Os sedimentos, pela sua capacidade de acumular compostos, têm grande importância na avaliação do nível de contaminação e poluição dos ecossistemas aquáticos continentais. Este trabalho tem como objetivo avaliar a qualidade do sedimento de um reservatório urbano (Reservatório Guarapiranga, SP, Brasil), quanto ao teor de metais fracamente ligados ao sedimento usando valores-guia de qualidade como parâmetro de comparação; e verificar a possível heterogeneidade dos metais contidos neste sedimento em um gradiente espacial horizontal. Foram amostrados onze pontos ao longo do eixo principal do Reservatório Guarapiranga, com a utilização de coletor tipo Ambhül e Bührer, em 05/10/2006 e 27/04/2007. As variáveis analisadas foram: matéria orgânica total, para cálculo do carbono orgânico total (COT); sulfeto volatilizável por acidificação (SVA), metais simultaneamente extraídos (MES), pH, EH, temperatura, oxigênio dissolvido, profundidade e granulometria. Pela relação molar (∑[MES] - [SVA])/ COT, critério de qualidade de sedimento estabelecido pela U.S.EPA, o sedimento não apresentou toxicidade provável à biota, ou seja, os metais presentes não estão biodisponíveis. As concentrações de SVA e de matéria orgânica encontradas no sedimento e as frações granulométricas silte e argila se mostraram como importantes fases complexadoras dos metais. Segundo os Valores-Guia de Qualidade de Sedimento, estabelecidos pelo Conselho Canadense do Ministério do Meio Ambiente (CCME), em outubro, a maioria dos pontos amostrados encontrou-se acima do intervalo com possíveis efeitos adversos à biota (PEL: Probable Effect Level), em relação a concentração de Cd, Cu e Ni; e em abril a maioria dos pontos amostrados apresentou concentrações acima de PEL para Cu e Cr. A maioria dos pontos amostrados teve concentrações dos metais Cd, Cu, Ni e Zn acima do Valor de Referência Regional (VRR) para sedimentos da Bacia do Rio Tietê, em outubro; e concentrações acima de VRR para Cd, Cu, Cr e Zn, em abril. Em relação à heterogeneidade espacial horizontal, pode-se dividir o reservatório em dois compartimentos, que diferem, de acordo com a PCA, quanto aos teores dos metais Cd e Cu e a profundidade, sendo a região com maiores concentrações de metais a que engloba a captação de água para abastecimento público. Os elevados teores de metais, apesar de este trabalho sugerir que não estão biodisponíveis, reforçam a necessidade do contínuo monitoramento não apenas da qualidade do sedimento, mas também da massa de água, principalmente por se tratar de um reservatório destinado ao abastecimento público para 20% da população da cidade de São Paulo. / Sediments are very important in assessing contamination and pollution level in continental aquatic ecosystems, because of their capacity of accumulating compounds. The objective of this project was to asses sediment quality of a tropical urban reservoir (Guarapiranga Reservoir, São Paulo State, Brazil), related to the level of weakly-bounded metals by using different sediment quality guidelines as reference; and to check possible space heterogeneity of these metals in a horizontal space gradient. Eleven sample stations along the main axis of Guarapiranga Reservoir were sampled by means of an Ambhül and Bührer collector, in October/05/2006 and April/27/2007. The variables analyzed were: total organic matter for calculation of the total organic carbon (TOC), acid volatile sulfide (AVS), simultaneously extracted metals (SEM), pH, EH, temperature, dissolved oxygen, depth and granulometry. According the molar relation (∑[SEM] - [AVS])/ TOC, sediment quality guidelines suggested by U.S.EPA, sediment did not show probable toxicity, in other words, metals were not bioavailable. The AVS, organic matter concentrations and clay silt percentiles showed be important phases of metal complexation, in sediment. According to sediment quality guidelines suggested by Canadian Council of Ministers of Environment (CCME), in October, most of sampling stations presented metal concentration above PEL (Probable Effect Level) for Cd, Cu and Ni; and in April, most of sampling stations presented concentration above PEL for Cu and Cr. Most of sampling stations presents Cd, Cu, Ni and Zn concentrations above the Regional Reference Values (RRV) for Tietê River Basin sediments, in October and concentrations above (RRV) for Cd, Cu, Cr and Zn, in April. In relation to space heterogeneity, the reservoir can be divided into two parts, which are different, according PCA, because of Cd and Cu concentrations and depth, being the region with higher concentrations that from where water is taken in for public supply. The high metal levels, eventhoug the present work indicates no- bioavailability, reinforce the necessity of continuous monitoring of sediment and water quality, especially due to the fact that this reservoir is used to supply 20% of the population from São Paulo city.

