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Zaryab A, Alijani F, Knoeller K, Minet E, Musavi SF, Ostadhashemi Z. Identification of groundwater nitrate sources in an urban aquifer (Alborz Province, Iran) using a multi-parameter approach. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:100. [PMID: 38407701 DOI: 10.1007/s10653-024-01872-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 01/12/2024] [Indexed: 02/27/2024]
Abstract
High concentrations of NO3̄ in water resources are detrimental to both human health and aquatic ecosystems. Identification of NO3̄ sources and biogeochemical processes is a crucial step in managing and controlling NO3̄ pollution. In this study, land use, hydrochemical data, dual stable isotopic ratios and Bayesian Stable Isotope Mixing Models (BSIMM) were integrated to identify NO3̄ sources and estimate their proportional contributions to the contamination of the Karaj Urban Aquifer (Iran). Elevated NO3̄ concentrations indicated a severe NO3̄ pollution, with 39 and 52% of groundwater (GW) samples displaying the concentrations of NO3̄ in exceedance of the World Health Organization (WHO) standard of 50 mg NO3̄ L-1 in the rainy and dry seasons, respectively. Dual stable isotopes inferred that urban sewage is the main NO3̄ source in the Karaj Plain. The diagram of NO3̄/Cl‾ versus Cl‾ confirmed that municipal sewage is the major source of NO3̄. Results also showed that biogeochemical nitrogen dynamics are mainly influenced by nitrification, while denitrification is minimal. The BSIMM model suggested that NO3̄ originated predominantly from urban sewage (78.2%), followed by soil organic nitrogen (12.2%), and chemical fertilizer (9.5%) in the dry season. In the wet season, the relative contributions of urban sewage, soil nitrogen and chemical fertilizer were 87.5, 6.7, and 5.5%, respectively. The sensitivity analysis for the BSIMM modeling indicates that the isotopic signatures of sewage had the major impact on the overall GW NO3̄ source apportionment. The findings provide important insights for local authorities to support effective and sustainable GW resources management in the Karaj Urban Aquifer. It also demonstrates that employing Bayesian models combined with multi-parameters can improve the accuracy of NO3̄ source identification.
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Affiliation(s)
- Abdulhalim Zaryab
- Engineering Geology and Hydrogeology, Faculty of Geology and Mines, Kabul Polytechnic University, District 5, Kabul, Afghanistan
| | - Farshad Alijani
- Department of Minerals and Groundwater Resources, Faculty of Earth Sciences, Shahid Beheshti University, Evin Ave, Tehran, Iran.
| | - Kay Knoeller
- Department Catchment Hydrology Helmholtz-Centre for Environmental Research-UFZ, 06120, Halle, Germany
| | - Eddy Minet
- Environmental Protection Agency (EPA), Dublin, Ireland
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Hermawan OR, Hosono T, Yasumoto J, Yasumoto K, Song KH, Maruyama R, Iijima M, Yasumoto-Hirose M, Takada R, Hijikawa K, Shinjo R. Mechanism of denitrification in subsurface-dammed Ryukyu limestone aquifer, southern Okinawa Island, Japan. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169457. [PMID: 38135078 DOI: 10.1016/j.scitotenv.2023.169457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 12/04/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023]
Abstract
Denitrification crucially regulates the attenuation of groundwater nitrate and is unlikely to occur in a fast-flowing aquifer such as the Ryukyu limestone aquifer in southern Okinawa Island, Japan. However, evidences of denitrification have been observed in several wells within this region. This study analyzed environmental isotopes (δ15NNO3 and ẟ18ONO3) to derive the rationale for denitrification at this site. Additionally, the presence of two subsurface dams in the study area may influence the processes involved in nitrate attenuation. Herein, we analyzed 150 groundwater samples collected spatially and seasonally to characterize the variations in the groundwater chemistry and stable isotopes during denitrification. The values of δ15NNO3 and δ18ONO3 displayed a progressive trend up to +59.7 ‰ and + 21 ‰, respectively, whereas the concentrations of NO3--N decreased to 0.1 mg L-1. In several wells, the enrichment factors of δ15NNO3 ranged from -6.6 to -2.1, indicating rapid denitrification, and the δ15NNO3 to δ18ONO3 ratios varied from 1.3:1 to 2:1, confirming the occurrence of denitrification. Denitrification intensively proceeds under conditions of depleted dissolved oxygen concentrations (<2 mg L-1), sluggish groundwater flow with longer residence times, high concentrations of dissolved organic carbon (>1.2 mg L-1), and low groundwater levels during the dry season with precipitation rates of <100 mm per month (Jun-Sep). SF6 analysis indicated the exclusive occurrence of denitrification in specific wells with groundwater residence times exceeding 30 years. These wells are located in close proximity to the major NE-SW fault system in the Komesu area, where the hydraulic gradient was below 0.005. Detailed geological and lithological investigations based on borehole data revealed that subsurface dams did not cause denitrification while the major NE-SW fault system uplifted the impermeable basement rock of the Shimajiri Group, creating a lithological gap at an equivalent depth that ultimately formed a sluggish groundwater area, promoting denitrification.
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Affiliation(s)
- Oktanius Richard Hermawan
- Department of Earth and Environmental Sciences, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
| | - Takahiro Hosono
- Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan; International Research Organization for Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan; Research Institute for Humanity and Nature, 457-4 Motoyama, Kamigamo, Kita-ku, Kyoto 603-8047, Japan
| | - Jun Yasumoto
- Department of Regional Agriculture Engineering, University of the Ryukyus, 1-Senbaru, Nakagami District, Nishihara, Okinawa 903-0213, Japan
| | - Ko Yasumoto
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan
| | - Ke-Han Song
- Graduate School of Engineering and Science, University of the Ryukyus, 1-Senbaru, Nakagami District, Nishihara, Okinawa 903-0213, Japan
| | - Rio Maruyama
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan
| | - Mariko Iijima
- National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 7, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8567, Japan
| | | | - Ryogo Takada
- Center for Strategic Research Projects, University of the Ryukyus, 1-Senbaru, Nakagami District, Nishihara, Okinawa 903-0213, Japan
| | - Kento Hijikawa
- Department of Regional Agriculture Engineering, University of the Ryukyus, 1-Senbaru, Nakagami District, Nishihara, Okinawa 903-0213, Japan; Overseas Land Improvement Cooperation Office, Rural Development Bureau, Ministry of Agriculture, Forestry, and Fisheries of Japan, 1-2-1 Kasumigaseki, Chiyoda, Tokyo 100-8950, Japan
| | - Ryuichi Shinjo
- Research Institute for Humanity and Nature, 457-4 Motoyama, Kamigamo, Kita-ku, Kyoto 603-8047, Japan; Graduate School of Engineering and Science, University of the Ryukyus, 1-Senbaru, Nakagami District, Nishihara, Okinawa 903-0213, Japan
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Wang F, Liu L, Xu W, Li Y, Ruan Q, Cao W. Multiple stable isotopic approaches for tracing nitrate contamination sources: Implications for nitrogen management in complex watersheds. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 269:115822. [PMID: 38091679 DOI: 10.1016/j.ecoenv.2023.115822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 12/07/2023] [Accepted: 12/10/2023] [Indexed: 01/12/2024]
Abstract
Nitrate (NO3-) contamination of surface water is a global environmental problem that has serious consequences for watershed ecosystems and endangers human health. It is crucial to identify influences of different sources of NO3-, especially the incoming water from upper reaches. A combination of hydrochemistry and multi-isotope tracers (δ11B, δ15N-NO3-, and δ18O-NO3-) were used to determine NO3- sources and their transformation the North Jiulong River (NJLR), Southeast China. The findings revealed that NO3-, which accounted for an average of 87.1% of dissolved inorganic nitrogen (DIN), was the main chemical form of nitrogen species. The integration of dual stable isotopes of NO3-, δ11B, and hydrochemistry showed that NO3- was primarily contributed by sewage, soil nitrogen (SN), and ammonium (NH4+) via precipitation or fertilizers. The contributions from the sewage and soil nitrate source were almost equivalent and much higher than those from other sources in the NJLR watershed. The contributions from diverse sources varied seasonally and spatially. Manure and sewage (M&S) were the leading sources in the summer and autumn, accounting for 60.9 ± 8.5% and 47.3 ± 7.9%, respectively. However, NO3- fertilizers were the predominant source in the spring and winter. The NO3- inflow from upper reaches was proposed as an additional end-member to identify its contribution in the midstream and downstream in this study. The contributions of NO3- from the upper reaches were significant sources in the midstream and downstream, accounting for 27.2 ± 17.8% and 42.9 ± 21.9%, respectively. The obvious decline in local NO3-contribution shares from midstream to downstream implied structural changes in pollutant sources and regional environmental responsibility. Therefore, tracing nitrate sources and quantifying their contributions is critical for clarifying environmental responsibilities for precise local nitrogen management in watersheds.
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Affiliation(s)
- Feifei Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Lihua Liu
- Fujian Xiamen Environmental Monitoring Central Station, Xiamen, Fujian 361022, China
| | - Wenfeng Xu
- Fujian Xiamen Environmental Monitoring Central Station, Xiamen, Fujian 361022, China
| | - Yasong Li
- Fujian Provincial Key Laboratory of Water Cycling and EcoGeological Processes, Xiamen 361021, China; Key Laboratory of Groundwater Contamination and Remediation of Hebei Province and China Geological Survey, Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Qizhen Ruan
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Wenzhi Cao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.
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Zaryab A, Farahmand A, Mack TJ. Identification and apportionment of groundwater nitrate sources in Chakari Plain (Afghanistan). ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:7813-7827. [PMID: 37462844 DOI: 10.1007/s10653-023-01684-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/06/2023] [Indexed: 10/29/2023]
Abstract
The Chakari alluvial aquifer is the primary source of water for human, animal, and irrigation applications. In this study, the geochemistry of major ions and stable isotope ratios (δ2H-H2O, δ18O-H2O, δ15N-NO3̄, and δ18O-NO3̄) of groundwater and river water samples from the Chakari Plain were analyzed to better understand characteristics of nitrate. Herein, we employed nitrate isotopic ratios and BSIMM modeling to quantify the proportional contributions of major sources of nitrate pollution in the Chakari Plain. The cross-plot diagram of δ15N-NO3̄ against δ18O-NO3̄ suggests that manure and sewage are the main source of nitrate in the plain. Nitrification is the primary biogeochemical process, whereas denitrification did not have a significant influence on biogeochemical nitrogen dynamics in the plain. The results of this study revealed that the natural attenuation of nitrate in groundwater of Chakari aquifer is negligible. The BSIMM results indicate that nitrate originated mainly from sewage and manure (S&M, 75‰), followed by soil nitrogen (SN, 13‰), and chemical fertilizers (CF, 9.5‰). Large uncertainties were shown in the UI90 values for S&M (0.6) and SN (0.47), whereas moderate uncertainty was exhibited in the UI90 value for CF (0.29). The findings provide useful insights for decision makers to verify groundwater pollution and develop a sustainable groundwater management strategy.
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Affiliation(s)
- Abdulhalim Zaryab
- Engineering Geology and Hydrogeology, Faculty of Geology and Mines, Kabul Polytechnic University, Kabul, Afghanistan.
- Highland Groundwater Research Group, Kabul, Afghanistan.
| | - Asadullah Farahmand
- Department of Hydrogeology, Ministry of Energy and Water, Kabul, Afghanistan
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Li J, Zou S, Wang J, Zhou C, Wu Y, Zhang H, Zhao Y, Yang G. Spatiotemporal variability and control factors of NO 3- in a polluted karst water system of an agricultural wetland in South China. CHEMOSPHERE 2023; 313:137435. [PMID: 36462567 DOI: 10.1016/j.chemosphere.2022.137435] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Nitrate (NO3-) pollution in karst water is an important environmental issue in intensive agricultural regions worldwide. The integrated understanding of the spatiotemporal variability and control factors of NO3- pollution in karst water is imperative for controlling the diffuse pollution caused by agricultural activities. In this study, 49 water samples were collected from surface water (SW) and groundwater (GW) in the Huixian karst wetland (HKW) and analyzed using hydrogeochemical and isotopic data (δ18O-NO3-, δ15N-NO3- and δ13CDIC) in combination with a Bayesian mixing model to investigate the spatiotemporal distribution and control factors in NO3--polluted karst water. The results showed that approximately 40.82% of the karst water samples exceeded the natural threshold value of 3 mg/L for NO3--N, and 32.14% of the GW samples exceeded the permissible limit for drinking water established by WHO (10 mg/L as NO3--N), indicating that high levels of NO3- were mainly found in GW samples from the agricultural core area, especially in the dry season. The NH4+-synthetic fertilizer (NHF) and soil organic nitrogen (SON) were the dominant factors controlling pollution sources in the HKW, accounting for 36.13% ± 4.66% and 28.68% ± 4.75% of the karst GW NO3- concentration, respectively. However, the seasonal differences in NO3- pollution sources were not significant in GW. Microbial nitrification was the main process affecting the NO3- levels in GW, whereas the occurrence of denitrification did not significantly affect NO3- concentration in the HKW due to the relatively low rate. Moreover, the HNO3 produced from NH4+ via microbial nitrification facilitated carbonate weathering, thereby controlling NO3- enrichment in karst GW. Our results suggest that NHF should be controlled to prevent further GW pollution in the HKW. Our study also provides a scientific basis for understanding the factors controlling the NO3- concentrations in karst water systems.
