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Part 2: Waste management Waste recycling industry in HK Sewage treatment in HK

Science Update Programmes for Secondary School Teachers 02-03 (Biology) Course 1. Human Responsibility for Environmental Conservation Part 2: Waste management Waste recycling industry in HK Sewage treatment in HK 1. Waste recycling industry in Hong Kong

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Part 2: Waste management Waste recycling industry in HK Sewage treatment in HK

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  1. Science Update Programmes for Secondary School Teachers 02-03 (Biology) Course 1. Human Responsibility for Environmental Conservation • Part 2: Waste management • Waste recycling industry in HK • Sewage treatment in HK

  2. 1. Waste recycling industry in Hong Kong A. Solid waste transfer & disposal in HK Source: http://www.epd.gov.hk/epd/

  3. B. HK’s waste problem • About 6 M ton of waste dumped in landfills each year : • 55% (3.4 M ton) municipal solid waste (MSW) • 38% construction and demolition waste (C&DW) • 7% other wastes (sludge, animal carcass) • The 3 Strategic Landfills are filling up fast • Remaining capacity: around 110M tonnes • Expected to last another 10-15 years • Annual operating cost = HK$420 Million

  4. C. Waste recycling in HK • I. MSW (2001) • 1.94 M ton (36 % of the total generated) were recovered • 8.8 % recycled locally • 91.2 % exported to the Mainland & other countries The waste recycling industry of MSW in HK is small

  5. Types & quantities of waste recovered from MSW in HK in 2001 Source: http://www.epd.gov.hk/epd/

  6. Key players in MSW recovery in HK EPD; green groups; corporate Street collectors; cleansing workers Medium or small size enterprises More exporters, few recyclers Source: http://www.epd.gov.hk/epd/

  7. Constraints • A. Waste separation • Lack of civic responsibilities from the public • No financial incentives for the public to separate waste • Space problem in waste separation and storage at source • B. Waste recovery & recycling • High running cost…labour, transportation • Low technology and low efficiency

  8. Efforts • Government measures to enhance waste reduction in 2001/ 2002 • Injected $100M into the ECF • Awarded 1.8 hectares of (STT) land to recyclers • Tried out new schemes on waste recycling • Launched a major publicity drive • Placed over 20,000 waste separation bins • Launched pilot mobile phone recycling programme • Commissioned a pilot recycling facility at Tuen Mun

  9. Future • Undertake pilot schemes on wet/dry waste separation • Increase the total number of waste separation bins to 28,000 • Develop voluntary product responsibility schemes • Commence detailed feasibility study and EIA for the proposed Recovery Park • Continue to make available STT land for recycling industry

  10. Future • Invite expressions of interest for Waste Management Facilities in 2001 • Aims to seek from the commercial sector state-of-the-art technologies and practices that provide better technical, environmental, economic and social benefits in comparison with traditional landfill disposal • Received 59 submissions

  11. Example Industrialized Recycling Source: P.C.C. Leung, EnviroSeries, Nov 2002

  12. Example The ArrowBio Process for MSW Source: Y. zadik, EnviroSeries, Nov 2002

  13. II. C & D Waste • Materials arising from construction, demolition, renovation & refurbishment: • Inert materials (rock, debris, rubble, excavated soil, concrete, asphalt, etc.) • Non-inert substances (bamboo, timber, paper, vegetation, packaging waste, organics, etc.) • Recyclable C&D Material: • Reusable / Recyclable Materials - soil, concrete, rock, asphalt, etc.

  14. "Waste" = 16,820tpd Landfill Inert C&D Material = 32,430tpd Public Filling Area / Stockpile C&D Waste* = 6,410tpd * Type I C&D Waste <= 30% Inert C&D Material. 2001 Total Waste Generation in Hong Kong = 49,250tpd MSW + Special Waste = 10,410tpd Mixed C&D Material = 38,840tpd Source: A. Bhanja, EnviroSeries, Nov 2002

  15. Total Waste Generation in Hong Kong = 49,250tpd MSW + Special Waste = 10,410tpd Total Waste = 14,900tpd Landfill MSW = 4,490tpd Mixed C&D Material = 38,840tpd C&D Waste* = 6,410tpd C&D = 1,920tpd Total Inert C&D Material = 34,350tpd Public Filling Area / Stockpile Inert C&D Material = 32,430tpd With Separation of C&D Materials * Type I C&D Waste <= 30% Inert C&D Material. Source: A. Bhanja, EnviroSeries, Nov 2002

  16. C&D Materials Inert Hard Others • road sub-base Soil/Clay Metals Wood • hardcore • topsoil • reuse steel bars • for energy recovery • drainage works • synthetic lightweight concrete • concrete • fibre board • landscape works Alternative Uses of C&D Materials Source: A. Bhanja, EnviroSeries, Nov 2002

  17. Constraints • No incentive for building constructors to separate and recycle C & D waste Efforts • Waste Reduction Framework Plan (WRFP) launched in November 1998 • Aims: • Discourage - Collection and transporting to landfills • Encourage - Waste prevention, reuse • Targets: • 84% of C&D material is to be diverted away from landfills

  18. Efforts • A pilot plant which was set up at the SENT Landfill in 1998 to recover usable materials (cover, roads, filling, landscaping and aggregate) • Another temporary facility provided by the Civil Engineering Department is also available at Tseung Kwan O Area 137.

