Microbial, Chemical and Methane Production Characteristics of Anaerobically Decomposed Refuse With and Without Leachate Recycling

Abstract

Microbial and chemical characteristics of refuse in an active state of methane production, incubated in the laboratory with and without leachate recycle, were compared. There were no significant differences in the total anaerobic population or the sub-populations of cellulolytic, hemicellulolytic, acetogenic or methanogenic (based on acetate or H2/CO2 utilization) bacteria in refuse incubated with or without leachate recycle. Therefore, leachate recycle may be used to accelerate refuse decomposition in laboratory-scale test lysimeters without changing the microbial composition of the aforementioned trophic groups. Differences in soluble constituent concentrations and methane production patterns between leachate recycle and non-leachate recycle containers were attributed to the mixing associated with leachate recycle. Under certain circumstances, leachate recycle is a useful technique for acceleration of refuse decomposition in the laboratory, thus reducing the period of time required to study the effect of an addition to the refuse ecosystem on methane production.