Le but de cette thèse est de comprendre la dynamique des graviers au sein des rivières alpines à faible contrainte en utilisant des expériences en laboratoire. Ces rivières sont souvent composées d’une large gamme de sédiments, allant des argiles aux galets. Ces différentes classes sédimentaires peuvent interagir entre elles, ce qui peut rendre difficile l’estimation du transport solide. Des expériences en laboratoire ont été conduites en écoulements instationnaires dans un canal de 18m de long et 1m de large. Deux types de lits ont été étudiés : lits unimodaux et bimodaux. Une attention particulière a été portée sur la réalisation des lits de graviers dans notre canal. Ils ont été créés dans le but d’approcher au mieux la configuration des lits de rivières alpines, c’est-à-dire avec différents arrangements et degrés de colmatage du lit par des sédiments fins. Les lits unimodaux sont composés de graviers peu triés avec divers arrangements de surface. Les lits bimodaux sont composés d’une matrice de graviers peu triés dans laquelle des sédiments fins se sont infiltrés (sables ou limons). Les processus régissant le transport de graviers ont été mis en avant. Le transport de graviers est impacté par l’arrangement du lit, la concentration de sédiments fins dans la couche de charriage, et par le changement de propriétés du lit due à la présence de sédiments fins (cohésion, perméabilité du lit). Plus le lit est arrangé, plus le transport est difficile. Plus la couche de charriage est concentrée en sédiments fins, plus le transport est facile. La forme des sédiments fins est aussi un facteur important pouvant modifier le transport des graviers. La présence de sédiments fins cohésifs dans la matrice peut considérablement réduire le taux de graviers transportés. Un modèle conceptuel a été développé pour résumer les différents processus contrôlant le transport de graviers. Il décrit le comportement des graviers dans les différentes configurations étudiées. L’outil proposé peut aider à comprendre, estimer et interpréter le transport de graviers. Il a été appliqué et discuté sur un cas de terrain sur la rivière de l’Arc. Basé sur ce modèle, nous avons proposé une nouvelle analyse dimensionnelle pour la construction d’un modèle de prédiction de transport solide prenant en compte des paramètres décrivant l’arrangement du lit, les propriétés géotechniques du lit et la présence de sédiments fins / This PhD thesis aims to understand gravel dynamics in Alpine rivers at low bed shear stress using laboratory experiments. Alpine river beds are often poorly sorted and composed of sediments ranging from clay to pebble. To understand interactions between these classes is an issue for predicting bedload rate. Laboratory experiments were performed in a 18m long and 1m wide flume, under unsteady flows. Two types of bed were investigated: unimodal and bimodal beds. A particular attention was paid to the bed construction, which was conducted in order to obtain a nature-like bed 12with different bed arrangements and degrees of clogging. Unimodal beds were made of moderately sorted gravels with different bed surface arrangements. Bimodal beds were made of moderately sorted gravels in which fine sediments (sand or silt) were infiltrated. Gravel rate was found to be impacted by the bed arrangement degree, the fine sediment concentration within the bedload layer and the changes in bed properties due to fine sediment presence (bed cohesion, bed permeability). The more packed the bed is; the more difficult it is to move gravels. The more concentrated in fine sediment the bedload layer is; the easier the transport of gravels is. The shape of fine sediments can also be an important factor for modifying the gravel rate. The presence of cohesive fine sediments within the bed matrix reduces significantly the gravel rate. A conceptual model was developed to recap the different processes controlling gravel transport. It provides a phenomenological description of the overall bed responses to a hydrograph. This tool is designed to help understanding, estimating or interpreting gravel transport in Alpine rivers. The conceptual model was discussed and applied to a field case made on the Arc River. Using the model, we also suggest a new dimensionless analysis for the construction of a bedload predicting model involving parameters describing bed arrangement, bed properties and fine sediment presence

