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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optimización hidráulica de la planta de tratamiento de aguas residuales aprovechando la pendiente pronunciada del terreno en Vítor – Arequipa – Arequipa / Hydraulic optimization of the wastewater treatment plant taking advantage of the steep slope of the land in Vitor – Arequipa - Arequipa

Daviran Paucar, Miguel Jhunior, Huamani Centeno, Carmen Del Rosario 21 July 2020 (has links)
Hoy en día, la problemática ambiental en el Perú es la contaminación del agua, debido al vertimiento de aguas residuales domesticas de las poblaciones que no tienen un sistema de tratamiento adecuado que presentan un tratamiento deficiente. Mediante la presente investigación se demuestra los procesos de depuración a través de la aireación en el flujo del conducto, esto debido a las pendientes pronunciadas en la red de alcantarillado y sistemas de conducción. Para esto se realizó el diseño de la PTAR convencional en base a la Norma OS-090 para luego realizar los cálculos de aireación basados en la teoría de Naudascher y proceder a realizar el diseño de la PTAR Optimizada. Los resultados obtenidos teóricamente fueron validados a través de pruebas de laboratorio realizado en campo. Al finalizar la investigación se concluye y recomienda lo siguiente: La Norma OS-090 no considera la remoción de contaminantes en la red de alcantarillado y sistemas de conducción. En el proceso de diseño generalmente no se considera condiciones geográficas particulares, como la fuerte pendiente que representa una gran ventaja en zonas rurales. Luego de realizar los cálculos de la aireación en la fuerte pendiente basados en los conocimientos de la Hidráulica y validarlos a través de un muestreo de campo, se logra comprobar la hipótesis inicial, las pendientes pronunciadas del terreno nos permiten optimizar la PTAR a través de la remoción del DBO y SST en las redes de alcantarillado y sistemas de conducción, por ende, se logra reducir costos en la etapa de construcción, operación, mantenimiento, aumentar la eficiencia del proceso y generar el menor impacto ambiental. Se recomienda poder realizar más pruebas de laboratorio para la obtención de mayor cantidad de datos que aumenten el rango de precisión de la remoción del DBO para cada pendiente. Para futuros diseños de PTAR en zonas rurales con pendiente pronunciada se recomienda considerar los cálculos de aireación en el proceso de diseño. / Today, the environmental problem in Peru is water contamination, due to the dumping of domestic wastewater from populations that do not have an adequate treatment system and that present poor treatment. This research demonstrates the purification processes through aeration in the flow, this due to steep slopes in the sewerage network and conduction systems. For this, the design of the conventional PTAR was carried out based on the OS-090 standard, then the aeration calculations based on Naudascher's theory were performed and the optimized PTAR was designed. The theoretical results were validated through laboratory tests conducted in the field. At the end of the research we conclude and recommend the following: The OS-090 standard does not consider the removal of pollutants from the sewer network or pipeline systems. The design process generally does not consider particular geographical conditions, such as the steep slope that represents a major advantage in rural areas. After performing the calculations of aeration on the steep slope based on the knowledge of hydraulics and validate them through a field sampling, it is possible to verify the initial hypothesis, the steep slopes of the ground allow us to optimize the PTAR through the removal of DBO and SST in the sewer networks and conduction systems, therefore, it is possible to reduce costs in the construction stage, operation, maintenance, Increase process efficiency and generate the least environmental impact. It is recommended that more laboratory tests can be performed to obtain more data that increases the range of accuracy of DBO removal for each slope. For future PTAR designs in steeper rural areas it is recommended to consider aeration calculations in the design process. / Tesis
2

Utveckling av nugget från filamentrös svamp från överblivet kokvatten från en tempeh fabrik / Development of nugget analogue from filamentous fungi cultivated in left over boiling water of tempeh factory

