L'objectif de cette thèse a été de mesurer comment les modifications des régimes hydrologiques, plus particulièrement les exondations, régissent 1) certains aspects du fonctionnement des zones humides, 2) l'organisation et la dynamique à court terme des communautés végétales aquatiques et 3) la survie et la réponse plastique des végétaux aquatiques. Cette thèse aborde les questions à des échelles spatio-temporelles différentes. Premièrement, à l'échelle de la décennie, j'ai mesuré la conséquence de la baisse de la hauteur d'eau des zones humides péri-fluviales sur leur physico-chimie. Deuxièmement, à l'échelle de la saison, j'ai mesuré l'influence des caractéristiques sédimentaires des zones humides sur la réponse à court terme des communautés végétales à l'exondation. Enfin, à l'échelle de quelques semaines, je me suis intéressée à l'aptitude des espèces d'angiospermes aquatiques à mettre en place un ajustement plastique face à l'exondation, en conditions expérimentales de laboratoire et in situ, j'ai recherché les déterminismes de cette réponse (écologiques, morphologiques, phylogénétiques). En termes de caractéristiques physico-chimiques des eaux de surface, l'étude sur 15 ans de la dynamique de zones humides péri-fluviales subissant des exondations, ne conclue pas, comme cela est habituellement décrit dans la littérature, à une augmentation de la teneur en nutriments de la masse d'eau, mais plutôt des changements suggérant des variations du fonctionnement hydrogéologique des zones humides, en faveur d'une plus grande influence de la nappe de versant dans leur alimentation. La réponse in situ des communautés végétales à l'exondation diffère selon le type de sédiment. La résistance et la résilience des communautés décroissent toutes deux avec la capacité de rétention d'eau du sédiment. La capacité des plantes aquatiques à tolérer l'exondation, en conditions expérimentales, semble différer selon leur position phylogénétique, mais pas selon leur forme de croissance (rosettes ou caulescentes) / The objective of this thesis was to measure how changes in hydrological regimes, particularly dewatering govern 1) aspects of the functioning of wetlands, 2) the organization and short-term dynamics of aquatic plant communities and 3 ) survival and plastic response of aquatic plants. This thesis addresses issues at different spatial and temporal scales. First, at the decade scale, I measured the effect of water-level decreases in riverine wetlands on their physico-chemistry characteristics. Second, at the season scale, I measured the influence of sedimentary characteristics of wetlands on short-term response of plant communities to dewatering. Finally, at the scale of a few weeks, I was interested in the ability of aquatic angiosperm species to develop a plastic adjustment to dewatering, in experimental laboratory conditions and in situ, and I looked determinism of this response (ecological, morphological, phylogenetic). In terms of physico-chemical characteristics of surface waters, the 15- year study of the dynamics of riverine wetlands undergoing dewatering, not reached, as is usually described in the literature, with an increase of water body nutrient contents, but rather changes suggesting variations of the hydrogeological functioning of wetlands in favor of a greater influence of the hillslope groundwater table in their water supply. In situ response of plant communities to dewatering differs according to sediment type. Both, resistance and resilience of communities decrease with the sediment water retention capacity. The ability of aquatic plants to tolerate dewatering, in experimental conditions, seems to differ according to their phylogenetic position, but not according to their growth form (rosettes or caulescentes). Species tolerating dewatering show phenotypic adjustments such as denser aerial organs and high plasticity of the leaves, which may explain the maintenance of a similar growth rate in terrestrial and aquatic conditions in these species

