title: Comparison of thermophilic anaerobic digestion characteristics between single-phase and two-phase systems for kitchen garbage treatment.
abstract: Lab-scale single-phase and two-phase thermophilic methane fermentation systems (SPS and TPS, respectively) were operated and fed with artificial kitchen waste. In both SPS and TPS, the highest methane recovery ratio of 90%, in terms of chemical oxygen demand by dichromate (CODcr), was observed at an organic loading rate (OLR) of 15 gCODcr/(l.d). The ratio of particle CODcr remaining to total CODcr in the influent was 0.1 and the ratio of NH(4)-N concentration to the input total nitrogen concentration was 0.5 in both SPS and TPS. However, the propionate concentration in the SPS reactor fluctuated largely and was 2 gCODcr/l higher than that in TPS, indicating less stable digestion. Regardless, efficient kitchen waste degradation can be accomplished in both SPS and TPS at an OLR of <20 gCODcr/(l.d), even though TPS may be more stable and easier to maintain. Bacillus coagulans predominated with an occupied ratio of approximately 90% in the acid fermentation reactor of TPS, and then a richer microbial community with a higher Shannon index value was maintained in the methane fermentation reactor of TPS than in the SPS reactor.
authors.affiliation: Department of Urban and Environmental Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Kyoto, Japan.
authors.forename: YongJin
authors.initials: Y
authors.lastname: Park
authors.forename: Feng
authors.initials: F
authors.lastname: Hong
authors.forename: JiHoon
authors.initials: J
authors.lastname: Cheon
authors.forename: Taira
authors.initials: T
authors.lastname: Hidaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuno
mesh_terms: D000693:Anaerobiosis; D001407:Bacillus / Q000302:isolation & purification; D019149:Bioreactors / Q000382:microbiology*; D005285:Fermentation; D005735:Garbage; D006358:Hot Temperature; D008697:Methane / Q000096:biosynthesis
chemical_list: D008697:Methane