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Practice review of five bioreactor/recirculation landfills
C H Benson1, M A Barlaz, D T Lane
1Department of Civil and Environmental Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, 2214 Engineering Hall, Madison, WI 53706, USA. benson@engr.wisc.edu
Waste Management (New York, N.Y.)
|June 13, 2006
Summary
Bioreactor and recirculation landfills function similarly to conventional ones, but leachate recirculation may accelerate waste decomposition and increase settlement. More data is needed for definitive conclusions on landfill operations.
Area of Science:
- Environmental Engineering
- Waste Management Science
- Geotechnical Engineering
Background:
- Bioreactor and recirculation landfill technologies aim to enhance waste decomposition and reduce environmental impact compared to conventional landfills.
- Understanding the operational differences and technical issues is crucial for optimizing landfill management.
- North American landfill practices vary, necessitating comparative studies.
Purpose of the Study:
- To compare the operational performance and technical issues of bioreactor/recirculation landfills with conventional landfills in North America.
- To assess the impact of leachate recirculation on waste decomposition rates and leachate characteristics.
- To evaluate settlement patterns in bioreactor/recirculation versus conventional landfill operations.
Main Methods:
- Analysis of operational data from five landfills, including bioreactor/recirculation and conventional types.
- Monitoring of leachate generation rates, depths, temperatures, and liner temperatures.
- Evaluation of gas production, leachate quality (BOD, COD, pH, ammonia), and settlement data.
Main Results:
- Bioreactor/recirculation and conventional landfills exhibited similar leachate generation, depths, temperatures, and liner temperatures.
- Accelerated waste decomposition was indicated by gas production at one site with leachate recirculation; data were ambiguous for others.
- Bioreactor/recirculation landfills produced stronger leachate (higher BOD, COD) initially, with similar characteristics to conventional landfills later.
- Elevated ammonia concentrations and neutral pH persisted in leachate, while settlements were larger and faster in bioreactor/recirculation landfills.
Conclusions:
- Bioreactor and recirculation landfills operate similarly to conventional designs but may accelerate decomposition and settlement.
- Leachate recirculation initially increases leachate strength, but long-term quality indicators become comparable.
- Further research with more comprehensive, long-term data is required to definitively establish the effects of bioreactor/recirculation operations.
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