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Affiliation(s)
- Jun Li
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou, 075000, China
| | - Shengzhang Zou
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin, 541004, China
| | - Jiawei Wang
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou, 075000, China
| | - Changsong Zhou
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin, 541004, China
| | - Yongqiang Wu
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou, 075000, China
| | - Haidao Zhang
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou, 075000, China
| | - Yi Zhao
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin, 541004, China
| | - Guoli Yang
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou, 075000, China.
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Yang F, Guo J, Qi R, Yan C. Isotopic and hydrochemical analyses reveal nitrogen source variation and enhanced nitrification in a managed peri-urban watershed. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120534. [PMID: 36341828 DOI: 10.1016/j.envpol.2022.120534] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 10/15/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Watershed management practices (WMPs) alter the sources and transformation of reactive nitrogen (N) in peri-urban watersheds, but a precise description of how WMPs impact N cycling is still lacking. In this study, four sampling campaigns were conducted in the wet and dry seasons of 2019 (before WMPs) and 2020 (after WMPs) to determine the spatiotemporal variations in nitrate isotopes (15N-NO3- and 18O-NO3-) and hydrochemical compositions in the Muli River watershed. The results showed that the WMPs could significantly reduce the N load in the middle and lower reaches, but substantial improvements were not observed in 2020. Manure and sewage (M&S, 36.2 ± 15.8-55.0 ± 19.4%) was the major source of nitrate (NO3-) in the stream water, followed by smaller-scale wastewater treatment plants (WWTPs, 14.0 ± 10.9-25.6 ± 11.5%). The WMPs were effective in controlling M&S, resulting in an approximately 16.7% (p < 0.01) lower M&S contribution during the dry season in 2020 compared to that in 2019. However, the smaller-scale WWTP input increased by approximately 5.4% (p < 0.01) after the WMPs. During the study period, the assimilation of NO3- by phytoplankton was important for NO3- loss, but the WMPs promoted nitrification in the watershed because of the elevated redox potential (Eh). Overall, the present study provides a better estimate of the variations in nitrogen sources and transformation in a peri-urban watershed after WMPs and provides an approach for developing timely nitrogen management solutions.
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Affiliation(s)
- Fan Yang
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Jianhua Guo
- Yellow River Institute of Hydraulic Research, Zhengzhou, 450003, China
| | - Ran Qi
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Changzhou Yan
- Key Laboratory of Urban Environment and Health, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
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Wu P, Xiao Q, Guo Y, Prelovšek M, Yu Q, Wang Q. Migration, transformation and nitrate source in the Lihu Underground River based on dual stable isotopes of δ 15N-NO 3- and δ 18O-NO 3. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:48661-48674. [PMID: 35195868 DOI: 10.1007/s11356-022-19277-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
Nitrate (NO3-) pollution is a common phenomenon in karst underground rivers, which are important water sources in karst landscapes. For drinking water safety and environmental protection, it is crucial to accurately identify NO3- sources and their migration and transformation processes in the Lihu Underground River. In this study, water samples of the Lihu Underground River in Guangxi were collected in May 2014, October 2014, January 2015, and July 2015, and water chemical and dual isotopic (δ15N-NO3- and δ18O-NO3-) approaches were used to evaluate the NO3- characteristics and sources in the Lihu Underground River. The concentration of NO3- in the Lihu Underground River ranged from 1.16 to 19.78 mg·L-1, with an average of 9.30 mg·L-1, which is more than 37% of the WHO standard (10 mg·L-1). The concentrations of NO3- in the wet season (May 2014 and July 2015) were slightly lower than those in the dry season (from October 2014 to January 2015) at most sampling sites due to dilution effects. The migration and transformation processes of NO3- were analyzed by comparing the measured and calculated concentrations of NO3- in the Lihu Underground River. In the dry season (from October 2014 to January 2015), the variation in NO3- concentration upstream and midstream of the Lihu Underground River was affected by exogenous input and nitrification. From midstream to the outlet of Xiaolongdong, it is affected by self-purification factors, including physical processes, chemical processes, and biological processes. In the wet season (May 2014 and July 2015), the dilution and mixing effects were the main factors controlling the variation in NO3- concentration in the Lihu Underground River. The contribution rates of potential NO3- sources (incl. atmospheric precipitation (AP), NO3- fertilizer (NF), NH4+ in fertilizer and rainfall (NFA), soil organic nitrogen (SON), and manure and sewage (M&S)) were quantitatively evaluated by using the IsoSource model. The results showed that in May 2014, the main sources of NO3- were M&S and NF, with contribution rates of 46% and 41%, respectively. In October 2014, NO3- sources were M&S with a contribution rate of 47%, followed by NFA with a contribution rate of 31%. In January 2015, NO3- sources in groundwater were M&S, with a contribution rate of 53%, followed by NFA (34%). In July 2015, the main NO3- sources were M&S and NF, whose contribution rates were 54% and 39%, respectively.
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Affiliation(s)
- Peiyan Wu
- China University of Geosciences, Beijing, 100083, China
- Key Laboratory of Karst Dynamics, MLR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China
| | - Qiong Xiao
- Key Laboratory of Karst Dynamics, MLR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China.
| | - Yongli Guo
- Key Laboratory of Karst Dynamics, MLR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China
| | | | - Qiong Yu
- China University of Geosciences, Beijing, 100083, China
- Key Laboratory of Karst Dynamics, MLR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China
| | - Qigang Wang
- Key Laboratory of Karst Dynamics, MLR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China
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Zaryab A, Nassery HR, Knoeller K, Alijani F, Minet E. Determining nitrate pollution sources in the Kabul Plain aquifer (Afghanistan) using stable isotopes and Bayesian stable isotope mixing model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 823:153749. [PMID: 35150690 DOI: 10.1016/j.scitotenv.2022.153749] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 06/14/2023]
Abstract
The Kabul urban aquifer (Afghanistan), which is the main source of drinking water for Kabul city's inhabitants, is highly vulnerable to anthropogenic pollution. In this study, the geochemistry of major ions (including reactive nitrogen species such as NO3-, NO2-, and NH4+) and stable isotope ratios (δ15N-NO3-, δ18O-NO3-, δ18O-H2O, and δ2H-H2O) of surface and groundwater samples from the Kabul Plain were analyzed over two sampling periods (dry and wet seasons). A Bayesian stable isotope mixing model (BSIMM) was also employed to trace potential nitrate sources, transformation processes, and proportional contributions of nitrate sources in the Kabul aquifer. The plotting of δ15N-NO3- against δ18O-NO3̄ (δ15N-NO3- and δ18O-NO3- values ranged from +4.8 to +25.4‰ and from -11.7 to +18.6‰, respectively) suggests that NO3- primarily originated from the nitrification of sewage rather than artificial fertilizer. The plotting of δ15N-NO3- versus NO3-/Cl- ratios also supported the assumption that sewage is the dominant nitrate source. The results indicate that denitrification did not influence the NO3- isotopic composition in the Kabul aquifer. The BSIMM model suggests that nitrate in the dry season originated mainly from sewage (~81%), followed by soil organic N (10.5%), and chemical fertilizer (8.5%). In the wet season, sewage (~87.5%), soil organic N (6.7%), and chemical fertilizer (5.8%) were the main sources of NO3- in the Kabul aquifer. Effective land management measures should be taken to improve the sewage collection system in the Kabul Plain.
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Affiliation(s)
- Abdulhalim Zaryab
- Department of Minerals and Groundwater Resources, Faculty of Earth Sciences, Shahid Beheshti University, Evin Ave, Tehran, Iran; Engineering Geology and Hydrogeology, Faculty of Geology and Mines, Kabul Polytechnic University, District 5, Kabul, Afghanistan
| | - Hamid Reza Nassery
- Department of Minerals and Groundwater Resources, Faculty of Earth Sciences, Shahid Beheshti University, Evin Ave, Tehran, Iran.
| | - Kay Knoeller
- Department Catchment Hydrology, Helmholtz-Centre for Environmental Research - UFZ, D-06120 Halle, Germany
| | - Farshad Alijani
- Department of Minerals and Groundwater Resources, Faculty of Earth Sciences, Shahid Beheshti University, Evin Ave, Tehran, Iran
| | - Eddy Minet
- Environmental Protection Agency (EPA), Dublin, Ireland
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Li J, Zhu D, Zhang S, Yang G, Zhao Y, Zhou C, Lin Y, Zou S. Application of the hydrochemistry, stable isotopes and MixSIAR model to identify nitrate sources and transformations in surface water and groundwater of an intensive agricultural karst wetland in Guilin, China. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 231:113205. [PMID: 35051764 DOI: 10.1016/j.ecoenv.2022.113205] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/05/2022] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
Karst water as the vital water supply source is generally suffered from NO3- contamination in intensive agricultural areas worldwide. Identifying NO3- sources and transformations is the key for understanding nitrogen pathways, and also for effectively controlling diffuse NO3- pollution. In this study, chemical variables and stable isotopes (δ2H-H2O, δ18O-H2O, δ15N-NO3- and δ18O-NO3-) were measured in 10 surface water (SW) samples and 13 groundwater (GW) samples collected from the Huixian karst wetland, with the application of a Bayesian stable isotope mixing model (MixSIAR) to identified NO3- sources and biogeochemical transformations. The results showed that the NO3- concentrations ranged from the below detection limit to 117 mg/L, with 30.8% of GW samples obtained from the north central part of the study area exceeding the maximum permissible limit for drinking water, and posing significant non-carcinogenic health risks for native people through drinking water pathway. Moreover, based on characteristics of the hydrochemistry and stable isotopes, different biogeochemical fates were evaluated in SW and GW: nitrification process was a dominant factor in GW, as a result of high NO3- levels, and this microbial process was unlikely occurred in SW associated with relatively anaerobic condition and low NO3- levels; however, the denitrification might not be a main process of degradation NO3- levels throughout the study area. The MixSIAR outputs revealed that the long-term application of synthetic NH4+ fertilizer (36.6%) and soil organic nitrogen (28.0%) were the main contributors to NO3- pollution, followed by synthetic NO3- fertilizer (16.8%) and domestic sewage and manure (15.1%), whereas NO3- in precipitation (3.44%) played a less important role. Additionally, NO3- concentration was significantly influenced by agricultural activities rather than NO3- source's contribution between SW and GW. This work suggests that synthetic NH4+ fertilizer should be the primary target for control to prevent further NO3- pollution of the karst groundwater.
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Affiliation(s)
- Jun Li
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou 075000, China; Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin 541004, China
| | - Danni Zhu
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin 541004, China
| | - Si Zhang
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou 075000, China
| | - Guoli Yang
- Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou 075000, China
| | - Yi Zhao
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin 541004, China
| | - Changsong Zhou
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin 541004, China
| | - Yongsheng Lin
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin 541004, China
| | - Shengzhang Zou
- Key Laboratory of Karst Dynamics, MNR&GZAR, Institute of Karst Geology, CAGS, Guilin 541004, China.
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10
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Ryu HS, Kang TW, Kim K, Nam TH, Han YU, Kim J, Kim MS, Lim H, Seo KA, Lee K, Yoon SH, Hwang SH, Na EH, Lee JH. Tracking nitrate sources in agricultural-urban watershed using dual stable isotope and Bayesian mixing model approach: Considering N transformation by Lagrangian sampling. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 300:113693. [PMID: 34547573 DOI: 10.1016/j.jenvman.2021.113693] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/16/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
A dual isotopes approach and the Bayesian isotope mixing model were applied to trace nitrogen pollution sources and to quantify their relative contribution to river water quality. We focused on two points to enhance the applicability of the method: 1) Direct measurement on the end-members to distinguish "sewage" and "manure" which used to be grouped in one pollution source as their isotope ranges overlap; 2) The Lagrangian sampling method was applied to consider the transport of nitrogen pollutants in a long river so that any fractionation process can be dealt with in the given Bayesian modeling framework. The results of the analysis confirmed the NO3- isotope composition in the river of interest to be within the range of NO3- with origins in "NH4+ in fertilizer", "Soil N", and "Manure and sewage" pollution. This suggests that nitrogen pollution is mostly attributed to anthropogenic sources. The δ18O NO3 value follows the range +2.5∼+15.0‰, implying that NO3- in the river is mainly derived from nitrification, and possible nitrification in groundwater or waterfront other than surface water. The ratio of the concentration of δ15N NO3 to that of δ18O NO3, and the corresponding regression equation indicates that the denitrification effect in surface water was insignificant during the study period. From the results of the contribution ratio of each source, improving the water quality of the discharge from the sewage treatment plants was proved to be the key factor to reduce nitrogen pollution in the river.
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Affiliation(s)
- Hui-Seong Ryu
- Nakdong River Environment Research Center, National Institute of Environmental Research, Daegu, 43008, Republic of Korea.
| | - Tae-Woo Kang
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Kyunghyun Kim
- Watershed and Total Load Management Research Division, National Institute of Environmental Research, Incheon, 22689, Republic of Korea.
| | - Tae-Hui Nam
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Yeong-Un Han
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Jihyun Kim
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Min-Seob Kim
- Environmental Measurement and Analysis Center, National Institute of Environmental Research, Incheon, 22689, Republic of Korea.
| | - Hyejung Lim
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Kyung-Ae Seo
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Kyounghee Lee
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Suk-Hee Yoon
- Environmental Measurement and Analysis Center, National Institute of Environmental Research, Incheon, 22689, Republic of Korea.
| | - Soon Hong Hwang
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Eun Hye Na
- Yeongsan River Environment Research Center, National Institute of Environmental Research, Gwangju, 61011, Republic of Korea.
| | - Jung Ho Lee
- Department of Biology Education, Daegu University, Kyeongsangbuk-do, 38453, Republic of Korea.