Barkman, Albin January 2023 (has links)
The circular economy is about rethinking the definition of waste into resource. Tempeh boiling water is cheap and would otherwise be washed into the river and pollute the water which would affect the environment badly. Tempeh boiling water is going to be used as substrate to produce mycoprotein with the fungi Rhizopus oligosporus. This study is about making a mycoprotein nugget and evaluate it with a sensory evaluation and to evaluate the protein content in the nugget and chemical oxygen demand of the boiling water. The sensory evaluation will have 65 panellists to assess the liking of the nugget with two control samples. The purpose of this project was to evaluate the potential of tempeh boiling water for the circular economy as substrate. To produce high mycoprotein nugget that will be accepted by the community. Assess the protein content in the mycoprotein nugget and assess the carbon used by the fungi with chemical oxygen demand analyse. The target group for evaluating the fungal nugget was students studying at Gadjah Mada University, Yogyakarta, Indonesia. The project was done in multiple following stages: Finding best formula of mycoprotein, mycoprotein production, sensory evaluation, and protein analyse with Kjeldahl method and COD analyse of the boiling water.The result of this study is that the mycoprotein nugget were not liked nor disliked with the average score of 3,9 out of 7. The overall characteristics (appearance, colour, texture, and taste) were 4,0 out of 7. The COD before and after fermentation were 6,6 g/L. The most COD were removed by pre-treatment of the boiling water from 172 to 121 g/L.The protein content of the mycoprotein nugget were 23,8%. The social aspect to produce healthy foods to a low cost at the same time improve water quality by removing foods for toxic microorganisms.
3

Alumina Thin Film Growth: Experiments and Modeling

Wallin, Erik January 2007 (has links)
The work presented in this thesis deals with experimental and theoretical studies related to the growth of crystalline alumina thin films. Alumina, Al2O3, is a polymorphic material utilized in a variety of applications, e.g., in the form of thin films. Many of the possibilities of alumina, and the problems associated with thin film synthesis of the material, are due to the existence of a range of different crystalline phases. Controlling the formation of the desired phase and the transformations between the polymorphs is often difficult. In the experimental part of this work, it was shown that the thermodynamically stable alpha phase, which normally is synthesized at substrate temperatures of around 1000 °C, can be grown using reactive sputtering at a substrate temperature of 500 °C by controlling the nucleation surface. This was done by predepositing a Cr2O3 nucleation layer. Moreover, it was found that an additional requirement for the formation of the α phase is that the depositions are carried out at low enough total pressure and high enough oxygen partial pressure. Based on these observations, it was concluded that energetic bombardment, plausibly originating from energetic oxygen, is necessary for the formation of α alumina (in addition to the effect of the chromia nucleation layer). Further, the effects of impurities, especially residual water, on the growth of crystalline films were investigated by varying the partial pressure of water in the ultra high vacuum (UHV) chamber. Films deposited onto chromia nucleation layers exhibited a columnar structure and consisted of crystalline α-alumina if deposited under UHV conditions. However, as water to a partial pressure of 1x10-5 Torr was introduced, the columnar growth was interrupted. Instead, a microstructure consisting of small, equiaxed grains was formed, and the gamma-alumina content was found to increase with increasing film thickness. When gamma-alumina was formed under UHV conditions, no effects of residual water on the phase formation was observed. Moreover, the H content was found to be low (< 1 at. %) in all films. Consequently, this shows that effects of residual gases during sputter deposition of oxides can be considerable, also in cases where the impurity incorporation in the films is found to be low. In the modeling part of the thesis, density functional theory based computational studies of adsorption of Al, O, AlO, and O2 on different alpha-alumina (0001) surfaces have been performed. The results give possible reasons for the difficulties in growing the α phase at low temperatures through the identification of several metastable adsorption sites, and also provide insights related to the effects of hydrogen on alumina growth. / Report code: LiU-TEK-LIC-2007:1.
4

