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Xiong G, Zhu X, Wu J, Liu M, Yang Y, Zeng X. Seawater intrusion alters nitrogen cycling patterns through hydrodynamic behavior and biochemical reactions: Based on Bayesian isotope mixing model and microbial functional network. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161368. [PMID: 36621512 DOI: 10.1016/j.scitotenv.2022.161368] [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: 10/17/2022] [Revised: 12/07/2022] [Accepted: 12/30/2022] [Indexed: 06/17/2023]
Abstract
Seawater intrusion is a global coastal environmental issue of great concern and significantly impacts the regional biogeochemical environment and material cycles, including nitrogen cycling. To reveal the mechanism of seawater intrusion altering nitrogen cycling patterns through hydrodynamic behavior and biochemical reactions, the Bayesian mixing model (δ15N-NO3- and δ18O-NO3-) and 16S rDNA gene amplicon sequencing are used to establish nitrogen cycling pathways and microbial functional network. The results show that the nitrate in the coastal groundwater is from manure and septic waste (M&S, over 44 %), soil organic nitrogen (SON, over 20 %), and nitrogen fertilizer (FN, over 16 %). The hydrological interaction has promoted the coupling between material cycling and microbial community in the coastal groundwater systems. Among them, precipitation infiltration has caused the gradual decrease of specific microbes along the flow direction, such as Lactobacillus, Acinetobacter, Bifidobacterium, etc. And seawater intrusion has caused the mutations of specific microbes (Planktomarina, Clade_Ia, Wenyingzhuangia, Glaciecola, etc.) and convergence of microbial community at the salt-freshwater interface in the aquifer. In the coastal intruded aquifer systems, the nitrogen cycling pattern can be divided into oxidation and reduction processes. The oxidation process involves the enhancement of nitrification while the weakening of denitrification and anammox with the increase of aquifer depth. The reduction process consists of the enhancement of denitrification and anammox while the erosion of nitrification and ammonification with increased seawater intrusion. In addition, seawater intrusion can mitigate nitrate contamination by promoting denitrification and anammox in coastal areas.
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Affiliation(s)
- Guiyao Xiong
- Key Laboratory of Surficial Geochemistry of Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
| | - Xiaobin Zhu
- Key Laboratory of Surficial Geochemistry of Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China.
| | - Jichun Wu
- Key Laboratory of Surficial Geochemistry of Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China.
| | - Mengwen Liu
- Key Laboratory of Surficial Geochemistry of Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
| | - Yun Yang
- School of Earth Sciences and Engineering, Hohai University, Nanjing 211100, China
| | - Xiankui Zeng
- Key Laboratory of Surficial Geochemistry of Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
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Torres-Martínez JA, Mora A, Mahlknecht J, Kaown D, Barceló D. Determining nitrate and sulfate pollution sources and transformations in a coastal aquifer impacted by seawater intrusion-A multi-isotopic approach combined with self-organizing maps and a Bayesian mixing model. JOURNAL OF HAZARDOUS MATERIALS 2021; 417:126103. [PMID: 34229392 DOI: 10.1016/j.jhazmat.2021.126103] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/17/2021] [Accepted: 05/06/2021] [Indexed: 06/13/2023]
Abstract
Over the past few decades, the La Paz aquifer system in Baja California Sur, Mexico, has been under severe pressure due to overexploitation for urban water supply and agriculture; this has caused seawater intrusion and deterioration in groundwater quality. Previous studies on the La Paz aquifer have focused mainly on seawater intrusion, resulting in limited information on nitrate and sulfate pollution. Therefore, pollution sources have not yet been identified sufficiently. In this study, an approach combining hydrochemical tools, multi-isotopes (δ2HH2O, δ18OH2O, δ15NNO3, δ18ONO3, δ34SSO4, δ18OSO4), and a Bayesian isotope mixing model was used to estimate the contribution of different nitrate and sulfate sources to groundwater. Results from the MixSIAR model revealed that seawater intrusion and soil-derived sulfates were the predominant sources of groundwater sulfate, with contributions of ~43.0% (UI90 = 0.29) and ~42.0% (UI90 = 0.38), respectively. Similarly, soil organic nitrogen (~81.5%, UI90 = 0.41) and urban sewage (~12.1%, UI90 = 0.25) were the primary contributors of nitrate pollution in groundwater. The dominant biogeochemical transformation for NO3- was nitrification. Denitrification and sulfate reduction were discarded due to the aerobic conditions in the study area. These results indicate that dual-isotope sulfate analysis combined with MixSIAR models is a powerful tool for estimating the contributions of sulfate sources (including seawater-derived sulfate) in the groundwater of coastal aquifer systems affected by seawater intrusion.
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Affiliation(s)
- Juan Antonio Torres-Martínez
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Monterey, Eugenio Garza Sada 2501, Monterrey 64149, Nuevo León, México
| | - Abrahan Mora
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Puebla, Atlixcáyotl 5718, Puebla de Zaragoza 72453, Puebla, México
| | - Jürgen Mahlknecht
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Monterey, Eugenio Garza Sada 2501, Monterrey 64149, Nuevo León, México.