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11
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Hu J, Pan M, Han T, Zhuang Z, Cao Y, Yang K, Li Y, Liu W. Identification of nitrate sources in the Jing River using dual stable isotopes, Northwest China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:68633-68641. [PMID: 34273081 DOI: 10.1007/s11356-021-15380-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
Nitrate (NO3-) contamination has become a dominant international problem in the aquatic environment, so identifying the sources and transformations of NO3- is the basis for improving water quality. Since the Jing River is the largest tributary of the Wei River, to understand its water quality, this study collected surface water samples from the Shaanxi section of the Jing River during the dry season. The potential sources of NO3- were analyzed by hydrochemical and bi-isotopic methods, and the SIAR model was used to estimate the proportional contribution of each source. Results indicated that NO3--N was the main form of inorganic nitrogen in this area, and the average total nitrogen content was 10.23 mg·L-1, which showed that nitrogen pollution was highly serious; the transformation process of nitrogen in this study area was mainly nitrification; The results of Bayesian model showed that manure and sewage contributed to the most NO3- (64.39%) in the dry season, followed by soil nitrogen, which was 26.35%. These results help to adopt better nitrogen management measures to meet the national environmental quality standards for surface water.
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Affiliation(s)
- Jing Hu
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China
| | - Mengyan Pan
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, School of Water and Environment, Chang' an University, Xi'an, 710054, China
| | - Tianhao Han
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, School of Water and Environment, Chang' an University, Xi'an, 710054, China
| | - Zhi Zhuang
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, School of Water and Environment, Chang' an University, Xi'an, 710054, China
| | - Yunning Cao
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China
| | - Kaili Yang
- Xi'an Institute for Innovative Earth Environment Research, Xi'an, 710061, China
| | - Yuliang Li
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, School of Water and Environment, Chang' an University, Xi'an, 710054, China.
| | - Weiguo Liu
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
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12
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Niu C, Zhai T, Zhang Q, Wang H, Xiao L. Research Advances in the Analysis of Nitrate Pollution Sources in a Freshwater Environment Using δ 15N-NO 3- and δ 18O-NO 3. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182211805. [PMID: 34831560 PMCID: PMC8623930 DOI: 10.3390/ijerph182211805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 11/16/2022]
Abstract
Nitrate is usually the main pollution factor in the river water and groundwater environment because it has the characteristics of stable properties, high solubility and easy migration. In order to ensure the safety of water supply and effectively control nitrate pollution, it is very important to accurately identify the pollution sources of nitrate in freshwater environment. At present, as the most accurate source analysis method, isotope technology is widely used to identify the pollution sources of nitrate in water environment. However, the complexity of nitrate pollution sources and nitrogen migration and transformation in the water environment, coupled with the isotopic fractionation, has changed the nitrogen and oxygen isotopic values of nitrate in the initial water body, resulting in certain limitations in the application of this technology. This review systematically summarized the typical δ15N and δ18O-NO3- ranges of NO3- sources, described the progress in the application of isotope technique to identify nitrate pollution sources in water environment, analyzed the application of isotope technique in identifying the migration and transformation of nitrogen in water environment, and introduced the method of quantitative source apportionment. Lastly, we discussed the deficiency of isotope technique in nitrate pollution source identification and described the future development direction of the pollution source apportionment of nitrate in water environment.
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Affiliation(s)
- Chao Niu
- College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China; (C.N.); (L.X.)
| | - Tianlun Zhai
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China;
| | - Qianqian Zhang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China;
- Correspondence: (Q.Z.); (H.W.)
| | - Huiwei Wang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China;
- Correspondence: (Q.Z.); (H.W.)
| | - Lele Xiao
- College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China; (C.N.); (L.X.)
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13
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Jiang H, Zhang Q, Liu W, Zhang J, Zhao T, Xu Z. Climatic and anthropogenic driving forces of the nitrogen cycling in a subtropical river basin. ENVIRONMENTAL RESEARCH 2021; 194:110721. [PMID: 33421426 DOI: 10.1016/j.envres.2021.110721] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/06/2020] [Accepted: 01/02/2021] [Indexed: 06/12/2023]
Abstract
To date, basin-scale understanding of nitrogen (N) cycling is lacking, which undermines riverine N pollution control efforts. Applying a multiple-isotopic approach, this study provided insights into the impacts of climate and anthropogenic activities on the N cycling at a basin scale. The isotopic compositions of the river water were regulated by a simple mixing process in winter, while unconservative processes (nitrification and denitrification) occurred in warm seasons. Denitrification dominated the N transformations in summer, while coupled nitrification-denitrification in soils after fertilization was responsible for the isotopic fractionations in spring and autumn. While at least 58.7% of the nitrate (NO3-) was removed from the basin, the NO3- loadings in the river remained high, suggesting that the ecosystem services could not balance the anthropogenic pollution. After correcting the isotopic fractionations, the sources of the riverine NO3- were quantified by a Markov chain Monte Carlo isotope mixing model. The contributions of point sources versus non-point sources changed dynamically with the precipitation and fertilization patterns. In summer and autumn, the soil organic N and chemical fertilizer dominated the riverine NO3-, with total contributions of 75.9% and 74.6%, respectively. The contributions from sewage and manure significantly increased during spring (47.9%) and winter (50.2%). Overall, the annual NO3- fluxes were from SON (28.7%), CF (28.1%), DS (18.2%), MA (23.9%), and AP (1.1%). In addition, we presented the large uncertainties in source apportionment that arose from the ignorance of isotope fractionations, highlighting the importance of considering the effect of isotopic fractionations in N source apportionment studies.
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Affiliation(s)
- Hao Jiang
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qianqian Zhang
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenjing Liu
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiangyi Zhang
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tong Zhao
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhifang Xu
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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14
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Jiang H, Liu W, Zhang J, Zhou L, Zhou X, Pan K, Zhao T, Wang Y, Xu Z. Spatiotemporal variations of nitrate sources and dynamics in a typical agricultural riverine system under monsoon climate. J Environ Sci (China) 2020; 93:98-108. [PMID: 32446463 DOI: 10.1016/j.jes.2020.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/14/2020] [Accepted: 03/15/2020] [Indexed: 06/11/2023]
Abstract
Nitrogen pollution is a serious environmental issue in the Danjiangkou Reservoir region (DRR), the water source of the South-to-North Water Diversion Project of China. In this research, seasonal surveys and a bi-weekly time series survey were conducted in the Qihe River Basin, one of the most densely populated agricultural basins in the DRR. Hydrochemical compositions (NO3- and Cl-), dual isotopes (δD-H2O, δ18O-H2O, δ15N-NO3-, and δ18O-NO3-), and a Markov Chain Monte Carlo isotope mixing model were jointly applied to unravel the sources, migrations, and transformations of the nitrate (NO3-) in the basin. It was revealed that the mixing between different sources was the main process controlling the isotopic compositions of the riverine NO3- in the upper-middle reaches. In contrast, denitrification occurred in the lower reaches. For the first time, the sources of NO3- were quantified at a basin scale in the DRR. Overall, the river transported 484.2 tons/year of NO3-N to the reservoir, of which 32.6%, 36.4%, 28.0%, and 3.0% was from soil organic nitrogen, chemical fertilizer, residential sewage and atmospheric precipitation, respectively. The NO3-N fluxes of the different sources were regulated by the monsoon climate and anthropogenic activities. For example, high precipitation and intense fertilization resulted in severe nonpoint source pollution. Denitrification thrived in soils and reservoirs in wet seasons. Temperature could regulate the migration, nitrification and denitrification processes. Based on the results, we suggest that the management strategies dealing with nitrogen pollution issue in the DRR should follow the specific spatiotemporal characteristics of NO3- sources, migration and transformation mechanisms.
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Affiliation(s)
- Hao Jiang
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China
| | - Wenjing Liu
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiangyi Zhang
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Zhou
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Xiaode Zhou
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ke Pan
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Tong Zhao
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yuchen Wang
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhifang Xu
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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15
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Nyilitya B, Mureithi S, Boeckx P. Land use controls Kenyan riverine nitrate discharge into Lake Victoria - evidence from Nyando, Nzoia and Sondu Miriu river catchments. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2020; 56:170-192. [PMID: 32067475 DOI: 10.1080/10256016.2020.1724999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/14/2019] [Indexed: 06/10/2023]
Abstract
Nitrate (NO3-) sources and discharge were investigated using isotope and hydrochemical analyses in three river catchments draining Lake Victoria basin, Kenya. Hierarchical cluster analysis grouped Nyando, Nzoia and Sondu Miriu River stations into clusters corresponding to major land use classes of the catchments. Mixed agriculture (MA) in Nyando showed higher NO3- compared to the other land uses. Nitrate levels obtained (0.1-11.6 mg L-1) are higher than those reported in previous studies. Hydrochemistry support isotope data indicating that ammonium-based fertilizers and soil N were the major NO3- sources in tea dominated areas with average δ15N (6.5 ± 1.3 ‰), δ18O (6.7 ± 2.3 ‰) values. Manure/sewage were the main source in MA areas with average δ15N (8.4 ± 2.4 ‰), δ18O (7.8 ± 5.4 ‰) values. Sewage was the likely source in urban, residential & industrial areas recording average δ15N (10.0 ± 2.4 ‰), δ18O (6.9 ± 3.7 ‰) values. δ15N between land uses were significantly different (p < 0.0001) while δ18O were similar (p = 0.4). Seasonally, inorganic/organic fertilizers influenced river NO3- mostly in the wet cropping season. Lower NO3- concentrations observed in Nyando and Sondu Miriu during dry or start-wet season could be a result of in situ denitrification.
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Affiliation(s)
- Benjamin Nyilitya
- Isotope Bioscience Laboratory - ISOFYS, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
- Department of Land Resource Management and Agricultural Technology, University of Nairobi, Nairobi, Kenya
| | - Stephen Mureithi
- Department of Land Resource Management and Agricultural Technology, University of Nairobi, Nairobi, Kenya
| | - Pascal Boeckx
- Isotope Bioscience Laboratory - ISOFYS, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
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16
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Zhang Q, Wang H. Assessment of sources and transformation of nitrate in the alluvial-pluvial fan region of north China using a multi-isotope approach. J Environ Sci (China) 2020; 89:9-22. [PMID: 31892404 DOI: 10.1016/j.jes.2019.09.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/19/2019] [Accepted: 09/19/2019] [Indexed: 06/10/2023]
Abstract
A multi-isotope approach and mixing model were combined to identify spatial and seasonal variations of sources, and their proportional contribution to nitrate in the Hutuo River alluvial-pluvial fan region. The results showed that the NO3- concentration was significantly higher in the Hutuo River valley plain (178.7 mg/L) region than that in the upper and central pluvial fans of the Hutuo River (82.1 mg/L and 71.0 mg/L, respectively) and in the river (17.0 mg/L). Different land use types had no significant effect on the groundwater nitrate concentration. Based on a multi-isotope approach, we confirmed that the main sources of groundwater nitrate in different land use areas were domestic sewage and manure, followed by soil nitrogen, ammonia fertilizer, nitrate fertilizer and rainwater, and there were no significant spatial or seasonal variations. Combining δ15N-NO3-, δ18O-NO3- and δ37Cl results can increase the accuracy of traceability. Nitrification could be the most important nitrogen migration and transformation process, and denitrification did not significantly affected the isotopic composition of the nitrate. The SIAR model outputs revealed that the main nitrate pollution sources in groundwater and river water were domestic sewage and manure, accounting for 55.9%-61.0% and 22.6% (dry season), 50.3%-60.4% and 34.1% (transition season), 42.7%-47.6% and 35.6% (wet season 2016) and 45.9%-46.7% and 38.4% (wet season 2017), respectively. This work suggests that the random discharge and disposal of domestic sewage and manure should be the first target for control in order to prevent further nitrate contamination of the water environment.
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Affiliation(s)
- Qianqian Zhang
- Hebei and China Geological Survey Key Laboratory of Groundwater Remediation, Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
| | - Huiwei Wang
- Hebei and China Geological Survey Key Laboratory of Groundwater Remediation, Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
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17
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Duprey NN, Wang TX, Kim T, Cybulski JD, Vonhof HB, Crutzen PJ, Haug GH, Sigman DM, Martínez-García A, Baker DM. Megacity development and the demise of coastal coral communities: Evidence from coral skeleton δ 15 N records in the Pearl River estuary. GLOBAL CHANGE BIOLOGY 2020; 26:1338-1353. [PMID: 31732999 DOI: 10.1111/gcb.14923] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 06/10/2023]
Abstract
Historical coral skeleton (CS) δ18 O and δ15 N records were produced from samples recovered from sedimentary deposits, held in natural history museum collections, and cored into modern coral heads. These records were used to assess the influence of global warming and regional eutrophication, respectively, on the decline of coastal coral communities following the development of the Pearl River Delta (PRD) megacity, China. We find that, until 2007, ocean warming was not a major threat to coral communities in the Pearl River estuary; instead, nitrogen (N) inputs dominated impacts. The high but stable CS-δ15 N values (9‰-12‰ vs. air) observed from the mid-Holocene until 1980 indicate that soil and stream denitrification reduced and modulated the hydrologic inputs of N, blunting the rise in coastal N sources during the early phase of the Pearl River estuary urbanization. However, an unprecedented CS-δ15 N peak was observed from 1987 to 1993 (>13‰ vs. air), concomitant to an increase of NH4+ concentration, consistent with the rapid Pearl River estuary urbanization as the main cause for this eutrophication event. We suggest that widespread discharge of domestic sewage entered directly into the estuary, preventing removal by natural denitrification hotspots. We argue that this event caused the dramatic decline of the Pearl River estuary coral communities reported from 1980 to 2000. Subsequently, the coral record shows that the implementation of improved wastewater management policies succeeded in bringing down both CS-δ15 N and NH4+ concentrations in the early 2000s. This study points to the potential importance of eutrophication over ocean warming in coral decline along urbanized coastlines and in particular in the vicinity of megacities.
