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Ding K, Zhang Y, Zhang H, Yu C, Li X, Zhang M, Zhang Z, Yang Y. Tracing nitrate origins and transformation processes in groundwater of the Hohhot Basin's Piedmont strong runoff zone through dual isotopes and hydro-chemical analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170799. [PMID: 38336049 DOI: 10.1016/j.scitotenv.2024.170799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 01/18/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
Nitrate, which poses a serious threat to the drinking water supply, is one of the most prevalent anthropogenic groundwater contaminants worldwide. With the development of the chemical industry, the nitrate pollution of groundwater in the Piedmont strong runoff zone of the Hohhot Basin, which is the main groundwater extraction area, is becoming increasingly severe. The special hydrogeological and complex pollution conditions in the study area make it difficult to identify nitrate sources and transformation processes. In order to identify the results more accurately, this study combined water chemistry, multivariate statistical analysis and isotope tracer methods to determine the sources and transformation processes of nitrate in the study area. The results showed that the groundwater in the eastern part of the study area (ESA) was clearly affected by anthropogenic activities, and its nitrate was mainly from nitrification of ammonia in industrial wastewater, nitrate in industrial wastewater (the sum of the two contributions was 62.2 %), and nitrate in manure (20.5 %). The hydrogeochemical characteristics of groundwater in the western part of the study area (WSA) are the same as those of natural groundwater in the Piedmont strong-runoff zone. The nitrate in groundwater in the WSA was mainly derived from soil nitrogen (63.8 %) and ammonia fertilizer (28.8 %). Nitrification and denitrification occurred only locally in the aquifer of the study area and were more pronounced in the ESA. Meanwhile, the transformation processes of nitrate in groundwater in the ESA and WSA was significantly influenced by contamination with chlorinated hydrocarbon volatile organic compounds and hydrogeological conditions, respectively. These findings provide a scientific basis for the development of groundwater pollution prevention measures in the study area and guide the traceability of nitrate in groundwater in areas with similar hydrogeological and pollution conditions.
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Affiliation(s)
- Kaifang Ding
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang 050061, China; School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China
| | - Yilong Zhang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang 050061, China
| | - Hengxing Zhang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang 050061, China.
| | - Chu Yu
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang 050061, China
| | - Xiaohan Li
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang 050061, China
| | - Min Zhang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang 050061, China
| | - Zepeng Zhang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang 050061, China
| | - Ye Yang
- School of Resource and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
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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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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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Qiu H, Gui H, Xu H, Cui L, Li Z, Yu H. Quantifying nitrate pollution sources of shallow groundwater and related health risks based on deterministic and Monte Carlo models: A study in Huaibei mining area, Huaibei coalfield, China. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 249:114434. [PMID: 38321656 DOI: 10.1016/j.ecoenv.2022.114434] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/22/2022] [Accepted: 12/12/2022] [Indexed: 02/08/2024]
Abstract
Nitrate pollution in groundwater is a global environmental concern. As a result, accurate identification of potential sources for such pollution is of critical significance to the effective control of groundwater quality. In this study, forty-nine shallow groundwater samples were collected from the Huaibei mining area. Hydro-chemical characterization, geospatial analysis technique, dual nitrate isotopes (δ15N-NO3- and δ18O-NO3-), Bayesian model and health risk assessment model were adopted for exploring the conditions, sources, proportion, and potential health risks of nitrate pollution for the first time in the study area. The results showed that the nitrate concentration ranged from 0.00 to 293.21 mg/L, and that 18.37% groundwater samples exceeded the standard of drinking water in China (GB 5749-2006). Based on the dual isotopic values of nitrate, it could be concluded that nitrification was dominated migration and transformation process of nitrogen. The results of Bayesian model showed that the proportional contributions of the potential nitrate pollution sources in shallow groundwater were manure and sewage (M&S) (39.54 %), NH4+ in fertilizer and precipitation (NHF&P) (34.93 %), soil nitrogen (SN) (14.89 %), and NO3- in atmospheric deposition (NAD) (10.64 %). The health risk assessment indicated that non-carcinogenic risks posed by NO3--N was higher for children than adults. The primary exposure pathway was oral ingestion. Monte Carlo simulation were applied to evaluate model uncertainty. The probabilities of non-carcinogenic risks were up to 12.54 % for children and 5.22 % for adults. In order to protect water quality and drinking water safety, it was suggested that effective nitrate reduction strategies and better management practices can be implemented.