Cerca de 230 milhões de toneladas de bauxita são produzidas por ano e, destas, 60 milhões são provenientes de operações que beneficiam esta bauxita usando água como meio para separar as frações mais finas. Como consequência do beneficiamento, estima-se que mais de 25 milhões de toneladas de rejeito sejam dispostas todo ano. Estas frações têm grandes quantidades de caulinita, um argilomineral de difícil desaguamento. Estes sólidos estão tipicamente em uma suspensão com água a cerca de 15% de concentração em massa antes de operações de desaguamento. As formas de desaguamento variam, bem como as opções de disposição. Este texto discorre sobre opções de desaguamento como sedimentação natural, espessamento, filtragem e centrifugação. Também se discorre sobre alternativas de disposição. Estas são condicionadas pela concentração de sólidos do material a ser disposto e são a disposição hidráulica em diques ou reaterro na mina. Após a descrição de cada uma das alternativas, são feitas análises de combinações destas formas de desaguamento e disposição, além de uma avaliação do fluxo de caixa livre descontado acumulado para cada uma. Esta abordagem, feita para um caso específico, permite avaliar qual opção implica em menor despesa financeira para a operação. Foram feitas considerações para avaliar características não econômicas de cada uma das operações, como o consumo de água, área ocupada pelo depósito, perigos de cada opção e seus descomissionamentos. A opção que apontou menor desembolso no período da operação, bem como a minimização de perigos, é o desaguamento com centrífugas e disposição do material reaterrando áreas lavradas. / More than 230 million tonnes of bauxite are produced each year and, from these, nearly 60 million come from operations that use water to beneficiate the ore, separating the finer fractions. By reason of this mineral treatment, it is estimated that more than 25 million dry tonnes of reject are disposed each year. The finer fractions have high kaolinite concentrations, a challenging to dewater mineral. These solids are typically in a suspension with about 15% solids concentration in mass before any dewatering. Both the dewatering options and disposal possibilities may vary. This text discusses dewatering options such as natural settling, thickening, filtering and centrifugation. It also describes alternatives of disposing the material. These options depend on the water concentration and consist of hydraulic disposition or using the dewatered material as mine backfill. After describing each alternative, an analysis of possible combinations among those is made along with an accumulated discount free cash flow evaluation for each one. Considerations were made to evaluate non-economic characteristics of each operation including the water consumption, surface occupied, operational hazards, decommissioning and closure. The option that has shown the lowest cost during the life of the operation, simultaneously reducing operational hazards is dewatering with centrifuges and using the material as backfill in mined out areas.

This diploma thesis is focused on sludge management of wastewater treatment plant. The research work contains an overview of the related legislation, outlines the problems of sludge treatment in the Czech Republic and also deals with technologies and technical solutions that are related to the processing and treatment of sewage sludge for various size categories of wastewater treatment plants. The second part is devoted to the technical and economic assessment of wastewater treatment plants in the category from 500 EO to 2 000 EO. The assessment is based on real data provided by WWTP operators and focuses on electricity consumption, investment costs and operating costs. Part of the diploma thesis is also determining the rentability of drainage equipment, and studying the convenience of using mobile or stationary drainage equipment.

The diploma thesis deals with foundations of a new learning and research center of the Charles University. Goal is economical and secure design of geotechnical structures. In this thesis, has been used less known technology of deep foundations. The author points to the diversity of utilization, such as sealing wall, anchored and unanchored sheeting, columns designed to influence tension and pressure. For the static calculation have been used programs Scia Engineer and Geo5 v19. Part of this thesis the technological process of technology of the soil improvement by DSM.

The thesis is focused on the sludge management at root sewage treatment plants with focus on volum eis highest – sludge manahement. Sludge dewatering using sludge dryiing bed is still condemned designers mainly due to their lack of experience, while at the same time enforcing technologically complex solutions. Therefore, the thesis focuses on the break down balance hydrological equation sludge drying bed, which includes all parameters affecting water balance system. The result is a proposal not only design, but in particular a description of input data and the governing equations in software Reed-Bed, which is calibrated own operational results obtainde for the two sewage treatment plants (village Dražovice and Kotenčice). Reed-Bed software will perform sevetal functions: setting the ground area of sludge bed, investment costs required for the implementation of sludge bed, return on investment, the determination of moisture contene of sludge in the sludge bed and maximum lenght of the dewatering period with regard to wetland vegetation. The second largest item within sludge system creates biomass wetland plants, so work deals with possibilities biomass processing plant at the end of the growing season. Technological processing of biomass was tested on common reed, final product pellets for heating.

Mit der Intensivierung der landwirtschaftlichen Produktion gewinnen Pumpstationen für die Be- und Entwässerung landwirtschaftlicher Nutzflächen zunehmend an Bedeutung. Zur Beseitigung schädlicher Bodennässe werden offene Gräben oder Dränrohrleitungen angelegt, welche das Wasser bei nicht vorhandener Vorflut einem Entwässerungsschöpfwerk zuleiten. Dieses Schöpfwerk fördert das Wasser aus einem Speicherraum (Mahlbusen) in den Vorfluter. In der DDR sind zahlreiche derartige Entwässerungsschöpfwerke vorhanden. (...):1. Einleitung S. 1 2. "Konventionelle" Pumpstationen S. 4 3. Pumpstationen mit Heberauslässen S. 9 4. Ökonomischer Vergleich S. 22 5. Vergleich mit anderen Anwendungsarten des Hebers S. 32 6. Gegenwärtiger Stand der hydraulischen Berechnung von Heberauslässen und Aufgabenstellung für eigene Untersuchungen S. 43 7. Hydraulische Versuche an Heberauslässen S. 47 8. Betriebsverhalten und hydraulische Berechnung von Heberauslässen S. 56 9. Zusammenfassung und Ausblick S. 186 10. Literatur-, Konsultations- und Exkursionsverzeichnis S. 190 11. Symbolverzeichnis S. 200