  19. Future • Put in place the landfill charging scheme for C&D Waste • Complete exploration on use of inert C&D materials outside HK • Commission another temporary fill bank at Tuen Mun • Two permanent sorting facilities are planned to be set up at Chai Wan and Kwai Chung

  20. References EPD, 2002. Municipal solid waste. http://www.epd.gov.hk/epd/english/environmentinhk/waste/prob_solutions/msw.html EPD, 2002. Construction and demolition waste. http://www.epd.gov.hk/epd/misc/cdm/en_menu.html EPD, 2002. Waste reduction guidelines and fact sheets. http://www.epd.gov.hk/epd/english/environmentinhk/waste/guide_ref/guide_wr.html ADA, 2002. Waste management and recycling. EnviroSeries Conference CD-Rom. HKCEC, 21 November 2002, Hong Kong. Business Environment Council.

  21. 2. Sewage treatment in HK Collection Treatment Disposal Sewerage system Sewage treatment plants Sewerage system • Division of labour: • Policy & Planning - EPD • Sewerage & Sewage Treatment - Drainage Services Department • Sewerage in New Towns - Territory Development Department

  22. Pollutants in sewage: • Solids e.g. paper, plastics • Organic material e.g. food waste, human waste - consumes oxygen from the water • Bacteria - public health concern • Ammonia - highly toxic to fish • Nitrogen - cause algal boom, sometimes forming red tides • Toxic metals – bioaccumulation hazard

  23. Sewage collection in HK Source: http://www.epd.gov.hk/epd/

  24. Sewage Treatment Levels • Primary treatment (sedimentation) • removes about 30% of organic material • 2. Secondary treatment • Chemical treatment - removes over 60% of organic material • Biological treatment - removes up to 90% of the organic material as well as ammonia and some of the nitrogen • Disinfection - removal most of the bacteria • 3. Tertiary treatment • Further removal of ammonia and nitrogen by biological method

  25. Level of treatment for sewage generated in Hong Kong Source: http://www.epd.gov.hk/epd/ Most sewage in HK receive 1 or 2 treatment

  26. Sewage treatment in Victoria Harbour • 65% of Hong Kong’s population • Treated/ raw sewage discharged have long exceed its natural assimilation Source: http://www.info.gov.hk/dsd/sewerage/

  27. 1989 Strategic Sewage Disposal Scheme (SSDS) Chemically Enhanced Primary Treatment (CEPT) Renamed as Harbour Area Treatment Scheme (HATS) in 2001 Source: http://www.epd.gov.hk/epd/

  28. 1999 • Delays in stage I raised widespread public concern • Continued criticism of the preferred treatment level and discharge arrangements International Review Panel (IRP) On Sewage Treatment for the Harbour Area

  29. IRP On Sewage Treatment for the Harbour Area • Started in 10 April 2000. • based on Stage I, whether the original SSDS remain the most sustainable arrangement in terms of cost, programme, practicality and environmental benefits • Report submitted on 30 November 2000

  30. IRP report results • Stage I works should be completed as soon as possible • Tertiary treatment facilities could be incorporated using Biological Aerated Filters (BAF) technology. • Sewage could then be discharged permanently into the Western Harbour • Suggested 4 options for full collection and treatment. All use: • - BAF technology • - Deep sewage-collection tunnels • - Short outfalls • - cheaper and quicker

  31. IRP report results The existing Chemically Enhanced Primary Treatment (CEPT) at Stonecutters Island Treatment Works is operating efficiently • Removes 83% of suspended solids • Removes 74% of BOD. • Equivalent to 90% of the efficiency of a conventional biological secondary treatment plant • It will be possible to move straight from CEPT treatment to tertiary treatment by adopting BAF technology

  32. Government's initial response to the IRP Report • will consider moving directly to tertiary treatment • will carry out the necessary environmental studies • Will conduct trials of BAF and other viable compact tertiary treatment technologies to confirm cost effectiveness

  33. References EPD, 2002. Planning for sewerage and sewage treatment. http://www.epd.gov.hk/epd/english/environmentinhk/water/prob_solutions/plan_sewerage.html HK SAR Government, 2002. A clean harbour for Hong Kong. http://info.gov.hk/cleanharbour/

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