title: Development of a sixth-generation down-flow hanging sponge (DHS) reactor using rigid sponge media for post-treatment of UASB treating municipal sewage.
abstract: A sixth-generation down-flow hanging sponge reactor (DHS-G6), using rigid sponge media, was developed as a novel aerobic post-treatment unit for upflow anaerobic sludge blanket (UASB) treating municipal sewage. The rigid sponge media were manufactured by copolymerizing polyurethane with epoxy resin. The UASB and DHS system had a hydraulic retention time (HRT) of 10.6 h (8.6 h for UASB and 2 h for DHS) when operated at 10-28 °C. The system gave reasonable organic and nitrogen removal efficiencies. The final effluent had a total biochemical oxygen demand of only 12 mg/L and a total Kjeldahl nitrogen content of 6 mg/L. The DHS reactor gave particularly good nitrification performance, which was attributed to the new rigid sponge media. The sponge media helped to provide a sufficient HRT, and retained a high biomass concentration, extending the solids retention time. The DHS reactor maintained a high dissolved oxygen concentration under natural ventilation.
authors.affiliation: Department of Civil and Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan; Center for Regional Environmental Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. Electronic address: onodera.takashi@nies.go.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Onodera
authors.affiliation: Department of Civil and Environmental Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Madan
authors.initials: M
authors.lastname: Tandukar
authors.affiliation: Department of Civil and Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan.
authors.forename: Doni
authors.initials: D
authors.lastname: Sugiyana
authors.affiliation: Department of Civil Engineering, Kisarazu National College of Technology, 2-11-1 Kiyomidaihigashi, Kisarazu, Chiba 292-0041, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Uemura
authors.affiliation: Department of Social and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8527, Japan.
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ohashi
authors.affiliation: Department of Civil and Environmental Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan. Electronic address: harada@epl1.civil.tohoku.ac.jp.
authors.forename: Hideki
authors.initials: H
authors.lastname: Harada
mesh_terms: D000042:Absorption; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors; D002947:Cities; D058465:Nitrification; D009584:Nitrogen / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D018508:Water Purification / Q000295:instrumentation*; D060753:Water Quality
chemical_list: D012722:Sewage; D009584:Nitrogen; D010100:Oxygen
keywords: Down-flow hanging sponge; Packing material; Sewage treatment; Upflow anaerobic sludge blanket; Ventilation