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Affiliation(s)
- Nicolas N Duprey
- Max Planck Institute for Chemistry, Otto Hahn Institute, Mainz, Germany
- The Swire Institute of Marine Science, The University of Hong Kong, Shek O, HKSAR
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, HKSAR
| | - Tony X Wang
- Department of Geosciences, Princeton University, Princeton, NJ, USA
- Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA, USA
| | - Taihun Kim
- The Swire Institute of Marine Science, The University of Hong Kong, Shek O, HKSAR
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, HKSAR
| | - Jonathan D Cybulski
- The Swire Institute of Marine Science, The University of Hong Kong, Shek O, HKSAR
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, HKSAR
| | - Hubert B Vonhof
- Max Planck Institute for Chemistry, Otto Hahn Institute, Mainz, Germany
| | - Paul J Crutzen
- Max Planck Institute for Chemistry, Otto Hahn Institute, Mainz, Germany
| | - Gerald H Haug
- Max Planck Institute for Chemistry, Otto Hahn Institute, Mainz, Germany
| | - Daniel M Sigman
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | | | - David M Baker
- The Swire Institute of Marine Science, The University of Hong Kong, Shek O, HKSAR
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, HKSAR
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18
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Kruk MK, Mayer B, Nightingale M, Laceby JP. Tracing nitrate sources with a combined isotope approach (δ 15N NO3, δ 18O NO3 and δ 11B) in a large mixed-use watershed in southern Alberta, Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:135043. [PMID: 31759727 DOI: 10.1016/j.scitotenv.2019.135043] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
Rapid population growth and land-use intensification over the last century have resulted in a substantial increase in nutrient loads degrading marine and freshwater ecosystems worldwide. In mixed-use watersheds, elevated nitrogen loads from wastewater treatment plant (WWTP) effluent or agricultural runoff often drive the eutrophication of waterways. Accordingly, the objective of this research was to identify sources of riverine nitrate (NO3), a deleterious dissolved species of nitrogen, with a combined isotopic tracing technique in the Bow River and the Oldman River in Alberta, Canada. Riverine NO3 and boron (B) concentrations, mean daily flux and δ15NNO3, δ18ONO3, and δ11B values were determined at 17 mainstem sites during high and low discharge periods in 2014 and 2015. The data for mainstem sites were then compared to results for effluent from seven WWTPs, eight synthetic fertilizers, cow manure, and three predominantly agricultural tributary sites to estimate point and non-point NO3 sources. The NO3 flux, δ15NNO3 and δ18ONO3 values indicated the city of Calgary's Bonnybrook WWTP effluent accounts for the majority of the NO3 flux in the Bow River downstream of Calgary. δ15NNO3 and δ11B values in the Bow River highlighted an increase in agricultural NO3 loading downstream of irrigation return-flows. A three-fold decrease in the NO3:B flux ratio indicated NO3-removal processes are active in the lower reaches of the Bow River. For the Oldman River, δ11B values revealed elevated nutrient loading from the Lethbridge WWTP effluent (10% of downstream B flux). Furthermore, the agricultural tributaries contributed 25% of the local B flux to the Oldman River. Overall, δ11B was proven to be an effective co-tracer for discriminating between urban and agricultural sources of NO3 in these large mixed-use watersheds. This combined isotope tracing approach has significant potential to identify point and non-point NO3 sources driving eutrophication around the world.
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Affiliation(s)
- M K Kruk
- Applied Geochemistry Group, Department of Geoscience, University of Calgary, Calgary, Alberta, Canada; Resource Stewardship Division, Alberta Environment & Parks, Government of Alberta, Calgary, Alberta, Canada.
| | - B Mayer
- Applied Geochemistry Group, Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
| | - M Nightingale
- Applied Geochemistry Group, Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
| | - J P Laceby
- Resource Stewardship Division, Alberta Environment & Parks, Government of Alberta, Calgary, Alberta, Canada
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19
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Samanta P, Shin S, Jang S, Song YC, Oh S, Kim JK. Stable carbon and nitrogen isotopic characterization and tracing nutrient sources of Ulva blooms around Jeju coastal areas. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:113033. [PMID: 31421580 DOI: 10.1016/j.envpol.2019.113033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/30/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
The present investigation was aimed to characterize the Ulva blooms and to identify the probable sources for Ulva blooms along the Jeju Island coast for pertinent control measures. Algal isotope signatures (δ13C, δ15N and δ18O) and tissue nitrogen and carbon were analyzed to map nutrient sources around the Jeju coastal areas. The algal δ13C values were ranged from -20.52 to -4.39‰, while δ15N and δ18O values ranged from 4.26 to 8.29‰ and 12.80-17.34‰, respectively. Moreover, site-specific significant differences were observed in algal stable isotope (δ13C, δ15N and δ18O) values. The bi-plot (δ15N vs δ18O) diagram indicated four dominant nitrogen sources along the Jeju coast, with 1) soil organic nitrogen mixed with livestock wastes (spring water samples and E), the 2) synthetic fertilizer input (A3 and B2), 3) sewage discharge (D1, D2 and I3) and 4) aquaculture waste (fish farm samples, A4, A5, B1, G and I2). Present findings revealed the different potential nitrogen sources for localized increase of algal growth along the Jeju coast. Finally, the present findings could be used as baseline data for efficient nutrient management to remediate Ulva blooms along Jeju coastal environment.
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Affiliation(s)
- Palas Samanta
- Research Institute of Basic Sciences, Incheon National University, Incheon 22012, South Korea; Department of Marine Science, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, South Korea
| | - Sookkyung Shin
- Research Institute of Basic Sciences, Incheon National University, Incheon 22012, South Korea; Department of Marine Science, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, South Korea
| | - Sojin Jang
- Research Institute of Basic Sciences, Incheon National University, Incheon 22012, South Korea; Department of Marine Science, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, South Korea
| | - Young-Cheol Song
- Research Institute of Health and Environment, Jeju Special Self-Governing Province, 41 Samdong-gil, Jeju, Jejul Special Self-Governing Province, 63152, South Korea
| | - Sangsil Oh
- Research Institute of Health and Environment, Jeju Special Self-Governing Province, 41 Samdong-gil, Jeju, Jejul Special Self-Governing Province, 63152, South Korea
| | - Jang K Kim
- Research Institute of Basic Sciences, Incheon National University, Incheon 22012, South Korea; Department of Marine Science, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, South Korea.
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20
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Sugimoto R, Tsuboi T, Fujita MS. Comprehensive and quantitative assessment of nitrate dynamics in two contrasting forested basins along the Sea of Japan using dual isotopes of nitrate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 687:667-678. [PMID: 31220720 DOI: 10.1016/j.scitotenv.2019.06.090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 06/05/2019] [Accepted: 06/06/2019] [Indexed: 06/09/2023]
Abstract
The recent deposition rates of atmospheric nitrate derived from east Asia to the Japanese forested watershed facing the Sea of Japan are of serious concern. However, export ratios and the seasonality of atmospheric nitrate versus microbial nitrate from forest soils to upstreams have not yet been quantified. Furthermore, the influence of local nitrogen sources and internal biogeochemical processes are still unclear. To determine the influence of watershed properties and atmospheric nitrogen deposition on nitrate dynamics in two adjacent basins (the Kita and Minami Rivers) located in central Japan, we conducted seasonal synoptic surveys using the dual isotopes of nitrate. It was found that nitrate regenerated through nitrification in the forest soil was likely the dominant nitrogen source in both basins from the upstream to downstream waters. However, nitrate concentrations and the direct leaching ratio of atmospheric nitrate were considerably higher in the Kita River Basin than in the Minami River Basin, possibly due to the difference in forest environments. In the Kita River Basin, geographic trait such as altitude may be one factor regulating the sensitivity of forest ecosystem to nitrogen deposition. Quantitative assessments of nitrate outflows from the sub-basins revealed that nitrogen leached from the forest soil was a major source (61-81%) of nitrate loading to the coastal sea.
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Affiliation(s)
- R Sugimoto
- Research Center for Marine Bioresources, Fukui Prefectural University, Obama, Fukui 917-0116, Japan.
| | - T Tsuboi
- Research Center for Marine Bioresources, Fukui Prefectural University, Obama, Fukui 917-0116, Japan
| | - M S Fujita
- Center for Southeast Asian Studies, Kyoto University, Kyoto 606-8501, Japan
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21
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Hu M, Wang Y, Du P, Shui Y, Cai A, Lv C, Bao Y, Li Y, Li S, Zhang P. Tracing the sources of nitrate in the rivers and lakes of the southern areas of the Tibetan Plateau using dual nitrate isotopes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 658:132-140. [PMID: 30577012 DOI: 10.1016/j.scitotenv.2018.12.149] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 12/06/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
Based on a quantitative analysis of nitrate concentrations, the nitrate sources and temporal variability of the rivers, lakes, and wetlands of Tibet were assessed for the first time using dual isotope technology. Water samples were collected once in July 2017 for analysis of nitrate concentration and isotopic composition. The overall values of δ15N-NO3- and δ18O-NO3- ranged from +1.8‰ to +23.0‰, and from -6.3‰ to +22.2‰ respectively. Duel isotopic composition suggested that nitrification of soil organic nitrogen was the main source of nitrate in the Yalu Tsangpo River. Furthermore, anthropogenic nitrogen inputs become more important in downstream than upstream because of intensive agricultural activities and urban input. In the rivers of the Ngari District, nitrate is mainly derived from desert deposits, manure and sewage, and chemical fertilisers. Different rivers show different characteristics of nitrate sources depending on the location, topography, landform, and climate of the river basins. Animal manure, nitrification of soil organic matter, and desert deposits are mainly responsible for the shifting of nitrate isotopic signatures in lakes, which are minimally affected by human activities. In wetlands, biological nitrification and denitrification could be the main processes of nitrogen migration and transformation. These results provide useful information in revealing the fate of nitrate in different aquatic ecosystems and different areas of Tibet.
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Affiliation(s)
- Mingming Hu
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 10038, China; Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 10038, China
| | - Yuchun Wang
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 10038, China; Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 10038, China.
| | - Pengcheng Du
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 10038, China; China Three Gorges University, Yichang 443002, China
| | - Yong Shui
- The Tibet Autonomous Region Hydrology and Water Resources Survey, Tibet Autonomous Region 850000, China
| | - Aimin Cai
- China Three Gorges University, Yichang 443002, China
| | - Cong Lv
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 10038, China
| | - Yufei Bao
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 10038, China; Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 10038, China
| | - Yanhui Li
- Taiyuan Normal University, Taiyuan 030619, China
| | - Shanze Li
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 10038, China; Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 10038, China
| | - Panwei Zhang
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 10038, China; Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 10038, China
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22
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Yang P, Li Y, Groves C, Hong A. Coupled hydrogeochemical evaluation of a vulnerable karst aquifer impacted by septic effluent in a protected natural area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 658:1475-1484. [PMID: 30678006 DOI: 10.1016/j.scitotenv.2018.12.172] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/26/2018] [Accepted: 12/11/2018] [Indexed: 06/09/2023]
Abstract
Karst aquifers are highly vulnerable to pollution from human activities. Among sources of these contaminants, septic tank effluent can easily pollute karst aquifers, especially concentrated inputs such as those, for example, from tourist hotels. However, the impacts of septic effluent from relatively large, concentrated inputs on karst aquifers have seldom been assessed previously and therefore provide the focus of this study. Artificial tracer tests, geochemical analysis, and dual nitrate stable isotopes were employed to evaluate the impacts of a concentrated input of septic effluent from the Jinfoshan Holiday Hotel (JHH) on the vulnerable Shuifang Spring (SFS) karst aquifer in a remote mountainous area, the Jinfoshan Karst World Heritage Site within Chongqing Municipality of southwest China. The results of artificial tracer tests showed that the underground flow mainly occurred in a primary conduit with a pooled or bifurcated flow path that connects a sinkhole input to SFS. The high tracer recovery rates suggest that the karst aquifer was characterized by high intrinsic vulnerability to contamination. Chemographs at SFS responded rapidly to the episodic release of effluent from JHH. Decreased pH and dissolved oxygen and elevated turbidity, specific conductance and NH4+ concentrations of SFS resulted from the episodic release of septic tank effluent from the JHH during high-use periods. Although the nitrate concentrations were far below the guideline value of the Standard for Groundwater Quality of China, the isotopes of δ15NNO3 and δ18ONO3 suggest that nitrate flowing from SFS was primarily derived from manure and sewage, in addition to soil organic N. Thus, episodic release of septic effluent provides a challenge to the sustainability of karst groundwater management. The results of this study may be relevant to other remote and mountainous karst environments where tourism provide otherwise scarce economic resources and particularly to protected sites throughout the world.