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The impact of agriculture on water resources has been a focus for problems associated with reservoir siltation, depletion of water quality, reduced infiltration and soil water storage, formation of floods and low water availability during drought periods. In this sense the estimation of gross erosion and sediment yield monitoring reflect the dynamic that occurs in catchments and the processes observed in the rivers. Studies of erosion in grain crop agricultural areas using no-tillage systems are scarce at catchment scale. Thus, this study estimated gross erosion and sediment yield in a large catchment representative of grain crop cultivation and its potential impacts on land degradation and consequent impacts on water resources. The catchment is located on the Riograndense plateau characterized by deep and weathered soils and landscape is gently sloping. Gross erosion estimation was performed with the RUSLE model along with a Geographic Information System where the attributes of soil, climate, landscape, and land use and management were spatialized for the entire drainage area of the catchment (800 km2). The catchment is drained by the Conceição River, which includes towns such as Cruz Alta and Ijuí, among others. The hydrossedimentometric monitoring was carried out for twenty months with automatic instruments, daily sample collection and sampling during rainfall-runoff events. The variables monitored were rainfall, flow, turbidity and suspended sediment concentration. From this data set sediment yield was estimated for the period and a sediment discharge rating curve was established to extrapolate sediment yield for the last decade. The average results of gross erosion for the catchment are in the order of 8 t ha-1 year-1 and average sediment yield was 140 mg km-2 year-1, generating sediment delivery ratio values of 17.5 %. From the temporal and spatial variability of the results, this study seeks to highlight the erosion processes operating at this scale and the implications for management and water and soil conservation programs for similar regions. / O impacto da agricultura nos recursos hídricos tem sido enfoque para problemas associados ao assoreamento de reservatórios, depauperamento da qualidade da água, reduzida infiltração e armazenamento de água no solo, formação de enxurradas e baixa disponibilidade hídrica em períodos de estiagem. Neste sentido a estimativa da erosão bruta e o monitoramento da produção de sedimentos refletem a dinâmica que ocorre nas bacias vertentes e os processos observados nos rios. Estudos de processos erosivos em áreas agrícolas sob produção de grãos em sistema plantio direto são incipientes na escala de bacia hidrográfica. Este estudo estimou a erosão bruta e a produção de sedimentos em uma grande bacia agrícola que representa o processo de produção de grãos e o seu potencial reflexo sobre a degradação dos solos e o impacto nos recursos hídricos. A bacia se localiza no planalto Riograndense caracterizada por solos profundos e intemperizados e relevo suave ondulado. A estimativa da erosão bruta foi realizada com o modelo RUSLE acoplado a um Sistema de Informação Geográfica, onde os atributos de solo, clima, relevo, uso e manejo foram espacializados para toda a área de drenagem da bacia (800 km2). A bacia em questão é drenada pelo rio Conceição que engloba os municípios de Cruz Alta e Boa Vista do Cadeado, dentre outros. O monitoramento hidrossedimentométrico foi realizado durante vinte meses com instrumentos automáticos, coletas de amostras diárias e amostras durante eventos de chuva-vazão. As variáveis monitoradas foram precipitação, vazão, turbidez e concentração de sedimentos em suspensão. A partir desse conjunto de dados foi estimada a produção de sedimentos no período, bem como estabelecida uma curva-chave de sedimentos utilizada para a extrapolação da PS para a última década. Os resultados médios da erosão bruta da bacia estão na ordem de 8 t ha-1 ano-1 e a produção de sedimentos média foi de 140 t km-2 ano-1, gerando valores de razão de entrega de sedimentos de 17,5%. A partir da variabilidade temporal e espacial dos resultados, o trabalho procura salientar os processos erosivos operantes nessa escala e as implicações para os programas de manejo e conservação de água e solo para regiões semelhantes.

