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Assessing The Fate Of Dissolved Inorganic Nitrogen In The Qishon Estuary Israel By Means Of Nitrate Stable Isotopes
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Book Synopsis Assessing the Fate of Dissolved Inorganic Nitrogen in the Qishon Estuary Israel, by Means of Nitrate Stable Isotopes by : Efrat Eliani-Russak
Download or read book Assessing the Fate of Dissolved Inorganic Nitrogen in the Qishon Estuary Israel, by Means of Nitrate Stable Isotopes written by Efrat Eliani-Russak and published by . This book was released on 2010 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Application of Nitrogen Stable Isotopes to Identify Sources of Nutrient Pollution by : Elizabeth A. Redon
Download or read book Application of Nitrogen Stable Isotopes to Identify Sources of Nutrient Pollution written by Elizabeth A. Redon and published by . This book was released on 2001 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nutrient pollution may perhaps be one of the oldest water quality problems and has recently been considered as one of the greatest threats to estuarine and coastal waters. Excessive nutrient loads have had a vast array of impacts on estuarine and coastal ecosystems globally. Direct negative effects include: shading out of benthic plant communities, hypoxia and anoxia due to increased biological oxygen demand, compositional change in plant and fauna! community structure and increased occurrences of harmful algal blooms. This has lead to decreased biodiversity, habitat, fisheries, tourism and aesthetics. So far environmental managers have had to rely on a posteriori assessments of the status of nutrient pollution, using indicators such as taxonomic shifts and changes in biological abundance, which have already occurred. By the time nutrient pollution is detected, restoration of habitats is costly and sometimes no longer an option. Therefore, there is a need for management tools to assess sources of nutrient loads before damage to estuarine and coastal ecosystems progresses beyond recovery. Early work using stable isotopes of dissolved inorganic nitrogen in groundwater samples demonstrated the potential for using stable isotopes to identify anthropogenic sources of nitrogen. These studies revealed that nitrogen sources such as fertilizers, soil organic nitrogen and wastewater nitrogen have isotopically distinct signatures that could be used to assess anthropogenic nitrogen contributions. Therefore, application of nitrogen stable isotope methods could potentially provide information on the anthropogenic nitrogen sources stimulating nutrient pollution in estuarine and coastal waters. However, when I assessed this approach for application, two sources of errors became apparent. First, laboratory isolation of dissolved inorganic nitrate from seawater delivered results depleted in 15N relative to the standard used to assess the method. Second, isotopic fractionation associated with nitrogen cycle processes complicates usage of an isotopic mass balance to solve for the nitrogen source and its fractional contribution based on isotopic data alone. As a result, isotopic analysis alone of dissolved inorganic nitrogen to determine anthropogenic sources of nutrient loads to estuarine and coastal waters is not a practical approach to obtain management information concerning nutrient pollution.
Book Synopsis Assessing the Use of Stable Isotopes to Monitor Anthropogenic Nitrogen Inputs to Estuarine Systems by : Rebecca O. Bannon
Download or read book Assessing the Use of Stable Isotopes to Monitor Anthropogenic Nitrogen Inputs to Estuarine Systems written by Rebecca O. Bannon and published by . This book was released on 2006 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Identification of the Sources of Nitrate Contamination in the Western Galilee Aquifers, Northern Israel, Using a Multi-proxy Stable Isotope and Chemical Approach by : B. Schilman
Download or read book Identification of the Sources of Nitrate Contamination in the Western Galilee Aquifers, Northern Israel, Using a Multi-proxy Stable Isotope and Chemical Approach written by B. Schilman and published by . This book was released on 2007 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Fate of Anthropogenic Nitrogen in a Redox Stratified Pond by : Luciana Villarroel
Download or read book The Fate of Anthropogenic Nitrogen in a Redox Stratified Pond written by Luciana Villarroel and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The environmental effects of both increased urbanization and eutrophication are of growing global concern. Coastal areas, like those found on Cape Cod, Massachusetts, often experience severe impacts associated with the biogeochemical effects accompanying increased nitrogen pollution. Cape Cod is home to roughly 1,000 ponds and lakes which play an important role in local ecosystems, but the cycling of nitrogen in these waters is not well understood. The goal of this research is to identify the major biogeochemical cycling processes responsible for the fate of nitrogen in a nitrogen-rich, coastal, stratified pond. The investigation was carried out through regular high-resolution measurement and monitoring of environmental conditions, nitrogen speciation, and isotopic composition over the course of a summer. Elevated nitrogen concentrations coupled with strong redox gradients make Siders Pond an ideal place for studying dynamics of nitrogen transformations, giving insight into nitrogen retention or removal, which influence water quality. These data demonstrate significant dissolved nitrogen loss from the pond over the course of the summer as well as internal nitrogen cycling that promotes dissolved nitrogen accumulation to extreme levels in the deepest depths. The physical dynamics of mixing promote a coupling of nitrification and denitrification across this redox gradient, driving N loss while also supplying the sunlit waters with nutrient-rich deep water. A simple time-resolved box model suggests that approximately 50% of the upwardly delivered N is removed, while the other portion supports recycling through photosynthetic uptake. While dissolved organic nitrogen (DON) is widely considered refractory material and is rarely measured or reported in environmental studies, here there is evidence for a large and dynamic pool of DON within Siders Pond suggesting important dynamics between organic and inorganic pools in regulating N loss. While nitrate is a commonly used measurement for assessing N contamination, this work highlights the parallel importance of monitoring additional species (including ammonium and DON) for determining eutrophication/contamination. A deeper understanding of Siders Pond can be used to elucidate nitrogen cycling dynamics in analogous redox-stratified systems, including other lakes and ponds, or modern ocean regions such as the Santa Barbara and Cariaco Basins and the Baltic and Black Seas.
