title: Cold Temperature Effects on Long-Term Nitrogen Transformation Pathway in a Tidal Flow Constructed Wetland.
abstract: The present study investigated long-term treatment performance and nitrogen transformation mechanisms in tidal flow constructed wetlands (TFCWs) under 4, 8, and 12 °C temperature regimes. High and stable ammonium (NH4(+)-N) removal efficiency (93-96%) was achieved in our TFCWs, whereas nitrate (NO3(-)-N) was accumulated at different levels under different temperatures. Quantitative response relationships showed anammox/amoA, (narG+napA)/amoA, and (narG+napA)/bacteria were the respective key functional gene groups determining 4, 8, and 12 °C NO3(-)-N reduction. Pathway analysis revealed the contribution of these functional gene groups along a depth gradient. In addition, denitrification process increased, while anammox process decreased consistent with a rise in temperature from 4 to 12 °C. Furthermore, cold temperatures exhibited different effects on anammox and denitrification and their long-term acclimatization capacities changed with temperature.
authors.affiliation: Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University , Beijing 100871, China.
authors.forename: Yunmeng
authors.initials: Y
authors.lastname: Pang
authors.affiliation: Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University , Beijing 100871, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University , Beijing 100871, China.
authors.forename: Xingjun
authors.initials: X
authors.lastname: Yan
authors.affiliation: Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University , Beijing 100871, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Ji
mesh_terms: D064751:Ammonium Compounds / Q000032:analysis / Q000378:metabolism; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D058440:Denitrification; D059013:Microbial Consortia / Q000235:genetics*; D009566:Nitrates / Q000032:analysis / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*; D053833:Wetlands
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009584:Nitrogen