Bioreactor Design: The Next Generation Landfills
Accelerate waste degradation with Waste Management’s Aerobic-Anaerobic Bioreactor*, which combines attributes of the aerobic bioreactor with the anaerobic bioreactor. The goal of sequential aerobic-anaerobic waste management treatment like this is to rapidly increase the biodegradation of food and other easily degradable waste in the aerobic stage to reduce the production of organic acids in the anaerobic stage. This will result in the earlier onset of methanogenesis.
- The uppermost lift (or layer) of waste is aerated
- The lift immediately below receives liquids
- Landfill gas is removed from each lift beneath the liquid-receiving lift
- Horizontal wells installed in each lift during landfill construction are used to convey air, liquids, and landfill gas
How Bioreactors Work
The advantage of this hybrid bioreactor approach is that it combines the operational simplicity of the anaerobic process with the treatment efficiency of the aerobic process, as well as an expanded potential for destruction of volatile organic compounds in the waste mass.
*US Patent 6,283,676 B1
Waste Management’s Facultative Landfill Bioreactor**
This bioreactor technology combines conventional anaerobic degradation with a method for controlling high ammonia concentrations. Leachate recirculation may cause an increase in the concentration of ammonia—to the point where bacteria find it toxic. By incorporating nitrogen cycle control, the ammonia can be partially treated to create “nitrated” leachate, which is leachate treated to convert ammonia to nitrate. The nitrated leachate serves as an electron donor, much the same way oxygen or air would in an aerobic landfill.
**US Patent 6,398,958.