Book Synopsis The Stable Isotopic Composition of Dissolved Organic Nitrogen and Nitrate in the Subtropical Ocean by : Angela Noel Knapp
Download or read book The Stable Isotopic Composition of Dissolved Organic Nitrogen and Nitrate in the Subtropical Ocean written by Angela Noel Knapp and published by . This book was released on 2006 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Stable Isotopic Assessment of the Inorganic Nitrogen Input to the Ground Water Near an Agricultural Area of Eastern Virginia by : Robert John Tapper
Download or read book A Stable Isotopic Assessment of the Inorganic Nitrogen Input to the Ground Water Near an Agricultural Area of Eastern Virginia written by Robert John Tapper and published by . This book was released on 1995 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Stable Isotope Tracers of Nitrogen Sources to the Neuse River, North Carolina by :
Download or read book Stable Isotope Tracers of Nitrogen Sources to the Neuse River, North Carolina written by and published by . This book was released on 1990 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Use of Stable Isotopes of Carbon, Nitrogen, and Sulfur to Identify Sources of Nitrogen in Surface Waters in the Lower Susquehanna River Basin, Pennsylvania by : Charles A. Cravotta
Download or read book Use of Stable Isotopes of Carbon, Nitrogen, and Sulfur to Identify Sources of Nitrogen in Surface Waters in the Lower Susquehanna River Basin, Pennsylvania written by Charles A. Cravotta and published by U.S. Government Printing Office. This book was released on 2002 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Application of Isotope Techniques for Assessing Nutrient Dynamics in River Basins by : International Atomic Energy Agency
Download or read book Application of Isotope Techniques for Assessing Nutrient Dynamics in River Basins written by International Atomic Energy Agency and published by IAEA Tecdoc. This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the application of isotope techniques as a tool for evaluating nutrient dynamics in river systems. The book shows that the application of isotope techniques could enable or facilitate the examination of sources, pathways, transformations, and fates of nutrients in river systems, contributing to integrated water resource management.
Book Synopsis Seasonal Variations in the Nitrogen Isotopic Composition of Dissolved Nitrate in the Changjiang River Estuary, China by :
Download or read book Seasonal Variations in the Nitrogen Isotopic Composition of Dissolved Nitrate in the Changjiang River Estuary, China written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Isotopic Biogeochemistry of Dissolved Organic Nitrogen by : Timothy P. Feuerstein
Download or read book Isotopic Biogeochemistry of Dissolved Organic Nitrogen written by Timothy P. Feuerstein and published by . This book was released on 1997 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Using Stable Nitrogen Isotopes to Characterize and Evaluate Nitrogen Sources to Greenwich Bay, RI and Their Influence on Isotopic Signatures in Estuarine Organisms by : Peter A. Dimilla
Download or read book Using Stable Nitrogen Isotopes to Characterize and Evaluate Nitrogen Sources to Greenwich Bay, RI and Their Influence on Isotopic Signatures in Estuarine Organisms written by Peter A. Dimilla and published by . This book was released on 2006 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Effect of Dissolved Organic Nitrogen Contamination on Δ15N–NH4 Determination in Water Samples by Modification of the Diffusion Method with Gas‐phase Trapping by :
Download or read book Effect of Dissolved Organic Nitrogen Contamination on Δ15N–NH4 Determination in Water Samples by Modification of the Diffusion Method with Gas‐phase Trapping written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Rationale: The isotopic tracer technique is widely used to identify the sources and fate of nitrogen (N) in order to understand the N cycle and contamination in water environments. The stable isotope ratio of ammonium is expected to greatly enhance the tracing analysis by combining it with the traditional nitrate isotope ratio. Diffusion followed by gas‐phase trapping is the most commonly applied method for ammonium isotope ratio measurement. Although dissolved organic nitrogen (DON) is abundant in natural water and its breakdown in the diffusion procedure has been reported, the interference of DON with the measurement of ammonium isotope ratios has not been fully examined. Methods: This