1. Land pollution

2. Introduction
Solid waste is classified into five main types by making reference to the sources of waste and the institutional arrangements for waste collection and disposal. These five types of solid waste are municipal solid waste, construction & demolition (C&D) waste, chemical waste, special waste and other solid waste. The detailed interpretations of some commonly used terms are described below.

4. Municipal solid waste
It includes domestic waste, commercial waste and industrial waste.

5. Domestic waste
It refers to household waste, waste generated from daily activities in institutional premises and refuse collected from public cleansing services. Public cleansing waste includes dirt and litter collected by the Food and Environmental Hygiene Department (FEHD), marine refuse collected by the Marine Department and waste from country parks collected by the Agriculture, Fisheries and Conservation Department.

6. The TWO major domestic wastes are plastic and metal cans.

7. Plastic
Bacteria can decompose some types of the plastics. These are called biodegradable materials, and will not cause serious pollution problem after decomposition. However, non-biodegradable plastics, which cannot be decomposed, will lead to serious pollution problems.

8. Metal can
Metal cans are not biodegradable. When they are thrown into the environment, they cause land or water pollution. Besides, these natural resources are wasted.

9. Commercial waste
It is waste arising from commercial activities taking place in shops, restaurants, hotels, offices, markets in private housing estates, etc. It is collected mainly by private waste collectors. However, some commercial waste is mixed with domestic waste and collected by the FEHD. Some not mixed is also collected by the FEHD for historical reasons.

10. Industrial waste
It is waste arising from industrial activities and does not include C&D waste and chemical waste. It is usually collected by private waste collectors. However, some industries may deliver their industrial waste directly to landfills for disposal

11. Current situation
Household and other municipal waste loads have risen steadily, in line with the growth in population and wealth of the community. There is no sign of a let-up because another two million people are expected to live in the SAR by 2016.

13. Effect
  The most important of land pollution is effect on hygiene. Bacteria, and give off bad smells may decay some of the materials in the garbage. The decayed materials will create problem of hygiene. Pathogenic bacteria and other pests may also grow on the decayed materials and diseases may then be spread.

16. What will happen to the landfills?

17.                                                                                                                     
The three strategic landfills will run out of space in 10 to 15 years. Without waste reduction measures and sufficient public filling areas, SENT landfill might run out as early as 2005.

18. Recycling
Hong Kong recycled about 35 percent of its municipal waste (mostly commercial and industrial waste) and the government wants to increase this to about 60 per cent by A number of initiatives were undertaken in 2000 with significant support from the green groups.

20. Some of the highlights were:
newspaper vendors were encouraged to stop distributing papers in plastic bags
the number of housing estates with waste separation bins doubled to more than 700
the number of items recycled by hotels and the airport were increased
more recycled products were added to the government's purchasing guidelines
four new temporary sites were allocated for use by the re-cycling industry

21. Special waste
-Clinical waste
-Animal carcasses
-Radioactive waste

22. Clinical waste
Source
-being produced in hospitals and government clinics
E.g. contaminated sharps, infectious waste and human tissues

23. Deal
-Segregating from ordinary refuse and being collected separately for proper disposal.
-Most clinical waste will be disinfected as far as practicable and disposed at designated landfills.
-Human tissues and body parts
from operating theatres shall
be disposed of by incineration
as far as practicable

24. Animal carcasses Source: Slaughterhouses Street collections
Society for Prevention of Cruelty to Animals
Hong Kong Jockey Club
Ocean Park

25. Deal
-Land filling of animal carcasses may generate health hazards. Some animal Carcasses are infectious and spread diseases.
-It is proposed to build animal carcass treatment facilities (ACTF) for proper disposal of animal carcasses to prevent the spread of diseases.

26. Low-level Radioactive waste
Source
-Industry and medical and educational institutions
Americium Smoke detector sources
Promethium Luminous watch dials &
contaminated articles
Radium Lightning conductors and
luminous watch dials
Thorium Rayon mantles for kerosene
lanterns

27. Deal
The wastes are properly packaged in new stainless steel standard containers

28. Chemical Waste

29. Definition
Chemical wastes are liquid, semi-solid and solid wastes which are dangerous in nature or cause a risk of pollution to the environment

30. Problems Indiscriminate disposal of chemical waste
Release into coastal waters causes damage to local marine life and accumulation of toxins in seafood
Uncontrolled disposal of municipal waste facilities and into sewerage systems and sewage treatment facilities resulting in costly repairs and replacement of these facilities

31. Solutions The chemical Waste Treatment Center-CWTC
Handle with 100,000 tones chemical waste per year

32. Main Activities of CWTC
Chemical Waste Collecting
Waste Profile Analysis
Chemical Waste Treatment
Physical/Chemical Treatment
Incinerator
The Ancillary System are designed to support the treatment processes. They are Waste Container Handling, Storage Tank Farm, Laboratory Computer System

33. The Waste Disposal Ordinance on Waste Management
Prohibit livestock keeping in urban areas
Controls of discharge or deposit of livestock waste in control areas
Waste Disposal Ordinance 1991
Controls of chemical waste about packaging, labeling, storage, collection, disposal, import and export activities

