The contribution of non-point source pollution to degrading surface water quality is considerable throughout Virginia and beyond. While research on agricultural best management practices in nutrient management and nutrient and soil stabilization has made progress in reducing agricultural contributions to nutrient and sediment loading of watersheds, little is known about how land covers of different vegetation representative of urban areas (e.g., bare soil versus turfgrass lawns versus urban forest) influence the potential for non-point source pollution. Ambient rainfall volumes were manipulated to provide 50%, 100%, and 150% of natural precipitation to plots with landscape covers of bare soil, shredded wood mulch, turfgrass, and simulated urban forest (complete pin oak canopy with shredded hardwood leaf mulch). Precipitation amounts, runoff volumes, and eroded sediment masses for ten rain events between July and December 2004 were measured. Runoff was analyzed for nitrate and orthophosphate concentrations for three rain events. Turfgrass was found to be the most effective of the land covers tested at reducing components of non-point source pollution from stormwater. Turfgrass plots produced, on average, the least runoff and sediment, and lower nitrate concentrations in runoff water as compared to the other land covers tested. Results from urban forest plots apparently reflected the disturbance of tree planting, even six months later. This study contributes to a sparse body of knowledge about the influences of urban landscapes on water quality, and will inform land use policy and urban Best Management Practices. / Master of Science

During high pressure pulsation tests repeated cracks of CP3. housings occur. High pressure pump CP3 is part of injection system Common Rail. Cracks can be caused by segregation of phosphorous from a washing medium on grain boundaries during subsequent heat treatment process. The present master´s thesis focuses on analysis of phosphorous compounds on specimen surface made from steel 20MnCr5, which were soaked in solutions with different concentration of phosphorous. Master’s thesis is also focused on potencial influence of phosphorous on structure and properties of this material. The first part of the thesis provides a summary of current knowledge in the studied field, experimental results can be found in the second part. The surface analysis XPS, the light microscopy, the scanning electron microscopy equipped by energy dispersive chemical analysis, the glow discharge optical emission spectroscopy, the methods of the phase analysis by means of the X-ray diffraction and impact test were used.

No description available.

