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Theoretical Degradation Curves for Chemical Activity in a Landfill (HTML version)

Robert Beauchamp

Program Director

Graduate School of Management and Technology

Category: » Learning-objects

This simulation illustrates the chemical activities that occur within a landfill during the three phases of degradation (aerobic, anaerobic, and methanogenic). (Flash version)

pH Level:

• Nearly 7 during aerobic phase.
• Drops significantly during anaerobic phase, then increases after anaerobic bacteria become dominant.
• Continues to increase during methanogenic phase, then stabilizes at 7.

Percent Carbon Dioxide:

• Increases significantly to 60-80% during aerobic phase.
• Decreases to 45-50% during anaerobic phase.
• Remains constant, then decreases during methanogenic phase.

Percent Methane:

• Not produced during aerobic phase.
• Begins to appear during later stages of anaerobic phase.
• Increases to 50-55% at beginning of methanogenic phase, then remains constant for several years.

Chemical Oxygen Demand (Organics):

• Very high during aerobic phase (maximum of 100,000 mg/l).
• Decreases significantly to 20,000-30,000 mg/l during anaerobic phase.
• Decreases significantly to 5,000-10,000 mg/l during methanogenic phase, then remains constant.

All Degradation Curves:

• During the aerobic phase: Chemical oxygen demand and percent carbon dioxide increase. pH starts at 7, then begins to decrease.
• During the anaerobic phase: pH, percent carbon dioxide and chemical oxygen demand decrease. In the latter half of this phase, pH increases and methane begins to appear.
• During the methanogenic phase: pH level and percent methane continue to increase, while percent carbon dioxide and chemical oxygen demand increase. As the phase continues, pH, percent methane, and chemical oxygen demand stabilize and remain constant.

Developed in 2002 for the course ENVM 649: Principles of Waste Management and Pollution Control
Produced by the UMUC Center for the Virtual University and Graduate School.