DEVELOPMENT OF BIOREACTOR LANDFILLS WITH DEDICATED TREATMENT ZONES

The feasibility of incorporating a dedicated treatment zone for controlled anaerobic stabilization of leachate within a bioreactor landfill was investigated at laboratory scale. Three cylindrical simulated landfill reactors were constructed; two reactors (control and test) of equal size received a synthetic waste mixture and were operated with leachate recirculation, while a third dedicated treatment zone reactor with a waste pine bark medium was seeded with anaerobically digested sludge to initiate methanogenesis. Each reactor was individually operated until both the control and test reactors exhibited similar acidogenic phase behavior, and the dedicated treatment zone reactor fully developed active methanogenesis. The dedicated treatment zone reactor was then connected to the test reactor to compare performance of bioreactor landfills with or without dedicated treatment zones, and eventually to the control reactor to demonstrate flexibility and effectiveness for treatment of excess leachate from newer landfill cells or areas as well. The overall experimental results indicated that more rapid and complete waste stabilization, as measured by gas and leachate indicator parameters, was achieved with leachate recirculation and a dedicated treatment zone than leachate recirculation alone.