<p>In connection with Henriksdals wastewater treatment plant (WWTP) a smaller plant is situated called Sjöstadsverket where new methods for wastewater treatment are tested and evaluated in different process lines. On one of the lines experiments with enhanced biological phosphorous removal (EBPR), have been carried out to evaluate if it is a good alternative to traditional chemical phosphorus removal. This thesis evaluates the results from the experiments conducted during fall 2005.</p><p>The incoming water from Hammarby Sjöstad consists of only household wastewater, which gives a wastewater with high concentrations of nutrients and organic carbon. This is partly positive, because one of the limiting factors for effective biological phosphorus removal is the lack of easily biodegradable organic carbon. The high concentrations of ammonium and phosphorus demand a high reduction to achieve the requirements of outgoing concentration.</p><p>To optimize the process experiments with different recirculations and different aeration techniques have been made. The experiments have shown that it is possible to obtain good results, with periods of very low outgoing phosphorus concentrations below 0,15 mg/L. It was, however, hard to obtain a stable process and to keep a good sludge quality during the period.</p><p>Primary sludge was hydrolysed to increase the amount of easily degradable organic material into the biological step of the process. The hydrolyse had a high efficiency during the test period, but with big variations. The most desirable fraction of organic material, VFA, increased to approximately 1500 mg/L during the best periods. This is only 9 % of the amount VFA in the primary sedimentation, but could be increased with a higher flux.</p><p>When the bioP sludge is fermented as a part of sludge treatment, a supernatant from digester sludge with high concentrations of phosphorus is received. To avoid to return phosphor into the activated sludge process and to recycle phosphorus, experiments with phosphorus precipitation were made. By using struvite precipitation up to 92 % of the phosphorus in the supernatant was reduced and precipitated. This was 12 % of the total amount of incoming phosphourus and was achieved at a pH just over 9 in the experiment tank and a Mg:P quote of 1:1.</p> / <p>I anslutning till Henriksdal’s reningsverk ligger Sjöstadsverket som är ett mindre reningsverk där nya reningsmetoder testas och utvärderas i på ett antal olika försökslinjer. På en av linjerna har försök med biologisk fosforrening, även kallat BioP, utförts för att undersöka om det är ett alternativ till konventionell kemisk rening av fosfor. Detta arbete sammanfattar resultaten från de experiment som utförts under hösten 2005.</p><p>I Hammarby Sjöstad, som förser Sjöstadsverket med avloppsvatten, separeras dag och spillvatten, vilket bidrar till ett näringsrikt vatten med en hög halt organiskt material. Detta är delvis positivt, då en av de begränsande faktorerna för en effektiv biologisk fosforrening är bristen på lättillgängligt organiskt material. De höga halterna inkommande fosfor och kväve kräver dock en högre reningsgrad för att de stränga utsläppsmålen ska nås. För att optimera processen har försök med olika inställningar på recirkulationsgrader genomförts och försök med olika luftningsstrategier. Försöksperioden har visat att det går att få mycket bra resultat, med periodvis utgående fosfathalter under 0,15 mg/L. Det har dock varit svårt att få en stabil process och behålla en bra slamkvalitet under hela försöksperioden.</p><p>Primärslam från försedimenteringen har hydrolyserats för att öka mängden lättillgängligt organiskt material in till det biologiska reningssteget. Hydrolysen fungerade bra under hela försöksperioden, dock med stora variationer. Den mest önskvärda fraktionen lättillgängligt organiskt material, VFA, hade under de bästa perioderna ökat till ca 1500 mg/L i hydrolysen. Detta utgör approximativt 9 % av mängden VFA i försedimenteringen, men skulle kunna ökas vid ett större flöde.</p><p>Då BioP-slammet rötas som en del av slambehandlingen fås ett fosforrikt rejektvatten. För att undvika att få in fosfor till aktivslamprocessen och för att ta till vara på fosfor som näringsämne har försök med fosforåtervinning från rejektvatten gjorts. Genom att använda sig av struvitfällning kunde upp till 92 % av fosforn i rejektvattnet reduceras och fällas ut. Detta motsvarar 12 % av den totala inkommande fosforhalten och uppnåddes vid pH strax över 9 i struvitfällningstanken och med en Mg:P kvot på 1:1.</p>

Cyanobacteria are ancient prokaryotic organisms capable of performing oxygenic photosynthesis. An increase in the temporal and spatial distribution of cyanobacteria blooms worldwide has drawn considerable research attention in recent decades because of the health risks cyanobacteria pose to humans and wildlife through the production of cyanotoxins, interference with recreation, and ecosystem changes. A variety of hypotheses have sought to explain the increasing frequency and severity of cyanobacteria blooms around the world, with the relationship between cyanobacteria abundance and eutrophication receiving considerable attention. While the impacts of phosphorus concentration on cyanobacteria success are relatively well-studied, less is known about how nutrient stoichiometry and nitrogen uptake kinetics of different species contribute to cyanobacteria dominance. The underlying mechanism for the impacts of nitrogen to phosphorus (N:P) ratio and nitrogen form on cyanobacteria involves internal cycling of nitrogen within lakes and aspects of cyanobacteria cell physiology. The primary objective of this study was to assess the impacts of N:P ratios and nitrogen form on the growth of Microcystis aeruginosa and Anabaena flos-aquae in both axenic cultures and natural phytoplankton assemblages from Missisquoi Bay, Lake Champlain. A second objective was to determine whether treatment condition affected the production of the cyanotoxin microcystin. A final objective was to document the presence of benthic ammonium in Missisquoi Bay and the vertical migration of cyanobacteria throughout the water column in the bay, to provide evidence in support of the underlying mechanisms that might provide advantages to cyanobacteria in the bay. In laboratory culture experiments with M. aeruginosa and A. flos-aquae alone and in a mixed community, N:P ratios were varied between 5, 15, 30 and 45:1, and nitrogen was supplied as both nitrate and ammonium at each ratio. Triplicate samples were preserved after one, three and six days for cell enumeration using the standard Ütermohl method. Differences in density between initial and later times were used as an estimate of growth. Microcystin concentration was measured with the ELISA method. Weekly field sampling was conducted in the summer of 2006 in Missisquoi Bay to measure benthic nitrogen concentrations. Nocturnal sampling at varied depths in the bay was used to explore the vertical migration of cyanobacteria throughout the water column. There were weak associations between ammonium-nitrogen and M. aeruginosa growth and nitrate-nitrogen and A. flos-aquae growth, while the effects of N:P ratio on growth was highly variable across time and treatment condition. Ammonium-nitrogen was documented in the benthic water of Missisquoi Bay throughout the growing season, and M. aeruginosa dominated the vertical migration of cyanobacteria throughout the water column. The lack of clear trends visible within the data from laboratory experiments can be in part attributed to high variability of cell density within treatment conditions and the limitations of the methodology used for cell enumeration. Taken together these data suggest that the distribution of nitrogen within an aquatic system and the ability of M. aeruginosa to vertically migrate may contribute to the M. aeruginosa dominance of the summer phytoplankton community.