Alumina Thin Film Growth: Experiments and Modeling

Wallin, Erik January 2007 (has links)
<p>The work presented in this thesis deals with experimental and theoretical studies related to the growth of crystalline alumina thin films. Alumina, Al<sub>2</sub>O<sub>3</sub>, is a polymorphic material utilized in a variety of applications, e.g., in the form of thin films. Many of the possibilities of alumina, and the problems associated with thin film synthesis of the material, are due to the existence of a range of different crystalline phases. Controlling the formation of the desired phase and the transformations between the polymorphs is often difficult.</p><p>In the experimental part of this work, it was shown that the thermodynamically stable alpha phase, which normally is synthesized at substrate temperatures of around 1000 °C, can be grown using reactive sputtering at a substrate temperature of 500 °C by controlling the nucleation surface. This was done by predepositing a Cr<sub>2</sub>O<sub>3</sub> nucleation layer. Moreover, it was found that an additional requirement for the formation of the <em>α</em> phase is that the depositions are carried out at low enough total pressure and high enough oxygen partial pressure. Based on these observations, it was concluded that energetic bombardment, plausibly originating from energetic oxygen, is necessary for the formation of <em>α</em> alumina (in addition to the effect of the chromia nucleation layer). Further, the effects of impurities, especially residual water, on the growth of crystalline films were investigated by varying the partial pressure of water in the ultra high vacuum (UHV) chamber. Films deposited onto chromia nucleation layers exhibited a columnar structure and consisted of crystalline <em>α</em>-alumina if deposited under UHV conditions. However, as water to a partial pressure of 1x10<sup>-5</sup> Torr was introduced, the columnar growth was interrupted. Instead, a microstructure consisting of small, equiaxed grains was formed, and the gamma-alumina content was found to increase with increasing film thickness. When gamma-alumina was formed under UHV conditions, no effects of residual water on the phase formation was observed. Moreover, the H content was found to be low (< 1 at. %) in all films. Consequently, this shows that effects of residual gases during sputter deposition of oxides can be considerable, also in cases where the impurity incorporation in the films is found to be low.</p><p>In the modeling part of the thesis, density functional theory based computational studies of adsorption of Al, O, AlO, and O2 on different alpha-alumina (0001) surfaces have been performed. The results give possible reasons for the difficulties in growing the <em>α</em> phase at low temperatures through the identification of several metastable adsorption sites, and also provide insights related to the effects of hydrogen on alumina growth.</p> / Report code: LiU-TEK-LIC-2007:1.
5

Mineralization of nutrients and plant growth in soils irrigated with wastewater from oil extraction / Ciclagem de nutrientes e crescimento de plantas em solos irrigados com Ãguas residuais da extraÃÃo de petrÃleo