Les systèmes côtiers, où le transport sédimentaire est perturbé par les aménagements côtiers sur la côte et l’avant côte, fournissent généralement d'excellents exemples permettant de mettre en lumière ces liens. Cela est faisable lorsque l’ensemble des données bathymétriques d’avant-côte, qui ne sont pas toujours disponibles, sont recueillies au fil du temps. La baie et la ville d'Agadir forment ensemble un des pôles de développement économique le plus important de la côte atlantique du Maroc. En utilisant une approche méthodologique basée sur la modélisation de la houle et des courants, le différentiel de levées topo-bathymétriques, la détermination de l’évolution du trait de côte et le suivi topographique de la zone intertidale, nous mettons en évidence les liens étroits entre les variations des petits fonds et la ligne du trait de côte. Ces liens impliquent à la fois les voies de transport cross-shore et longshore, les variations du budget sédimentaire et la détermination de cellules sédimentaires. Nous avons également suivi l’évolution morphologique de la zone intertidale de la baie en réponse à huit tempêtes qui ont lieu entre Janvier 2014 et Mars 2014. Les résultats obtenus par les simulations numériques montrent que les deux premières tempêtes sont responsables des changements morphologiques majeurs au niveau de la zone intertidale. / Coastal systems where sediment transport is perturbed by engineering interventions on the shoreline and shoreface commonly provide fine examples liable to throw light on these links. This is especially so where shoreface bathymetric datasets, which are generally lacking, are collected over time, enabling more or less fine resolution of the meso-scale coastal sediment budget. Agadir Bay and the city of Agadir together form one of the two most important economic development poles on the Atlantic coast of Morocco. Using a combined methodological approach based on wave–current modelling, bathymetric chart-differencing, determination of shoreline fluctuations, and beach topographic surveying, we highlight the close links between variations in the bed of the inner shoreface and the bay shoreline involving both cross-shore and longshore sand transport pathways, sediment budget variations and new sediment cell patterns. This work discusses also the morphological changes and evolution of Agadir Bay beach (Morocco) in response to eight storms between January 2014 and March 2014. A comparison is carried out of the evolution and variability of the beach in a sector of the bay protected by the commercial harbour of Agadir relative to a sector down drift of the harbour that is more exposed to waves, and changes affecting the beach following these storms are examined. Wave influence is evaluated using numerical simulations. The results show that despite being of relatively low intensity, the two first storm events, and especially storm 1, are responsible for major beach morphological changes.

Different magnitude, intensity and timing of precipitation can impact runoff, hillslope erosion and transport of sediment along river channels.  Human activities, such as dam construction and surface mining can also considerably influence transport of sediment and sediment-bound contaminants. Many river basins of the world are currently subject to changes in climate at the same time as pressures from other human activities increase. However, because there are often complex interactions between such multiple drivers of change, it is challenging to understand and quantify contributions of individual drivers, which is needed in predictive modelling of future sediment and contaminant flows. This thesis considers sediment transport in the Lake Baikal basin, which is hydrologically dominated by the transboundary Selenga River of Russia and Mongolia. The Selenga River basin is, for instance, subject to climate change and increasing pressures from mining, but process complexity is reduced by the fact that the river basin is one of few large basins in the world that still is essentially undammed and unregulated. A combination of field measurement campaigns and modelling methods are used in this thesis, with the aim to: (i) identify historical hydroclimatic trends and their possible causes, (ii) analyse the spatial variability of riverine sediment loading in the mining affected areas, and (iii) investigate sediment transport and storage processes within river channels and in river deltas. Results show that, during the period 1938-2009, the annual maximum daily flow in the Selenga River basin has decreased, as well as the annual number of high flow events, whereas the annual minimum daily flow