Ce travail de thèse se divise en trois parties. Dans un premier temps, nous avons mis au point une nouvelle méthode simple et efficace de synthèse d'arylphosphonates, aryphosphinates et arylphosphines, faisant appel à un système catalytique au cuivre.Dans un second temps, nous nous sommes intéressés à la synthèse, à partir des sels de phosphonium correspondants, de diylures azotés ou carbonés du phosphore. A partir de ces derniers une méthode de synthèse de phosphines vinyliques ou butadiéniques, difficiles à obtenir par d'autres voies, a été mise au point. Ces phosphines se sont avérées être d'excellents ligands pour la réaction d'arylation de nucléophiles azotés catalysées au cuivre.Enfin, dans une dernière partie, nous avons développé un système catalytique d'oxydation d'alcools en cétones correspondantes à travers une réaction de type Oppenauer, en présence d'une quantité catalytique de base (NaOtBu). Cette découverte permet de s'affranchir des oxydants et métaux couramment utilisés dans les nombreux exemples décrits dans la littérature. / This thesis is divided into three parts. At first, we developed a new simple and effective synthesis method of arylphosphonates, aryphosphinates and arylphosphines, using a new copper catalytic system. In a second step, we have been interested in the synthesis of phosphorus nitrogen and carbon diylids from their corresponding salts. From these, a method of synthesis of butadiene or vinyl phosphines, difficult to obtain by other methods described in the literature, has been developed. These phosphines were found to be excellent precursors for copper catalytic arylation reactions of nitrogen nucleophiles from halogenated aromatics.Finally, in a last part, we developed a catalytic system for oxidation of alcohols to their corresponding ketones through an Oppenauer type reaction in the presence of a catalytic amount of base (NaOtBu). This finding eliminates oxidants and metals commonly used in many examples described in the literature.

