title: Nitrogen removal and its relationship with the nitrogen-cycle genes and microorganisms in the horizontal subsurface flow constructed wetlands with different design parameters.
abstract: This study aims to investigate nitrogen removal and its relationship with the nitrogen-cycle genes and microorganisms in the horizontal subsurface flow constructed wetlands (CWs) with different design parameters. Twelve mesocosm-scale CWs with four substrates and three hydraulic loading rates were set up in the outdoor. The result showed the CWs with zeolite as substrate and HLR of 20 cm/d were selected as the best choice for the TN and NH3-N removal. It was found that the single-stage mesocosm-scale CWs were incapable to achieve high removals of TN and NH3-N due to inefficient nitrification process in the systems. This was demonstrated by the lower abundance of the nitrification genes (AOA and AOB) than the denitrification genes (nirK and nirS), and the less diverse nitrification microorganisms than the denitrification microorganisms in the CWs. The results also show that microorganism community structure including nitrogen-cycle microorganisms in the constructed wetland systems was affected by the design parameters especially the substrate type. These findings show that nitrification is a limiting factor for the nitrogen removal by CWs.
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: Guang-Guo
authors.initials: GG
authors.lastname: Ying
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: You-Sheng
authors.initials: YS
authors.lastname: Liu
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Wei
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: Shuang-Shuang
authors.initials: SS
authors.lastname: Liu
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: Liang-Ying
authors.initials: LY
authors.lastname: He
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Yang
authors.affiliation: a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
authors.forename: Fan-Rong
authors.initials: FR
authors.lastname: Chen
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D058440:Denitrification / Q000235:genetics; D005798:Genes, Bacterial; D059013:Microbial Consortia / Q000235:genetics; D058465:Nitrification / Q000235:genetics; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D058458:Nitrogen Cycle / Q000235:genetics*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology; D053833:Wetlands
chemical_list: D009584:Nitrogen; D062065:Wastewater
keywords: Constructed wetland; denitrification; nitrification; nitrogen-cycle genes; nitrogen-cycle microorganisms; nitrogenous substances