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, South Korea
| | - Damia Barceló
- Department of Environmental Chemistry, IIQAB, 08034 Barcelona, Spain
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Romanelli A, Soto DX, Matiatos I, Martínez DE, Esquius S. A biological and nitrate isotopic assessment framework to understand eutrophication in aquatic ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 715:136909. [PMID: 32018104 DOI: 10.1016/j.scitotenv.2020.136909] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/22/2020] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
Eutrophication is a globally significant challenge facing aquatic ecosystems, mostly associated with human induced enrichment of these ecosystems with nitrogen and phosphorus. Given the complexity of assigning eutrophication issues to local primary N sources in field-based studies, this paper proposes a multi-stable isotope and biological framework to track nitrogen biogeochemical transformations, inputs and fate of nitrate in groundwater-dependent shallow lakes. Three representative freshwater ecosystems from the Pampa Plain (Argentina), with different land uses and topographic features were selected. Groundwater (N = 24), lake (N = 29) and stream (N = 20) samples were collected for isotope (δ15N-NO3- and δ18O-NO3-, δ18O-H2O) and hydrogeochemical (major ions and nutrients) determinations, and in the case of surface water, also for biological determinations (chlorophyll-a, fecal coliforms and nitrifying bacteria abundance). Both chemical and isotopic characteristics clearly indicated that denitrification was limited in lakes and streams, while evidence of assimilation in shallow lakes was confirmed. The results suggested that groundwater denitrification plays a role in the nitrate concentration pattern observed in the Pampeano Aquifer. The proportional contribution of nitrate sources to the inflow streams for all years were estimated by using Bayesian isotope mixing models, being ammonium nitrified in the system from soil and fertilizers ~50 - 75 %, sewage/manure ~20 - 40 % and atmospheric deposition ~5 - 15 %. In this sense, agricultural practices seem to have a relevant role in the eutrophication and water quality deterioration for these watersheds. However, limnological, bacterial and algal variables, assessed simultaneously with isotopic tracers, indicated spatio-temporal differences within and between these aquatic ecosystems. In the case of Nahuel Rucá Lake, animal manure was a significant source of nitrogen pollution, in contrast to La Brava Lake. In Los Padres Lake, agricultural practices were considered the main sources of nitrate input to the ecosystem.
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Affiliation(s)
- Asunción Romanelli
- Instituto de Investigaciones Marinas y Costeras, Consejo Nacional de Investigaciones Científicas y Técnicas (UNMdP-CONICET), FCEyN, CC1260, 7600 Mar del Plata, Argentina; Instituto de Geología de Costas y del Cuaternario, Universidad Nacional de Mar del Plata-CIC, 3350 Funes St., Level 1, 7600 Mar del Plata, Argentina.
| | - David X Soto
- Department of Earth and Environmental Sciences, KU Leuven, B-3001 Leuven, Belgium; UK Centre for Ecology and Hydrology, Lancaster Environment Centre, Lancaster LA1 4AP, UK
| | - Ioannis Matiatos
- International Atomic Energy Agency, Vienna International Centre, 1400 Vienna, Austria
| | - Daniel E Martínez
- Instituto de Investigaciones Marinas y Costeras, Consejo Nacional de Investigaciones Científicas y Técnicas (UNMdP-CONICET), FCEyN, CC1260, 7600 Mar del Plata, Argentina; Instituto de Geología de Costas y del Cuaternario, Universidad Nacional de Mar del Plata-CIC, 3350 Funes St., Level 1, 7600 Mar del Plata, Argentina
| | - Soledad Esquius
- Instituto de Investigaciones Marinas y Costeras, Consejo Nacional de Investigaciones Científicas y Técnicas (UNMdP-CONICET), FCEyN, CC1260, 7600 Mar del Plata, Argentina
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Assessment of the Trophic Status of the South Lagoon of Tunis (Tunisia, Mediterranean Sea): Geochemical and Statistical Approaches. J CHEM-NY 2018. [DOI: 10.1155/2018/9859546] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The trophic status assessment of the South Lagoon of Tunis, a shallow Mediterranean coastal area after its restoration, is addressed herein with respect to its various environmental settings which are taken as indicators of water quality. The lagoon had, in the past, witnessed severe environmental quality issues. To resolve these problems, a large restoration project of the lagoon was undertaken which consisted of dredging the bottom sediments removing areas of water stagnation and improving water circulation. After this restoration work, the lagoon morphology has radically changed. In this paper, we attempt to evaluate the lagoon water’s trophic state to analyze the eutrophication risk after almost 16 years. In order to achieve these purposes, two water quality monitoring campaigns were conducted (July 2013 and February 2014). Natural and anthropogenic factors controlling the nutrient content of the lagoon water have been assessed through both geochemical methods and multivariate statistical tools. The results show that the nutrients are from external sources due to the discharge of municipal and industrial wastewater from the surrounding city of the catchment in the lagoon’s south side. According to the TRIX index, the lagoon remains eutrophic presenting a “poor” water quality, notwithstanding the engineering project due to the high level of nutrients.
