Anaerobic Digestion of Municipal Solid Wastes

Abstract

Anaerobic digestion of municipal solid waste (MSW) is a controlled process of microbial decomposition where a consortium of microorganisms convert organic matter into methane, carbon dioxide, inorganic nutrients, and humus. In a generalized scheme for anaerobic digestion, feedstock is harvested or collected, coarsely shredded, and placed into a reactor which has an active inoculum of microorganisms required for the methane fermentation. This chapter reviews the status of anaerobic digestion as applied to MSW. It discusses principles of the microbiology of biomethanogenesis and their application in the design, operation, and evaluation of the anaerobic digestion process. The predominant hydrolytic microorganisms in rumen differ from anaerobic digestion systems. Anaerobic digestion models can be used for optimizing process design and operation and for process control. The starting point for developing a process model for anaerobic digestion is developing mass balance equations which account for the changes in concentration of the substrates, microbial populations, and products during the course of the digestion process.