has increased. These changes in discharge characteristics are consistent with expected impacts of basin-scale permafrost thaw. Both field observations and modelling results show that changes in magnitude and number of high-flow events can considerably influence the transport of bed sediment. In addition, the average discharge has decreased in the past 20 years due to an extended drought. Under conditions of low flow, metal-enriched sediment from mining areas was observed to dominate the river water. If discharge will continue to decrease in the Selenga River (or other mining-impacted rivers of the world), further increases in riverine metal concentrations may hence be one of the consequences. Furthermore, under current conditions of extended drought, less sediment may have been distributed over the floodplain wetlands in the Selenga River delta. Present estimates, however, show that sediment can still be transported to, and deposited within, the banks and water bodies located in the backwater zone of the Selenga River delta. This can aid bank and levee stabilization, support the development of wetlands and foster net sedimentation.​ / Nederbördens olika magnitud, intensitet och tidpunkt kan påverka ytavrinning, vattenerosion och transport av sediment längs flodkanaler. Mänskliga aktiviteter, som dammkonstruktion och gruvdrift i dagbrott kan också påtagligt påverka transport av sediment och sedimentbundna föroreningar. Många avrinningsområden i världen påverkas för närvarande av klimatförändringar samtidigt som trycket från andra mänskliga aktiviteter ökar. Men eftersom det ofta förekommer komplexa interaktioner mellan sådana multipla orsaker till förändring, är det utmanande att förstå och kvantifiera bidrag från enskilda orsaker, vilket behövs vid prediktiv modellering av framtida sediment- och föroreningsflöden. Denna avhandling behandlar sedimenttransport i Bajkalsjöns tillrinningsområde, som hydrologiskt domineras av den internationella Selengafloden i Ryssland och Mongoliet. Selengaflodens tillrinningsområde är exempelvis påverkat av klimatförändringar och ökat tryck från gruvdrift, men processkomplexiteten reduceras av det faktum att tillrinningsområdet är ett av världens få stora som fortfarande väsentligen saknar dammar och flödesreglering. I denna avhandling används en kombination av fältmätningskampanjer och modelleringsmetoder, i syfte att: (i) identifiera historiska hydroklimattrender och deras möjliga orsaker, (ii) analysera den rumsliga variationen i flodens sedimentbelastning inom de gruvpåverkade områdena, och (iii) undersöka sedimenttransport- och retentionsprocesser inom flodkanaler och i floddeltan. Resultaten visar att det årliga maximala dygnsflödet, liksom det årliga antalet högflödeshändelser, har minskat i Selengafloden under perioden 1938-2009, medan det årliga minimala dygnsflödet har ökat. Dessa förändringar i flödeskaraktäristika överensstämmer med förväntade effekter av storskaligt tinande permafrost. Både fältobservationer och modelleringsresultat visar att förändringar i högflödeshändelsers magnitud och årligt antal kan påverka transporten av bottensediment påtagligt. Dessutom har medelflödet minskat under de senaste 20 åren på grund av långvarig torka. Under lågflöden observerades metallberikat sediment från gruvområdena dominera flodvattnet. Om flödena fortsätter att minska i Selengafloden (eller andra gruvdriftspåverkade floder i världen), kan således ytterligare ökningar av flodvattnens metallkoncentrationer vara en av konsekvenserna. Under den långvariga torka som nu råder mängden sediment som fördelats över våtmarkerna i Selengaflodens delta ha minskat. Sediment beräknas dock fortfarande kunna transporteras till och deponeras inom flodbankar och vattenkroppar i Selengadeltats backwaterområden. Detta kan bidra till stabilisering av bankar och skyddsvallar, stödja våtmarkers utveckling och främja nettosedimentering. / Wielkość, czas trwania oraz intensywność opadów atmosferycznych oddziałuje na charakter odpływu, erozję oraz transport osadów rzecznych. Również ingerencja człowieka w środowisko – np. budowa zapór i zbiorników wodnych, czy górnictwo odkrywkowe – w różnym stopniu może wpływać na transport osadów oraz powiązanych z nimi zanieczyszczeń. Wiele dorzeczy na Ziemi, będących pod wpływem obecnych zmian klimatycznych, jest jednocześnie poddawanych narastającej antropopresji. W celu przewidywania przyszłych zmian w transporcie osadów i powiązanych z nimi zanieczyszczeń, potrzeba dogłębnego zrozumienia i oceny wpływu poszczególnych czynników powodujących te zmiany. Taka analiza jest jednak często utrudniona ze względu na złożone interakcje pomiędzy