Thesis (Ph.D.) -- La Trobe University, 2006. / Research. "A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy, [to the] Centre for Applied Alpine Ecology, Department of Agricultural Sciences, School of Life Sciences, Faculty of Science, Technology and Engineering, La Trobe University, Bundoora". Includes bibliographical references (leaves 172-186). Also available via the World Wide Web.

Thesis (M.Sc.) -- Memorial University of Newfoundland. 1976. / Typescript. Bibliography : leaves 164-190. Also available online.

In the general section of this thesis are shortly characterized fossil fuel, peat bogs and peat, process of their origin, their types and importance. Another important part of this work is the extraction of peat, its trend, subsequent restoration and environmental problem of the peat extraction. The main part is the characteristic of the area Borkovická blata, mapping out mining process in the area and the present condition. Furthermore, there is shortly characterized the company Rašelina, a. s., which extracted in Borkovická blata peat for a long time and is still engaged in the extraction and processing of peat.

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Orientador: Cesar Costapinto Santana / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-17T10:22:11Z (GMT). No. of bitstreams: 1 SepulvedaCuevas_LuisaAntonia_D.pdf: 5246232 bytes, checksum: 77d48b5832e64e906a8627c25be24f24 (MD5) Previous issue date: 2011 / Resumo: O objetivo deste trabalho foi estudar a remoção dos corantes Naftol Azul Preto (NAP), Azul Maxilon 5G (AM) e Azul Brilhante de Remazol R (ABRR) em fase aquosa por adsorção em turfa de origem magalhânica. De acordo com a caracterização físico-química do adsorvente, os principais grupos funcionais detectados foram os carboxílicos, fenólicos, hidroxilas, aminas e metil, que lhe conferiram uma carga preferencialmente negativa e um Ponto de Carga Zero (PCZ) igual a 3,68. Os resultados dos experimentos em batelada mostraram que a adsorção do corante NAP foi fortemente dependente da carga superficial da turfa. Os modelos de isotermas de Langmuir, Freundlich e Sips foram bem correlacionados aos dados experimentais de equilíbrio de ambos os corantes. As capacidades máximas de adsorção (qm) e o parâmetro de energia de Langmuir (b) dos corantes NAP e AM alcançados foram de 33,7 e 33,1 mg/g e 0,031 e 0,139 L/mg, respectivamente. De acordo com os resultados dos experimentos cinéticos em tanque agitado, as porcentagens de remoção e as capacidades de adsorção atingidas foram de 81 e 97 %, 12 e 30 mg/g para os corantes NAP e AM, respectivamente. Os modelos cinéticos de segunda ordem e de Langmuir foram bem correlacionados aos dados experimentais para baixas concentrações iniciais de corante. A modelagem do sistema mostrou que a difusão intrapartícula acontece de forma paralela no volume e na superfície do poro e é a etapa que controla a velocidade de transporte das moléculas de corante até os sítios ativos da turfa. Os coeficientes de difusão no poro foram determinados entre 1,08-3,5 10-10 m2/s e os coeficientes de difusão na superfície entre 0,2-1,5 10-11 m2/s. Dos ensaios em colunas de leito fixo, as capacidades de adsorção na saturação variaram entre 17,1 e 30,1 mg/g para o corante AM nas condições selecionadas. A altura de transferência de massa foi dependente da concentração e vazão da alimentação com valores entre 14 e 23 cm. De forma oposta, as capacidades de adsorção do corante NAP foram entre 2-3 mg/g, equivalente a 20-30 % da capacidade de equilíbrio em ensaios em batelada. Esses resultados foram atribuídos às baixas energias de adsorção do corante em turfa. O modelo de THOMAS apresentou uma boa predição da concentração de corante na fase inicial das curvas de ruptura (C/Cf < 0,5), quando o corante AM foi adsorvido em um leito de turfa. No entanto, o modelo não foi capaz de predizer o comportamento do corante NAP / Abstract: The aim of this work was to study the removal of dyes Naphthol Blue Black (NBB) and Maxilon Blue 5G (MB) in the aqueous phase by adsorption on Magellan peat. According to the peat physicochemical characterization, the carboxylic, phenolic, hydroxyl and methyl amines were identified as the main functional groups, that giving it a preferably negative charge and a Point of Zero Charge (PZC) equal to 3.68. The results of batch experiments showed that the adsorption of the NBB dye is strongly dependent on surface charge of the peat, but it did not happen with the MB dye. The Langmuir, Freundlich and Sips isotherm models were well correlated to equilibrium experimental data of both dyes. The maximum adsorption capacities (qm) and the Langmuir energy parameter (b) of the NBB and MB dyes obtained were 33.7 and 33.1 mg/g and 0.031 and 0.139 L/mg, respectively. On the kinetic experiments in stirred tank, the removal rate and the adsorption capacities were 81 and 97%, 12 and 30 mg/g for NBB and MB dyes, respectively. The kinetic models of second order and Langmuir were well fitted to experimental data for low initial concentrations of dye. The system modeling showed that happens pore and surface diffusion and was the rate-determining step of the adsorption process. The diffusion coefficients were estimated in 1.08 to 3.5.10-10 m2/s in the pore and 0.2 to 1.5.10-11 m2/s on the surface. From tests in fixed bed columns, the adsorption capacities at saturation ranged between 17.1 and 30.1 mg/g for MB dye in the selected conditions. The mass transfer height was dependent on the concentration and flow rate of feeding from 14 to 23 cm. In the other side, the adsorption capacities of the NBB dye ranged between 2 and 3 mg/g, equivalent to 20 - 30% of equilibrium capacity in batch tests. These results were attributed to the low energies of the dye adsorption on peat. The THOMAS model showed a good quality in prediction of the dye concentration in initial portion of the breakthrough curves (C/Co < 0.5), when the MB dye were adsorbed on a peat bed. However, the model failed to predict the behavior of the NBB dye / Doutorado / Desenvolvimento de Processos Biotecnologicos / Doutor em Engenharia Química