34. Waste Disposal Ordinance 1994
Introduce a heavy penalty for illegal damping of
waste and make it an offence to breach of the license conditions of the waste collection and disposal licenses
Waste Disposal Ordinance 1995
Control import and export of hazardous and other waste in accordance with the requirement
Waste Disposal Ordinance 1998
Expands the regulations making powers for implementation of the various waste disposal charging schemes

35. Development of New Waste Legislation
Control for the arrangement of clinical waste and improves control of waste import and export and illegal dumping of waste
Specifies the requirement of clinical waste producers, collectors and disposal facility operatorsAmend the schedules and prescribes fees for clinical waste collection licenses
Gives effect to the new charging scheme for clinical waste through amendment of the regulation

36. Gives effect to the new charging scheme for clinical waste through amendment of the regulation
Amends the schedules and clarities the definition of chemical waste in light of amendment to the Dangerous Goods Ordinance –DGO
Gives effect to the revised landfill charging scheme

37. Composition of domestics waste disposed of at waste facilities (% by weight)

38. Solutions to pollution problem of plastics
By using degradable plastics instead of the non-degradable one
Recycling plastics wastes ( remold the plastic)

39. Development of degradable plastics
Plastics normally undergo extremely slow degradation because the enzymes in micro-organism tend to attract only the ends of the polymer chains
Example????????

40. 1.Biopolymers
It is made by living micro-organism such as paracoccus, bacillus and spirullum.
Poly(hydroxybutyrate) PHB, is a natural polyester made by bacteria

41. Advantage and disadvantage????
Micro-organisms found in soil and natural water sources are able to break down the polymer completely within 9 months.
Disadvantage:
Very expensive (15 times more expensive that polyethene)

42. 2.Photodegradable plastics
As polymer consist of long chain
Therefore, light sensitive functional group –c=o are incorporated in the polymer chains.
As a result, the long polymer chains will be broken down into shorter fragment which will facilitate the process of biodegradation under sunlight

43. 3.Synthetic biodegradable process
By incorporating starch or cellulose into the polymer during production.

44. Advantage
Since micro-organisms digest starch or cellulose the plastic is broken down into tiny pieces.
--larger surface area for the
biodegradable
--speed up process

45. Disadvantage
The products of biodegradation may cause water pollution and the rate of biodegradation is still too slow for the large quantity of plastic wastes generated.

46. B. Recycling of plastics
Direct recycling -----This applies only to thermoplastics. The remolded into plastic items.
Recycling of energy -----This applies to most plastics. The plastic wastes are burned in the incinerators. The calorific values contained in plastics are quite high.

47. Advantages: Reduces air pollution due to the incineration of plastic
Less dumping area is required.
Reduces the use of petroleum

48. Disadvantages:
The regenerated plastics usually have deteriorated properties due to repeated thermal and mechanical processing and can only be used for articles which are not subjected to high stress.
It is not very economical to separate the plastic items from the other wastes at present. Moreover, plastic products may contain dyes, politicizes and fillers so that it is very difficult to classify them by observation.

49. Advantages: Disadvantages:
2. Recycling of energy -----This applies to most plastics. The plastic wastes are burned
Advantages:
a.   The energy obtained from burning plastic waste can be used for heating or generation of electricity
b.   It is not necessary to separate the plastics
c.   Less dumping area is required
Disadvantages:
Burning plastics produces toxic gases e.g. PVC will give HCl. Expensive scrubber systems have to be used to remove them.

50. 3. Recycling of chemicals by pyrolysis------for all plastics
Similar to cracking, the plastic wastes can be pyrolyzed (decomposed at high temperature in the absence of air) at to give useful small molecules similar to those obtained from the fractional distillation of crude oil. These small molecules (mainly hydrocarbons) are separated by fractional distillation. Some of the small molecules can be used directly as fuels. Other larger molecules may be employed as raw materials in plastic production.

51. Advantages:
The products are useful raw materials for the manufacture of plastics – this reduces the use of petroleum
It is not necessary to separate the plastics
Less dumping area is required / saves more lands for other uses

52. Disadvantages :
Pyrolysis may produce toxic gases & expensive scrubber systems have to be used to remove them. The capacity of handling plastic waste by a pyrolysis plant is also small compared to the total amount of plastic waste produced. The running cost of disposal of plastics waste produced. The running cost of disposal of plastics by pyrolysis is much more expensive than land filling.

53. Measures to Reduce Solid Waste – Reuse & Recycling
The key concept in minimizing waste is “Reduce, Reuse & Recycle (3Rs)”
The practice of reduce, reuse and recycle helps in minimizing waste, reducing the demand for scarce landfill space & saving resources.

54. Examples:
Metal wastes are collected, identified, separated into different metals. The metals are further cleaned & purified.
Newspaper & office paper can be collected for recycling for making corrugated card box and paper board.
Most of the locally filled glass beverage bottles recovered for reuse through a deposit system.

55. The end