czynnikami powodującymi zmiany. Niniejsza rozprawa doktorska przedstawia wyniki badań związanych z analizą transportu osadów rzecznych w zlewni jeziora Bajkał, zdominowanej hydrologicznie transgraniczną rzeką Selengą, przepływającą przez tereny Rosji i Mongolii. Zlewnia rzeki Selengi podlega współczesnym zmianom klimatycznym oraz wzrastającej presji związanej z górnictwem. Złożoność procesów hydrologicznych jest jednak w tym wypadku ograniczona, ponieważ zlewnia Selengi jest jednym z nielicznych, względnie dużych dorzeczy na świecie, którego przepływy są – jak dotychczas – naturalne, nieuregulowane przez żadne zapory lub zbiorniki wodne. Dla poszczególnych celów: (i) identyfikacji historycznych trendów hydroklimatycznych i ich przyczyn, (ii) analizy przestrzennych zmian w transporcie osadów rzecznych w części zlewni dotkniętej górnictwem odkrywkowym oraz (iii) badania procesów transportu i magazynowania osadów w korycie i delcie rzeki; zostały w pracy zastosowane hydrometryczne dane pomiarowe, dane pochodzące z badań terenowych oraz metody modelowania. Wyniki badań wskazują na to, że w latach 1938-2009 zmalały roczne przepływy maksymalne oraz liczba wezbrań, podczas gdy w tym samym czasie wzrosły roczne przepływy minimalne. Powyższe zmiany są zgodne z oczekiwanym wpływem rozmarzania wiecznej zmarzliny na ustrój przepływów rzecznych. Analiza danych pomiarowych oraz wyników modelowania wskazują na to, że obecne zmiany dotyczące liczby oraz wielkości wezbrań mogą znacznie wpłynąć na transport osadów dennych w korytach rzek. Dodatkowo, w ciągu ostatnich 20 lat (1995-2014), średnie roczne przepływy znacznie spadły ze względu na przedłużający się okres suszy na terenie zlewni. Analiza danych terenowych pochodzących z obszarów górniczych wykazała, że podczas obniżonych przepływów, w zanieczyszczonych znaczną ilością metali osadach rzecznych, dominuje materiał pochodzący z działalności człowieka (około 80\% transportowanych osadów). Należy zatem przewidywać, że jeśli obecne zmiany w ustroju przepływów w dorzeczu Selengi (lub w innych podobnych dorzeczach na świecie) będą postępować, to ich następstwem może być dalszy wzrost koncentracji zanieczyszczeń (metali pochodzących z obszarów górniczych) rzek. Ponadto, w obecnym okresie obniżonych przepływów, na terenach zalewowych i jeziorach delty rzeki Selengi zatrzymuje się prawdopodobnie mniej osadów. Wyniki badań wskazują jednak na to, że osady rzeczne mogą być wciąż transportowane do brzegów i obszarów wodnych znajdujących się w strefie, w której stany wodne cieków delty są pod wpływem stanów wodnych jeziora Bajkału. Akumulacja materiału w tych częściach delty Selengi może pozytywnie wpływać na stabilizację naturalnych wałów oraz mokradeł i zwiększać sedymentację netto. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p>

This thesis deals with analysis of flow inside integral SPM sampler. Flowing is described for one-phase flow and multi-phase flow (water-solid particles) approaches. Results of computational modeling and experimental modeling are compared. Experimental box was constructed and its construction is noticed. Methods of used computational and experimental modeling are described. Optimal computational model is recommended. The theme of this thesis was chosen in co-operation with Czech Geological Survey whitin the frame of project MŽP „SP/1b7/156/07“.

Urban streams are influenced by number of human activities. Diploma thesis discusses the impact of urban drainage (specifically storm water drains) on toxic metal concentrations, of, in one of Prague's minor creeks - Zátišský Creek. Zátišský Creek flows from the right side to the Vltava River. The creek is 3080 m long with a natural flow 1.9 m3 /s. The creek is affected by seven storm water drains and three rain settling tanks. The creek was monitored from April 2009 to June 2010 during this period six sampling campaign was conducted. The samples were collected from seven remote sampling points, located both upstream and downstream from the storm water drains and rain settling tanks. The impact of storm water drains was assessed based on monitoring of toxic metals content in different parts of the aquatic environments, samples of water, sediment and aquatic biota (benthic organisms and attached algae) were collected and analyzed. The sediment samples and organisms were dried by lyophilisation (freeze dry), and digested in a microwave oven using a solution of nitric acid and hydrogen peroxide. Metal concentrations were determined by Atomic Absorption Spectrometry utilizing instrument Solaar S. Overall nine metals were identified: cadmium, lead, nickel, chromium, copper, zinc, aluminum, manganese...