Le devenir des anciens sites miniers est un sujet de préoccupation sociétale. Afin de garantir la protection de l'écosystème ainsi qu'un impact radiologique minimal sur la biosphère, il est important de comprendre les paramètres qui régissent la migration de l'uranium (et de ses produits de désintégration, en particulier le radium 226) et d'être capable de le modéliser. Dans la nature, parmi les phases qui peuvent retenir 238U(VI) et 226Ra(II), la tourbe est connue pour avoir une forte affinité pour l'uranium VI. La tourbe sèche étant généralement composée à près de 90% de matière organique, l'objectif de cette étude est de qualifier et de quantifier la capacité d'adsorption et de désorption de la matière organique de la tourbe pour 238U(VI) et 226Ra(II). Les échantillons de tourbe prélevés à proximité de l'ancien site d'extraction d'uranium des Sagnes (Limousin, France) ont été caractérisés et ont ensuite été utilisés pour des expériences d'adsorption et de désorption en btach. Les résultats montrent que l'adsorption de 226Ra(II) sur la tourbe est supérieure à 97% pour pH>4-6 (suivant la teneur en particules détritiques dans la tourbe), ce qui correspond à des valeurs de Kd de 4500 pour 500mL/g. Quand à elle, l'adsorption de 238U(VI) est supérieure à 80% à pH>3, avec des valeurs de Kd qui atteignent 11000 mL/g vers pH 4.5. La désorption mesurée après un mois reste très faible. Contrairement aux tourbes classiques, la tourbière des Sagnes présente la particularité d'avoir une charge détritique importante (jusqu'à 50% de la masse de la tourbe sèche). L'interprétation des courbes de rétention de 238U(VI) et 226Ra(II) nécessite au préalable de discriminer à l'aide de modélisations, la contribution des différentes phases minérales présentes (oxyde de fer, phyllosilicates). Un modèle opérationnel, représentant la fraction organique comme un échangeur d'ions, a été proposé. Celui-ci permet de décrire le comportement de ces deux radioéléments sur la fraction organique de la tourbe. / The environmental footprint of former uranium mining sites is a major concern for society. In order to guarantee the protection of ecosystems and thus a minimal radiological impact on the biosphere, it si important to understand and to be able to model the phenomena controlling the migration of uranium and its decay products, specially radium (226Ra) (AREVA's Envir@Mines project). In the environment, among solid phases which can retain 238U(VI) and 226Ra(II), peat is known to have relevant affinity for U(VI). Because peat is usually composed at 90 % dry weight of organic matter, the aim of this study was to qualify and quantify peat organic matter affinity for 238U(VI) and 226Ra(II). Peat samples extracted from Les Sagnes (close to a former uranium mining site in Limousin area, France) was characterized andbatch adsorption/desorption experiments were conducted. The results indicate that 226Ra(II) adsorption onto that peat is higher than 97 % for pH>4-6 (depending on the organic/mineral ratio in dry peat) corresponding to Kd values about 4500 for 500mL/g and 238U(VI) adsorption is higher than 80 % at pH>3 with Kd maximal values reaching 11000 mL/g around pH 4.5 . Only a little desorption was measured after one month.An ion exchange modelling for radium adsorption onto one type of organic matter sorption site was enough to fit the experimental adsorption Kd for the peat over the whole range of Ph . However, uranium sorption on peat can be modelled on that organic sorption site only for pH 5 to 10. From Ph 5 to 10, to explain the experimental uranium adsorption Kd values (close to 1500 mL/g), uranium sorption onto mineral phases (such as smectite and iron oxide in this study) has to be considered. An operational data set is given for both 238U(VI) and 226RA(II) sorption onto Les Sagnes peat. Unlike usual peat, peat from Les Sagnes contains more than 10 % dry weight of mineral matter. That is why it is necessary to modele sorption of those two radioelements onto mineral phases (such as smectite and iron oxide, in this study), to discriminate which part of the sorption is due to mineral phases and which one id from organic matter. An operational dataset for 238U(VI) and 226Ra(II) sorption onto Les Sagnes organic matter was determined.