Adervan Fernandes Sousa 03 March 2016 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O grande volume de Ãgua utilizado na agricultura compromete a sua disponibilidade para o consumo humano. Diante desse problema, Ã necessÃrio avaliar a utilizaÃÃo de Ãguas residuais na produÃÃo agrÃcola, como uma opÃÃo para a conservaÃÃo dos recursos hÃdricos. Ãguas residuais oriundas de campos de petrÃleo podem ser uma boa opÃÃo para irrigaÃÃo, especialmente em regiÃes de pouca e alta variabilidade de chuvas como o Nordeste brasileiro. No entanto, Ã necessÃrio avaliar os seus efeitos no solo, como acÃmulo de nutrientes e decomposiÃÃo da matÃria orgÃnica, bem como no aspecto nutricional e no crescimento das plantas. Os objetivos deste trabalho foram: i) Avaliar as mudanÃas ocorridas nos sais solÃveis e nas fraÃÃes da matÃria orgÃnica do solo e no crescimento de plantas de girassol (Helianthus annuus L.) cv. BRS 321, cultivadas em solo de textura arenosa irrigado com Ãgua residual oriunda da extraÃÃo de petrÃleo tratada por filtragem e osmose reversa; ii) Avaliar as alteraÃÃes nutricionais do girassol (Helianthus annuus) BRS 321 irrigado com Ãgua residual da extraÃÃo de petrÃleo e os efeitos sobre a produÃÃo de biomassa e de aquÃnios; e iii) Avaliar a decomposiÃÃo dos restos culturais de girassol (Helianthus annuus) cv. BRS 321 em Ãreas irrigadas com Ãgua residual da extraÃÃo de petrÃleo. O girassol foi cultivado durante trÃs perÃodos sucessivos em Ãreas irrigadas com Ãgua residual da extraÃÃo de petrÃleo tratada por filtragem (APF) e por osmose reversa (APO) ou Ãgua subterrÃnea do aquÃfero AÃu (ACA). Ao fim de cada ciclo foram determinados os valores de pH, condutividade elÃtrica (CE), a razÃo de adsorÃÃo de sÃdio (RAS) e os teores de Na, Cl, Mg, Ca, K, HCO3-, Ag, As, B, Ba, Cd, Co, Cr3+, Hg, Ni, Pb, Zn, alÃm de C nas fraÃÃes hÃmicas. Em raÃzes, parte aÃrea e aquÃnios determinaram-se os teores de N, P, K, Ca, Mg, S e Na e avaliaram-se o crescimento e o acÃmulo de biomassa. AlÃm disso, avaliou-se a decomposiÃÃo dos resÃduos da parte aÃrea das plantas de girassol. Houve alteraÃÃes nos atributos quÃmicos do solo, em destaque o acrÃscimo de sais, que foi maior nas Ãreas irrigadas com APF, e elevaÃÃo do pH, independente do tipo de Ãgua utilizado. A elevaÃÃo da salinidade e alcalinidade do solo reduziu o crescimento e o acÃmulo de biomassa das plantas. AlÃm disso, a irrigaÃÃo proporcionou alteraÃÃes nutricionais das plantas, que refletiram no crescimento e na produÃÃo de aquÃnios do girassol e na decomposiÃÃo dos resÃduos da cultura, com efeitos positivos ou negativos, conforme o tratamento da Ãgua residual. Concluiu-se que a Ãgua residual da extraÃÃo de petrÃleo utilizada na irrigaÃÃo afeta os atributos quÃmicos do solo, bem como a composiÃÃo nutricional e o desenvolvimento das plantas, principalmente quando irrigadas com a APF. AlÃm disso, a irrigaÃÃo com Ãgua residual alterou a mineralizaÃÃo dos resÃduos vegetais do girassol, mas nÃo a de decomposiÃÃo do carbono orgÃnico nas fraÃÃes hÃmicas. / The large volume of water used in agriculture compromises its availability for human consumption. Faced with this problem, it is necessary to evaluate the use of wastewater in agricultural production as an option for the conservation of water resources. Wastewater from oil fields can be a good choice for irrigation, especially in regions of low or high rainfall variability, as in the Brazilian Northeast. However, it is necessary to evaluate its effects on the soil, such as the accumulation of nutrients and decomposition of organic matter, as well as the nutritional aspect and plant growth. The aims of this study were: i) to assess the changes that take place in the soluble salts and soil organic matter fractions, and in the growth of plants of the BRS 321 cultivar of the sunflower (Helianthus annuus L.) cultivated in soil of a sandy texture and irrigated with wastewater obtained from oil extraction and treated by filtration and reverse osmosis; ii) to assess the nutritional changes in the BRS 321cultivar of the sunflower (Helianthus annuus) irrigated with wastewater from oil extraction, and the effects on biomass and achene production; and iii) to evaluate the decomposition of plant residue from the BRS 321 cultivar of the sunflower (Helianthus annuus) in areas irrigated with wastewater from oil extraction. The sunflower was grown for three successive periods in areas irrigated with wastewater from oil extraction treated by filtering (APF) and reverse osmosis (APO), or with groundwater from the AÃu aquifer (ACA). At the end of each cycle, pH values were determined, together with electrical conductivity (EC), the sodium adsorption ratio (SAR) and the levels of Na, Cl, Mg, Ca, K, HCO3-, Ag, As, B, Ba, Cd, Co, Cr3+, Hg, Ni, Pb, Zn, and of C in the humic fractions. The concentrations of N, P, K, Ca, Mg, S and Na were determined in the roots, shoots and achenes, along with growth and the accumulation of biomass. In addition, the decomposition of shoot residue from the sunflower plants was evaluated. Changes were seen in the chemical properties of the soil, highlighting an increase in salts, which was greater in the areas irrigated with APF; a rise was also seen in pH irrespective of the type of water used. The rise in soil salinity and alkalinity reduced the growth and accumulation of plant biomass. Moreover, irrigation resulted in nutritional changes in the plants, which were reflected in the growth and production of achenes, and in the decomposition of the plant residue, having positive or negative effects according to the treatment of the wastewater. It was concluded that wastewater from oil extraction used in irrigation affects the chemical properties of the soil as well as the nutritional composition and development of the plants, especially when irrigated with APF. Furthermore, irrigation with wastewater changed the mineralisation of the sunflower plant residue, but not the decomposition of the organic carbon in the humic fractions.
6

Mejoramiento de las PTAR de uso minero usando un sistema integrado de clarificación de agua de 3 procesos, mina Coimolache - Cajamarca / Improvement of the WWTP for mining use using an integrated 3-process water clarification system, Coimolache mine - Cajamarca

