title: Characteristics of nitrogen and phosphorus removal by a surface-flow constructed wetland for polluted river water treatment.
abstract: The characteristics of nitrogen (N) and phosphorus (P) removal were studied during the 2-year operation of a free water surface flow wetland of 900 m² with hydraulic loading of 0.1 m/d to evaluate its potential to treat water from an urban stream polluted with municipal and industrial wastewater. Attention was focused on the removal of dissolved N and P by harvesting plants (local Phragmites australis and Typha orientalis) at the end of each growing season. According to findings, the removals of N and P increased from 47.1% and 17.6%, respectively, in the 1st year to 52.3% and 32.4%, respectively, in the 2nd year. Increments of N and P removal were largely attributable to plant biomass, which increased from an average dry weight of 1.77 kg/m² in the 1st year to 3.41 kg/m² in the 2nd year. The amount of nutrients assimilated by plants in the 2nd year was almost double that of the 1st year. Increasing biomass in the 2nd year also improved redox conditions in the substrate layer, which contributed to increasing the efficiency of N removal. Compared with T. orientalis, P. australis was more competitive and adapted to conditions in the wetland better; it regenerated more vigorously and contributed more to nutrient removal.
authors: Key Laboratory of Northwest Water Resources, Environment and Ecology, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail: xcwang@xauat.edu.cn; UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, University College Dublin, Newstead Building, Belfield, Dublin 4, Ireland.
authors: Mawuli
authors: M
authors: Dzakpasu
authors: Key Laboratory of Northwest Water Resources, Environment and Ecology, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail: xcwang@xauat.edu.cn.
authors: Xiaochang
authors: X
authors: Wang
authors: Key Laboratory of Northwest Water Resources, Environment and Ecology, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail: xcwang@xauat.edu.cn.
authors: Yucong
authors: Y
authors: Zheng
authors: Key Laboratory of Northwest Water Resources, Environment and Ecology, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail: xcwang@xauat.edu.cn.
authors: Yuan
authors: Y
authors: Ge
authors: Key Laboratory of Northwest Water Resources, Environment and Ecology, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail: xcwang@xauat.edu.cn.
authors: Jiaqing
authors: J
authors: Xiong
authors: UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, University College Dublin, Newstead Building, Belfield, Dublin 4, Ireland.
authors: Yaqian
authors: Y
authors: Zhao
mesh_terms: D018533:Biomass; D002681:China; D009584:Nitrogen / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism*; D045483:Rivers; D032401:Typhaceae / Q000254:growth & development / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D053833:Wetlands
chemical_list: D009584:Nitrogen; D010758:Phosphorus; D062065:Wastewater; D014874:Water Pollutants, Chemical