Surficial geochemistry, particularly selective leach technology, has proven effective in revealing anomalous concentrations of ore indicator metals overlying zones of buried mineralization. This study focuses on the buried Zn-Cu-Au-Ag VMS deposit at McIlvenna Bay in the Flin Flon Greenstone Belt to determine whether the peat swamp at the surface contains any anomalies of ore indicator metals using simple surficial geochemical techniques. Three selective leaches were performed, ammonium acetate pH 5.0, hydroxylamine, and sodium pyrophosphate. The hydroxylamine leach, which selects for metals in the reducible phase often associated with Mn and Fe oxides, has the clearest anomaly for multiple metals observed simultaneously, at the greatest magnitude. The pyrophosphate leach, which selects for metals that are oxidizable, often associated with organics showed a clear anomaly only for Cu, despite the abundance of organic matter and its great affinity for binding metals, likely because the organic-metal complexes formed in this system are easily exchangeable and highly soluble, not allowing for the formation of clear anomalies. The use of selective leach technology on surficial soil or peat has shown to be effective for delineating ore indicator metal anomalies, giving surface projections of buried mineralization in various types of systems, as long as the dynamics of the system are well understood in order to determine the phase the metals are associated with.

Peatlands are an important store of soil carbon, play a vital role in global carbon cycling, and can also act as sinks of atmospherically deposited heavy metals. Large areas of the UK’s blanket peat are significantly degraded and actively eroding, which negatively impacts carbon and pollutant storage. The restoration of eroding UK peatlands is a major conservation concern, and over the last decade measures have been taken to control erosion and restore large areas of degraded peat. In severely eroded peatlands, topography is highly variable, and an appreciation of geomorphological form and process is key in understanding the controls on peatland function, and in mitigating the negative impacts of peatland erosion. The blanket peats of the Peak District, Southern Pennines, UK, embody many problems and pressures faced by peatlands globally, and are amongst the most heavily eroded and contaminated in the world. The near-surface layer of the peat is contaminated by high concentrations of anthropogenically derived, atmospherically deposited heavy metals, which are released into the fluvial system as a consequence of widespread erosion. Whilst not desirable, this legacy of lead pollution and its release, offer a unique opportunity to trace peatland sediment movements and thus investigate the controls on sediment and contaminant mobility. A suite of established field, analytical and modelling techniques have been modified and adapted for use in peatland environments: (i) by incorporating a simple correction for moisture content, field portable XRF has been shown to be an accurate, cost-effective, and rapid tool for assessing in situ lead concentrations in wet organic sediments; (ii) a lightweight time integrated mass flux sampler has been developed for deployment at multiple remote peatland field sites, and has been used to explore spatial and temporal suspended sediment dynamics; and (iii) sediment source fingerprinting and numerical mixing models, traditionally used to determine sources of fine sediment in minerogenic systems, have been used to investigate suspended sediment composition in contaminated organic rich catchments. These modified methods have been successfully employed in combination to address issues of sediment and contaminant release. Several mechanisms and controls have been shown to be important influences on sediment dynamics and Pb release across a range of spatial and temporal scales: (i) the presence of vegetation is key in stabilising the peat’s surface and trapping mobilised sediment; (ii) sediment preparation influences the timing of POC and Pb release; (iii) antecedent water tables may control the timing and the nature of sediment entering