Villalta Yupanqui, Danny Willer, Lévano Lévano, William César 17 November 2021 (has links)
La minería es considerada un motor clave para el desarrollo económico de un país. En este sector, el mejoramiento en la eficiencia de usos del agua es un punto crítico desde el punto de vista económico y ambiental, por ello se siguen implementando nuevos procesos en el tratamiento del agua en el sector minero. Por tal motivo, el objetivo de esta investigación es demostrar que es posible mejorar las PTAR (planta de tratamiento de aguas residuales) de uso minero, lo que implica el mejor funcionamiento del sistema, usando de la mejor forma los recursos que se tienen. Esta investigación se desarrolló bajo los lineamientos de una metodología experimental, donde se diseñó el coagulador, floculador y clarificador de agua de rastras y el diseño del sistema integrado de clarificación de agua de 3 procesos que lo reemplazaría. El propósito de esto es realizar un análisis comparativo entre ambos sistemas usado en la mina “Coimolache” Con los resultados de los cálculos realizados para ambos diseños, tanto el clarificador de rastras y el sistema integrado de clarificación de agua de 3 procesos se demostrará que es posible una reducción en área (m2) a ocupar en el terreno, y de volumen (m3) de movimiento de tierra para contribuir la reducción del impacto ambiental. Así mismo, se evaluó la variación de los costos de implementación, operación y mantenimiento. Finalmente se busca dar a conocer, documentar y demostrar que el uso del sistema integrado de clarificación de agua de 3 procesos tiene múltiples ventajas para promover su implementación al nivel nacional. / Mining is considered a key for the economic development of a country. In this sector, improvement in water use efficiency of use is a critical point from the economic and environmental point of view, is because this reason, new processes are being implemented in the treatment of water in the mining sector. For this reason, the principal objective of this research is to demonstrate that it is possible to optimize the WWTP (wastewater treatment plant) for mining even to get the best operation of the system using in the right way the resources that we have. This research was developed under the guidelines of an experimental methodology, where coagulator, flocculator, and dredge water clarifier were designed and the design of the integrated 3-process water clarification system that would replace them. The purpose is to realize a comparative analysis between these systems used in the "Coimolache" mine. With the results of the calculations carried out for both designs, dredge water clarifier and integrated 3-process water clarification system, it will demonstrate that a reduction in area (m2) to be occupied on the ground and volume (m3) of earth movement is possible to contribute to the reduction of environmental impact. Likewise, the variation in implementation, operation and maintenance costs it was evaluated. Finally, this research intends to make known, document, and demonstrate that the use of the integrated 3-process water clarification system has multiple advantages to promote its implementation at the national level. / Tesis
7

Comportamento de reator anaeróbio operado em batelada seqüencial, contendo biomassa imobilizada e submetido a aumento progressivo da concentração de substrato de fácil degradação / Behavior of the anaerobic sequencing batch reactor containing immobilized biomass and submitted to a progressive increasing of the concetration of easy degradation substrate

