초록
<P><B>Abstract</B></P><P>To avoid the inhibition of methane production by ammonia that occurs during the degradation of garbage, anaerobic digestion with prior ammonia production and subsequent stripping was investigated. In the ammonia production phase, the maximum ammonia concentration was approximately 2800mgN/kg of total wet sludge in the range of 4days of sludge retention time, indicating that only 43% of total nitrogen in the model garbage was converted to ammonia. The model garbage from which ammonia was produced and stripped was subjected to semi-continuous thermophilic dry anaerobic digestion over 180days. The gas yield was in the range of 0.68 to 0.75Nm<SUP>3</SUP>/kg volatile solid, and it decreased with the decrease of the sludge retention time. The ammonia–nitrogen concentration in the sludge was kept below 3000mgN/kg total wet sludge. Microbial community structure analysis revealed that the phylum <I>Firmicutes</I> dominated in the ammonia production, but the community structure changed at different sludge retention times. In dry anaerobic digestion, the dominant bacteria shifted from the phylum <I>Thermotogae</I> to <I>Firmicutes</I>. The dominant archaeon was the genus <I>Methanothermobacter</I>, but the ratio of <I>Methanosarcina</I> increased during the process of dry anaerobic digestion.</P>