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Affiliation(s)
- Pingheng Yang
- Field Scientific Observation & Research Base of Karst Eco-Environments at Nanchuan in Chongqing, Ministry of Natural Resources of the People's Republic of China, School of Geographical Sciences, Southwest University, Chongqing 400715, China; Crawford Hydrology Laboratory, Department of Geography and Geology, Western Kentucky University, Bowling Green, KY 42101, USA.
| | - Ying Li
- Field Scientific Observation & Research Base of Karst Eco-Environments at Nanchuan in Chongqing, Ministry of Natural Resources of the People's Republic of China, School of Geographical Sciences, Southwest University, Chongqing 400715, China
| | - Chris Groves
- Crawford Hydrology Laboratory, Department of Geography and Geology, Western Kentucky University, Bowling Green, KY 42101, USA.
| | - Aihua Hong
- The Laboratory of Chongqing Groundwater Resource Utilization and Environmental Protection, Chongqing 401121, China
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23
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Ding J, Xi B, Xu Q, Meng H, Shen Y, Cheng H. Isotopic evidence of nitrate sources and its transformations in a human-impacted watershed. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:575-583. [PMID: 30758007 DOI: 10.1039/c8em00424b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The considerable spatial and temporal variabilities of nitrogen (N) processing introduce large uncertainties for quantifying N cycles on a large scale, particularly in plain river network regions with complicated hydrographic connections and mixed multiple N sources. In this paper, the dual isotopes δ15N and δ18O and dissolved anions in regularly collected samples (n = 10) from the studied river, which is one of the most seriously polluted rivers in the plain river network regions of the Taihu Lake catchment, were analyzed to ascertain the main nitrate (NO3-) sources and watershed N processing in the context of monsoon climate. The seasonal variations in precipitation, temperature, and hydrology play key roles in the regulation of the river NO3- concentration, NO3- sources, and watershed N processing. Nitrification of N-containing materials in the soil was possibly the major source of NO3- all year round, especially in the rainy season, whereas manure and sewage significantly contributed to the NO3- load in the Taige River in the dry season. Nitrification and denitrification processes within the area were closely related. The significant negative relationship between the water temperature and δ18O-NO3- values indicated the occurrence of nitrification in the soil throughout the year. By contrast, seasonal variations of denitrification were apparent from May to July with the high soil temperature and moisture, thereby indicating the occurrence of denitrification (22.9%) within the watershed. After the assessment of temporal variations of NO3- sources and watershed N processing, improved environmental management practices can be implemented to protect water resources and prevent further water quality deterioration in human-impacted watersheds.
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Affiliation(s)
- Jingtao Ding
- Institute of Energy and Environmental Protection, Chinese Academy of Agricultural Engineering Planning & Design, Beijing 100125, China.
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24
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Parra Suárez S, Peiffer S, Gebauer G. Origin and fate of nitrate runoff in an agricultural catchment: Haean, South Korea - Comparison of two extremely different monsoon seasons. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 648:66-79. [PMID: 30114590 DOI: 10.1016/j.scitotenv.2018.08.115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 08/08/2018] [Accepted: 08/08/2018] [Indexed: 06/08/2023]
Abstract
The monsoon season in South Korea has great influences on biogeochemical and hydrological processes in the entire country, but is specifically of concern in the Soyang lake watershed, the main drinking water reservoir for the 20-million-people metropolis Seoul. Therefore, water quality and nitrate concentration control in Lake Soyang is of high public priority. The Haean catchment is the most prominent agriculture-dominated sub-catchment of the Soyang lake watershed. It is a complex terrain influenced by extreme rain events and non-point nitrate sources. In this investigation we used input-output calculations and a stable isotope approach to quantify and determinate the origin of nitrate inputs into the rivers that later flow into the lake. During pre-monsoon and monsoon seasons in 2013 and 2014 we measured daily rainfall and river water discharge within the Haean catchment and collected rain, river water and groundwater samples in order to analyze nitrate concentrations and nitrate nitrogen and oxygen isotope abundances. Furthermore, we collected nitrogen fertilizers as applied in the catchment. Heavy monsoon events, as in 2013, were the most pronounced drivers of nitrate leaching being responsible for >80% of the nitrate output in the river runoff. On the other hand, an almost missing summer monsoon in 2014 drove the nitrate runoff in a different manner, being responsible for only 0.4% of the total nitrate nitrogen river discharge in the previous year. Results of nitrate nitrogen and oxygen isotope abundance analyses suggest soil microbial nitrification as the most important contributor to the nitrate in the river runoff. In addition, nitrate from groundwater partially affected by microbial denitrification contributed to the nitrate in the runoff due to river-aquifer exchange fluxes during the monsoon season. Direct leaching of nitrate from mineral fertilizers and atmospheric nitrate deposition were obviously only minor contributors to the nitrate in the runoff.
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Affiliation(s)
- Silvia Parra Suárez
- Laboratory of Isotope Biogeochemistry, Bayreuth Center of Ecology and Environmental Research - BayCEER, University of Bayreuth, 95440 Bayreuth, Germany
| | - Stefan Peiffer
- Department of Hydrology, Bayreuth Center of Ecology and Environmental Research - BayCEER, University of Bayreuth, 95440 Bayreuth, Germany
| | - Gerhard Gebauer
- Laboratory of Isotope Biogeochemistry, Bayreuth Center of Ecology and Environmental Research - BayCEER, University of Bayreuth, 95440 Bayreuth, Germany.
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25
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Qin Y, Zhang D, Wang F. Using nitrogen and oxygen isotopes to access sources and transformations of nitrogen in the Qinhe Basin, North China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:738-748. [PMID: 30414029 DOI: 10.1007/s11356-018-3660-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 11/01/2018] [Indexed: 06/08/2023]
Abstract
Nitrate pollution in water is a common environmental problem worldwide. The Qinhe Basin (QHB) faces with the risk of eutrophication. To clarify nitrate pollution of river water, water chemical data, water isotope values (δD and δ18O-H2O), and dual nitrate isotope values (δ15N-NO3- and δ18O-NO3-) were used to discern sources and transformation mechanisms of nitrogen in the QHB. The nitrate concentrations of river water ranged from 0.71 to 20.81 mg L-1. The δD and δ18O-H2O values of river water varied from - 74 to -52‰ and from - 10.8 to - 7.2‰, with an average value of - 60‰ and - 8.2‰, respectively. The δ15N-NO3- and δ18O-NO3- values of nitrate ranged from - 6.7 to + 14.8‰ and from - 6.0 to + 5.6‰, with a mean value of + 4.6‰ and - 0.6‰, respectively. Assimilation by algae and the mixing of soil nitrogen, chemical fertilizer, sewage, and industrial wastewater could account for increasing δ15N-NO3- values. There was neither significantly positive nor negative correlation between δ15N-NO3- and δ18O-NO3- in river water, indicating that no obvious denitrification shifted isotopic values of nitrate in the QHB. Based on the dual isotopic values of nitrate and land use change in the watershed, it could be concluded that intensive nitrification dominated in the QHB, and dissolved nitrate was mainly derived from nitrification of ammonium in fertilizer, soil nitrogen, and domestic sewage. As the primary nitrate sources identified in the QHB, effective fertilization and afforestation can be taken to protect water resource from nitrate pollution.
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Affiliation(s)
- Yong Qin
- School of Environmental and Chemical Engineering, Shanghai University, No.99, Shangda Road, Baoshan District, Shanghai, 200444, China
| | - Dong Zhang
- School of Resources & Environment, Henan Polytechnic University, No.2001, Shiji Road, Jiaozuo, 454000, Henan, China.
| | - Fushun Wang
- School of Environmental and Chemical Engineering, Shanghai University, No.99, Shangda Road, Baoshan District, Shanghai, 200444, China
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26
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Li C, Li SL, Yue FJ, Liu J, Zhong J, Yan ZF, Zhang RC, Wang ZJ, Xu S. Identification of sources and transformations of nitrate in the Xijiang River using nitrate isotopes and Bayesian model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 646:801-810. [PMID: 30064106 DOI: 10.1016/j.scitotenv.2018.07.345] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 07/24/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
Coupled nitrogen and oxygen isotopes of nitrate have proven useful in identifying nitrate sources and transformation in rivers. However, isotopic fractionation and low-resolution monitoring limit the accurate estimation of nitrate dynamics. In the present study, the spatio-temporal variations of nitrate isotopes (15N and 18O) and hydrochemical compositions (NO3- and Cl-) of river water were examined to understand nitrate sources in the Xijiang River, China. High-frequency sampling campaigns and isotopic analysis were performed at the mouth of the Xijiang River to capture temporal nitrate variabilities. The overall values of δ15N-NO3- and δ18O-NO3- ranged from +4.4‰ to +14.1‰ and from -0.3‰ to +6.8‰, respectively. The results of nitrate isotopes indicated that NO3- mainly originated from soil organic nitrogen (SON), chemical fertilizer (CF), and manure and sewage wastes (M&S). The negative correlation of nitrate isotopic values with NO3-/Cl- ratios suggested the importance of denitrification in NO3- loss. The results of Bayesian model with incorporation of isotopic fractionation during the denitrification showed that SON and CF contributed to the most (72-73%) nitrate in the wet season; whereas approximately 58% of nitrate was derived from anthropogenic inputs (M&S and CF) in the dry season. The nitrate flux was 2.08 × 105 tons N yr-1 during one hydrologic year between 2013 and 2014, with 86% occurring in the wet season. Long-term fluctuations in nitrate flux indicated that nitrate export increased significantly over the past 35 years, and was significantly correlated with nitrate concentrations. The seasonal pattern of nitrate dynamics indicated the mixing of nitrified NO3- and denitrified NO3- between surface flow and groundwater flow under different hydrological conditions. Overall, the present study quantitatively evaluates the spatio-temporal variations in nitrate sources in a subtropical watershed, and the high-frequency monitoring gives a better estimate of nitrate exports and proportional contributions of nitrate sources.
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Affiliation(s)
- Cai Li
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Si-Liang Li
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
| | - Fu-Jun Yue
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Jing Liu
- School of Management Science, Guizhou University of Finance and Economics, Guiyang 550025, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Jun Zhong
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Zhi-Feng Yan
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Ruo-Chun Zhang
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Zhong-Jun Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Sen Xu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
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Erostate M, Huneau F, Garel E, Lehmann MF, Kuhn T, Aquilina L, Vergnaud-Ayraud V, Labasque T, Santoni S, Robert S, Provitolo D, Pasqualini V. Delayed nitrate dispersion within a coastal aquifer provides constraints on land-use evolution and nitrate contamination in the past. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:928-940. [PMID: 30743890 DOI: 10.1016/j.scitotenv.2018.06.375] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/27/2018] [Accepted: 06/29/2018] [Indexed: 06/09/2023]
Abstract
Identifying sources of anthropogenic pollution, and assessing the fate and residence time of pollutants in aquifers is important for the management of groundwater resources, and the ecological health of groundwater dependent ecosystems. This study investigates anthropogenic contamination in the shallow alluvial aquifer of the Marana-Casinca, hydraulically connected to the Biguglia lagoon (Corsica, France). A multi-tracer approach, combining geochemical and environmental isotopic data (δ18O-H2O, δ2H-H2O, 3H, δ15N-NO3-, δ18O-NO3-, δ11B), and groundwater residence-time tracers (3H and CFCs) was carried out in 2016, and integrated with a study of land use evolution in the catchment during the last century. Groundwater NO3- concentrations, ranged between 2 mg/L and up to 30 mg/L, displaying the degradation of groundwater quality induced by anthropogenic activities (agricultural activities). Comparatively high δ15N-NO3- values (up to 19.7‰) in combination with δ11B values that were significantly lower (between 23‰ and 26‰) than the seawater background are indicative of sewage contamination. The ongoing deterioration of groundwater quality can be attributed to the uncontrolled urbanization development all over the alluvial plain, with numerous sewage leakages from the sanitation network and private sewage systems. Integration of contaminant and water-residence time data revealed a progressive accumulation of pollutants with time in the groundwater, particularly in areas with major anthropogenic pressure and slow dynamic groundwater flow. Our approach provides time-dependent insight into nitrogen pollution in the studied aquifer over the past decades, revealing a systematic change in the dominant NO3- source, from agricultural to sewage contamination. Yet, today's low groundwater quality is to large parts due to legacy pollution from land-use practices several decades ago, underlining the poor self-remediating capacity of this hydrosystem. Our results can be taken as warning that groundwater pollution that happened in the recent past, or today, may have dire impacts on the quality of groundwater-dependent ecosystems in the future.