Varje år i Sverige sker ca 24 000 skallskador på grund av yttre trauma och 30 000 strokeskador. Ett betydande antal får sekundära skador på grund av den ökade vattenhalten kring den skadade hjärnvävnaden. Föreslagen metod är att inducera vattenflöde från skadad till frisk vävnad baserat på teorin om elektroosmotiskt flöde. Teorin bakom elektroosmotiskt flöde är att ett flöde induceras då en spänning läggs över ett medium. Elektroosmotiskt flöde tillämpas i industrin och kallas då electro-osmotic dewatering (EOD). Tekniken används för avvattning av biomaterial, leror, tofu ark samt inom tumörbehandling. I arbetet har utförts flera experiment på hjärnfantomer av agarosgel för att undersöka om metoden kan användas för att leda bort vatten. Första experimentet gjordes för att bevisa att ett flöde induceras vid pålagd spänning över fantom. Andra experimentet undersöker förhållandet mellan flödet, spänningen och strömmen. Resultatet blev linjära förhållanden mellan flödet och spänningen, flödet och strömmen samt mellan spänningen och strömmen. Med litteraturkällor och experimentella resultat härleddes ett samband för att kunna bestämma flödet vid pålagt elektriskt fält. Arbetet avslutades med litteraturstudie i elektrodens material, utformning och placering. Rekommendationerna blev att använda platta elektroder med en strömtäthet under 25 mA/m2. Placeringen optimeras genom förbestämda Finite Element (FE) simuleringar av typskador. / Every year in Sweden there is about 24,000 head injuries due to external trauma and 30,000 strokes. A significant number may develop secondary damage because of the increased water content around the damaged brain tissue. The proposed method is to induce water flow from damaged to healthy tissue based on the theory of electroosmosis. The theory behind the electroosmosis is that a flow is induced when a voltage is applied across a medium. The theory of electroosmosis is applied in industry and called electro-osmotic dewatering (EOD) which is used as a drying technique for the dewatering of bio-materials, clays, tofu sheets and electroosmosis is also applied in clinical treatment of tumors. Several experiments were performed on brain phantoms consisting of agarose gel to examine whether the method can be used to divert water. The first experiment was done prove that a flow can be induced when a voltage is applied over the phantom. The second experiment was to investigate the relationship between the flow rate, voltage and current. The result showed linear correlation between flow rate and voltage, flow rate and current, and between the voltage and current. The literature sources and experimental results were referred to a relationship which is developed to determine the flow induced by electrical field. The work was completed with recommendations in electrode material, design and placement. The recommendations are to use plate electrodes at a current density under 25 mA/m2. Electrode placement is predetermined by Finite Element (FE) simulations of different types of injuries.

Tato práce o energetickém využití čistírenských kalů obsahuje popis vlastností kalu (hustota, měrná tepelná kapacita a dynamická viskozita). Stěžejní kapitoly jsou věnovány desintegraci kalu pro zvýšení obsahu sušiny po odvodnění a experimentálnímu zkoumání tvorby emisí při spalování kalu, kde byl posuzován vliv přídavku alkálie. Spalování vysušeného kalu proběhlo ve fluidní vrstvě, byla zkoumána produkce škodlivin a distribuce těžkých kovů. Druhá ucelená část práce je věnována termochemické desintegraci stabilizovaného kalu, přičemž byl experimentálně vyhodnocován vliv na obsah vody v odvodněném kalu. Provedené experimenty sloužily k detekci vhodné teploty a dávky chemikálie. Výsledky experimentů byly rovněž podkladem pro ekonomickou bilanci, která je založena na úsporách za likvidaci menšího množství kalu.

