Biogasification of solid wastes by two-phase anaerobic fermentation

摘要

Municipal, industrial and agricultural solid wastes, and biomass deposits cause large-scale pollution of land and water. Gaseous products of waste decomposition pollute the air and contribute to global warming. This paper describes the development of a two-phase fermentation system that alleviates methanogenic inhibition encountered with high-solids feeds, accelerates methane fermentation of solid be, and captures mehtane(renewable energy) for captive use to reduce global warming. The innovative system consisted of a solid-bed reactor packed with simulated solid waste at a density of 160 kg/m~3 and operated with recirculation of the percolated culture (bioleachate) through the bed. A rapid onset of solids hydrolysis, acidification, denitrification and hydrogen gas formation was observed under these operating conditions. However, these fermentative reactions stopped after about 2.5 months of solid-bed fermentation at which time total volatile fatty acids (VFA) concentration accumulated to 13,000 mg/l (as acetic) at pH 5, and the reactor head-gas consisted of 75 carbon dioxide, 20 nitrogen,2 hydrogen and 3 methane.