title: Treatment of low-strength wastewater in an anaerobic down-flow hanging sponge (AnDHS) reactor at low temperature.
abstract: The process performance of a novel anaerobic down-flow hanging sponge (AnDHS) reactor for the treatment of low strength wastewater was investigated. A lab-scale experiment was conducted in which 300-400 mgCOD L(-1) of artificial wastewater was fed in over 600 days. The reactor exhibited sufficient performance: 70-90% of total COD removal, and 60-90% of methane recovery were maintained at 20°C, with a hydraulic retention time (HRT) of 2 h. It was possible to maintain COD removal by extending the HRT to 4 h at 15°C and 10 h at 10°C. With regard to the wastewater feed, one-pass mode (without effluent recirculation) gave better performance in COD removal as compared with recirculation mode. The results of batch feeding experiments using single substrates (such as acetate, propionate or sucrose) indicated that acetate degradation was more strongly affected by decreasing operational temperature. In addition, the AnDHS reactor system had no significant problems related to sludge retention such as massive loss of sludge throughout the experiment. Microbial structure analysis of the retained sludge with respect to the domain Archaeal 16S rRNA gene showed the proliferation of relatives of both the acetate-utilizing genus Methanosaeta and the hydrogen-utilizing genus Methanolinea.
authors: Department of Civil Engineering, Gifu National College of Technology, Motosu, Gifu, Japan.
authors: Haruhiko
authors: H
authors: Sumino
authors: Ryuichi
authors: R
authors: Murota
authors: Ai
authors: A
authors: Miyashita
authors: Hiroyuki
authors: H
authors: Imachi
authors: Akiyoshi
authors: A
authors: Ohashi
authors: Hideki
authors: H
authors: Harada
authors: Kazuaki
authors: K
authors: Syutsubo
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D003080:Cold Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*