Les dérivés hétérocycliques sont incorporés dans la structure de nombreuses molécules biologiquement actives, naturelles ou de synthèse. Ce travail de thèse décrit les efforts réalisés pour développer de nouvelles voies d'accès à deux familles de ces composés hétérocycliques : les hétérocycles phosphorés et les pyrimidines. Le premier chapitre est dédié à une étude bibliographique de l'ensemble des méthodologies d'hydrophosphonylation et d'hydrophosphinylation connues à ce jour. Le second chapitre décrit nos efforts pour développer des réactions de formation de liaisons carbone-phosphore pallado-catalysées. Le dernier chapitre est consacré à la mise au point d'une synthèse originales de β-enaminones protégées et de leur utilisation pour la synthèse de pyrimidines diversement substituées. / Compounds classified as heterocyclic are found in numerous natural products and molecules biogically active. The work described herein will focus on the synthesis of two families of heterocyclic compounds through two distincts synthetic pathways. The first one lays in the organophosphorus chemistry. In Chapter I, numerous methodologies known in the literature will be explained. The significance of metal-catalyzed hydrophosphonylation / hydrophosphinylation reactions will be described. Chapter II stands for the experimental exploration of metal-catalyzed intramolecular and intermolecular P-C bond formation. In Chapter III the attention will be turned to the development of a base-catalyzed synthesis of Cbz-protected β-enaminones and their subsequent implementation in the cyclization reaction towards 2,4,6-trisubstituted pyrimidines.

Master of Science / Department of Agronomy / Nathan O. Nelson / Phosphorus (P), an essential nutrient for plant growth and animal needs, has been identified as an ubiquitous water quality impairment in the United States. In Kansas, a major agricultural state, P loading to the surface waters is a top priority because of the critical role of P enrichment in eutrophication processes and resultant water quality degradation. The objective of this study was to quantify the P sorption and desorption of both stream sediments and upland soils in two Kansas watersheds with contrasting degrees of animal agriculture; Upper West Emma Creek (UWEC) and Red Rock Creek (RRC) watersheds. In-stream sediments were collected from banks, pools, riffles and depositional features. Soils were sampled from wheat, row crop, pasture, and manure-amended fields. Stream water samples were taken under baseflow and storm flow conditions. Our analyses of sediments and soils included equilibrium P concentration at zero net P sorption (EPC[subscript]0), maximum adsorption capacity (P[subscript]max), anion exchange extractable P (P[subscript]lab) and degree of P saturation (DPS). Water samples were analyzed for dissolved reactive phosphorous (DRP). Bank erosion pins were installed in order to estimate bank erosion rates in both watersheds. Results showed that in-stream sediments do not have much more sorption capacity remaining indicated by low P[subscript]max and high DPS. A comparison between mean P[subscript]lab of stream sediments (8.8 mg P kg[superscript]-1 soil) versus field soils (61.2 mg P kg[superscript]-1 soil) reflected that they represent a relatively minor long-term P supply. Of the stream sediments, bank soils had the highest Plab concentrations (24.8 mg P kg[superscript]-1 soil) and would be the largest in-stream P source. Manure-amended fields had the highest Plab (118.6 mg P kg[superscript]-1 soil) due to continued inputs of manure-based P; therefore, representing a large available P pool. Bank erosion contributed about 41% and 11% of the total sediment load in UWEC and RRC respectively. Sediments loads indicated that RRC has more upland sediment inputs than UWEC. Moreover, DRP during storm flow was higher at RRC than UWEC, indicating higher P inputs in RRC from upland soils. Finally, in order to minimize P inputs to the stream system, bank stabilization should be addressed in UWEC and upland best management practices should be implemented in RRC.

