are fly ash and unburned solid
residue.
Emissions of fly ash and other particles are often
controlled by wet scrubbers, electrostatic precipitators,
and bag filters.

10. In a Modern Landfill, refuse is spread in thin layers, each of which is compacted by a bulldozer before the next is spread.
When about 3 m of refuse has been laid down, it is covered by
a thin layer of clean earth, which also is compacted.
Pollution of surface and groundwater is minimized by :
1.Lining and contouring the fill,
2.Compacting and planting the cover,
3.Selecting proper soil,
4.Diverting upland drainage, and
5.Placing wastes in sites not subject to flooding or high groundwater levels.
Gases are generated in landfills through anaerobic decomposition of organic solid waste. If a significant amount of methane is present, it may be explosive; proper venting(making holes) eliminates this problem.

11. Composting Operations of solid wastes include preparing refuse and degrading organic matter by aerobic microorganisms.
Refuse is presorted, to remove materials that might have salvage value or cannot be composted,
Then it is ground up to improve the efficiency of the decomposition process.
The refuse is degraded biologically to a humus with a total nitrogen, phosphorus, and potassium content of 1 to 3 %, depending on the material being composted.
After about three weeks, the product is ready for curing, mixing with additives, bagging, and marketing.

12. Composting In Garden Air Some soil Water
kitchen wastes leaves grass clippings
Air
Water
Some soil
fertilizer

14. What is Recycling ?
Recycling is the act of recovering a waste material for
reuse and processing into another useful product.
Recycling include collection, processing, and procurement or reuse of the recovered materials.
All three activities must be completed in order to make recycling programs effective.

15. Recyclable Waste Metals e.g.Aluminium cans Waste paper like newspaper
Plastic and glass bottles

16. - Paper should be separated from other waste
in homes and offices for recycling.
- Re-usable items get thrown away, such as this
wood used to decorate an office or flat.
- Refrigerators and other appliances contain metals
that could be recycled.

17. Burning in the incinerator

19. Waste Reduction in the present
Waste separation facilities are now
available in all public housing estates
and many private residential
developments.
Government has provided land to facilitate the operation of the waste collection and recycling industry.

20. Waste Reduction in the future
The Waste Reduction Committee was established earlier this year.
Its target is to double the overall rate of municipal waste reduction and recycling by 2007.
As for collecting a waste disposal fee, the Government will put forward a proposal for a landfill charging scheme shortly.
From 99 Policy Address

21. Recycling
In 2000, 8% of recoverable domestic waste was recycled in Hong Kong.
The government will seek funding in the coming year to construct new waste separation facilities.
The government will also encourage the new District Councils to explore ways to increase the recovery rate of reusable materials in collaboration with the business sector and local communities.

22. Waste to Energy
The government are restoring old landfill sites at a cost of $2.3 billion and are seeking to turn the combustible gases into energy.
The government will be consulting the community in the coming year on proposals for new waste management facilities, including waste-to-energy incinerators.

23. Waste Reduction Framework Plan [1]
Targets
Diverting 58% of municipal solid waste from landfills by 2007 (compared with 30% in 1997).
Extending the life span of the existing landfills from 2015 to 2019
Diverting 84% of Construction and Demolition (C&D) material from landfills by 2007 (compared with 80% in 1997)
Extending the life span of the existing landfills by further 6 months

24. Waste Reduction Framework Plan [2]
Scope
To extend the life-span of the strategic landfills
To minimize the amount of waste produced that requires disposal;
To conserve the earth’s non-renewable resources;
To increase the waste recycling rate
To identify the true costs of waste management in order to maximize efficiency and minimize the cost of collection, treatment and disposal of wastes;
To improve the institutional arrangement

25. Waste Reduction Framework Plan [3]
Three Main Areas of the Plan
Prevention of Waste Programme
Institutional Programme
Waste Bulk Reduction Programme

26. Waste Management in HK [1]
Waste Management Hierarchy
(source: EPD website,

27. Waste Management in HK [2]
Facilities of Waste Management
Landfills

28. Waste Management in HK [3]
Landfills - filling refuse in constructed areas
Typical Landfill
(Source: EPD website,

29. Waste Management in HK [4]
Refuse Truck Unloading at Tipping Face in Landfill
(Source: EPD website,

30. Waste Management in HK [5]
Refuse Transfer Stations - Collect and compact municipal waste for further transport to landfills
Locations of Operating RTSs
(source: EPD website,

31. Waste Management in HK [6]
Operation of Refuse Transfer Station
(Source: : EPD website,

32. Waste Management in HK [7]
Chemical Waste Treatment Centre - Centre for treating chemical wastes
CWTC in Tsing Yi
(Source: EPD website,

33. Discussion What wastes are generated from our home and schools?
What can be recycled? How much? How to?
How to reduce waste in our daily life?
What would it be if all the current landfills are fully filled?
Is there any effective alternatives for waste treatment?

34. Relevant Websites [1]
Environmental Protection Department (
Waste Facilities Business Unit (WFBU) (
Strategic Landfills (

35. Relevant Websites [2]
Waste Reduction Committee (WRC) (
Waste Reduction Framework Plan (WRFP) (
Directory of Recovery/Recycling Companies in Hong Kong (
Outlets for Used Items (

36. Relevant Websites [3]
Locations of Waste Separation Bins at Public Areas (
Environmental Campaign Committee (ECC) (
Green Power (

37. Waste treatment in the U.S.
Solid Waste Reduction
Incineration
can be used to treat and destroy combustible materials in transuranic, low-level, and some mixed waste.
Compaction
is a means of reducing the volume of noncombustible waste by compressing it into a smaller, denser waste form.

38. By a calcining process, liquid waste can be solidified
Solidification processes
The New Waste Calcining Facility converts high-level liquid waste into calcine.
The granular end product is transported through pipes to stainless steel bins.
The bins are encased in underground vaults.

39. Waste treatment in the Japan
Incineration
Recycling

40. Waste Incinerator and Heat Collection System
System flow diagram of the incinerator

41. A Recycling Plant

42. Relevant websites Waste treatment in Japan http://www.greenpeace.org/
Waste reduction campaign

43. Littering problem in Hong Kong
The underlying attitudes that lead to antisocial behaviour.
Education, and acceptable methods of modifying antisocial behaviour.
The impact of law enforcement via litter warder and litter courts.
The school environment as a starting point.

44. The end