Geotextildukar används idag som tillfällig kontroll av sedimentgrumling vid vattenarbeten. Syftet med examensarbetet är att ge ökad kunskap kring olika geotextildukars genomsläpplighet med avseende på suspenderat material, PAH (Polycykliska aromatiska kolväten) och kvicksilver vid suspension av sediment från Karlbergskanalen. Detta har gjorts genom en laboration. Resultaten visar att det inom några minuter bildas en filterkaka på de tre undersökta dukarna. Dukarna blir täta då de utsätts för finpartikulärt suspenderat sediment med koncentrationen 57 g/l hämtat från Karlbergskanalen. Under de 2,5 timmar långa försöken har dukarnas permeabilitet kraftigt reducerats. Under laborationen var PAHtot och mängden PAH i den filtrerade fraktionen störst vid turbiditetsmaximum. Den filtrerade fraktionen PAH följde turbiditeten och reducerades med 21 % samtidigt som turbiditeten reducerades med 24 % under försöket. Även den totala kvicksilvermängden var störst vid turbiditetsmaximum, resultaten är dock inte statistiskt säkerställda. Under laborationen gav en högre halt suspenderat material en lägre andel PAH i den filtrerade fraktionen, troligtvis beroende på re-adsorption. För att utvärdera hur stor andel av PAH, kvicksilver, kadmium och koppar som befinner sig i den filtrerade fasen har det genomförts försök där sediment och vatten skakats 3x10 timmar. Av den totala PAH koncentrationen var 0,07 % i den lösta fasen. Endast en låg andel av koppar, kadmium och kvicksilver återfanns i den lösta fasen (&lt; 1 %). Trots den låga andelen i den filtrerade fraktionen skulle motsvarande haltökningar i Karlbergskanalen innebära halter långt över aktuella gränsvärden[1]i dukbassängen. Innan filterkakan bildats sker ingen reduktion av turbiditeten för två av de tre undersökta dukarna. Geotextilskärmarna förhindrar således ingen spridning av miljögifter utan bildningen av en filterkaka. Om filterkakan bildas och består i fält går inte att fastställa utifrån laborationen. [1]MKN MAC för löst Hg och Cd, Naturvårdsverkets föreslagna GV för löst Cu MKN MAC för den totala PAH koncentrationen / Geotextiles are used as temporary sediment controls in water during construction work. The aim of this project is to give background information to a cost effective control program and to increase the knowledge about geotextiles and their permeability for suspended sediment, PAH and Hg for a site specific sediment. Laboratory studies have been conducted in order to evaluate three geotextiles with regard to their ability to separate suspended sediment, PAH and Hg. The results show that a filter cake is formed. The textiles became clogged within a time period of 15 minutes and no sediment passed the textiles after this. A sediment concentration of 57 g/l was used. The separation of suspended particulate matter is 28-78 % and the textile with the greatest reduction capacity was the thinnest one. The separation of PAHtot was 79 %, meanwhile the average separation of suspended sediments was 78 %. The geotextile did not reduce the dissolved fraction of PAH. This fraction was larger on the outside suggesting that the concentration of suspended material was too low to re-adsorb the dissolved PAH. The turbidity decreased with 24 % during the experiment due to sedimentation, the dissolved fraction of PAH was reduced with 21 % during the same time period. The amount of Hgtot was largest at turbidity maximum. Laboratory experiments where sediment was shaken 3x10 hours with distilled water have also been conducted in order to evaluate the amounts of PAH, Hg, Cu and Cd that partition in the dissolved phase. 0, 07 % of the total amount of PAH was found in the filtered phase and only small fractions of Cu, Cd and Hg (&lt; 1 %). Despite the small percentage in the filtered fractions the corresponding increase in Karlbergskanalen would result in concentrations well above maximum allowed concentrations[1]in the geotextile encircled area. There is no reduction of the turbidity before the filter cake is formed. It is not possible to draw any conclusions about the formation of a filter cake in field and if a formed filter cake would be broken by hydraulic forces or not. [1]MKN MAC for dissolved Hg and Cd, Swedish Environmental Protection Agency’s suggested limit value for dissolved Cu, MKN MAC for the total PAH concentration

Pulp and paper industries in Sweden have since the end of the 19th century until late 70s been active in dumping wastewater into adjacent water bodies that have created fibrous sediments called fiberbank and fiber-rich sediment. Fiberbanks are large banks of predominantly organic material while fiber-rich sediment is fibrous sediment that has been mixed with bottom sediment. The fiberbanks comprise of high levels of processed wood fibres and contaminants such as heavy metals and persistent organic pollutants (POPs). It also produces carbon dioxide and methane gas by microbial activity and leaves the sediment with exit holes called pockmarks. These sediments have been proven to cause environmental harm to the benthic biological environment around it, also causing it to become anoxic/hypoxic. Some of the POPs bioaccumulate which also affect humans through fishing. If the fiberbanks are disturbed through e.g. mass movement, toxic contaminants could be released into the aquatic environment. Fiberbanks need to be remediated and more research