Aerobic Bioreactor

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Aerobic Bioreactor

• CEGR 4143/5143

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Definition

• Any permitted Subtitle D landfill or landfill
  cell where liquid and air is injected in a
  controlled fashion into the waste mass in order
  to accelerate or enhance biostabilization of the
  waste (SWANA)

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The Aerobic Landfill
Leachate
Air
Landfill Cover
Leachate Collection System
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Aerobic Landfill
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UNCC Research
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UNCC Research

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UNCC Research

• Objectives
• Microbiology
• Determine decay rate constants for saturated
  solid waste based on variations in moisture,
  temperature, O2 consumption
• Collect and analyze data on oxygen uptake rates,
  methane production, and bacterial concentrations

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Research Objectives Contd

• Hydrodynamics
• Model three-dimensional multi-phase flow patterns
• Predict necessary spacing of vertical injection
  wells using non-dimensional analysis
• Geotechnical
• Settlement and stability characteristics of
  saturated solid waste
• Geotechnical issues associated with rapid
  decomposition
• General
• Develop standard practices, monitoring methods,
  and analysis techniques that can be applied to
  field conditions

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Future Applications

• Rowan County, North Carolina
• 4-acre aerobic landfill cell
• Design based on UNCC laboratory scale model

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Aerobic vs. Anaerobic Bioreactors

• Anaerobic Bioreactor
• Moisture is added to the waste mass in the form
  of re-circulated leachate and other sources to
  obtain optimal moisture levels. Biodegradation
  occurs in the absence of oxygen and produces
  landfill gas.

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Aerobic vs. Anaerobic Bioreactors

• Leachate
• Anaerobic - create volumes of leachate that
  contain Volatile Organic Compounds (VOCs).
• Aerobic improve leachate quality by reducing
  BOD and VOCs.

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Aerobic vs. Anaerobic Bioreactors

• Landfill Gas
• Anaerobic produces methane gas (toxic,
  explosive greenhouse gas).
• Aerobic virtual elimination of methane gas
  (over 90 elimination)

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Aerobic vs. Anaerobic Bioreactors

• Odors
• Anaerobic produce foul odors
• Aerobic eliminates foul odors produces earthy,
  musty scent.
• Stabilization
• Anaerobic 5 to 10 years
• Aerobic 3 years

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AEROBIC BIOREACTOROther Potential Benefits

• Leachate
• Elimination of the costs associated with offsite
  leachate disposal (100).
• Improved leachate quality reduces treatment
  surcharges (BOD).
• Landfill Gas
• Possible avoidance of Landfill Gas Recovery
  System (35,000/acre) due to reduced methane and
  NMOCs

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AEROBIC BIOREACTOROther Potential Benefits

• Revenue
• Book value of over 15 airspace recovery
• Environmental Protection
• Reduction of anaerobic odors. PR costs.
• Perception as natural process.
• Addresses unlined landfills with groundwater
  issues

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Post Degradation Options

• Fill New Airspace with additional waste
• Increase revenues
• Fill New Airspace with Inert Materials
• Site redevelopment (e.g. commercial/industrial)
• Compact to meet geotechnical standards
• Final Closure and Post-Closure
• Conduct Risk Assessment to obtain data to lessen
  current closure/post-closure requirements.

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Economic Benefits Single Cell
Assume 2-yr operation, 7-Acre cell 76,000 tons
of waste in place 35 feet in height 35/ton tip
fee.
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Design/Operational Considerations
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More information on Aerobic Bioreactors

• www.bioreactor.org
• www.aerobiclandfill.com
• www.wm.com/bio.asp
• www.yolocounty.org/org/PPW/diwm/bioreactor.htm
• www.epa.gov/epaoswer/non-hw/muncpl/landfill/biorea
  ctors.htm

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Questions?