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Affiliation(s)
- M Erostate
- Université de Corse Pascal Paoli, Faculté des Sciences et Techniques, Laboratoire d'Hydrogéologie, Campus Grimaldi, BP 52, F-20250 Corte, France; CNRS, UMR 6134, SPE, F-20250 Corte, France
| | - F Huneau
- Université de Corse Pascal Paoli, Faculté des Sciences et Techniques, Laboratoire d'Hydrogéologie, Campus Grimaldi, BP 52, F-20250 Corte, France; CNRS, UMR 6134, SPE, F-20250 Corte, France.
| | - E Garel
- Université de Corse Pascal Paoli, Faculté des Sciences et Techniques, Laboratoire d'Hydrogéologie, Campus Grimaldi, BP 52, F-20250 Corte, France; CNRS, UMR 6134, SPE, F-20250 Corte, France
| | - M F Lehmann
- University of Basel, Department of Environmental Sciences, Basel, 4056, Switzerland
| | - T Kuhn
- University of Basel, Department of Environmental Sciences, Basel, 4056, Switzerland
| | - L Aquilina
- Université de Rennes, OSUR, Plateforme Condate eau, CNRS/Université Rennes-1, F-35042 Rennes, France
| | - V Vergnaud-Ayraud
- Université de Rennes, OSUR, Plateforme Condate eau, CNRS/Université Rennes-1, F-35042 Rennes, France
| | - T Labasque
- Université de Rennes, OSUR, Plateforme Condate eau, CNRS/Université Rennes-1, F-35042 Rennes, France
| | - S Santoni
- Université de Corse Pascal Paoli, Faculté des Sciences et Techniques, Laboratoire d'Hydrogéologie, Campus Grimaldi, BP 52, F-20250 Corte, France; CNRS, UMR 6134, SPE, F-20250 Corte, France
| | - S Robert
- Aix-Marseille Université, UMR CNRS 7300 ESPACE, Technopôle de l'environnement Arbois Méditerranée, BP 80, F-13545 Aix-en-Provence Cedex 4, France
| | - D Provitolo
- Université Côte d'Azur, CNRS, OCA, IRD, Géoazur, 250 rue Albert Einstein, Sophia Antipolis, F-06560 Valbonne, France
| | - V Pasqualini
- Université de Corse Pascal Paoli, Faculté des Sciences et Techniques, Laboratoire d'Hydrogéologie, Campus Grimaldi, BP 52, F-20250 Corte, France; CNRS, UMR 6134, SPE, F-20250 Corte, France
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28
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Zhang M, Zhi Y, Shi J, Wu L. Apportionment and uncertainty analysis of nitrate sources based on the dual isotope approach and a Bayesian isotope mixing model at the watershed scale. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 639:1175-1187. [PMID: 29929286 DOI: 10.1016/j.scitotenv.2018.05.239] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/18/2018] [Accepted: 05/19/2018] [Indexed: 06/08/2023]
Abstract
Identifying and eliminating pollutant sources of water bodies is critical for drinking water safety. In this research, river water, reservoir water and groundwater samples (n = 259) were collected from November 2015 to January 2017. Spatial Analysis was made of the isotopic compositions of potential nitrate sources (i.e., manure, sewage, chemical nitrogen fertilizer, soil organic nitrogen and rainfall) so as to obtain the site source isotopic signatures. Different sources pools and fractionation factors were loaded to a Bayesian isotope mixing model to ensure posterior estimates with less uncertainty. Results showed that the total nitrogen (TN) concentrations in Hexi Reservoir watershed were higher than the Environmental Quality Standards for Surface Water of China (GB 3838-2002), and NO3--N was the dominant form of TN (accounting for 68.63% on average). There are significant spatio-temporal variations in the isotope data (δ15N-NO3- and δ18O-NO3-) and the dominant nitrate sources, which were related to the land use types. Loading the site source isotopic signatures to the Bayesian isotope mixing model effectively improved the accuracy and precision of nitrate source apportionment. Chemical nitrogen fertilizer (NF) was the foremost largest contributor of NO3--N (38.82%), especially for Hexi North Stream (34.19%) and Yangmei Stream (44.39%), while atmospheric deposition (AD) contributed the least to NO3--N (0.47%) of river water in the watershed; soil organic nitrogen (NS) contributed more to NO3--N in the dry season than in the wet season; and manure and sewage (M&S) contributed approximately 30.22% in the whole study period, 53.60% in September 2016 and 41.33% in Hexi South Stream. This research suggests that combination of Spatial Analysis and the Bayesian isotope mixing model with the measured isotopic signatures of potential nitrate sources accurately apportion the nitrate source contributions.
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Affiliation(s)
- Man Zhang
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural and Environment, Zhejiang University, Hangzhou 310058, China
| | - Yuyou Zhi
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural and Environment, Zhejiang University, Hangzhou 310058, China
| | - Jiachun Shi
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural and Environment, Zhejiang University, Hangzhou 310058, China.
| | - Laosheng Wu
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural and Environment, Zhejiang University, Hangzhou 310058, China; Department of Environmental Sciences, University of California, Riverside, CA 92521, USA
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Yu Q, Wang F, Li X, Yan W, Li Y, Lv S. Tracking nitrate sources in the Chaohu Lake, China, using the nitrogen and oxygen isotopic approach. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:19518-19529. [PMID: 29732507 DOI: 10.1007/s11356-018-2178-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 04/30/2018] [Indexed: 06/08/2023]
Abstract
The Chaohu Lake is highly polluted and suffers from severe eutrophication. Nitrate is a key form of nitrogen that can cause water quality degradation. In this study, hydrochemical and dual isotopic approaches were utilized to identify the seasonal variation of nitrate sources in the Chaohu Lake and its inflowing rivers. The average nitrate concentrations ([NO3-]) of the lake and its inflowing rivers were 89.9 and 140.8 μmol L-1, respectively. The isotopic values of δ15N-NO3- and δ18O-NO3- in the lake ranged from - 1.01 to + 16.67‰ and from - 4.39 to + 22.20‰, respectively. The two major rivers had distinct isotopic compositions, with average δ15N-NO3- values of + 17.52 and + 3.51‰, and average δ18O-NO3- values of + 2.71 and + 7.47‰ for the Nanfei River and Hangbu River, respectively. The results show that soil organic ammonium and urban wastewater discharge were the main sources of nitrate in the Chaohu Lake, and nitrate assimilation was an important process affected [NO3-] and isotopic compositions, especially in the western Chaohu Lake. The elevated [NO3-] and δ15N-NO3- values in the western Chaohu Lake indicate the high influence of human activities. Urban wastewater discharge was the primary nitrate source in the Nanfei River and soil organic ammonium was the main source in the Hangbu River. Although nitrate from direct atmospheric deposition was low, its strong flushing effect can substantially improve riverine [NO3-] and nitrate loading from terrestrial ecosystem. The relatively high nitrate fluxes from the Hangbu River indicate that nitrogen loading from agricultural watershed is unneglectable in watershed nitrogen sources reduction strategies.
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Affiliation(s)
- Qibiao Yu
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fang Wang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xinyan Li
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Weijin Yan
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Yanqiang Li
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shucong Lv
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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30
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Soldatova E, Guseva N, Sun Z, Bychinsky V, Boeckx P, Gao B. Sources and behaviour of nitrogen compounds in the shallow groundwater of agricultural areas (Poyang Lake basin, China). JOURNAL OF CONTAMINANT HYDROLOGY 2017; 202:59-69. [PMID: 28545847 DOI: 10.1016/j.jconhyd.2017.05.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 02/03/2017] [Accepted: 05/15/2017] [Indexed: 06/07/2023]
Abstract
Nitrogen contamination of natural water is a typical problem for various territories throughout the world. One of the regions exposed to nitrogen pollution is located in the Poyang Lake basin. As a result of agricultural activity and dense population, the shallow groundwater of this area is characterised by a high concentration of nitrogen compounds, primarily NO3-, with the concentration varying from 0.1mg/L to 206mg/L. Locally, high ammonium content occurs in the shallow groundwater with low reduction potential Eh (<100mV). However, in general, the shallow groundwater of the Poyang Lake basin has Eh>100mV. To identify sources of nitrogen species and the factors that determine their behaviour, the dual stable isotope approach (δ15N and δ18О) and physical-chemical modelling were applied. Actual data were collected by sampling shallow groundwater from domestic water supply wells around the lake. The δ18О values from -4.1‰ to 13.9‰ with an average value of 5.3 permille indicate a significant influence of nitrification on nitrogen balance. The enrichment of nitrate with the 15N isotope indicates that manure and domestic sewage are the principal sources of nitrogen compounds. Inorganic nitrogen speciation and thermodynamic calculations demonstrate the high stability of nitrate in the studied groundwater. Computer simulation and field observations indicate the reducing conditions formed under joint effects of anthropogenic factors and appropriate natural conditions, such as the low-level topography in which decreased water exchange rate can occur. The simulation also demonstrates the growth in pH of the groundwater as a consequence of fertilisation, which, in turn, conduced to the clay mineral formation at lower concentrations of aqueous clay-forming components than the ones under the natural conditions.
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Affiliation(s)
- Evgeniya Soldatova
- Research and Education Centre "Water", National Research Tomsk Polytechnic University, 30 Lenina Avenue, Tomsk 634050, Russia.
| | - Natalia Guseva
- Research and Education Centre "Water", National Research Tomsk Polytechnic University, 30 Lenina Avenue, Tomsk 634050, Russia
| | - Zhanxue Sun
- East China University of Technology, 418 Guanglan Avenue, Nanchang 330013, China
| | - Valeriy Bychinsky
- A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, 1a Favorsky Street, Irkutsk 664033, Russia
| | - Pascal Boeckx
- Isotope Bioscience Laboratory - ISOFYS, Ghent University, Coupure Links 653, 9000 Gent, Belgium
| | - Bai Gao
- East China University of Technology, 418 Guanglan Avenue, Nanchang 330013, China
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31
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Using δ15N and δ18O Signatures to Evaluate Nitrate Sources and Transformations in Four Inflowing Rivers, North of Taihu Lake. WATER 2017. [DOI: 10.3390/w9050345] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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McAleer EB, Coxon CE, Richards KG, Jahangir MMR, Grant J, Mellander PE. Groundwater nitrate reduction versus dissolved gas production: A tale of two catchments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 586:372-389. [PMID: 28228237 DOI: 10.1016/j.scitotenv.2016.11.083] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/13/2016] [Accepted: 11/14/2016] [Indexed: 06/06/2023]
Abstract
At the catchment scale, a complex mosaic of environmental, hydrogeological and physicochemical characteristics combine to regulate the distribution of groundwater and stream nitrate (NO3-). The efficiency of NO3- removal (via denitrification) versus the ratio of accumulated reaction products, dinitrogen (excess N2) & nitrous oxide (N2O), remains poorly understood. Groundwater was investigated in two well drained agricultural catchments (10km2) in Ireland with contrasting subsurface lithologies (sandstone vs. slate) and landuse. Denitrification capacity was assessed by measuring concentration and distribution patterns of nitrogen (N) species, aquifer hydrogeochemistry, stable isotope signatures and aquifer hydraulic properties. A hierarchy of scale whereby physical factors including agronomy, water table elevation and permeability determined the hydrogeochemical signature of the aquifers was observed. This hydrogeochemical signature acted as the dominant control on denitrification reaction progress. High permeability, aerobic conditions and a lack of bacterial energy sources in the slate catchment resulted in low denitrification reaction progress (0-32%), high NO3- and comparatively low N2O emission factors (EF5g1). In the sandstone catchment denitrification progress ranged from 4 to 94% and was highly dependent on permeability, water table elevation, dissolved oxygen concentration solid phase bacterial energy sources. Denitrification of NO3- to N2 occurred in anaerobic conditions, while at intermediate dissolved oxygen; N2O was the dominant reaction product. EF5g1 (mean: 0.0018) in the denitrifying sandstone catchment was 32% less than the IPCC default. The denitrification observations across catchments were supported by stable isotope signatures. Stream NO3- occurrence was 32% lower in the sandstone catchment even though N loading was substantially higher than the slate catchment.
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Affiliation(s)
- E B McAleer
- Geology Department/Trinity Centre for the Environment, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland; Agricultural Catchments Programme, Teagasc, Environment Research Centre, Johnstown Castle, Wexford, Ireland; Crops, Environment and Land Use Programme, Teagasc Environment Research Centre, Johnstown Castle, Wexford, Ireland.
| | - C E Coxon
- Geology Department/Trinity Centre for the Environment, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
| | - K G Richards
- Crops, Environment and Land Use Programme, Teagasc Environment Research Centre, Johnstown Castle, Wexford, Ireland.
| | - M M R Jahangir
- Crops, Environment and Land Use Programme, Teagasc Environment Research Centre, Johnstown Castle, Wexford, Ireland
| | - J Grant
- Teagasc, Ashtown Food Research Centre, Dublin, Ireland
| | - Per E Mellander
- Agricultural Catchments Programme, Teagasc, Environment Research Centre, Johnstown Castle, Wexford, Ireland
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Weng TN, Liu CW, Kao YH, Hsiao SSY. Isotopic evidence of nitrogen sources and nitrogen transformation in arsenic-contaminated groundwater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 578:167-185. [PMID: 27852448 DOI: 10.1016/j.scitotenv.2016.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/23/2016] [Accepted: 11/02/2016] [Indexed: 05/27/2023]
Abstract
High concentrations of naturally occurring arsenic (As) are typically found in young alluvial and deltaic deposits, and high concentrations of ammonium (NH4+) and nitrate (NO3-) are often present in groundwater affected by anthropogenic activities. In this study, on the basis of physicochemical characteristics of groundwater and the nitrogen and oxygen isotope composition of NO3-, it was inferred that the main sources of NO3- in the proximal fan of the Choushui River alluvial fan are likely to be ammonium fertilizers, manure, and septic waste; that in the mid-fan and the distal fan, the possible sources are nitrate fertilizers and marine nitrate. In the proximal fan, the oxidative state obviously promotes microbial nitrification. Denitrification occurs from the upstream region to the downstream region of the Choushui River, and therefore, the decrease in NO3- concentration along streams connecting the Choushui River to the ocean appears plausible. High DO concentrations and relatively low values of δ18ONO3 in the deeper aquifer of the proximal fan may be attributed to unconfined granular nature and groundwater pumping by agricultural activities. In the mid-fan, NO3- assimilation is the dominant response to NO3- attenuation, and denitrification is insignificant; however, high concentrations of As, NH4+ and Fe and depletion of δ15NNO3 imply the occurrence of feammox process. By contrast, denitrification evidently occurs in the distal fan, through assimilation, mineralization, and dissimilatory NO3- reduction to NH4+, resulting in depletion of NO3- and increase in NH4+ in groundwater. Feammox in the mid-fan and denitrification in the distal fan may be the main processes leading to the release of As from As-bearing Fe oxyhydroxides into groundwater.