is needed to characterise it. In-situ capping is a remediation technique that is being tested at the laboratory scale for its application to fiberbanks. It involves placing a layer of clean material on top of the sediment, in order to stabilize it and to limit contaminant release.Because of their high organic content and low density, these sediments might behave differently than typical natural sediments. Therefore, laboratory experiments are necessary to understand their key properties. This thesis focuses on the Sandviken site, for which the bearing capacity of fiberbanks, their thickness, and the compression rate of fiber-rich sediments are studied. The bearing capacity is the capacity for a sediment to hold a weight, and in the case of in-situ capping it is an important parameter to study. The thickness was interpreted from physical data collected by a fluid mud penetrometer (FluMu), from the University of Bremen to assess the fiberbank volume. Fiber-rich sediment is examined to expand the knowledge on its physical properties by testing consolidation and potential gas production.Bearing capacity was tested by placing sediment in a tank and placing a cap on top of it. The site thicknesses were interpolated in ArcMap into a visual topography where the volume could be calculated. Fiber-rich sediment consolidation was tested by placing the sediment in columns with different capping thicknesses. By monitoring bubbles and pockmarks, gas production was confirmed.Results show that the tank sediment construction kept its shape without collapsing or failing at the edges. Sediment/cap interface was sharp, it means little to no mixing between the layers. This proves that Sandviken fiberbank has enough bearing capacity to hold up a cap and that it contains contaminants well. FluMu interpretation resulted in a fiberbank volume of 51885 m3. The fiberbank thickest layer was interpreted as being in front of the sulphate factory which is a credible result. The fiberbank volume is not conclusive since the FluMu has not measured complete thicknesses of the layers. This can be said since thicknesses have been measured at a minimum of 6 m and the thickest point interpreted was 1,11 m. The fiber-rich sediment consolidation showed that a cap that is very thick will cause most consolidation and more rapid dissipation of pore water. Bubbles and pockmarks were observed and confirm gas production. / Papper- och massa-industrin i Sverige har varit aktiv fram till 1970-talet och har dumpat förorenat vatten i angränsande vattendrag. Detta har gett upphov till fibersediment som kallas fiberbank och fiberrikt sediment. Fiberbanker är stora banker av övervägande organiskt material och fiberrikt sediment är en blandning av fiberbank sediment och bottensediment. Fiberbankerna består mestadels av bearbetade träfibrer och föroreningar som tungmetaller och långlivade organiska föroreningar (POPs). Sedimentet producerar även växthusgaser genom mikrobiell aktivitet. Dessa sediment orsakat miljöskada på den biologiska bottenmiljön i omgivningen då den förlorat syreinnehåll. Samtliga POPs samlas i fisk vilket därav även påverkar människors hälsa. Om fiberbankerna skulle störas, släpps giftiga föroreningar ut i miljön. Fiberbanker måste åtgärdas och en saneringsteknik som undersöks i laboratorieskala är in-situ övertäckning. Detta innebär att placera ett lager av rent material ovanpå sedimentet för att stabilisera det och stoppa frigöring av föroreningar.På grund av sedimentets annorlunda karaktär är experiment i laboratorier nödvändiga för att förstå deras nyckelegenskaper. Detta arbete fokuserar på fiberbanken i Sandviken, fiberbankens bärförmåga, dess tjocklek och kompressionshastigheten för fiberrika sediment studeras. Bärförmågan är kapaciteten för ett sediment att hålla en vikt och när man ska belasta ett sediment med ett övertäckningslager är detta viktigt. Tjockleken av sedimentet undersöks för att bedöma fiberbankens volym i området. Fiberrikt sediment undersöks för att utöka kunskapen om dess fysiska egenskaper genom att testa konsolidering och om det producerar gas likt fiberbanksediment.Bärförmågan testades genom att placera sediment i en tank och placera ett lager av rent material på. Platstjocklekarna tolkades från fysiska data från en typ av sensor som penetrerar sediment och interpolerades därefter i ArcMap till en visuell topografi där volymen kunde beräknas. Fiberrik sedimentkonsolidering och gasproduktion testades genom att placera sedimentet i kolumner med olika locktjocklekar.Resultaten visar att bärförmågan av fiberbanksedimentet var tillräckligt för att klara av en grundlig belastning. Gränsen mellan sedimentet och övertäckningslagret var skarp i slutskedet, det innebär liten eller ingen blandning mellan skikten. Detta bevisar att sedimentet bibehåller övertäckningslager väl över sig då ytan är platt. Tolkningen av sensordata resulterade i en fiberbankvolym på 51885 m3. Fiberbankvolymen är inkomplett eftersom FluMu inte har uppmätt skiktens fullständiga tjocklekar eftersom tjocklekar har tidigare uppmätts till minst 6 m och den tolkade tjockaste punkten var 1,11 m. Den fiberrika sedimentkonsolideringen visade att ett övertäckningslager som är mycket tjock kommer att orsaka mest och snabbast konsolidering. Observationer bekräftade även gasproduktion i sedimentet.

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