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 37 for “"N removal"”.
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Analysis of temporal trends in southern Nevada wastewater pond parameters with an emphasis on ammonia removal
… A major focus of this paper is on ammonia-N removal. Individual pond ammonia-N removal performance is compared to published models. A model based solely on HRT in a given temperature regime is developed. Models describing Ammonia-N removal performance as a function of HRT, temperature, and pH …
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Hydraulic evaluation of a denitrifying bioreactor with baffles
… untreated which limits a bioreactor’s overall N removal performance. Bioreactors designed to be wider would potentially have greater flow capacity, minimizing this untreated water. To maintain a consistent surface area footprint and not encroach on cropped areas, a wider and shorter bioreactor …
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Optimization of Biological Nitrogen Removal From Fermented Dairy Manure Using Low Levels of Dissolved Oxygen
A pilot scale nitrogen (N) removal system was constructed and operated for approximately 365 days and was designed to remove inorganic total ammonia nitrogen (TAN) from solids-separated dairy manure. An anaerobic fermenter, upstream of the N removal reactor, produced volatile fatty acids (VFAs), to …
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Agronomic and Nitrate Leaching Impacts of Pelletized versus Granular Urea
… study, corn silage yield, corn nitrogen (N) removal, and nitrate-N (NO₃⁻-N) leaching from urea pellets (1.5 g each) and granules (0.01-0.02 g each) applied at 184 kg-N/ha were compared. A control treatment (no N) and two other N application rates (110 and 258 kg-N/ha) were also included. Urea …
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The Potential for Eutrophication Mitigation from Aquaculture of the Native Oyster, Crassostrea virginica, in Chesapeake Bay: Quantitative Assessment of an Ecosystem Service
… from Bay waters. Results clarified that nutrient removal of nitrogen (N), phosphorous (P), and carbon (C) through harvest of cultivated oyster biomass can be quantified and modeled with high levels of statistical confidence. A simple, yet accurate, method is now available for estimating the amount …
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Simulating the Cost and Legacy N Reduction Potential of Denitrifying Spring Bioreactors Installation in the Chesapeake Bay Watershed
… be diverted to the bioreactor and a bioreactor N removal efficiency of 20%, we estimate that it would cost $3,325,400 yr-1 to abate 106,911 kg N yr-1. The driving factor of driving the unit costs of N removal is the amount of spring flow treated by the bioreactor. Further research is needed to …
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Microbial contaminant removal and alternative nitrogen removal pathways in denitrifying bioreactors
… and low-cost technology for the effective removal of nitrogen (N) from water by enhancing denitrification (i.e. the bacterial conversion of nitrate [NO3-] to N gas). To date, studies on denitrifying bioreactors have mainly focused on the ability of, and factors influencing, the removal of …
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Impact of Biochar Amendment, Hydraulic Retention Time, and Influent Concentration on N and P Removal in Horizontal Flow-Through Bioreactors
… nitrate (NO3--N) and phosphate (PO43--P) removal in DNBRs. This study investigated biochar's potential as an amendment to the traditional woodchip media by conducting nine, five-day trials on twelve laboratory-scale, horizontal flow-through DNBR columns. Three media types were tested: …
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The effect of temperature on denitrification kinetics and biological excess phosphorus removal in nutrient removal activated sludge systems in temperate climates (12°C - 20°C)
Filamentous bulking in nutrient (N & P) removal activated sludge systems is a problem of considerable magnitude - three quarters of 45 plants surveyed were found to have bulking sludges to the extent that sludge settleability (DSVI) was adversely affected. If filamentous organism proliferation …
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Challenges and Opportunities for Denitrifying Bioreactors in the Mid-Atlantic
… 1) a pilot study investigating controls on N removal, 2) a laboratory study investigating controls on emission of greenhouse gases nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), and 3) a field study of one of the first denitrifying bioreactors implemented in the Atlantic Coastal …
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The controls of watershed nutrient export
… at the global scale. The strength of aquatic N removal varied considerably by watershed, depending on the spatial distribution of N loading, hydraulic characteristics, and biological activity. The representation of biological activity strongly influenced predicted N removal of aquatic systems, …
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Examination of synergism in nitrate and orthophosphate removal in bioreactors
… known to have a high affinity for nitrate-N removal. The evaluation of materials was conducted via a bench-top batch study and led to the selection of a locally available iron-based scrap steel material, which was able to remove over 99% of orthophosphate from solution at the 24 hour …
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Optimization of Phosphorus Removal and Mineral Characterization in Aerated Anaerobic Digestate with Divalent Cation Addition
… can reduce struvite buildup, enhance phosphorus removal, and provide additional benefits such as nitrogen and COD removal. The pilot setup at Hampton Roads Sanitation District's Atlantic Treatment Plant (ATP) consisted of four 45-gallon tanks operated as daily batch fed continuously stirred tank …
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Using Tall Fescue to Remove Nutrients from Renovated Turkey Processing Wastewater
… time. With 1-day of retention time nutrient removal fluctuated. Two days of retention achieved 60% NO3--N removal and 75% PO43--P and was considered optimal for nutrient removal.
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Evaluation of Nutrients and Suspended Solids Removal by Stormwater Control Measures Using High Flow Media
… area were monitored over 11 months to assess the removal of Total Suspended Solids (TSS), Nitrogen, and Phosphorus in First Flush (FF) stormwater runoff. Excellent removal of TSS and particulate-bound nutrients was noted, but, in most SCMs, removal of dissolved species was limited. Sorption of …
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Switchgrass as an Energy Crop: Fertilization, Cultivar, and Cutting Management
… A closer look at Alamo revealed much higher N removal in the midsummer harvests, late-season N translocation out of tillers, and fewer tillers developing under one-cut management. Switchgrass appears to be capable of truly perennial productivity in the upper Southeast USA with 50 kg N ha-1 yr-1 …
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Using Monte Carlo Analysis to Assess Outcome-based Payment for Environmental Services for Denitrifying Bioreactors in the Chesapeake Bay
… springs (Easton et al., 2019). Since nitrogen removal can be directly measured, there is potential to implement an outcome-based PES program. Little information exists on the costs and risks sellers face under such a program or the impact of contractual conditions. This research applies Monte …
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Low temperature biological treatment of a high ammonia municipal landfill leachate
… to be an efficient method for ammonia nitrogen removal. However, because of the sensitivity of microbial growth to temperature changes, this process may be seriously affected at low temperatures. The objective of this project was to study the effects of low operating temperatures on the …
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A framework for assessing viability of adoption of conservation practice for reducing nitrate-N
… study shows that practices with higher Nitrate-N removal tend to be the less desirable to users. These practices tend to be less desirable due to high construction and maintenance efforts and long learning processes, and hence, less adoption potential, which makes state-of-art engineering …
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The influence of plant age and nitrogen rate on nutrient removal from the container medium solution
… 0 and 6, and analyzed for N, P and K. Nitrogen removal from the medium solution was greatest by 45 and 50 day old plants at the higher N treatments. Phosphorous and K removal also increased with plant age. Medium solutions were tested and analyzed again, 10 days later. Nitrogen removal, 10 days …
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