1. Solid Waste Management
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2. Outline Introduction Refuse Disposal/collection in Buildings
Transfer Station
Solid Waste Disposal Methods
Sanitary Landfills
Legislation of Waste Control/Management
Solid Waste Management Strategy in Hong Kong
Construction & Environment
Environmental Management System
Appendix 1 – Wastes
Appendix 2 – What have we done ?
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3. Introduction Classification of Solid Wastes
Composition of Wastes in Hong Kong
Recycle, Recover, and other pretreatment processes
Summary of Waste Disposal Methods
What are the problems we are facing on solid waste disposal ?
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4. Classification of Solid Wastes
Domestic wastes
Commercial wastes
Industrial wastes including food-processing residue, ash, plastic, package wastes, etc.
Construction wastes
Hospital wastes
Bulky waste including trees, furniture, telephone poles, etc.
Hazardous wastes comprising of explosives, radioactive materials, toxic material, etc.
Others : marine mud, sludge, livestock, abattoir, PFA, etc.
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5. Methods of Waste Disposal
Domestic Wastes – by landfill, incineration, recycling
Construction wastes – by public dump, recycle, landfill,
Dredged & Excavated spoil – by marine dumping, public dumping
Etc…….
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6. What are the problems with solid wastes ?
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7. What are the major solid wastes in HK ?
Construction & Demolition
Domestics
Industrial
Commercial
Special
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8. How Construction Wastes are disposed of ?
Reclamation (public dump)
By landfills
Moving towards more dumping dump
Not much reuse
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9. What are the major composition of Domestic Wastes ?
Putrescibles
Papers
Plastics
Others
Textiles, metals, Glass, Bulky wastes
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10. What are the major composition of Industrial & Commercial Wastes ?
Papers
Plastics
Rattan/Wood
Putrescibles
Others
Metals, glass, bulky wastes
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11. Disposal of chemical wastes
Chemical wastes disposed at Chemical wastes Treatment centre at Tsing Yi,
Others by landfills
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12. What conclusion can you draw ?
Disposal is mainly one-way result in resource scarcity at one end and disposal problems at the other.
Papers, Construction wastes, glass, etc. are valuable wastes that can be recycled, reused, recover
Government should promote to use less and produce less wastes
A lot of wastes are disposed of by landfill that requires a lot of land
Landfill also creates environmental problems such as groundwater, air and noise pollution, explosion, traffic, disease, etc.
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13. What else can we do ?
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14. Use of Pre-treatment process (see figure)
Grinding
Pulverizing
Sorting
Separating
Compacting
Reuse, Recycle
Disposed of by landfill, incineration,
Generate power
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15. Waste Recover in HK
Papers, Metals
Glass
Rubber tyres
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16. What other countries are doing ?
Recycling and resource recovery in Japan – well organised and successful
Use of other methods such as composting, pyrolysis, Anaerobic digestion
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17. Solid Waste Disposal Path
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18. Solid Waste Disposal Path
Waste Collection
Waste Reception & Transfer
Waste disposal
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19. Waste Collection in Building
Refuse chute
Pneumatic system
On-site incineration
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20. What are the pros and cons of the following Waste Collection methods ?
Refuse chute
Pneumatic system
On-site incineration
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21. Waste Reception & Transfer
Refuse transfer stations
Refuse collection points
Barge loading areas
Waste handling facilities
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22. Solid Disposal Methods
Open dumping
Sanitary landfill
Incineration
Composting
Pyrolysis
High-temperature
Size reduction (shredding, grinding pulverizing)
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23. Transfer Station
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24. What are the functions of a transfer station ?
Compaction
Size reduction by grinding, shredding, pulverising
Material recovery
Loading for transportation
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25. What are the considerations of a transfer station ?
Haul distance to the disposal site
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26. Transfer Station in HK 1992 – Island East 1994 - Sha Tin
1997 – Island west, Kowloon west
outlying islands
NWNT
NNT
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27. Solid Waste Disposal Methods
Open dumping
Sanitary landfill
Incineration
Composting
Pyrolysis
High-temperature
Size reduction
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28. Sanitary Landfill
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29. Pros of Sanitary Landfill
Process is sanitary
Highly skilled personnel not required
After restoration, landfill site can become recreational land
Natural resource returned to land
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30. Cons of Sanitary Landfill
Large area is required
Transportation cost
Produce hazardous gas
Ground and Surface Water contamination
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31. Selection of Landfill site
Economic
Socioeconomic
Environmental/Geotechnical
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32. Process of Landfill
Trench method – trucks dump the wastes into trench and a bulldozer spreads & compacts, and covers them at the end of day
Area method – bulldozers spread out the waste and a scraper hauls the cover materials
Ramp method – the wastes are compacted but the cover is excavated directly in front of the working face
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33. What are the problems with landfill ?
