Related Experiment Video
Updated: May 12, 2026
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
Characterization of the retained sludge in a down-flow hanging sponge (DHS) reactor with emphasis on its low excess
Takashi Onodera1, Kengo Matsunaga, Kengo Kubota
1Department of Civil and Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan. onodera.takashi@nies.go.jp
Abstract:
Experiments to characterize retained sludge in a down-flow hanging sponge (DHS) reactor fed with upflow anaerobic sludge blanket (UASB) treated sewage under moderate conditions were conducted. Plenty of oxygen was supplied through the DHS reactor without aeration and the effluent qualities after the reactor were comparable to activated sludge processes. The average excess sludge production rate was 0.09 g SS g(-1) COD removed. The DHS reactor maintained a high sludge concentration of 26.9 g VSS L(-1) sponge, resulting in a low loading rate of 0.032 g COD g(-1) VSS day(-1). The endogenous respiration rate of DHS sludge was comparable to previously reported aerobic sludges. The numbers of microfauna were one order of magnitude greater than those in activated sludge. The results indicated that low excess sludge production was attributable to the high sludge concentration, sufficient oxygen supply, adequate endogenous respiration rate, and a high density and diversity of microfauna.
