1. Bioreactors Landfills

2. Bioreactor Defined
“……a sanitary landfill operated for the purpose of transforming and stabilizing the readily and moderately decomposable organic waste constituents within five to ten years following closure by purposeful control to enhance microbiological processes. The bioreactor landfill significantly increases the extent of waste decomposition, conversion rates and process effectiveness over what would otherwise occur within the landfill.”

3. Why Operate a Landfill as a Bioreactor?
to increase potential for waste to energy conversion,
to store and/or treat leachate,
to recover air space, and
to ensure sustainability

4. Status 1993 - less than 20 landfills recirculating leachate
My estimate - ~ 5-10% of landfills

5. Regulatory Status
EPA permits recirculation of indigenous liquids into landfills with Subtitle D liners
Some states more stringent
EPA is considering nonindigenous liquid addition

6. Europe
The European Union Council Directive on Landfilling of Waste has identified the need to optimize final waste disposal methods and ensure uniform high standards of landfill operation and regulation throughout the European Union (EU).

7. Essential Needs for a Bioreactor
Composite liner
Appropriate density of MSW
Appropriate daily cover
Leachate recirculation system
Active gas collection system
Appropriate final cover system
Competent landfill operator

8. Leachate Recirculation

9. Waste Heterogeneity Ponding Water Impermeable Cover Preferential
Gas Flow
Preferential
Channels
Impermeable Cover
Heterogeneity
Waste

10. Impact of Waste Processing

11. Gas Collection

12. LFG Generation Curves Cubic meters LFG Year Half-Life = 1.35 yr
25,000,000
Half-Life = 1.35 yr
20,000,000
Cubic meters LFG
15,000,000
Half-Life = 3.68 yr
10,000,000
Half-Life = 20 yr
5,000,000 10 20 30 40 50
Year

13. LFG Collection From Operating Landfills
Sub-Cap Collector
Horizontal
Collectors o o o o o o o
Leachate Collection System - LFG Collector Network

14. Odor Potential

15. Cover Issues

16. Leachate Outbreaks

17. Alternative Daily Cover

18. Waste Compaction

19. Landfill Stability

20. Recovery of Composted Materials

21. Research Issues - Aerobic Bioreactor
How much air is needed?
How can air be delivered?
What is the impact on the water balance?
How are landfill fires prevented?
What are the economic implications?

22. Economic Impacts Benefits Enhanced gas production Recovered space
Reduced env. impact
Reduced post-closure care
Costs
Capital costs
Operating costs

24. Return to Home Page Return to Home Page
Last updated July 2004 by Dr. Reinhart