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We are provided countless products from the forest industry and has been through many years. Paper, paper board, packaging materials and furniture to mention a few. A special type of paper used in food packaging for example, is greaseproof paper. Many producers of greaseproof papers use the toxic and harmful group of chemicals called per- and polyfluorinated alkyl substances (PFAS) in coating since they possess grease resistance. Nordic Paper is a manufacturer of iamKraft® kraft paper and greaseproof paper with over a hundred years of experience without the use of PFAS. Without PFAS, they instead rely on excess refining to form a very dense paper. Nordic Paper has decided to introduce the addition of eucalyptus fibers to the softwood sulfate pulp to enhance the formation of the paper. This study aims to investigate the effects of ~20% addition of eucalyptus fibers to softwood sulfate pulp in regard to refiner energy expended, air permeance (as a measure of grease resistance) and formation. Laboratory work has been done on hand made sheets with a vacuum suction box in laboratory scale. Eight different pulps (four with addition of eucalyptus), provided from Nordic Paper Seffle AB, Säffle, with different refining degree was used in this study. The vacuum pressure used was 20 kPa through all tests, with dwell times 0, 1, 2.5, 5, 10, and 20 ms on sheets with a grammage of 50 g/m2. The study has shown that the pulp with ~20% addition of eucalyptus achieved 86°SR with only 82% expended energy relative to the softwood pulp, which had a refining degree of 87°SR. This small difference in refining degree led to a similar development in dewatering after 20 ms dwell time and 20 kPa, where the softwood pulp achieved a dryness of 9.2% and the pulp with addition of eucalyptus achieved 9.0% dryness. The formation of the softwood pulp was worse, which was the reason for the implementation of addition of eucalyptus. The air permeance on the other hand was not improved by the eucalyptus, but more data is needed to confirm since it is based on only one occasion. So, if the air permeance (grease resistance) allows, Nordic Paper Seffle AB may be able to save 20% in expended energy for refining of softwood sulfate pulp with addition of eucalyptus. / Vi tillhandahåller otaliga produkter från skogsindustrin och har gjort i många år. Papper, kartong, förpackningsmaterial och möbler för att nämna några. En speciell typ av papper som används i till exempel livsmedelsförpackningar är fettresistent papper. Många tillverkare av dessa papper använder den giftiga och skadliga gruppen av kemikalier som kallas per- och polyfluorerade alkylämnen (PFAS) i beläggning eftersom de har fettbeständiga egenskaper. Nordic Paper är en tillverkare av iamKraft® kraftpapper och ”greaseproofpapper” med över hundra års erfarenhet utan användning av PFAS. Utan PFAS förlitar de sig istället på extra malning av fibrer för att bilda ett mycket tätt papper. Nordic Paper har beslutat att införa tillsats av eukalyptusfibrer till sulfatmassa av barrved för att förbättra formationen på papperet. Denna studie syftar till att undersöka effekterna av ~20 % tillsats av eukalyptusfibrer till barrsvedssulfatmassan med avseende på förbrukad malningsenergi, luftpermeans (som ett mått på fettbeständighet) och formation. Laborationer har utförts på handgjorda ark med vakuumsuglåda i laboratorieskala. Åtta olika massor (fyra med tillsats av eukalyptus), tillhandahållna från Nordic Paper Seffle AB, Säffle, med olika malningsgrad användes i denna studie. Vakuumtrycket som användes var 20 kPa genom alla tester, med uppehållstider 0, 1, 2.5, 5, 10 och 20 ms på ark med en ytvikt på 50 g/m2. Studien har visat att massan med ~20% tillsats av eukalyptus uppnådde 86°SR med endast 82% förbrukad energi i förhållande till sulfatmassan, som hade en malningsgrad på 87°SR. Denna lilla skillnad i malningsgrad ledde till en liknande utveckling i avvattning efter 20 ms uppehållstid och 20 kPa, där sulfatmassan uppnådde en torrhalt på 9.2% och massan med tillsats av eukalyptus uppnådde 9.0% torrhalt. Formationen på sulfatmassan var sämre, vilket var anledningen till genomförandet av tillsats av eukalyptus. Luftpermeansen å andra sidan förbättrades inte av eukalyptusen, men mer data behövs för att bekräfta detta eftersom den enbart är baserad på ett enda tillfälle. Så om luftpermeansen (fettbeständigheten) tillåter kan Nordic Paper Seffle AB spara 20% i förbrukad energi för malning av barrvedssulfatmassa med tillsats av eukalyptus.