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Gikas GD, Tsihrintzis VA, Sykas D. Effect of trees on the reduction of nutrient concentrations in the soils of cultivated areas. ENVIRONMENTAL MONITORING AND ASSESSMENT 2016; 188:327. [PMID: 27147240 DOI: 10.1007/s10661-016-5325-0] [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: 11/28/2015] [Accepted: 04/25/2016] [Indexed: 06/05/2023]
Abstract
The function of trees in reducing nutrient migration to groundwaters in cultivated areas, under Mediterranean climate conditions, is tested. Three cultivated fields were monitored for two cultivation periods. The common characteristic of the three fields was that on one side, they bordered with a poplar tree field. Four different crops were cultivated, and two cultivation periods were monitored. Based on the number of fields (i.e., three) and the cultivation periods (i.e., two), six different conditions (systems) were studied with four crops (i.e., sunflower, cotton, rapeseed, and corn). Soil samples were collected in all systems at the beginning, the middle, and the end of the cultivation period at various sampling sites (i.e., various distances from the tree row) and at various depths, and were analyzed in the laboratory for the determination of ΝΟ3-Ν and P-Olsen. In all systems, the greatest concentration of P-Olsen was measured in the surface layers (0-5, 10-15, and 30-35 cm) and was gradually decreased in the deeper layers (55-60 and 75-80 cm) indicating that P mobility is low. The ΝΟ3-Ν concentration in the deeper layers (55-60 and 75-80 cm) at all sampling sites was equal to or greater than that of the surface layers, indicating that ΝΟ3-Ν has high mobility in soils. At the sampling sites in the soil zone near the tree row, the ΝΟ3-Ν concentration in the deeper layers was lower than that of the surface, indicating that the tree root system takes up nutrients which otherwise would move toward the water table. There was also a reduction observed of the depth-averaged P-Olsen and ΝΟ3-Ν concentrations at the soil zone at a distance of 2.0-3.5 m from the tree row compared to locations more distant from the trees; this reduction ranged between 15 and 50 % and 36 and 54 %, respectively. The results indicate that planting of trees in cultivated fields can contribute to the reduction of nitrate pollution of groundwaters.
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Affiliation(s)
- Georgios D Gikas
- Department of Environmental Engineering, School of Engineering, Laboratory of Ecological Engineering and Technology, Democritus University of Thrace, 67100, Xanthi, Greece
| | - Vassilios A Tsihrintzis
- Centre for the Assessment of Natural Hazards and Proactive Planning and Laboratory of Reclamation Works and Water Resources Management, Department of Infrastructure and Rural Development, School of Rural and Surveying Engineering, National Technical University of Athens, 9 Iroon Polytechniou St., Zografou, 157 80, Athens, Greece.
| | - Dimitrios Sykas
- Department of Environmental Engineering, School of Engineering, Laboratory of Ecological Engineering and Technology, Democritus University of Thrace, 67100, Xanthi, Greece
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Zhang Y, Li F, Zhang Q, Li J, Liu Q. Tracing nitrate pollution sources and transformation in surface- and ground-waters using environmental isotopes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 490:213-222. [PMID: 24858219 DOI: 10.1016/j.scitotenv.2014.05.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 04/30/2014] [Accepted: 05/01/2014] [Indexed: 06/03/2023]
Abstract
Water pollution in the form of nitrate nitrogen (NO3(-)-N) contamination is a major concern in most agricultural areas in the world. Concentrations and nitrogen and oxygen isotopic compositions of nitrate, as well as oxygen and deuterium isotopic compositions of surface and groundwater from a typical irrigated region in the North China Plain (NCP) collected from May to October in 2012 were analyzed to examine the major nitrate sources and transformations. Concentrations of NO3(-)-N ranged from 0.2 to 29.6 mg/L (mean of 11.2 mg/L) in surface water, and from 0.1 to 19.4 mg/L (mean of 2.8 mg/L) in groundwater. Approximately 46.7% of the surface water samples and 10% of the groundwater samples exceeded the World Health Organization (WHO) drinking water standard for NO3(-)-N. Surface water samples that exceeded the standard were collected mainly in the dry season (May and October), while groundwater samples that exceeded the standard were collected in the wet season (June). Overall, the highest nitrate levels were observed in surface water in May and in groundwater in June, indicating that fertilizer application, precipitation, and irrigation strongly influence the NO3(-)-N concentrations. Analyses of isotopic compositions suggest that the main sources of nitrate are nitrification of fertilizer and sewage in surface water, in contrast, mineralization of soil organic N and sewage is the groundwater sources during the dry season. When fertilizers are applied, nitrate will be transported by precipitation through the soil layers to the groundwater in the wet season (June). Denitrification only occurred in surface water in the wet season. Attempts should be made to minimize overuse of nitrogen fertilizers and to improve nitrogen use efficiency in irrigated agricultural regions.
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Affiliation(s)
- Yan Zhang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fadong Li
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Qiuying Zhang
- Center for Agricultural Resources Research, Chinese Academy of Sciences, Shijiazhuang 050021, China
| | - Jing Li
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiang Liu
- Key Laboratory of Ecosystem Network Observation and Modeling, 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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