Groundwater contamination by leachate
Gas generation
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34. What is leachate ?
Leachate is a liquid produced from a landfill that contains dissolved, suspended and/or microbial contaminants from solid wastes
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35. How leachate can be contained ?
Provide soil cover and surface drainage to prevent infiltration of rain
Liners to contain or attenuate the leachates
Use under drains (single or double) to collect the leachate for further treatment
Use slurry cut off wall/trench to contain the leachate
To select a site in arid area
To select a site above ground water
To continuously monitor groundwater quality in the vicinity of the site
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36. What typical gases are generated from landfill ?
CH4 CO
H2S N2
NH4 H2 …
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37. How Gas Generation is controlled ?
Passive Venting – the local geology allows the migration of gas to be collected by perimeter trench
Active Venting – install gas extraction vent which is connected to a vacuum or blower to force the gas for collection
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38. What Constitute a good landfill ?
Provide Extensive protection on
Aesthetics measures regarding health and safety and quality of life of neighbours or pass by
Ground water protection
Surface water protection
Control of landfill gas
On site health & safety
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39. Aesthetics
Provide slope berm and vegetation along the perimeter of the site
Provide dust screen
Prevent wind-blown dust
Prevent erosion and animals
Do not allow ponding of water
Compact and cover waste daily
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40. Groundwater protection
Provide liner
Provide leachate collection system
No groundwater around site
Provide ground water monitoring
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41. Surface water protection
Choose site in arid (dry) area
Provide surface drainage to divert surface runoff
No ponding of water on site
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42. Control of landfill gas
Provide fully lined landfill
Provide active venting system
Choose site away from people
Monitor gas around site
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43. Confine in-coming waste to one working area
On site health & safety
Cover soil daily
Confine in-coming waste to one working area
Provide safety training and safety procedures
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44. Solid waste disposal Open dumping Sanitary landfill Incineration
Composting
Pyrolysis
High-temperature
Size reduction
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45. What is incineration ?
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46. What are the pros and cons of incineration ?
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47. What is composting ?
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48. What is pyrolysis ?
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49. What is high temperature Incineration ?
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50. Comparing the cost of incineration and landfill
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51. Legislation for Waste Management
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52. What are the legislation for Waste Management
Waste Disposal Ordinance, responsible for licensing of all types of wastes
Regulations for livestock wastes in 1987.
Regulations for chemical waste disposal, 1992.
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53. What are the industries and community facilities that require special requirements for waste disposal ?
Industries e.g.
Electricity, gas generation
Metal finishing
Printed circuit board,
Tannery processing
..etc
Community facilities e.g.
abattoirs
Hospitals
Markets, cooked food stalls
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54. Government structure
Policy Development – Environmental Protection Department
Service Provision – Refuse collection (FEH); Special Waste collection (EPD); Solid Waste disposal (EPD); Special waste disposal (EPD); Sewage treatment (DSD)
Legislation enforcement – Waste import/export (EPD); Livestock waste (EPD); Marine dumping (EPD); Domestic waste storing, collection, littering (FEH);
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55. Solid Waste Management in HK
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56. Waste Management in HK
Municpal disposal by - 3 large landfills, 9 planned transfer stations
Construction wastes disposal by - public dump for reclamation after segregation, sorting and recycling. Also adopt Polluters Pay Principle
30% clinical waste by incineration and 70% by landfill
Marine mud by controlled dumping at specified seabed
Waste reduction Plan by
Waste minimisation by changes in people’s practice
Waste recovery and recycling
Reduce the volume of waste
Disposal in environmentally satisfactory ways
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57. Environment & Construction
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58. Impact of Construction
Cause changes to ecosystem
Loss of forest
Loss of cultivated land
Air, noise, groundwater, ozone pollution
Continuous reclamation
Extraction of fossil fuel and minerals
Consumption of resources
Construction activities
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59. Measures to reduce Impact to Environment
Reuse of building materials – e.g. use brick on pavement surface instead of concrete
Recycle of materials – e.g. Use crushed concrete for roadbase
Reduce energy consumption – e.g. use less energy means less electricity means less wastes from electric company
Design & build energy efficient buildings
Promotion by education programme
Conduct EIA and EMS
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60. Environmental Management System
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61. What is a EMS
EMS is a systematic approach for implementing environment management particularly at organisation level.
Through identifying, minimising, preventing and managing the environment impacts
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62. What does EMS consist ? 1. Environmental policy
2. Organisation Structure
3. Environmental Management Programme
4. Audit of the programme & system
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63. Why EMS ? Comply with legislation Demand from customers Competition
Save cost
Reduce risk
Investment approval
Pressure from environmentalists
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64. What is ISO14000 ? A series of standards on environmental management
ISO14001 set out the framework in management system for
tracking environmental performance,
setting objectives,
developing procedures, and
reviewing progress.
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65. END
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