Landfill Technology and Sanitary Landfills: Advantages and Disadvantages

1. LANDFILL

2. Landfill Type • aerobic landfill • anaerobic sanitary landfill with daily cover • improve anaerobic sanitary landfill with buried leachate collection facilities • landfill with forced aeration

3. Only the anaerobic and semi-aerobic landfill are desirable when leachate and gas quality to be considered

4. Advantages

5. Disadvantages • Open dumping • potential source of disease • fires are uncontrolled • air pollution • smell • pollute nearby waterways & ground water • ugly • scavenging

6. Sanitary landfill • destruction of habitats - (wetland) • cause of urban land shortage • hence transportation cost – (distant) • lost of resources – cannot be replace • leachate leakage - (groundwater contamination) • maintenance after completion require 10 to 15 years • Non-available of suitable cover material

7. Level of Sanitary Landfill • Level 1: control tipping • Level 2: sanitary landfill with bound and daily soil cover • Level 3: sanitary landfill with leachate recirculation • Level 4: sanitary landfill with leachate treatment facilities.

8. Landfill Technology • The most common landfill technologies are • area method • trench method • ramp method • sandwich method

9. Area method/Depression • terrain is unsuitable for the excavation of trenches • Solid waste cells constructed in a large area • layers of cells are created until the permitted height reached • Each cell represents the waste received and compacted in place and covered each day.

10. Can accommodate very large volume operation • Earth dyke with height of one lift (2-3 m) is first constructed to gate the support for compacting. • The wastes are unloaded at the top of the earth dyke and spread and compacted on the slope of the dyke. • The layers dept is from 30 – 60 cm.

11. Depression method best for area where natural depression exist. • The installation liners and leachate collection system is relative easy. • The earth cover of this system is usually obtain from borrow-pit or brought from elsewhere.

12. Area method

13. Trench Method • Waste is spread and compacted in an excavated trench • The excavator tailings are used as cover material • Best for flat land where the excavation of trenches can be carryout easily. • The ground water level should be sufficiently low

14. The trench size varies in length and width: • dept: 1 – 2 metre • width: 2 – 5 metre • length: 30 – 120 metre • Wastes are spread into thin layers from 30 -60 cm and compacted before soil cover in introduced.

15. Trench Method

16. Ramp method • also call progressive slope. • A combination of area method and trench method • Solid waste is spread and compacted on a slope • cover material is obtained directly from the front of the working face. • The excavation of cover material provides a depression for the next day waste.

17. Ramp is about 15 metre wide and 30 metre length and suitable height. • Trucks come on the top of the ramp and discharge their contents inside the trench.

18. Sandwich method • Used when the solid waste is deposited horizontally into narrow valleys. • Cover soil layer is added over each layer of solid waste

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