title: Development of slow sponge sand filter (SpSF) as a post-treatment of UASB-DHS reactor effluent treating municipal wastewater.
abstract: In this study, conventional slow sand filter (SSF) and modified slow sponge sand filter (SpSF) were investigated for the post-treatment of up-flow anaerobic sludge blanket (UASB)-down-flow hanging sponge (DHS) reactor effluent. The seasonal variation did not show significant differences in removal efficiencies of both filters. However in summer, both filters were able to achieve high total suspended solids and total biochemical oxygen demand removal averaging 97% and 99%, respectively. Contrary to organic removal, total nitrogen removal efficiency was satisfactory, showing increased removal efficiencies averaging 58% and 62% for SSF and SpSF in summer. On the other hand, average total coliform removal of SSF and SpSF was 4.2 logs and 4.4 logs and corresponding Escherichia coli removal was 4.0 logs and 4.1 logs, respectively. From our observation, it could be concluded that the relative performance of SpSF for nutrients and coliforms was better than SSF due to the effectiveness of sponge media over fine sands. Moreover, microbial community analysis revealed that the members of phylum Proteobacteria were predominant in the biofilms of both filters, which could have contributed to pollutant removal. Therefore, SpSF could be concluded to be a suitable post-treatment of UASB-DHS system in warmer conditions.
authors.affiliation: Department of Civil and Environment Engineering, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: namita.maharjan@yahoo.com.
authors.forename: N
authors.initials: N
authors.lastname: Maharjan
authors.affiliation: Department of Civil and Environment Engineering, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: namita.maharjan@yahoo.com.
authors.forename: K
authors.initials: K
authors.lastname: Kuroda
authors.affiliation: Nihon Suiko Sekkei Co. Ltd, 2-9-8, Minamisenba, Chuo-ku, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Dehama
authors.affiliation: Department of Civil and Environment Engineering, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: namita.maharjan@yahoo.com; Top Runner Incubation Center for Academia-Industry Fusion, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hatamoto
authors.affiliation: Department of Civil and Environment Engineering, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: namita.maharjan@yahoo.com; Department of Science of Technology Innovation, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D001673:Biodegradation, Environmental; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology; D009584:Nitrogen / Q000032:analysis; D012722:Sewage / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D009584:Nitrogen; D012722:Sewage; D012822:Silicon Dioxide; D062065:Wastewater