title: Pilot-scale experiment of down-flow hanging sponge for direct treatment of low-strength municipal wastewater in Bangkok, Thailand.
abstract: A pilot-scale experiment of a down-flow hanging sponge (DHS) reactor for treatment of low-strength municipal wastewater was conducted over 1 year in Bangkok, Thailand, to establish an appropriate method for treatment under tropical climate conditions. Municipal wastewater with an average BOD of 19 mg/L was fed directly into the DHS reactor. Superior effluent quality (5.1 ± 3.4 mg/L TSS, 21.1 ± 9.0 mg/L COD, 2.8 ± 1.4 mg/L BOD, and 4.1 ± 1.0 mg/L TN) was achieved at a hydraulic retention time (HRT) of 1 h under an average temperature of 30 °C. The DHS reactor reached an actual HRT of 19.0 min, indicating good contact efficiency between wastewater and retained sludge. The DHS reactor retained dense sludge at 15.3-26.4 g VSS/L based on the sponge media volume. The sludge activity in terms of specific oxygen uptake rate was good. Excess sludge was produced as 0.051 g TSS/g COD removed (0.11 g TSS/g BOD removed), and a good SVI of 28 mL/g was observed. The sufficient performance was attributed to dense sludge with high activity, regardless of the low-strength wastewater. Overall, the DHS was advantageous owing to its simple operation, lack of operational problems, and low power consumption.
authors.affiliation: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Onodera
authors.forename: Wilasinee
authors.initials: W
authors.lastname: Yoochatchaval
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Sumino
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Mizuochi
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Okadera
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Fujita
authors.forename: Pathan
authors.initials: P
authors.lastname: Banjongproo
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Syutsubo
mesh_terms: D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D004867:Equipment Design; D010865:Pilot Projects; D012722:Sewage; D013785:Thailand; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater
chemical_list: D012722:Sewage; D062065:Wastewater