Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"Nitrogen Loading"”.
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Nitrogen spiraling in stream ecosystems spanning a gradient of chronic nitrogen loading
… is a study of the relationships between nitrogen (N) availability and spiraling (the paired processes of nutrient cycling and advective transport) in stream ecosystems. Anthropogenic activities have greatly increased rates of N loading to aquatic ecosystems. However, streams may be …
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The effect of development on nitrogen loading on St. John, U.S. Virgin Islands
… to the growing population is increased nitrogen loading to the bays, which can impact the benthic habitat. The purpose of this thesis is to evaluate the extent of the effects of human developments on nitrogen loading of the bays on St. John, U. S. Virgin Islands. This is accomplished by …
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Quantifying groundwater discharge using thermal imagery and conventional groundwater exploration techniques for estimating the nitrogen loading to a meso-scale inland estuary
… to evaluate groundwater inflow and nutrient loadings to the Great Bay Estuary, New Hampshire. The evaluation of inflow was accomplished independently by two methods: one, used thermal imagery, and the other, piezometric mapping. The thermal imagery method assessed groundwater that was …
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Comparative Ecological Modeling for Long-term Solution of Excess Nitrogen Loading to Surface Waters and Related Chronic and Systemic Human-Environment Problems
… CO2 emissions and climate change, 2) excess nitrogen export and eutrophication of surface waters, and 3) dependence on non-renewable fossil fuel energy supplies can be considered interdependent symptoms of a single systemic "humans in the environment disorder". This dissertation presents …
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Statistical and Realistic Numerical Model Investigations of Anthropogenic and Climatic Factors that Influence Hypoxic Area Variability in the Gulf of Mexico
… Mexico was caused by the increased anthropogenic nitrogen loading of the Mississippi River; however, the nitrogen-area relationship is complicated by many other factors, such as wind, river discharge, and the ratio of Mississippi to Atchafalaya River flow. These factors are related to large-scale …
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Development of High Efficiency Partial Nitrification as a First Step of Nitrite Shunt Process using Ammonium-Oxidizing Bacteria (AOB)
Shortcut biological nitrogen removal is a non-conventional way of removing nitrogen from wastewater using two processes either nitrite shunt or deammonification. In this research, a complete partial nitrification as a first step of the Nitrite Shunt process has been developed under a high nitrogen …
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Nitrogen transport and transformation in the Aberjona watershed
… and industrial effluent. A large amount of nitrogen loading to watersheds nation-widely comes from agricultural areas, but the Aberjona watershed has a considerable nitrogen inflow from .an industrial area. The nitrogen compounds in the Aberjona watershed might be delivered to the estuary …
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The Impact of Nitrogen Additions On Cyanobacterial Abundance In Stormwater Detention Ponds On Kiawah Island, Sc
… pond network is subject to high levels of nitrogen and phosphorus loading from golf course, residential, and road runoff, atmospheric inputs, wildlife waste, and oceanic inputs. This system is characterized by eutrophic conditions and recurrent water quality problems (hypoxia and anoxia, …
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RESPONSE OF A SPARTINA PATENS-DOMINATED OLIGOHALINE MARSH TO NITROGEN ENRICHMENT IN COASTAL NORTH CAROLINA, USA.
… may depend on the type of marsh being impacted. Nitrogen loading into coastal environments has accelerated with increased use of fertilizers for agricultural production. Previous work has demonstrated that some marsh plants respond to nitrogen inputs by allocating more biomass into aboveground …
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The source of excess nutrients to Pine Draw, Turnbull National Wildlife Refuge
<p>Nitrogen and phosphorus are the most common limiting nutrients for biological activity in freshwater ecosystems. Applying inorganic nitrogen fertilizer has increased crop productivity but caused excess nitrogen inputs to the hydrosphere. Nitrate contamination is a worldwide environmental …
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Impact of spatial and temporal distribution of ammonia emissions from chemical fertilizer usage on predictions of air quality in the Midwest United States
… Atmospheric deposition of NH3 and other reactive nitrogen compounds exacerbates surface water eutrophication, soil acidity and ecosystem damages. Accurate prediction of impacts of NH3 emissions on PM formation and reactive nitrogen deposition using chemical transport models (CTMs), require …
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Removal of Endocrine Disrupting Compounds Using Membrane Bioreactor
… designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and extreme low …
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Denitrification as a means of addressing nitrate-contaminated groundwater on Cape Cod, Massachusetts
… sensitive to eutrophication from excess nitrogen loading. In order to address nitrate-contaminated groundwater on Cape Cod, solutions based on biological denitrification should be considered. In this work, these solutions are discussed and explored. First, the major sources of …
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Design of a watershed-based nitrogen trading system or the Big and Little Wood Rivers Watershed
A watershed-based nitrogen trading system was designed for the Big and Little Wood Rivers Watershed in south-central Idaho as a policy tool to help manage increasing nitrogen loads within the Watershed. The study was performed on behalf of the Blaine County Commissioners in response to concerns …
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Quantifying The Increased Resiliency Of Chesapeake Bay Hypoxia To Environmental Conditions: A Benefit Of Nutrient Reductions
… same interval that used organic and inorganic nitrogen concentrations representative of 1985 values. Differences between these sensitivity results and the realistic hindcast suggest that had nitrogen reductions not occurred, annual hypoxic volumes (O2 < 3 mg L-1) would have been ~50-120% …
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Denitrification of anthropogenic nitrogen in groundwater : measurement and modeling using stable isotopic and mass balance approaches
… in designing strategies to control anthropogenic nitrogen loading.
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A multiple objective approach to evaluate economic and environmental impacts of agricultural management systems from a sustainable development perspective
… no possibility of achieving a 40% reduction of nitrogen loading as required by Chesapeake Bay Agreement by employing the any of 14 agricultural management systems analyzed in this study.
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Improved Environmental Characterization to Support Natural Resource Decision Making: (1) Distributed Soil Characterization, and (2) Treatment of Legacy Nutrients
… (1) accurate soil mapping and (2) treatment of nitrogen to affect water quality change.The current method of soil mapping, SSURGO (USDA‐NRCS Soil survey), is often erroneous and misleading. Two studies in this dissertation are conducted to evaluate the potential that different resolution digital …
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Partitioning the influence of anthropogenic and oceanic nutrient fluxes in the coastal ocean, and the question of cultural eutrophication
… conurbation. These coastal waters are typically nitrogen limited with respect to idealised Redfield ratios for optimal phytoplankton growth, indicating plankton sensitivity to nitrogen loading. Three deepwater outfalls servicing the city of Sydney represented the principal (~80%), continuous, …
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Effect of Golf Course Turfgrass Management on Water Quality of Non-tidal Streams in the Chesapeake Bay Watershed
… in local streams, (2) estimations of total nitrogen (N) discharging to the watershed from stream outlet points as a function of land use and watershed area, and (3) other factors potentially affecting water quality on golf courses, including soil characteristics and use of best management …
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