Design of a laboratory scale bioreactor for treating landfill waste

Abstract

This article documents the design and construction of a laboratory-scale (1.5 m(3)) bioreactor system that can be used to simulate anaerobic microbial processes in landfills. This design has use in feasibility studies of landfill bioreactor operation and management technologies. The system was designed for gas collection and to provide leachate recirculation and moisture addition to accelerate biodegradation. Two bioreactors were located with fresh municipal solid waste (MSW) from a sanitary landfill and instrumented to monitor temperature, mass, leachate production, and preferential flow of leachate within the heterogeneous material. One of the bioreactors received a layer of municipal sewage sludge to assess the feasibility of co-disposal. In this initial phase of the study, the decomposition of landfill waste in the bioreactors was monitored over 15 months. The decomposition was not intense, and it was concluded that microbial biodegradative activity was limited by a high C:N ratio and a high proportion of paper and plastic (ca. 70%-wt/wt) of the MSW.