ABSTRACT
Anaerobic digestion (AD) is a natural, biological waste conversion process that humans have harnessed, initially to treat human and animal wastes and more recently to generate renewable energy from residues and fuel crops. AD microbes use the readily degradable part of the waste to provide their nutrients and energy but less degradable parts of the waste stream will be largely unaffected –AD is not a waste “disposal” process. In fact there will be little reduction in the volume of material but the treated output will be less smelly, contain fewer pathogens and be better as a plant fertilizer than the input. There is also have the benefit of renewable energy, in the form of methane, released during the digestion process. Because of the development from a simple, natural system (that actually also occurs in stomachs) to a modern industrialized process AD can be implemented in a range of configurations, from the quite simple systems used at household level in developing countries to large, complex industrial systems favored in the western world.
