Sanitary Landfill and Hazardous waste management

1. Prof. M.R.Ezhilkumar
Assistant Professor
Department of Civil Engineering
Sri Krishna College of Engineering and Technology
Coimbatore
ezhilkumar@skcet.ac.in
I only feel angry when I see waste.
When I see people throwing away
things we could use. – Mother
Teresa
1
17CE413
SOLID AND HAZARDOUS
WASTE MANAGEMENT
3.3 – Landfill gas management

2. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 2
Learning Outcomes
☼ Landfill gas
☼ Generation
☼ Movement
☼ Control
3.3 – Landfill gas management

3. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 3
Video Session

4. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 4
Landfill Gas
Stages of Gas Generation
I. Aerobic
II. Anaerobic, non-
methanogenic (acid
anaerobic)
III. Anaerobic,
methanogenic, unsteady
IV. Anaerobic,
methanogenic, steady

5. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 5
Landfill Gas
Stoichiometric Estimate of Potential
Gas Potential
Biochemical Methane Potential

6. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 6
Landfill Gas
Problems with Stoichiometric Estimates
 Some fractions are not biodegradable (lignin, plastics)
 Moisture limitations
 Toxins
 Some fractions are not accessible (plastic bags)

7. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 7
Landfill Gas
Estimates of Gas Production Rates
 Rapid degradation conditions: 3 to 7 years (4 to 10 L/kg/yr)
 Moderate degradation conditions: 10 to 20 years (1.5 t 3 L/kg/yr)
 Slow degradation conditions: 20 to 40 years (0.7 to 1.5 L/kg/yr)

8. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 8
Landfill Gas
Gas Enhancement Techniques
 Moisture Content
 Shredding
 Leachate Recycle
 Inoculum Addition
 Buffer
 Nutrient Addition
 Temperature

9. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 9
Landfill Gas
Gas Composition - Major Gases
 Methane (45 - 60 % by volume)
 Carbon Dioxide (40 - 60 % by volume)
 Nitrogen (2 - 5 % by volume)
 Oxygen (0.1 - 1.0 % by volume)
 Ammonia (0.1 - 1.0 % by volume)
 Hydrogen (0 - 0.2% by volume)

10. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 10
Landfill Gas
Gas Composition - Trace Gases (less than 0.6 % by volume)
 Odor causing compounds
 Aromatic hydrocarbons
 Chlorinated solvents
 Aliphatic hydrocarbons
 Alcohols
 Polyaromatic hydrocarbons

11. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 11
Landfill Gas
Why Bother with Landfill Gas?
 Odor
 Toxics
 Greenhouse Gas
 Explosive Gas
 Potential Energy Source

12. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 12
Landfill Gas
Landfill Gas Management
 • Containment
 – Natural barriers
 High groundwater table
 Streams/Waterbodies tied to
groundwater
 Impermeable geologic strata
 – Manmade barriers
 Composite liner
 Composite cover
 Cutoff walls
 Negative pressure trenches
 Positive pressure systems
(Brewers Stadium)

13. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 13
Landfill Gas
Landfill Gas Management
 Landfill Gas Collection Systems
 – Components
• Gas extraction wells or
trenches
• Gas extraction well heads
• Gas header pipes
• Condensate management
• Drip legs
• Condensate knockouts
• Control valves
• Blower station
• Flare (open or closed)

14. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 14
Landfill Gas
Components of Gas Recovery System
 One or more wells placed within the refuse
 A header system to connect the wells to the gas pumphouse system creating
the suction
 A flare system providing the opportunity to combust the landfill gas in the event
that the gas is not needed
 An end user of the gas

15. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 15
Landfill Gas
Landfill Gas Management
 Landfill Gas Collection Systems (continued)
 – Objective of system
• Migration control
• Regulatory compliance
• Energy recovery “$”
• Listen to clients needs
• Always consider health and safety

16. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 16
Landfill Gas
Landfill Gas Management
 Landfill Gas Collection System Design Steps
 – Consider objectives
 – Define limits of landfill
• Horizontally and vertically
 – Gas extraction wells or trenches
 – Layout gas wells
• Shallow wells - small ROI; • Deep wells - large ROI
• Typically 150’ ROI (per NR 500); • Liquid levels in landfill

17. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 17
Landfill Gas
Landfill Gas Management
 Landfill Gas Collection System Design Steps (continued)
– Locate gas header pipe
– Establish condensate management
– Adjust gas wells, if needed
– Prepare a well schedule (example)
• 0.5 to 1.5 cfm/slotted foot of pipe
– Determine gas generation and flow

18. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 18
Landfill Gas
Landfill Gas Management
 Landfill Gas Collection System Design Steps (continued)
– Header and blower sizing calculations
• Calculate by hand
• Spreadsheet
• Computer model KY GAS (Hardy cross method)
– Condensate calculations
– Select blower flare system

19. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 19
Landfill Gas
Landfill Gas Management
 Rules of Thumb for Header Design
• A velocity of 50 feet per second is the maximum allowed during concurrent
flow conditions
• A velocity of 30 feet per second is the maximum allowed during
countercurrent flow conditions
• A velocity of 30 feet per second is the maximum allowed within condensate
management structures
• A pressure drop of 1 inch water column per 100 feet of header is the
maximum allowed under any flow conditions

20. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 20
Landfill Gas
Landfill Gas Management
 Rules of Thumb for Header Design (continued)
• Flow conditions within a header must not exceed either pressure loss nor
velocity limitations
• 10 inches of vacuum required at furthest extraction well
• 10 to 20 inch loss of vacuum at blower flare station

21. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 21
Landfill Gas
Landfill Gas Migration - Wells

22. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 22
Landfill Gas
Landfill Gas Migration - Trench

23. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 23
Landfill Gas
Passive systems

24. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 24
Landfill Gas
Passive Landfill Gas Control

25. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 25
Landfill Gas
Landfill Gas Control

26. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 26
Landfill Gas
Landfill Gas is Typically Extracted to a Blower-Flare Station

27. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 27
Landfill Gas
Gas Extraction Wells
 Vertical piping system: installed following the refuse placement
 Horizontal piping system: installed as the refuse is placed
 Design considerations
• Spacing: zone of influence - apparent zone of vacuum influence around
a well
• Location: site topography, age of refuse, and system expansion over
time
• Depth: refuse depth, leachate mound, and cell construction

28. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 28
Landfill Gas
Gas Extraction Wells
 Factors affecting performance of gas extraction system
 Daily cover
 Elevated or perched liquids
 Shallow depth
 Sludge or liquid depth
 Permeability of final cover

29. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 29
Landfill Gas
Gas Extraction Wells
 Passive Wells (wells open to
atmosphere)
 Active Wells (wells connected
to a gas extraction system).

30. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 30
Landfill Gas
Vertical Piping System

31. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 31
Landfill Gas
Equilateral Triangular Distribution

32. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 32
Landfill Gas
Types of Collection Wells: Vertical wells

33. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 33
Landfill Gas
Condensate collection and Pump Station
 Landfill gas condensate – as gas cools while it is transported through the gas
collection system a liquid is formed (cutting of vacuum to the wells), separated
from gas flow and collected in the low spots of the system
 Pumping station reservoir – condensate forced to drain into it from low spots

34. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 34
Landfill Gas
Gas Treatment Methods
 Gas flaring – controlled combustion unit, reduces odors and more
environmentally sound than passive venting, enclose flares more efficient than
open flares
 Gas processing and energy recovery – gas processed by removing water,
carbon dioxide, and other impurities

35. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 35
Landfill Gas
Oxidation of Methane in Landfill “Bio Cover” (by Methanotrophs)

36. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 36
Landfill Gas
Oxidation of Methane in Landfill “Bio Cover” (by Methanotrophs)

37. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 37
Landfill Gas
Factors affecting gas generation

38. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 38
Landfill Gas
Comparison of Biodegradation Time

39. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 39
Assessment Time
Review
Question
Recommend a suitable landfill gas management

40. SHWM – Module 3 – SANITARY LANDFILL AND HAZARDOUS WASTE MANAGEMENT  Mr.M.R.Ezhilkumar 40