title: Robust biological nitrogen removal by creating multiple tides in a single bed tidal flow constructed wetland.
abstract: Achieving effective total nitrogen (TN) removal is one of the major challenges faced by constructed wetlands (CWs). To address this issue, multiple "tides" were proposed in a single stage tidal flow constructed wetland (TFCW). With this adoption, exceptional TN removal (85% on average) was achieved under a high nitrogen loading rate (NLR) of around 28 g Nm(-2)day(-1), which makes the proposed system an adequate option to provide advanced wastewater treatment for peri-urban communities and rural area. It was revealed that the multiple "tides" not only promoted TN removal performance, but also brought more flexibility to TFCWs. Adsorption of NH4(+)-N onto the wetland medium (during contact period) and regeneration of the adsorption capacity via nitrification (during bed resting) were validated as the key processes for NH4(+)-N conversion in TFCWs. Moreover, simultaneous nitrification denitrification (SND) was found to be significant during the bed resting period. These findings will provide a new foundation for the design and modeling of nitrogen conversion and oxygen transfer in TFCWs.
authors.affiliation: UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, Newstead Building, University College Dublin, Belfield, Dublin 4, Ireland; Key Laboratory of Urban Stormwater System and Water Environment/R&D Centre for Sustainable Wastewater Treatment (Beijing University of Civil Engineering and Architecture), Ministry of Education, Beijing 100044, China. Electronic address: yuanshenghu@hotmail.com.
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Hu
authors.affiliation: UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, Newstead Building, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Yaqian
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, Newstead Building, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Anna
authors.initials: A
authors.lastname: Rymszewicz
mesh_terms: D052918:Environmental Restoration and Remediation / Q000379:methods*; D009584:Nitrogen / Q000032:analysis*; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical; D009584:Nitrogen
keywords: Constructed wetland; Nitrogen; Simultaneous nitrification denitrification (SND); Tidal flow