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Affiliation(s)
- Huili Qiu
- National Engineering Research Center of Coal Mine Water Hazard Controlling, Suzhou University, Suzhou 234000, PR China; School of Information Engineering, Suzhou University, Suzhou 234000, PR China; Key Laboratory of Mine Water Resource Utilization of Anhui Higher Education Institutes, Suzhou University, Suzhou 234000, PR China
| | - Herong Gui
- National Engineering Research Center of Coal Mine Water Hazard Controlling, Suzhou University, Suzhou 234000, PR China; Key Laboratory of Mine Water Resource Utilization of Anhui Higher Education Institutes, Suzhou University, Suzhou 234000, PR China.
| | - Haifeng Xu
- School of Information Engineering, Suzhou University, Suzhou 234000, PR China.
| | - Lin Cui
- School of Information Engineering, Suzhou University, Suzhou 234000, PR China
| | - Zhichun Li
- National Engineering Research Center of Coal Mine Water Hazard Controlling, Suzhou University, Suzhou 234000, PR China
| | - Hao Yu
- National Engineering Research Center of Coal Mine Water Hazard Controlling, Suzhou University, Suzhou 234000, PR China
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Zhang J, Cao M, Jin M, Huang X, Zhang Z, Kang F. Identifying the source and transformation of riverine nitrates in a karst watershed, North China: Comprehensive use of major ions, multiple isotopes and a Bayesian model. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 246:103957. [PMID: 35176529 DOI: 10.1016/j.jconhyd.2022.103957] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 11/17/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Nitrate (NO3-) contamination of surface water is a globally concern, especially in karstic regions affected by intensive agricultural activities. This study combines hydrochemistry, and environmental isotopes (δ2HH2O, δ18OH2O, δ15NNO3, and δ18ONO3) with a Bayesian isotope mixing model (Simmr) to reduce the uncertainty in estimating the contributions of different pollution sources. Samples were collected from 32 surface water sites in the Yufu River (YFR) watershed, North China, in September and December 2019. The results revealed that NO3--N was the predominant form of inorganic nitrogen that caused the deterioration of water quality in the watershed, accounting for approximately 58% of the total nitrogen (TN). The hydrochemical compositions and nitrate isotopes indicated that NO3- mainly originated from soil nitrogen (SN), ammonium fertilizer (AF), but nitrate fertilizer (NF), manure and sewage (M&S) and atmospheric precipitation (AP) were limited. The isotopic composition of nitrate in the upper reaches of the watershed was mainly affected by microbial nitrification, while the mixture of multiple sources was the dominant nitrogen transformation process in the mid-lower reaches of the watershed. Simmr model outputs revealed that SN (56.5%) and AF (29.5%) were the primary contributor to riverine NO3- pollution, followed by NF (7.1%), MS (3.6%), and AP (3.4%) sources. Moreover, an uncertainty index (UI90) of the isotope mixing showed that SN (0.73) and AF (0.67) had the highest values, followed by NF (0.22), M&S (0.22) and AP (0.10). Chemical fertilizer and SN collectively contributed >50% of nitrate during the two sampling campaigns. These results indicated that reducing the application of nitrogen fertilizers and rational irrigation are the keys to alleviate of NO3- pollution. The study is helpful in understanding the source and transformation of riverine NO3- and effectively reducing NO3- pollution in karst agricultural rivers or watersheds.
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Affiliation(s)
- Jie Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, Hubei, PR China; School of Environmental Studies, China University of Geosciences, Wuhan 430078, Hubei, PR China
| | - Mingda Cao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, Hubei, PR China; School of Environmental Studies, China University of Geosciences, Wuhan 430078, Hubei, PR China
| | - Menggui Jin
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, Hubei, PR China; School of Environmental Studies, China University of Geosciences, Wuhan 430078, Hubei, PR China.
| | - Xin Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, Hubei, PR China; School of Environmental Studies, China University of Geosciences, Wuhan 430078, Hubei, PR China
| | - Zhixin Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, Hubei, PR China; School of Environmental Studies, China University of Geosciences, Wuhan 430078, Hubei, PR China
| | - Fengxin Kang
- Shandong Provincial Bureau of Geology and Mineral Resources, Jinan 250013, Shandong, PR China; Shandong Provincial Research Center of Groundwater Environment Protection and Remediation, Jinan 250014, Shandong, PR China
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Yu J, Zhang W, Tan Y, Zong Z, Hao Q, Tian C, Zhang H, Li J, Fang Y, Zhang G. Dual-isotope-based source apportionment of nitrate in 30 rivers draining into the Bohai Sea, north China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 283:117112. [PMID: 33862341 DOI: 10.1016/j.envpol.2021.117112] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
Excessive nitrate (NO3-) in rivers can lead to water quality deterioration, and can also be directly input into estuaries and oceans, thus posing a serious threat to the stability of their ecosystems. In this study, the concentration, isotopes and sources of NO3- in 30 rivers discharging into the Bohai Sea were comprehensively investigated. The mean concentration of NO3--N was 2.24 ± 2.11 mg L-1, with obvious seasonal and spatial variations. In total, 104.24 kt of NO3--N was discharged into the Bohai Sea annually, to which the Yellow River Basin and Liao River Basin made the largest contributions. The range of δ15N-NO3- was -1.1‰ to +33.2‰ (mean value, +11.4 ± 5.0‰), with no significant seasonal or spatial differences; the mean value of δ18O-NO3- was +9.4 ± 7.2‰, with much higher values seen in June. Based on the MixSIAR model, manure (24.3 ± 7.5%) and sewage (19.1 ± 14.5%) were the primary sources of NO3- in the 30 rivers, followed by NO3- fertilizers (16.3 ± 12.5%), soil N (15.5 ± 11.9%), atmospheric deposition of NO3- (13.5 ± 5.7%) and NH4+ fertilizers (11.4 ± 8.9%). This finding highlights the vital roles of sewage and manure management in riverine NO3-. Using a mathematical method, the contributions of various sources to each river were simulated. The results indicated that management of the Yellow River, Daliao River, Liao River, and Xiaoqing River is more urgently needed than that of other rivers to control Bohai NO3- pollution. We believe that this finding will provide guidance for scientific management of NO3- pollution in these 30 rivers and the Bohai Sea.
