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Showing 1 to 20 of 208 for “"nitrogen and phosphorus"”.
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Biological nitrogen and phosphorus removal on large plants.
Full scale implementation of biological excess phosphorus removal by means of the activated sludge process commenced in South Africa at the Johannesburg Alexandra Plant in 1974. Originally the plant was designed to operate in the nitrifying extended aeration mode; but by switching off some surface …
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Nitrogen and Phosphorus Management in the Mid-Atlantic
Managing nitrogen (N) and phosphorus (P) in agricultural systems in the Mid-Atlantic is an important practice due to environmental and economic concerns. The objectives of the experiments reported in this dissertation were: (1) evaluate irrigation via evapotranspiration (ET) calculations for fresh …
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Removal of Wastewater Nitrogen and Phosphorus by an Oligohaline Marsh
Wetlands potentially contribute to water quality improvement. The objective of this thesis was to determine the role of wastewater processing by oligohaline Council Creek marsh (0.16 km2), which receives wastewater from Easton, MD. Tidal flushing, nutrient distributions, plant uptake, and sediment …
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Nitrogen and phosphorus fertilization for efficient corn production in Virginia
… methods of broadcasting N fertilizer, and applying P fertilizer to soils testing high to very high in plant-available P, can be inefficent. Experiments were conducted at several locations in Virginia to evaluate if band applications of N fertilizer are more efficient than surface …
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Denitrification kinetics in biological nitrogen and phosphorus removal activated sludge systems
… order to size the anoxic reactors in nutrient (N and P) removal activated sludge plants, it is essential to know the denitrification kinetics that are operative in such systems. To date, denitrification kinetics have been accurately defined only for systems that remove N alone; little research has …
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Responses of Quercus alba L. seedlings to fertilization with nitrogen and phosphorus
… with diammonium phosphate on growth and foliar N and P concentrations of 1-0 Quercus alba seedlings were evaluated one year after planting and fertilization. Soil P tests were made by three methods: dilute acid extractable P (Mehlich), acid flouride extractable P (Bray no. 1), and …
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Effects of Low Bioavailable Nitrogen and Phosphorus on Cyanobacteria Dynamics in Eutrophic Lake Erie
The growth and abundance of phytoplankton in freshwater lakes has long been attributed to the concentration of phosphorus (P), and this idea of P-limitation has been a paradigm accepted by limnologists. Hence, lake managers have relied on the strategy of reducing P to restore water quality of …
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Genetic Control of the Response to Sulfur, Nitrogen, and Phosphorus Supply in Arabidopsis thaliana
… deficiency is a relatively new problem in Europe and the studies on sulfur use efficiency are still lagging behind those on the other major nutrients such as nitrogen or phosphorus. Therefore, the main aim of this work was to improve the understanding of the sulfate assimilation pathway, its …
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Modeling Fate and Transport of Nitrogen and Phosphorus in Crop Fields Under Tropical Conditions
… models were developed for temperate conditions and, thus, do not appropriately represent tropical conditions. The objective of this research was to develop or adapt a nonpoint source pollution model to simulate transformations and losses of nitrogen (N) and phosphorus (P) in leachate and runoff …
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Mathematical Modeling and Evaluation of Ifas Wastewater Treatment Processes for Biological Nitrogen and Phosphorus Removal
… become popular for enhanced nitrification and denitrification in aerobic zones because it is an alternative to increasing the volume of treatment plant units to accomplish year round nitrification and nitrogen removal. Biomass is retained on the fixed-film media and remains in the aerobic …
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Availability and distribution of nitrogen and phosphorus from sewage sludge in the plant-soil-water continuum
Research was conducted in 1984 and 1985 to determine N and P availabilities for barley (Hordeum vulgare L.) and com ( Zea mays L.) grown on four sludge-amended soils. Tests were conducted on the Acredale silt loam (Typic Ochraquall), Bojac loamy sand (Typic Hapludult), Davidson clay loam (Rhodic …
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Sources of nitrogen and phosphorus in stormwater drainage from established residential areas and options for improved management
… to June 2003, a study was conducted at Wanneroo and Bannister Creek in Perth's metropolitan area (Western Australia), aiming to quantify major sources of nitrogen (N) and phosphorus (P) entering urban residential catchments on two of the major dunal systems. The export of N and P from these …
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The Role of Nitrogen and Phosphorus in the Growth, Toxicity, and Distribution of the Toxic Cyanobacteria, Microcystis aeruginosa
… </em> have been linked to liver failure and death in aquatic mammals, like the endangered California sea otter, and provide a serious public health risk to humans. Once characterized as a freshwater problem, <em>M. aeruginosa</em> is expanding on a global scale, making persistent returns …
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A Method Comparison and Stressor-Response Experimental Study of Nitrogen and Phosphorus Impacts to Periphyton in Ozark Streams
<p>Stream bioassessment is important for understanding algal-nutrient relationships and the development of scientifically defensible numeric nutrient criteria. However, multiple methods of periphyton data collection are currently used, and little is known about the comparability of resulting …
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