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Affiliation(s)
- Tsung-Nan Weng
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Da'an Dist., Taipei City 10617, Taiwan, ROC.
| | - Chen-Wuing Liu
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Da'an Dist., Taipei City 10617, Taiwan, ROC.
| | - Yu-Hsuan Kao
- Agricultural Engineering Research Center, No. 196-1, Zhongyuan Rd., Zhongli Dist., Taoyuan City 32061, Taiwan, ROC
| | - Silver Sung-Yun Hsiao
- Graduate Institute of Hydrological and Oceanic Sciences, National Central University, No. 300, Zhongda Rd., Zhongli Dist., Taoyuan City 32001, Taiwan, ROC.
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Fritts AK, Fritts MW, Haag WR, DeBoer JA, Casper AF. Freshwater mussel shells (Unionidae) chronicle changes in a North American river over the past 1000years. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 575:199-206. [PMID: 27741455 DOI: 10.1016/j.scitotenv.2016.09.225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/23/2016] [Accepted: 09/29/2016] [Indexed: 06/06/2023]
Abstract
The Illinois River was substantially altered during the 20th century with the installation of navigational locks and dams, construction of extensive levee networks, and degradation of water quality. Freshwater mussels were affected by these changes. We used sclerochronology and stable isotopes to evaluate changes over time in age-and-growth and food sources for two mussel species: Amblema plicata and Quadrula quadrula. Specimens were collected in years 1894, 1897, 1909, 1912, 1966, and 2013, and archeological specimens were collected circa 850. The von Bertalanffy growth parameter (K) was similar between 850 and 1897, but it increased by 1912 and remained elevated through 2013. Predicted maximum size (Linf) increased over the past millennium, and 2013 individuals were over 50% larger than in 850. Growth indices showed similar patterns of continual increases in growth. Shells were enriched in 13C and 15N during the 20th century, but exhibited a partial return to historical conditions by 2013. These patterns are likely attributable to impoundment, nutrient pollution and eutrophication beginning in the early 20th century followed by recent water quality improvement.
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Affiliation(s)
- Andrea K Fritts
- Illinois Natural History Survey, Illinois River Biological Station, Havana, IL 62644, USA.
| | - Mark W Fritts
- Illinois Natural History Survey, Illinois River Biological Station, Havana, IL 62644, USA.
| | - Wendell R Haag
- Center for Bottomland Hardwoods Research, US Forest Service, Oxford, MS 38655, USA.
| | - Jason A DeBoer
- Illinois Natural History Survey, Illinois River Biological Station, Havana, IL 62644, USA.
| | - Andrew F Casper
- Illinois Natural History Survey, Illinois River Biological Station, Havana, IL 62644, USA.
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35
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García AM, Alexander RB, Arnold JG, Norfleet L, White MJ, Robertson DM, Schwarz G. Regional Effects of Agricultural Conservation Practices on Nutrient Transport in the Upper Mississippi River Basin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:6991-7000. [PMID: 27243625 DOI: 10.1021/acs.est.5b03543] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Despite progress in the implementation of conservation practices, related improvements in water quality have been challenging to measure in larger river systems. In this paper we quantify these downstream effects by applying the empirical U.S. Geological Survey water-quality model SPARROW to investigate whether spatial differences in conservation intensity were statistically correlated with variations in nutrient loads. In contrast to other forms of water quality data analysis, the application of SPARROW controls for confounding factors such as hydrologic variability, multiple sources and environmental processes. A measure of conservation intensity was derived from the USDA-CEAP regional assessment of the Upper Mississippi River and used as an explanatory variable in a model of the Upper Midwest. The spatial pattern of conservation intensity was negatively correlated (p = 0.003) with the total nitrogen loads in streams in the basin. Total phosphorus loads were weakly negatively correlated with conservation (p = 0.25). Regional nitrogen reductions were estimated to range from 5 to 34% and phosphorus reductions from 1 to 10% in major river basins of the Upper Mississippi region. The statistical associations between conservation and nutrient loads are consistent with hydrological and biogeochemical processes such as denitrification. The results provide empirical evidence at the regional scale that conservation practices have had a larger statistically detectable effect on nitrogen than on phosphorus loadings in streams and rivers of the Upper Mississippi Basin.
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Affiliation(s)
- Ana María García
- U.S. Geological Survey, 3916 Sunset Ridge Rd., Raleigh, North Carolina 02906, United States
| | - Richard B Alexander
- U.S. Geological Survey, 432 National Center, Reston, Virginia 20192, United States
| | - Jeffrey G Arnold
- U.S. Department of Agriculture, Agricultural Research Service, Grassland Soil and Water Research Laboratory, 808 East Blackland Rd. Temple, Texas 76502, United States
| | - Lee Norfleet
- U.S. Department of Agriculture, Natural Resources and Conservation Service, 101 East Blackland Rd. Temple, Texas 76502, United States
| | - Michael J White
- U.S. Department of Agriculture, Agricultural Research Service, Grassland Soil and Water Research Laboratory, 808 East Blackland Rd. Temple, Texas 76502, United States
| | - Dale M Robertson
- U.S. Geological Survey, 8505 Research Way, Middleton, Wisconsin 53562, United States
| | - Gregory Schwarz
- U.S. Geological Survey, 432 National Center, Reston, Virginia 20192, United States
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Xue D, Pang F, Meng F, Wang Z, Wu W. Decision-tree-model identification of nitrate pollution activities in groundwater: A combination of a dual isotope approach and chemical ions. JOURNAL OF CONTAMINANT HYDROLOGY 2015; 180:25-33. [PMID: 26231989 DOI: 10.1016/j.jconhyd.2015.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 07/16/2015] [Accepted: 07/17/2015] [Indexed: 05/24/2023]
Abstract
To develop management practices for agricultural crops to protect against NO3(-) contamination in groundwater, dominant pollution activities require reliable classification. In this study, we (1) classified potential NO3(-) pollution activities via an unsupervised learning algorithm based on δ(15)N- and δ(18)O-NO3(-) and physico-chemical properties of groundwater at 55 sampling locations; and (2) determined which water quality parameters could be used to identify the sources of NO3(-) contamination via a decision tree model. When a combination of δ(15)N-, δ(18)O-NO3(-) and physico-chemical properties of groundwater was used as an input for the k-means clustering algorithm, it allowed for a reliable clustering of the 55 sampling locations into 4 corresponding agricultural activities: well irrigated agriculture (28 sampling locations), sewage irrigated agriculture (16 sampling locations), a combination of sewage irrigated agriculture, farm and industry (5 sampling locations) and a combination of well irrigated agriculture and farm (6 sampling locations). A decision tree model with 97.5% classification success was developed based on SO4(2-) and Cl(-) variables. The NO3(-) and the δ(15)N- and δ(18)O-NO3(-) variables demonstrated limitation in developing a decision tree model as multiple N sources and fractionation processes both resulted in difficulties of discriminating NO3(-) concentrations and isotopic values. Although only the SO4(2-) and Cl(-) were selected as important discriminating variables, concentration data alone could not identify the specific NO3(-) sources responsible for groundwater contamination. This is a result of comprehensive analysis. To further reduce NO3(-) contamination, an integrated approach should be set-up by combining N and O isotopes of NO3(-) with land-uses and physico-chemical properties, especially in areas with complex agricultural activities.
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Affiliation(s)
- Dongmei Xue
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China
| | - Fengmei Pang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Fanqiao Meng
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
| | - Zhongliang Wang
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China
| | - Wenliang Wu
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
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Li WB, Song YB, Xu HK, Chen LY, Dai WH, Dong M. Ion-exchange method in the collection of nitrate from freshwater ecosystems for nitrogen and oxygen isotope analysis: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:9575-9588. [PMID: 25940469 DOI: 10.1007/s11356-015-4522-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 04/09/2015] [Indexed: 06/04/2023]
Abstract
Nitrate (NO3(-)) contamination of freshwater is considered one of the most prevalent global environmental problems. Dual stable isotopic compositions (δ(15)N and δ(18)O) of NO3(-) can provide helpful information and have been well documented as being a powerful tool to track the source of NO3(-) in freshwater ecosystems. The ion-exchange method is a reliable and precise technique for measuring the δ(15)N and δ(18)O of NO3(-) and has been widely employed to collect NO3(-) from freshwater ecosystems. This review summarizes and presents the principles, affecting factors and corresponding significant improvements of the ion-exchange method. Finally, potential improvements and perspectives for the applicability of this method are also discussed, as are suggestions for further research and development drawn from the overall conclusions.
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Affiliation(s)
- Wen-Bing Li
- Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
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38
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Tracing the Nitrate Sources of the Yili River in the Taihu Lake Watershed: A Dual Isotope Approach. WATER 2014. [DOI: 10.3390/w7010188] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Ding J, Xi B, Gao R, He L, Liu H, Dai X, Yu Y. Identifying diffused nitrate sources in a stream in an agricultural field using a dual isotopic approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 484:10-18. [PMID: 24686140 DOI: 10.1016/j.scitotenv.2014.03.018] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/06/2014] [Accepted: 03/06/2014] [Indexed: 06/03/2023]
Abstract
Nitrate (NO3(-)) pollution is a severe problem in aquatic systems in Taihu Lake Basin in China. A dual isotope approach (δ(15)NNO3(-) and δ(18)ONO3(-)) was applied to identify diffused NO3(-) inputs in a stream in an agricultural field at the basin in 2013. The site-specific isotopic characteristics of five NO3(-) sources (atmospheric deposition, AD; NO3(-) derived from soil organic matter nitrification, NS; NO3(-) derived from chemical fertilizer nitrification, NF; groundwater, GW; and manure and sewage, M&S) were identified. NO3(-) concentrations in the stream during the rainy season [mean±standard deviation (SD)=2.5±0.4mg/L] were lower than those during the dry season (mean±SD=4.0±0.5mg/L), whereas the δ(18)ONO3(-) values during the rainy season (mean±SD=+12.3±3.6‰) were higher than those during the dry season (mean±SD=+0.9±1.9‰). Both chemical and isotopic characteristics indicated that mixing with atmospheric NO3(-) resulted in the high δ(18)O values during the rainy season, whereas NS and M&S were the dominant NO3(-) sources during the dry season. A Bayesian model was used to determine the contribution of each NO3(-) source to total stream NO3(-). Results showed that reduced N nitrification in soil zones (including soil organic matter and fertilizer) was the main NO3(-) source throughout the year. M&S contributed more NO3(-) during the dry season (22.4%) than during the rainy season (17.8%). AD generated substantial amounts of NO3(-) in May (18.4%), June (29.8%), and July (24.5%). With the assessment of temporal variation of diffused NO3(-) sources in agricultural field, improved agricultural management practices can be implemented to protect the water resource and avoid further water quality deterioration in Taihu Lake Basin.
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Affiliation(s)
- Jingtao Ding
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Beidou Xi
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Rutai Gao
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Liansheng He
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Hongliang Liu
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xuanli Dai
- Changzhou Environmental Monitoring Center, Jiangsu 213001, China
| | - Yijun Yu
- Changzhou Environmental Monitoring Center, Jiangsu 213001, China
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40
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Hale RL, Turnbull L, Earl S, Grimm N, Riha K, Michalski G, Lohse KA, Childers D. Sources and transport of nitrogen in arid urban watersheds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:6211-6219. [PMID: 24803360 DOI: 10.1021/es501039t] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Urban watersheds are often sources of nitrogen (N) to downstream systems, contributing to poor water quality. However, it is unknown which components (e.g., land cover and stormwater infrastructure type) of urban watersheds contribute to N export and which may be sites of retention. In this study we investigated which watershed characteristics control N sourcing, biogeochemical processing of nitrate (NO3-) during storms, and the amount of rainfall N that is retained within urban watersheds. We used triple isotopes of NO3- (δ15N, δ18O, and Δ17O) to identify sources and transformations of NO3- during storms from 10 nested arid urban watersheds that varied in stormwater infrastructure type and drainage area. Stormwater infrastructure and land cover--retention basins, pipes, and grass cover--dictated the sourcing of NO3- in runoff. Urban watersheds were strong sinks or sources of N to stormwater depending on runoff, which in turn was inversely related to retention basin density and positively related to imperviousness and precipitation. Our results suggest that watershed characteristics control the sources and transport of inorganic N in urban stormwater but that retention of inorganic N at the time scale of individual runoff events is controlled by hydrologic, rather than biogeochemical, mechanisms.
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Affiliation(s)
- Rebecca L Hale
- School of Life Sciences, §Global Institute of Sustainability, and ◆School of Sustainability, Arizona State University , Tempe, Arizona 85287, United States
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41
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Fang Y, Koba K, Makabe A, Zhu F, Fan S, Liu X, Yoh M. Low δ18O values of nitrate produced from nitrification in temperate forest soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:8723-30. [PMID: 22809398 DOI: 10.1021/es300510r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Analyses of δ(18)O of nitrate (NO(3)(-)) have been widely used in partitioning NO(3)(-) sources. However the δ(18)O value of NO(3)(-) produced from nitrification (microbial NO(3)(-)) is commonly estimated using the δ(18)O of environmental water and molecular oxygen in a 2:1 ratio. Here our laboratory incubation of nine temperate forest soils across a 1500 m elevation gradient demonstrates that microbial NO(3)(-) has lower δ(18)O values than the predicted using the 2:1 ratio (by 5.2-9.5‰ at low elevation sites), in contrast to previous reports showing higher δ(18)O values (up to +15‰) than their predicted values. Elevated δ(18)O values of microbial NO(3)(-) were observed at high elevation sites where soil was more acidic, perhaps due to accelerated O-exchange between nitrite, an intermediate product of nitrification, and water. Lower δ(18)O of microbial NO(3)(-) than the predicted and from previous observations suggests that the contribution of anthropogenic N inputs, such as fertilizer and atmospheric deposition, to a given ecosystem and the progress of denitrification in nitrogen removal are greater than we know. More than half of the δ(18)O of stream NO(3)(-) lower than the predicted value along the elevation gradient also indicate the impropriety using the 2:1 ratio for differentiating NO(3)(-) sources.
