title: Nitrogen removal in Myriophyllum aquaticum wetland microcosms for swine wastewater treatment:15N-labelled nitrogen mass balance analysis.
abstract: BACKGROUND
  Ecological treatments are effective for treating agricultural wastewater. In this study, wetland microcosms vegetated with Myriophyllum aquaticum were designed for nitrogen (N) removal from two strengths of swine wastewater, and15N-labelled ammonium (NH4+-N) was added to evaluate the dominant NH4+-N removal pathway.
  
  
  RESULTS
  The results showed that 98.8% of NH4+-N and 88.3% of TN (TN: 248.6 mg L-1) were removed from low-strength swine wastewater (SW1) after an incubation of 21 days, with corresponding values for high-strength swine wastewater (SW2) being 99.2% of NH4+-N and 87.8% of TN (TN: 494.9 mg L-1). Plant uptake and soil adsorption respectively accounted for 24.0% and 15.6% of the added15N. Meanwhile, above-ground tissues of M. aquaticum had significantly higher biomass and TN content than below-ground (P < 0.05).15N mass balance analysis indicated that gas losses contributed 52.0% to the added15N, but the N2O flux constituted only 7.5% of total gas losses. The dynamics of NO3--N and N2O flux revealed that strong nitrification and denitrification occurred in M. aquaticum microcosms, which was a dominant N removal pathway.
  
  
  CONCLUSIONS
  These findings demonstrated that M. aquaticum could feasibly be used to construct wetlands for high N-loaded animal wastewater treatment. © 2016 Society of Chemical Industry.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.|Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.
authors.forename: Shunan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.|Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.|Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.
authors.forename: Runlin
authors.initials: R
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.|Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.|Graduate University of Chinese Academy of Sciences, Beijing, 100039, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: He
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.|Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, People's Republic of China.
authors.forename: Jinshui
authors.initials: J
authors.lastname: Wu
mesh_terms: D000641:Ammonia / Q000032:analysis; D064751:Ammonium Compounds / Q000032:analysis; D000818:Animals; D001673:Biodegradation, Environmental; D018533:Biomass; D058440:Denitrification; D005525:Food-Processing Industry; D005740:Gases; D019684:Magnoliopsida / Q000254:growth & development / Q000378:metabolism*; D008460:Meat; D009566:Nitrates / Q000032:analysis; D058465:Nitrification; D009584:Nitrogen / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis; D035261:Plant Components, Aerial / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D013552:Swine; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
chemical_list: D000641:Ammonia; D064751:Ammonium Compounds; D005740:Gases; D009566:Nitrates; D009584:Nitrogen; D009609:Nitrous Oxide; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: 15N-labelled nitrogen; Myriophyllum aquaticum; gas emission; plant uptake; swine wastewater