ABSTRACT
Anaerobic digestion process is very complex. It is composed of a large number of parallel an sequential steps, by participating in different types of microorganisms (Batstone et al., 2002; Pavlostathis. 1991; Rittman & McCarty, 2001). The biochemical process in general can be explained by three theories: two-stage theory, the three-stage and four-stage theory of three kinds of opinions. The two-stage theory, in which the AD was divided into acid fermentation phase and alkaline fermentation phase, is proposed by Thumm, Reichie and Imhoff, and developed by Buswell, NeaVe, and perfection. The two-stage theory was mainly used to describe AD of soluble organic matter. In 1979, on the basis of the discovery of hydrogenotrophic methanogens, Bryant put forward to the three-stage theory. The theory of the anaerobic fermentation was divided into three stages: hydrolysis phase, acetic acid
1 GENERAL INSTRUCTIONS
With the development of economy, the emissions of industrial solid waste, agricultural waste and domestic solid wastes are increasing in worldwide. According to the statistics, China has become the largest discharge quantity country in organic solid waste of agricultural wastes, the annual output reached 8 million tons (Xing, 2000), forestry waste 16,000 tons, emissions from livestock and poultry manure 134 tons, city garbage more than 70,000 tons (Lu, 2002). These solid wastes increased as an average speed of 5∼10% per year (Li & Wang, 2009). Solid waste disposal is not reasonable; it will cause the waste of resources and environmental pollution problems. Therefore, the need for the disposal of solid waste is imminent.
