Author/Authors :
Takahashi، M نويسنده Nagaoka University of Technology, Niigata, Japan 2 Tohoku University, Miyagi, Japan , , Ohya، A نويسنده Nagaoka University of Technology, Niigata, Japan , , Kawakami، S نويسنده Nagaoka University of Technology, Niigata, Japan , , Yoneyama، Y نويسنده Ebara Engineering Service Co., Ltd., Tokyo, Japan , , Onodera، T نويسنده National Institute for Environmental Studies, Ibaraki, Japan , , Syutsubo، K نويسنده National Institute for Environmental Studies, Ibaraki, Japan , , Yamazak i، S نويسنده Kochi National College of Technology, Kochi, Japan , , Araki، N نويسنده Nagaoka National College of Technology, Niigata, Japan , , Ohashi، A نويسنده Hiroshima University, Hiroshima, Japan , , Harada، H نويسنده Tohoku University, Miyagi, Japan , , Yamaguchi، T نويسنده Nagaoka University of Technology, Niigata, Japan ,
Abstract :
The evaluation of treatment characteristics and sludge properties of an upflow anaerobic sludge
blanket (UASB) process was investigated using a pilot-scale 1.15 m3
reactor. The UASB, inoculated with
digester sludge, was operated at a hydraulic retention time of 8 h at sewage temperatures ranging from 10.6 to
27.7 °C for more than 1100 days. The stable removal efficiencies for total CODCr
and SS were 63 ± 13% and
66 ± 20%, respectively. The average concentration of the retained sludge increased to more than 24.5 gSS/L of
the column volume after two years of operation. In summer, the water temperature increased above 20 °C, and
biodegradation of solid organic matter was enhanced. The solid retention time was evaluated to be as long as
293 ± 114 days; this is sufficient for mineralisation of solid organic matter, as indicted by a low sludge
conversion of 0.029 gVSS/gCODremoved
and a growth yield of 0.132 gVSS/gCOD, determined by seasonal sludge
profiling. The bacterial communities, based on bacterial 16S rRNA genes in the retained sludge, were significantly
diverse. Bacteroidetes and Firmicutes were the dominant phyla of the decomposers of solid organic matter in
the library. A Ruminococcus-related clone detected in the Firmicutes phylum acted as a cellulose decomposer.
