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295 Uppsatser om Nitrogen retention - Sida 7 av 20
Batch flow behandling och kontinuerligt flöde av lakvatten i en rotzonsanläggning : En jämförande studie i pilotskala
This report deals with the performance of a batch flow treatment of landfillleachate compared with a continuous flow system. The parameters in focus were total Kjeldahl nitrogen (TKN), BOD5 and COD. The pilot-scale experiment used eight barrels with a volume of 150 liters. Each barrel was constructed differently concerning its flow, its bed material grain size and its presence of plants or not. Four of the barrels worked in batch mode, thus four in continuous flow mode.
Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet
Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish national forest inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).
Lyviken : -bedömning av dagvattenkvalitet
AbstractStormwater is defined as rain- and melted water. Ludvika kommun had little knowledgde about the stormwater that reaches a specific recipient Lyviken. Therefore they intended to do an research of the stormwater that leads down to Lyviken. The aim with this study was to assess the quality of the contents in the stormwater based on pH, conductivity, phosphorous, nitrogen, bacterias, oil and one sample that meassured the value of several methals. Since the population has increased for decades, the area of hard surfaces and asphalts areas also has increased. This can increase the pollutions that finally ends up in the recipient.
Utvärdering av avloppsvattenreningen vid Hallsta Pappersbruk : Kartläggning av inkommande avloppsvatten och optimering av driftparametrar
Hallsta paper mill uses large amounts of water during the pulp and paper making processes. The wastewater is treated in two separate activated sludge processes referred to as BIO 1 and BIO 2. The main aim is to reduce the organic substance content, measured as COD (Chemical Oxygen Demand) before the wastewater is released into the environment. Since the effluent produced is very rich in organic substances, the addition of nitrogen (N) and phosphorus (P) are necessary to give satisfactory treatment results. Problems with sludge bulking sometimes occur which lead to increased levels of suspended matter and nutrients in the effluent.
Möjligheter till ökat utnyttjande av fosfor genom grödan med mineralgödselmedel
The objective of this thesis is to explore opportunities to enhance the phosphorus use efficiencyof inorganic fertilizers in crop production, with techniques available today and in thefuture. Phosphorus is a finite resource of declining quality; therefore a phosphorus use efficiencyin crop production of only 15-30 % is unacceptable. The main reason for low efficiencyis the retention by Ca and Mg in calcareous soils and Fe and Al in non-calcareoussoils. Due to the low mobility of phosphorus, plant uptake is mainly dependent on root growthrather than diffusion. Therefore, measurements need to be taken that benefit contact betweenroot and fertilizer, before fertilizer phosphorus becomes unavailable to the plant.
Effekten av kvävegödsling på gasproduktionen vintertid i boreala sjöar
To investigate effects of nitrogen on in-lake CO2 and CH4 production during winter, three pair of lakes was subject for a fertilizing experiment in which one lake in each pair was fertilized with nitric acid (HNO3) directly into the water column in the summer of 2012. The lakes in each pair are assumed to be morphologically, hydrologically and biologically similar, that is, the non-fertilized lakes are considered references. The pairs do differ in one major way by being progressively less humic, going from around 25 mg/l to 10 mg/l DOC. Sampling and analysis was carried out at the end of the frozen period in 2013. Results show a significantly higher concentration of both CO2 (p<0,001) and CH4 (?=0,1, p=0,053) between impact and reference sites in the two less humic pairs.
Årlig gödsling med NPK bäst för gröda, miljö och ekonomi
Yesterdays common fertilizing strategy was to apply phosphor (P) and potassium (K) in thefall a few times in the crop rotation. In the spring only nitrogen (N) was applied. Recent trialsand studies has shown that this strategy, N+P/PK, is ineffective compared with the systemwhere NPK is spread every year in the spring. The strategy with annual NPK-fertilizer in thespring has proven to be better for the crop, the environment and the farmers economy.In the NPK-system the crop responds with higher yields and better quality, especially in thespring cereals. This is mainly because of an interaction between the different nutrients in thefertilizer.
Övertänjd urinblåsa- redan före operation? En observationsstudie
Introduction: Urinary retention is a common postoperative complication associated with bladder distension. Permanent damage to the bladder affects the patient?s quality of life and may lead to a lifelong inability to empty the bladder and needs of self-catheterization with the risk of urinary tract infection. Bladder distension was classified as the fourth largest health care related injury in Sweden in 2013. Bladder distension may occur before the operation starts and is more common among orthopedic patients.
