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Ye F, Duan L, Sun Y, Yang F, Liu R, Gao F, Wang Y, Xu Y. Nitrogen removal in freshwater sediments of riparian zone: N-loss pathways and environmental controls. Front Microbiol 2023; 14:1239055. [PMID: 37664113 PMCID: PMC10469909 DOI: 10.3389/fmicb.2023.1239055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/27/2023] [Indexed: 09/05/2023] Open
Abstract
The riparian zone is an important location of nitrogen removal in the terrestrial and aquatic ecosystems. Many studies have focused on the nitrogen removal efficiency and one or two nitrogen removal processes in the riparian zone, and less attention has been paid to the interaction of different nitrogen transformation processes and the impact of in situ environmental conditions. The molecular biotechnology, microcosm culture experiments and 15N stable isotope tracing techniques were used in this research at the riparian zone in Weinan section of the Wei River, to reveal the nitrogen removal mechanism of riparian zone with multi-layer lithologic structure. The results showed that the nitrogen removal rate in the riparian zone was 4.14-35.19 μmol·N·kg-1·h-1. Denitrification, dissimilatory reduction to ammonium (DNRA) and anaerobic ammonium oxidation (anammox) jointly achieved the natural attenuation process of nitrogen in the riparian zone, and denitrification was the dominant process (accounting for 59.6%). High dissolved organic nitrogen and nitrate ratio (DOC:NO3-) would promote denitrification, but when the NO3- content was less than 0.06 mg/kg, DNRA would occur in preference to denitrification. Furthermore, the abundances of functional genes (norB, nirS, nrfA) and anammox bacterial 16S rRNA gene showed similar distribution patterns with the corresponding nitrogen transformation rates. Sedimentary NOX-, Fe(II), dissolved organic carbon (DOC) and the nitrogen transformation functional microbial abundance were the main factors affecting nitrogen removal in the riparian zone. Fe (II) promoted NO3- attenuation through nitrate dependent ferrous oxidation process under microbial mediation, and DOC promotes NO3- attenuation through enhancing DNRA effect. The results of this study can be used for the management of the riparian zone and the prevention and control of global nitrogen pollution.
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Affiliation(s)
- Fei Ye
- School of Water and Environment, Chang’an University, Xi’an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang’an University, Xi’an, China
| | - Lei Duan
- School of Water and Environment, Chang’an University, Xi’an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang’an University, Xi’an, China
| | - Yaqiao Sun
- School of Water and Environment, Chang’an University, Xi’an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang’an University, Xi’an, China
| | - Fan Yang
- Power China Northwest Engineering Corporation Limited, Xi’an, Shaanxi, China
- Shaanxi Union Research Center of University and Enterprise for River and Lake Ecosystems Protection and Restoration, Xi’an, Shaanxi, China
| | - Rui Liu
- Power China Northwest Engineering Corporation Limited, Xi’an, Shaanxi, China
- Shaanxi Union Research Center of University and Enterprise for River and Lake Ecosystems Protection and Restoration, Xi’an, Shaanxi, China
| | - Fan Gao
- Power China Northwest Engineering Corporation Limited, Xi’an, Shaanxi, China
- Shaanxi Union Research Center of University and Enterprise for River and Lake Ecosystems Protection and Restoration, Xi’an, Shaanxi, China
| | - Yike Wang
- School of Water and Environment, Chang’an University, Xi’an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang’an University, Xi’an, China
| | - Yirong Xu
- School of Water and Environment, Chang’an University, Xi’an, China
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang’an University, Xi’an, China
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Cai Y, Liang J, Zhang P, Wang Q, Wu Y, Ding Y, Wang H, Fu C, Sun J. Review on strategies of close-to-natural wetland restoration and a brief case plan for a typical wetland in northern China. CHEMOSPHERE 2021; 285:131534. [PMID: 34329151 DOI: 10.1016/j.chemosphere.2021.131534] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 07/03/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
Wetlands play an important role in sustaining ecosystems on the earth, which regulate water resources, adjust local climate and produce food for human beings, etc. However, wetlands are facing huge challenges due to human activities and other natural evolution, such as area shrinkage, function weakening and biodiversity decrease, and so on, therefore, some wetlands need to be urgently restored. In this study, the main technology components of close-to-natural restoration of wetlands were summarized. The ecological water requirement and water resource allocation can be optimized for the water balance between social, economy and ecology, which is a key prerequisite for maintaining wetland ecosystem. The pollution of wetland sediments and soils can be assessed by various indicators to provide the scientific basis for natural restoration of wetland base, and suitable strategies should be taken according to the actual conditions of wetland bases. The hydrological connectivity in wetlands and with related water system can be numerically simulated to make the optimal plan for improvement of hydrological connectivity. The ecological restoration of wetlands with the synergetic function of plants, animals and microorganisms was summarized, to improve the quality of wetland water environment and maintain the ecosystem stability. Based on the wetland close-to-natural restoration strategies, a brief ecological restoration plan for a typical wetland, Zaozhadian Wetland, near Xiong'an New Area in the north China was proposed from water resource guarantee, base pollution management, hydrological connectivity improvement and biological restoration. The close-to-natural restoration shows more effective, sustainable and long-lasting and thus a practical prospect.
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Affiliation(s)
- Yajing Cai
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China
| | - Jinsong Liang
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China
| | - Panyue Zhang
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China; School of Environmental Chemical Engineering, Chongqing Three Gorges University, Chongqing, 404632, China.
| | - Qingyan Wang
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China
| | - Yan Wu
- School of Environmental Chemical Engineering, Chongqing Three Gorges University, Chongqing, 404632, China
| | - Yiran Ding
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China
| | - Hongjie Wang
- Xiong'an Institute of Eco-Environment, Hebei University, Baoding, 071002, China
| | - Chuan Fu
- School of Environmental Chemical Engineering, Chongqing Three Gorges University, Chongqing, 404632, China
| | - Jiajun Sun
- Beijing Engineering Research Center of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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