study aims to test the effect of DON contamination by using organic N compounds, viz. humic acid and alanine. A series of diffusion experiments was conducted at a temperature of 80°C for a maximum of 7days. Ammonia was transferred from alkaline solution and trapped with an acidic filter. This method was applied for samples with ammonium concentrations between 0.5 and 2.0mg‐N/L. Results: There was no difference between the ammonium N stable isotope ratios for samples with and without added DON compounds; the fractionation between the observed value and the actual value was negligible, in the range of 0.2 to 1.0‰. The modifications of previous studies, i.e. shorter diffusion period, no vigorous shaking and using gas‐phase trapping, successfully avoided any breakdown of DON in fresh water samples. Conclusions: The modified method provides high precision and accuracy and it is recommended for the analysis of anthropogenically influenced water samples, such as paddy fields, ground water, rivers and lakes.
Book Synopsis Use of Natural Abundance Stable Nitrogen Isotope Ratio Measurements to Investigate Mechanisms of Nitrogen Loss in the Hidden Valley Wildlife Area Ponds, Riverside, CA by : Marlene Ann Braun
Download or read book Use of Natural Abundance Stable Nitrogen Isotope Ratio Measurements to Investigate Mechanisms of Nitrogen Loss in the Hidden Valley Wildlife Area Ponds, Riverside, CA written by Marlene Ann Braun and published by . This book was released on 1991 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis N and O Isotope Ratios of NO3- as a Tracer for Nitrogen Cycling and Water Mass Distribution by : Nadine Lehmann
Download or read book N and O Isotope Ratios of NO3- as a Tracer for Nitrogen Cycling and Water Mass Distribution written by Nadine Lehmann and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen plays a central role in marine biogeochemistry. Its distribution, chemical speciation and ratio relative to other nutrients governs the presence and abundance of microbial communities, and of large scale ocean production. In this respect, my thesis examines how biochemical and physical processes regulate the distribution of different nitrogen (N) species and their transformation in various marine environments by evaluating the spatial distribution of nitrogen and oxygen isotopes of nitrate (NO3-), in combination with a varying set of complementary biogeochemical tracers. Chapter 2 examines the isotopic composition of NO3- and total dissolved inorganic carbon (DIC) to elucidate the hydrography of the Western Equatorial Pacific (WEP) and biogeochemical evolution of water masses that contribute to the Equatorial Undercurrent (EUC). Based on isotope data and water mass mixing estimates, I highlight the different biogeochemical histories of nutrients feeding the northern and southern WEP, and provide support for the theory of a predominantly Southern Ocean source of NO3- to the EUC. Chapter 3 focuses on Baffin Bay, which represents a major link between the high Arctic and the northwestern Atlantic, owing to its effect on the salt and nutrient budgets of the adjacent Labrador Sea and the wider Atlantic Ocean. I combine NO3- isotope ratios with nitrous oxide (N2O) isotope measurements to identify the origin of the pronounced N-deficit and N2O supersaturation prevalent in deep Baffin Bay. The set of isotopic tracers used in this study allows the identification of different, yet complementary, N transformation processes. NO3- isotopes reflect substantial in situ remineralization of organic matter originating from surface productivity fueled by Pacific-derived nutrients, whereas N2O isotopomer abundances point to sedimentary denitrification as a potential source of the N-deficiency observed in the deep basin. In chapter 4, I use NO3- isotope ratios measured in the Canada Basin and in the Baffin Bay together with hydrographic data and nutrient ratios as a baseline to evaluate the distribution of Pacific- and Atlantic-derived water masses throughout the Arctic Archipelago. With this work, I highlight the importance and applicability of dual isotope measurements as water mass tracers and provide insights into individual processes within the N cycle.
Book Synopsis Characterising Dissolved Nitrate in Precipitation Using Stable Nitrogen and Oxygen Isotopes by : Vanessa Eileen Lee
Download or read book Characterising Dissolved Nitrate in Precipitation Using Stable Nitrogen and Oxygen Isotopes written by Vanessa Eileen Lee and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