the fluvial system during storm events; and (iv) the degree of degradation influences both Pb storage and release. At the landscape scale, peatland restoration significantly mitigates sediment production in eroding peatlands and substantially reduces carbon and pollutant export. At the catchment scale, sediment preparation and hydrological connectivity are important controls on the magnitude and timing of sediment and lead fluxes from eroding peatland catchments. At the plot scale, complex small scale spatial patterns of contaminant storage in eroding headwater catchments can be explained by interactions between topographic setting and vegetation cover, and the mobilisation of sediment by wind and water. This deeper understanding of the multi-scalar dynamics of sediment movements in eroding peatlands is important in the context of: (i) the release and reworking of legacy contamination in organic rich systems; (ii) the response of blanket peats to climate change; (iii) informing future restoration strategies that aim to manage peatland sediment and contaminant fluxes.

On the recent lobe of the Fraser River Delta, peat deposition is occurring in three distinct settings: the distal delta plain, the transitional upper delta to lower delta plain, and the upper delta plain to alluvial plain. Each de-positional setting contains a unique sequence of lithofacies and biofacies. Distal lower delta plain peats, although widespread, form a thin, discontinuous peat network dominated by a sedge-grass facies. The peats contain numerous intercalations of silt and silty clay, with a moderate to high pH and a high concentration of sulphur values. The peats overlie a thin fluvial sequence, which in turn overlies a thick coarsening upward sequence of prodelta clay and silty clay. Peats from this environment will form thin lenticular seams of high ash and high sulphur coal. The coal maceral precursors in the peat suggest that the base of the coal will be comprised mainly of desmocol1inite, whereas near the top of the seam oxyfusinite, macrinite, and interlaminated cutinite and vit-rodetrinite would be common. Initial lower delta plain-upper delta plain peats developed from interdistributary brackish marshes. High concentrations of sulphur and ash in these peats decreased in overlying freshwater sedge-grass facies as the delta prograded and the natural levees formed. Sphagnum dominated communities eventually succeeded in areas where fluvial influence was minimal. Laterally, however, along active channel margins, sedge-grass peats intercalate with silty clay overbank and sandy splay deposits. A thin fluvial unit of fining upward sand, silt and clay and a thick sequence of coarsening upward prodelta clay and silty clay underly the deposit. These peats will form relatively thick, widespread coal seams. The seams will be thin and possibly discontinuous adjacent to channels and areas where extensive splaying has occurred. High sulphur concentrations will be confined to the base of seams. The maceral precursors suggest that interbanded telenite, cu-tinite and cerenite will be abundant in the base of the seam and will grade vertically into suberinite, telocollinite, and telenite rich coal. Stumps which will form massive telenite will occur locally. Alluvial plain peats accumulated in freshwater backswamp environments. Earliest sedge-clay and gyttjae peats developed over thin fining upward cycles of silty sand, silt and clay and inter laminated silt, and silty clay of flood origin. Overlying sedge grass and Sphagnum peats are horizontally stratified and form sharp contacts with.bordering flood sediments, at active channel margins, sedge-grass peats intercalate with overbank silty clay to form well developed natural levees, these peats will form a thick seam of high quality coal. The microlithotype composition is comprised of vitritic carbar-gillites and liptites near the base of the seams, and will shift to a clarite and then primarily vitrite near the top. Compared to delta plain peats, maceral distribution will be less complex. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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