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Affiliation(s)
- Jing Yu
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
| | - Wei Zhang
- School of Environmental and Material Engineering, Yantai University, Yantai, Shandong, 264005, PR China
| | - Yang Tan
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
| | - Zheng Zong
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China.
| | - Qinqin Hao
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, PR China
| | - Chongguo Tian
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
| | - Hua Zhang
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China
| | - Jun Li
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Yunting Fang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, 110164, PR China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
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Weitzman JN, Brooks JR, Mayer PM, Rugh WD, Compton JE. Coupling the dual isotopes of water (δ 2H and δ 18O) and nitrate (δ 15N and δ 18O): A new framework for classifying current and legacy groundwater pollution. ENVIRONMENTAL RESEARCH LETTERS : ERL [WEB SITE] 2021; 16:1-45008. [PMID: 33897808 PMCID: PMC8059602 DOI: 10.1088/1748-9326/abdcef] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Nitrate contamination of groundwater is a concern globally, particularly in agricultural regions where decades of fertilizer nitrogen (N) use has led to a legacy of N accumulation in soils and groundwater. Linkages between current management practices and groundwater nitrate dynamics are often confounded by the legacy effect, and other processes unrelated to management. A coupled analysis of dual stable isotopes of water (δH2O = δ2H and δ18O) and nitrate (δNO3 - = δ15N and δ18O) can be a powerful approach to identify sources and processes responsible for groundwater pollution. To assess how management practices impact groundwater nitrate, we interpreted behavior of δH2O and δNO3 -, together with nitrate concentrations, in water samples collected from long-term monitoring wells in the Southern Willamette Valley (SWV), Oregon. The source(s) of nitrate and water varied among wells, suggesting that the nitrate concentration patterns were not uniform across the shallow aquifer of the valley. Analyzing the stability versus variability of a well's corresponding δH2O and δNO3 - values over time revealed the mechanisms controlling nitrate concentrations. Wells with stable δH2O and δNO3 - values and nitrate concentrations were influenced by one water source with a long residence time and one nitrate source. Variable nitrate concentrations of other wells were attributed to dilution with an alternate water source, mixing of two nitrate sources, or variances in the release of legacy N from overlying soils. Denitrification was not an important process influencing well nitrate dynamics. Understanding the drivers of nitrate dynamics and interaction with legacy N is crucial for managing water quality improvement. This case study illustrates when and where such coupled stable isotope approaches might provide key insights to management on groundwater nitrate contamination issues.