In plants, phenotypic plasticity, the ability to morphologically adapt to new or broad environmental conditions, is a consequence of long-term evolutionary genetic processes. Thus, plants adapted to low phosphate (P) environments exhibit only limited plasticity to take advantage of nutrient enrichment, a global phenomenon in terrestrial and aquatic environments. In the face of anthropogenic P-enrichment, low nutrient adapted resident plant species are frequently displaced by species with high morphological and genetic plasticity. However, it remains unclear whether plasticity is systemically expressed across molecular, biochemical, physiological, and morphological processes that ultimately contribute to the root and shoot phenotypes of plants. In this study, we demonstrated high plasticity in root-borne traits of sawgrass (Cladium jamaicense), the dominant plant species of the P-impoverished Everglades, and counter the idea of inflexibility in low P adapted species. However, sawgras s expressed inflexibility in processes contributing to shoot phenotypes, in contrast to cattail, which was highly plastic in shoot characteristics vii in response to P enrichment. In fact, plasticity in cattail shoots is likely a function of its growth response to P that was globally regulated by P-availability at the level of transcription. Plasticity and inflexibility in the growth of both species also diverged in their allocation of P to the chloroplast for growth in cattail versus the vacuole for P storage in sawgrass. In the Everglades, anthropogenic P-enrichment has changed the environment from a P-limited condition, where plasticity in root-borne traits of sawgrass was advantageous, to one of light-competition, where plasticity in shoot-borne traits drives competitive dominance by cattail. / We hypothesize that these shifts in plasticity competitive advantage from root to shoots has been a major driver of cattail expansion in the Everglades ecosystem. Further, this understanding of how natural plant species adapt and shift in response to nutrient availability could also be used a model system to optimize agricultural systems to increase efficiencies in food production and protect low nutrient adapted natural systems from cultural eutrophication. / by James Webb. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 200?. Mode of access: World Wide Web.

Afin de limiter les rejets de polluants dans l’atmosphère par les véhicules, les normes Euro ont été mises en place en Europe à partir des années 1990. Ces normes sont de plus en plus strictes. Par exemple, pour les cas des poids lourds, le maximum d’émission des NOx a été divisé par cinq lors du passage Euro V (2009) à Euro VI (2014). Parallèlement à cela, certaines flottes captives de poids lourds roulent au 100 % biodiesel. Or, ce carburant contient des minéraux (Na, K, P) qui peuvent interagir avec la ligne de dépollution des gaz d’échappement.Dans ces travaux, l’étude a porté sur l’impact de Na et P déposés séparément ou simultanément sur des catalyseurs de réduction catalytique sélective des oxydes d’azote par l’ammoniac (NH3-SCR) à base de zéolithe Ferrierite (FER) contenant du cuivre.En mettant en relation les activités catalytiques en NH3-SCR et les différentes caractérisations mises en œuvre avant et après ajout des minéraux, il a été conclu que l’ajout de sodium entrainait une perte d’activité à basse température (< 300 °C) liée à l’empoisonnement des sites acides du catalyseur, et que la perte d’activité à haute température (> 450 °C) est liée à la formation de CuO. Cette formation de CuO est due à un échange entre le cuivre et le sodium lors de l’empoisonnement par voie aqueuse. Pour l’empoisonnement au phosphore, la désactivation à basse température (< 300 °C) apparait liée à une interaction entre le cuivre et le phosphore. Cette interaction entraine une augmentation de la température de réduction du cuivre. L’ajout simultané de sodium et phosphore entraine une désactivation des catalyseurs plutôt similaire à celle du phosphore qu’à celle du sodium. / In order to decrease the air pollution due to vehicles, European legislation have been implemented since the 90’s. The European norm are stricter. For example, the NOx emissions limit for trucks were divided by five between Euro V (2009) and Euro VI (2014). In parallel, some trucks use exclusively 100 % biodiesel. Unfortunately, biodiesel contains some minerals (Na, K, P) with can interact with the exhaust gas post-treatment system.This work presents the impact of Na and/or P deposits on Selective Catalytic Reduction catalysts with dedicated to the NH3-SCR process, based on copper/Ferrierite (FER).By combining the results of NH3-SCR catalytic activity and characterisations before and after adding minerals, the main parameters of deactivation were highlighted. Sodium deactivation at low temperature (< 300 °C) is due to the decrease of acidity. The deactivation at high temperature (> 450 °C) is due to the formation of copper oxide when sodium was added in water. This formation of CuO results of an exchange of Na and Cu in the exchange positions of the zeolite. Phosphorous addition mainly leads to a catalytic deactivation at low temperature (< 300 °C), the deactivation seems to be link to Cu-P interaction. This interaction leads to the increase of the reduction temperature of copper. Overall, the simultaneous addition of sodium and phosphorous leads to a decrease of catalytic activity similar to the one with phosphorous alone.