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Affiliation(s)
- Yunting Fang
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, Tokyo 183-8509, Japan
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42
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Sasaki Y, Koba K, Yamamoto M, Makabe A, Ueno Y, Nakagawa M, Toyoda S, Yoshida N, Yoh M. Biogeochemistry of nitrous oxide in Lake Kizaki, Japan, elucidated by nitrous oxide isotopomer analysis. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jg001589] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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43
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Nestler A, Berglund M, Accoe F, Duta S, Xue D, Boeckx P, Taylor P. Isotopes for improved management of nitrate pollution in aqueous resources: review of surface water field studies. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2011; 18:519-533. [PMID: 21246297 DOI: 10.1007/s11356-010-0422-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 11/23/2010] [Indexed: 05/26/2023]
Abstract
BACKGROUND Environmental agencies have to take measures to either reduce discharges and emissions of nitrate or to remediate nitrate-polluted water bodies where the nitrate concentrations exceed threshold values. Isotope data can support the identification of nitrate pollution sources and natural attenuation processes of nitrate. REVIEW This review article gives an overview of the information available to date regarding nitrate source apportionment in surface waters with the ambition to help improving future studies. Different isotope approaches in combination with physicochemical and hydrological data can successfully be used in source apportionment studies. A sampling strategy needs to be developed based on possible nitrate sources, hydrology and land use. Transformations, transport and mixing processes should also be considered as they can change the isotope composition of the original nitrate source. CONCLUSION Nitrate isotope data interpreted in combination with hydrological and chemical data provide valuable information on the nitrate pollution sources and on the processes nitrate has undergone during its retention and transport in the watershed. This information is useful for the development of an appropriate water management policy.
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Affiliation(s)
- Angelika Nestler
- European Commission, Joint Research Centre (JRC), Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440, Geel, Belgium
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44
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An improved method of ion exchange for nitrogen isotope analysis of water nitrate. Anal Chim Acta 2010; 686:107-14. [PMID: 21237315 DOI: 10.1016/j.aca.2010.11.051] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2010] [Accepted: 11/28/2010] [Indexed: 11/24/2022]
Abstract
Nitrate nitrogen and oxygen isotopes have been widely used to trace the nitrogen biogeochemical cycle by identifying NO(3)(-) sources. An improved method of anion exchange was developed to measure δ(15)N-NO(3)(-) in fresh water by continuous-flow elemental analyzer/isotope ratio mass spectrometry (EA-IRMS). We used a custom-built exchange resin column, a peristaltic pump and the oven-drying method in our experiments. Consequently, the amount of Ag(2)O used as a neutralizer was reduced, time was saved, and operation became simpler than before. Meanwhile, analytical precision remained identical to previous studies. KNO(3) solutions were prepared at 0.2, 5 and 25 mg-N L(-1) from KNO(3) standard salt (δ(15)N=+6.27‰), and the average δ(15)N values of the solutions after having been absorbed on and subsequently stripped from anion columns were +6.62±0.22‰ (n=6), +6.38±0.09‰ (n=6), and +6.26±0.07‰ (n=6), respectively. In addition, the "natural" water sample δ(15)N-NO(3)(-) showed consistency in comparison to standards, and the mean standard deviation by the different approaches was 0.08‰. Accordingly, by these improvements the anion exchange resin technique is demonstrated to be more suitable for measuring δ(15)N in NO(3)(-) than original techniques.
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45
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Osaka K, Ohte N, Koba K, Yoshimizu C, Katsuyama M, Tani M, Tayasu I, Nagata T. Hydrological influences on spatiotemporal variations ofδ15N andδ18O of nitrate in a forested headwater catchment in central Japan: Denitrification plays a critical role in groundwater. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jg000977] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ken'ichi Osaka
- Graduate School of Agriculture; Kyoto University; Kyoto Japan
- International Research Center for River Basin Environment; University of Yamanashi; Yamanashi Japan
| | - Nobuhito Ohte
- Graduate School of Agriculture; Kyoto University; Kyoto Japan
- Graduate School of Agricultural and Life Sciences; The University of Tokyo; Tokyo Japan
| | - Keisuke Koba
- Interdisciplinary Graduate School of Science and Engineering; Tokyo Institute of Technology; Yokohama, Tokyo Japan
- Institute of Symbiotic Science and Technology; Tokyo University of Agriculture and Technology; Fuchu Japan
| | - Chikage Yoshimizu
- Japan Science and Technology Agency; Kawaguchi Japan
- Center for Ecological Research; Kyoto University; Otsu Japan
| | - Masanori Katsuyama
- Graduate School of Agriculture; Kyoto University; Kyoto Japan
- Research Institute for Humanity and Nature; Kyoto Japan
| | - Makoto Tani
- Graduate School of Agriculture; Kyoto University; Kyoto Japan
| | - Ichiro Tayasu
- Center for Ecological Research; Kyoto University; Otsu Japan
| | - Toshi Nagata
- Center for Ecological Research; Kyoto University; Otsu Japan
- Ocean Research Institute; University of Tokyo; Tokyo Japan
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46
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Li SL, Liu CQ, Li J, Liu X, Chetelat B, Wang B, Wang F. Assessment of the sources of nitrate in the Changjiang River, China using a nitrogen and oxygen isotopic approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:1573-1578. [PMID: 20121182 DOI: 10.1021/es902670n] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The Changjiang River is the largest freshwater river in China. Here, the sources and variability in nitrate of the Changjiang River are assessed for the first time using dual isotopic approach. Water samples were collected once in August 2006 from the main channel of the Changjiang and its major tributaries. The concentrations and isotopic composition of nitrate were then analyzed for the waters in the Changjiang River. The delta(15)N and delta(18)O of NO(3)(-) ranges from 7.3 per thousand to 12.9 per thousand and 2.4 per thousand to 11.2 per thousand in the Changjiang River waters, respectively. The ranges of isotopic compositions of nitrate suggested that nitrification (including "modified fertilizer") and urban sewage effluent are the major sources of nitrate in the Changjiang River. The high delta(18)O-NO(3)(-) values were observed in the water of the upper reaches, indicated that the current drought might be one important reason for shifting of isotopes in the special sampling period. In addition, there was a strong positive relationship between delta(15)N-NO(3)(-) and delta(18)O-NO(3)(-), which indicated that denitrification added to the enrichment of heavy isotopes of nitrate.
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Affiliation(s)
- Si-Liang Li
- The State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
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47
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Diebel MW, Vander Zanden MJ. Nitrogen stable isotopes in streams: effects of agricultural sources and transformations. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2009; 19:1127-34. [PMID: 19688921 DOI: 10.1890/08-0327.1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The nitrogen stable isotope ratio of biological tissue has been proposed as an indicator of anthropogenic N inputs to aquatic ecosystems, but overlap in the isotopic signatures of various N sources and transformations make definitive attribution of processes difficult. We collected primary consumer invertebrates from streams in agricultural settings in Wisconsin, U.S.A., to evaluate the relative influence of animal manure, inorganic fertilizer, and denitrification on biotic delta15N. Variance in biotic delta15N was explained by inorganic fertilizer inputs and the percentage of wetland land cover in the watershed, but not by animal manure inputs. These results suggest that denitrification of inorganic fertilizer is the primary driver of delta15N variability among the study sites. Comparison with previously collected stream water NO3-N concentrations at the same sites supports the role of denitrification; for a given N application rate, streams with high biotic delta15N had low NO3-N concentrations. The lack of a manure signal in biotic delta15N may be due its high ammonia content, which can be dispersed outside the range of its application by volatilization. Based on our findings and on agricultural census data for the entire United States, inorganic fertilizer is more likely than manure to drive variability in biotic delta15N and to cause excessive nitrogen concentrations in streams.
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Affiliation(s)
- Matthew W Diebel
- Center for Limnology, University of Wisconsin, 680 N. Park Street, Madison, Wisconsin 53706, USA.
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48
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Buzek F, Bystricky V, Kadlecova R, Kvitek T, Ondr P, Sanda M, Zajicek A, Zlabek P. Application of two-component model of drainage discharge to nitrate contamination. JOURNAL OF CONTAMINANT HYDROLOGY 2009; 106:99-117. [PMID: 19264375 DOI: 10.1016/j.jconhyd.2009.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 01/20/2009] [Accepted: 02/02/2009] [Indexed: 05/27/2023]
Abstract
A conceptual two-component model of drainage discharge based on delta(18)O, nitrate content and delta(15)N data was constructed. It comprises the infiltrated precipitation and the local groundwater, both discharging into the drainage system. The movement of the water via the unsaturated zone is described as a piston-like flow with a varying amount contributing to the total drainage. Two tile drainage systems were studied for nitrate loss. The transit time between the rainfall infiltration and the drainage into the tile system is estimated to be approximately one year. This process is strongly dependent on the duration of the infiltration and its magnitude, and thus on the discharge dynamics in general. The local groundwater contribution to the system formed a significant part of the drainage discharge (varying as 65-98% of the whole drained amount). Nitrate content and delta(15)N data were used for the specification of the nitrate flux and nitrate origin in the drainage discharge.
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Affiliation(s)
- Frantisek Buzek
- Czech Geological Survey, Geologicka 6, Prague 5, Czech Republic.
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49
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Burns DA, Boyer EW, Elliott EM, Kendall C. Sources and transformations of nitrate from streams draining varying land uses: evidence from dual isotope analysis. JOURNAL OF ENVIRONMENTAL QUALITY 2009; 38:1149-1159. [PMID: 19398512 DOI: 10.2134/jeq2008.0371] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Knowledge of key sources and biogeochemical processes that affect the transport of nitrate (NO(3)(-)) in streams can inform watershed management strategies for controlling downstream eutrophication. We applied dual isotope analysis of NO(3)(-) to determine the dominant sources and processes that affect NO(3)(-) concentrations in six stream/river watersheds of different land uses. Samples were collected monthly at a range of flow conditions for 15 mo during 2004-05 and analyzed for NO(3)(-) concentrations, delta(15)N(NO3), and delta(18)O(NO3). Samples from two forested watersheds indicated that NO(3)(-) derived from nitrification was dominant at baseflow. A watershed dominated by suburban land use had three delta(18)O(NO3) values greater than +25 per thousand, indicating a large direct contribution of atmospheric NO(3)(-) transported to the stream during some high flows. Two watersheds with large proportions of agricultural land use had many delta(15)N(NO3) values greater than +9 per thousand, suggesting an animal waste source consistent with regional dairy farming practices. These data showed a linear seasonal pattern with a delta(18)O(NO3):delta (15)N(NO3) of 1:2, consistent with seasonally varying denitrification that peaked in late summer to early fall with the warmest temperatures and lowest annual streamflow. The large range of delta (15)N(NO3) values (10 per thousand) indicates that NO(3)(-) supply was likely not limiting the rate of denitrification, consistent with ground water and/or in-stream denitrification. Mixing of two or more distinct sources may have affected the seasonal isotope patterns observed in these two agricultural streams. In a mixed land use watershed of large drainage area, none of the source and process patterns observed in the small streams were evident. These results emphasize that observations at watersheds of a few to a few hundred km(2) may be necessary to adequately quantify the relative roles of various NO(3)(-) transport and process patterns that contribute to streamflow in large basins.
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50
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Xue D, Botte J, De Baets B, Accoe F, Nestler A, Taylor P, Van Cleemput O, Berglund M, Boeckx P. Present limitations and future prospects of stable isotope methods for nitrate source identification in surface- and groundwater. WATER RESEARCH 2009; 43:1159-70. [PMID: 19157489 DOI: 10.1016/j.watres.2008.12.048] [Citation(s) in RCA: 372] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 12/16/2008] [Accepted: 12/18/2008] [Indexed: 05/22/2023]
Abstract
Nitrate (NO3(-)) contamination of surface- and groundwater is an environmental problem in many regions of the world with intensive agriculture and high population densities. Knowledge of the sources of NO3(-) contamination in water is important for better management of water quality. Stable nitrogen (delta15N) and oxygen (delta18O) isotope data of NO3(-) have been frequently used to identify NO3(-) sources in water. This review summarizes typical delta15N- and delta18O-NO3(-) ranges of known NO3(-) sources, interprets constraints and future outlooks to quantify NO3(-) sources, and describes three analytical techniques ("ion-exchange method", "bacterial denitrification method", and "cadmium reduction method") for delta15N- and delta18)O-NO3(-) determination. Isotopic data can provide evidence for the presence of dominant NO3(-) sources. However, quantification, including uncertainty assessment, is lacking when multiple NO3(-) sources are present. Moreover, fractionation processes are often ignored, but may largely constrain the accuracy of NO3(-) source identification. These problems can be overcome if (1) NO3(-) isotopic data are combined with co-migrating discriminators of NO3(-) sources (e.g. (11)B), which are not affected by transformation processes, (2) contributions of different NO3(-) sources can be quantified via linear mixing models (e.g. SIAR), and (3) precise, accurate and high throughput isotope analytical techniques become available.
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Affiliation(s)
- Dongmei Xue
- Laboratory of Applied Physical Chemistry-ISOFYS, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
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