Karakterisering och klassificering av gotländska ytvatten enligt ramdirektivet för vatten
In this study the practical work with the EU Water Framework starts on the island of Gotland. 33 lakes and 32 streams have been characterized and classified regarding to their ecological status. The aim with the characterisation is to create a uniform discription of all waterbodies and a comparable estimation for the future. The aim with the classification is both to study the waterbodies ecological status and to gain knowledge of where the resources should be concentrated so that the ecological status in all waterbodies will be good in 2015.The characterisation has been done according to the EU Water Framework Directive, and the factors that have been applied are the mean depth and area of the lake. The length and size on the catchment area are the factors that have been used on streams.
The effect of arginine on root system development in Norway spruce (Picea abies L. Karst) somatic embryos
The demands for higher production yields and better quality materials from the forests are increasing globally. Tree breeding programs are directed to meet the future demands on forests. In order to capture the full benefits from the breeding programs, clonal propagation is necessary. For most conifer species, somatic embryogenesis (SE) is the only available option for large scale clonal propagation of Elite clonal material. For Norway spruce (Picea abies L.
Metoder för att bevara värdefull personal i företag
Utvecklingen av informationssamhället har bidragit till att organisationer idag är mer kunskapsberoende. Människor beskrivs som organisationernas viktigaste tillgång och det är företagen som bäst lyckas utnyttja och ta hand om sina anställda som i framtiden kommer att vinna konkurrensfördelar. Ekonomisk ersättning är ett ständigt lockbete för att attrahera och behålla personal i företagen. Däremot kräver dagens högpresterande arbetare mer än ekonomisk trygghet för att stanna i en organisation..
Epiphytic lichens associated with different traffic intensities along the highway E4
Inventories of epiphytic lichens on Scots pine (Pinus sylvestris) were conducted at three sites in east central Sweden: along the newly build motorway (Road E4), along the old road (Road 600) and in a reference site, to compare the effects of traffic pollution on lichen diversities. At each site, species richness, lichen mean sensitivity value (MK), air quality index of the forest stand/sample plot (LKI) and nitrogen impact value (N) were calculated and it was tested if there was any difference between the sites. Twenty-four species were observed in total, and Parmeliopsis ambigua and Hypogymnia physodes were the most common species at all sites. At Road E4, fewer lichen species were observed than at the other sites and this might be due to the impact of air pollution. The species richness at Road 600 was similar to that of the reference site, which might be explained by the improved air quality.
Avgång av lustgas från luftningsprocessen på Käppalaverket
The requirements for wastewater treatment plants (WWTP) are gradually increasing, partly because of higher incoming loads, which in turn require a more efficient treatment process. In parallel with environmental and economic goals there are also desires to lower energy consumption without compromising the wastewater treatment. Furthermore, there is a demand on WWTP´s to alter eutrophication in aquatic systems through better nitrogen and phosphorus removal. An increasing number of WWTP´s have acquired biological nitrogen and phos-phorus removal. A by-product of this type of biological treatment is the formation of nitrous oxide, which is a potent greenhouse gas.
Genus på menyn : Analyser av stabila kol- och kväveisotoper på skelettmaterial från Bjärbygravfältet från äldre romersk järnålder i Kastlösa på Öland
This paper deals with diet and gender in the early roman iron age in Sweden. Human bone and tooth material from the Iron Age cemetery at Bjärby in Kastlösa parish on the island of Öland have been analysed for stable carbon and nitrogen isotopes. 21 individuals were sampled. Where possible 4 samples were taken from each individual, from the first, second and third molar respectively and from one compact bone. By doing so it is possible, at least in theory, to trace intra-individual diets throughout life.
Hyggesbränning på Orsa besparingsskog - en studie på tillväxt och föryngring,15år efter etablering
The main purpose with this study was to investigate whether the tree growth differs or not in prescribed burnt areas compared to mechanically scarified. Together with the result from the main purpose, answers of whether it's possible or not to combine nature conservation with tree production in prescribed burnt areas was presented. In these areas the regeneration were analyzed to see if there was enough tree plants to comply with the Swedish Forestry Act regulations terms for approved regeneration. A field survey was conducted at 6 objects, three objects for prescribed burning and three for mechanically scarification. All objects were planted within the same year.