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Affiliation(s)
- Julie N. Weitzman
- ORISE Fellow at Pacific Ecological Systems Division, Center for Public Health and Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Newport, OR, United State of America
| | - J. Renée Brooks
- Pacific Ecological Systems Division, Center for Public Health and Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR, United States of America
| | - Paul M. Mayer
- Pacific Ecological Systems Division, Center for Public Health and Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR, United States of America
| | - William D. Rugh
- Pacific Ecological Systems Division, Center for Public Health and Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR, United States of America
| | - Jana E. Compton
- Pacific Ecological Systems Division, Center for Public Health and Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR, United States of America
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Chen X, Jiang C, Zheng L, Dong X, Chen Y, Li C. Identification of nitrate sources and transformations in basin using dual isotopes and hydrochemistry combined with a Bayesian mixing model: Application in a typical mining city. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:115651. [PMID: 33254675 DOI: 10.1016/j.envpol.2020.115651] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 08/19/2020] [Accepted: 09/11/2020] [Indexed: 06/12/2023]
Abstract
The external nitrogen load input caused by human activities exacerbates the eutrophication process of aquatic ecosystems in mining areas, causing water quality problems. However, knowledge of the sources and environmental behavior of nitrate in the surface water of mining areas is still very limited. This study investigated the nitrate content and spatiotemporal variation characteristics of surface water in the Linhuan mining area, identified the sources and transformation processes of nitrate using isotopes and hydrochemistry, and evaluated the contribution rates of different potential nitrate sources based on a Bayesian mixing model. The nitrogen pollution in the surface water in the mining area seriously exceeded class Ⅴ of the Environmental Quality Standard of Surface Water of China (GB3838-2002). The NO3- content ranged from 0.87 to 3.41 mg/L, showing obvious seasonal and spatial differences. Isotope and NO3-/Cl- analysis indicated that nitrate in the subsidence area water (SAW) was mainly derived from chemical fertilizer (NF) and soil organic nitrogen (NS), while nitrate in the mainstream of the Huihe River water (HRW) was mainly derived from manure/sewage (MS). The nitrate in the tributary of the Baohe River water (BRW) was mainly derived from soil NS, and nitrification was a nitrogen conversion pathway in the soil. The results of the Bayesian mixing model showed that the main sources of nitrate in the BRW, HRW and SAW were NF (34.5%), MS (68.8%) and NF (40.8%) in the wet season, and NS (33.4%), MS (70.9%) and NF (58.1%) in the dry season, respectively. The results of this study provide a new integrated method for the identification of nitrate pollution sources in mining areas, and this method can be used to improve the biogeochemical information of nitrogen in the aquatic ecosystems of mining areas and help formulate relevant measures to reduce water nitrogen pollution.
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Affiliation(s)
- Xing Chen
- School of Resources and Environmental Engineering, Anhui University, Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, 230601, Anhui, China
| | - Chunlu Jiang
- School of Resources and Environmental Engineering, Anhui University, Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, 230601, Anhui, China
| | - Liugen Zheng
- School of Resources and Environmental Engineering, Anhui University, Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, 230601, Anhui, China.
| | - Xianglin Dong
- Geological Survey Division, Huaibei Coal Mining Group Corporation, Huaibei, 235001, Anhui, China
| | - Yongchun Chen
- National Engineering Laboratory of Coal Mine Ecological Environment Protection, Huainan, 232001, Anhui, China
| | - Chang Li
- School of Resources and Environmental Engineering, Anhui University, Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, 230601, Anhui, China
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Zhao H, Xiao Q, Miao Y, Wang Z, Wang Q. Sources and transformations of nitrate constrained by nitrate isotopes and Bayesian model in karst surface water, Guilin, Southwest China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:21299-21310. [PMID: 32266624 DOI: 10.1007/s11356-020-08612-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/26/2020] [Indexed: 06/11/2023]
Abstract
Surface water suffering from nitrate (NO3-) contamination in karst area is not only harmful to human health as drinking water but can also affect the process of carbonate rock weathering, so it is crucial to trace the sources and transformations of NO3- in karst surface water. In this study, an investigation of water chemical data and NO3- isotopes (δ15N and δ18O) was used to elucidate the transformations of NO3- and quantify a proportional apportionment of NO3- sources of individual potential sources (incl. soil organic nitrogen (SON), atmospheric precipitation (AP), manure and sewage wastes (M&S), and chemical fertilizer (CF)) in the Lijiang River (typical karst surface water), Guilin, Southwest China. δ15N-NO3- and δ18O-NO3- values of water samples from the Lijiang River range from 2.14 to 13.50‰ (mean, 6.59‰) and from - 2.44 to 6.97‰ (mean, 3.76‰), respectively. A positive correlation between Cl- and NO3- but no correlations between NO3- and δ15N-NO3- or δ18O-NO3- are found and the δ18O-NO3- values fitted the theoretical δ18O-NO3- values produced from nitrification, suggesting that the genesis of NO3- in waters of the Lijiang River is affected by nitrification processes and the mixing process has a major effect on NO3- transportation. Results of the Bayesian stable isotope mixing model show that the M&S and SON are the main NO3- source through the whole year (accounting for ~ 61% and 65% of the total NO3- in the wet and dry season, respectively), followed by CF (~ 29%). Furthermore, we find that nitrification of nitrogen in fertilizers, soil, and manure and sewage can promote the carbonate rock weathering. The estimated contribution of such nitrification to the weathering of carbonate rocks accounts for about 11% of the total carbonate rock weathering flux (calculated by HCO3-) in the Lijiang River. This finding indicates that the weathering of carbonate rock is probably affected by nitrogen nitrification processes in karst catchment.
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Affiliation(s)
- Haijuan Zhao
- Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing, 400715, 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.
| | - Ying Miao
- Key Laboratory of Karst Dynamics, MLR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China
| | - Zhijun Wang
- 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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