Energy Production and Compost Generation from a Segregated Municipal Waste Stream Using Bi-phasic Anaerobic Digestion

Municipal solid wastes are major sources of air, water and soil contamination. There is a need for alternative waste management techniques to better utilize the waste and minimize its adverse environmental impact. A two-phase bio-fermentation system was used to evaluate the feasibility of producing methane from high carbon segregated waste from a major City's municipal solid waste stream. The bi-phasic system consists of a solid phase and a methane phase. Leachate is re-circulated through the solid phase until a desired level of volatile fatty acid (VFA) is accumulated in the leachate. The leachate is transferred to the methane reactor where the VFA is converted to methane. The average methane concentration in the produced gas was in excess of 71 percent. The material remaining after the anaerobic stabilization was composted. The compost was sufficient quality for use in agricultural application, and thus the research represented a full beneficial reuse of the solid waste stream.