Comparison of leachate treatments in the simulated landfill bioreactors with different operation modes

Abstract

In this study, the leachate treatments were compared in two simulated landfill bioreactors with different operation modes. In one reactor, the leachate was circulated between a landfi ll and a methanogenic reactor, while the other reactor was operated using direct recirculation of the leachate. The pH, Chemical Oxygen Demand (COD), volatile fatty acids (VFA), NH₄ ⁺−N of leachate, and the biologically degradable material (BDM), the enzymatic activities of municipal solid waste (MSW) were analyzed to achieve the essential characterization of the landfill. The results revealed that the loss of organic materials from the landfill occurred in an active methanogenic environment in the later period, while the environment was acidic due to a high concentration of VFA and contained a large volume of BDM during the early stage. In addition, the dehydrogenase and polyphenol oxidase activities of refuse were majority higher in the bioreactor landfill that was connected to a methanogenic reactor. Furthermore, the effi ciency of leachate treatment was enhance at least 20%, and the stabilization process was accelerated over 50% in the landfill that was operated in conjunction with the methanogenic reactor when compared to the landfill in which there was direct leachate recirculation.

Keywords:

• Simulated landfill bioreactor
• Leachate treatment
• Leachate recirculation
• Municipal solid waste
• Methanogenic reactor