Miqueleto, Ana Paula 24 March 2003 (has links)
Os objetivos deste trabalho foram avaliar o desempenho do reator anaeróbio operado em batelada seqüencial quando submetido ao aumento progressivo da concentração de glicose e estimar os parâmetros cinéticos da degradação da glicose. Inicialmente o reator foi operado com ciclos de 8 horas, tratando glicose nas concentrações, aproximadas, de 500, 1000 e 2000 mg/L. Não foi detectada glicose no efluente nas três condições. O reator operou de maneira estável, tratando aproximadamente 500 mg/L de glicose, com eficiência na remoção da DQO filtrada entre 93% e 97%. Na operação com concentrações de glicose no afluente próximas de 1000 mg/L e 2000 mg/L, observou-se instabilidade operacional, principalmente devido à produção de polímeros extracelulares (EPS) que comprometeram a hidrodinâmica e a transferência de massa no sistema. Os valores médios da concentrações de ácidos voláteis no efluente foram de 159 ± 72 mg/L e 374 ± 92 mg/L, respectivamente. Aos perfis de concentração de glicose foi ajustado modelo de primeira ordem, enquanto que um modelo modificado, contemplando concentração residual de matéria orgânica, foi ajustado aos perfis temporais de DQO. Para verificar a formação do EPS, operou-se o reator com 3 horas de ciclo nas concentrações, aproximadas, de 500 e 1000 mg/L. Esta fase teve como objetivo verificar a hipótese, segundo a qual, a produção de EPS seria resultado da exposição da biomassa a baixas concentrações de matéria orgânica por longo período. Dessa forma, reduzindo o tempo de ciclo, a exposição a baixas concentrações também seria reduzida. No entanto, embora o reator tenha operado com relativa estabilidade, verificou-se formação de grande quantidade de EPS logo na primeira condição operacional, com aproximadamente, 500 mg/L de glicose no afluente, indicando que a hipótese não estava correta. / The main objectives of this study were to evaluate the performance of the anaerobic sequencing batch reactor when subjected to a progressive increasing of the influent glucose concentration and estimate the kinetic parameters of glucoses degradation. Initially the reactor was operated with 8-hour cycles, treating glucose at concentrations of 500, 1000 and 2000 mg/L. Glucose was not detected in the effluent in all these three conditions. The reactor showed operating stability treating glucose concentration of approximately 500mg/L, with efficiencies between 93% to 97% in the filtrated COD removal. In the operation with glucose concentrations of 1000 mg/L and 2000 mg/L, approximately, it could be noticed an operational instability, caused mainly by a production of extracellular polymers (EPS) leading to hydrodynamic and mass transfer problems in the reactor. The mean values of volatile acids concentration in the effluent were about 159 ± 72mg/L and 374 ± 92mg/L, respectively. A first order model was adjusted to glucose concentration profiles, and a modified model, including a residual concentration of substrate, was adjusted to COD temporal profiles. To verify the EPS formation, the reactor was operated with 3-hour cycle in the concentrations of 500 and 1000 mg/L This stage had the objective of verifying if the EPS production would result from the exposure of the biomass to low concentration of substrate for a long period of time. Thus, reducing the time cycle, the exposure to low concentrations would also be reduced. Nevertheless, even with the reactor operating with relative stability, the hypotheses could not be verified due the formation of a large amounts of EPS right in the first operational condition with approximately to 500 mg/L of glucose in the influent, showing that the hypothesis was not right.
8

Experimental Study on the Engineering Properties of Gelfill

Abdul-Hussain, Najlaa 29 March 2011 (has links)
Gelfill (GF) is made of tailings, water, binder and chemical additives (Fillset, sodium silicate gel). The components of GF are combined and mixed on the surface and transported (by gravity and/or pumping) to the underground mine workings, where the GF can be used for both underground mine support and tailings storage. Thermal (T), hydraulic (H), and mechanical (M) properties are important performance criteria of GF. The understanding of these engineering properties and their evolution with time are still limited due to the fact that GF is a new cemented backfill material. In this thesis, the evolution of the thermal, hydraulic, mechanical, and microstructural properties of small GF samples are determined. Various binder contents of Portland cement type I (PCI) are used. The GF is cured for 3, 7, 28, 90, and 120 days. It is found that the thermal, hydraulic and mechanical properties are time-dependent or affected by the degree of binder hydration index. Furthermore, a relationship is found between the compressive strength and the saturated hydraulic conductivity of the GF samples. The unsaturated hydraulic properties of GF samples have also been investigated. The outcomes show that unsaturated hydraulic conductivity is influenced by the degree of binder hydration index and binder content, especially at low suction ranges. Simple functions are proposed to predict the evolution of air-entry values (AEVs), residual water content, and fitting parameters from the van Genuchten model with the degree of hydration index (α). Furthermore, two columns are built to simulate the coupled thermo-hydro-mechanical (THM) behaviour of GF under drained and undrained conditions. The obtained results from the GF columns are compared with the small samples. It is observed that the mechanical properties, hydraulic properties (suction and water content), and temperature development are strongly coupled. The magnitude of these THM coupling factors is affected by the size of the GF. The findings also show that the mechanical, hydraulic and thermal properties of the GF columns are different from samples cured in plastic moulds.
9

Experimental Study on the Engineering Properties of Gelfill

Abdul-Hussain, Najlaa 29 March 2011 (has links)
Gelfill (GF) is made of tailings, water, binder and chemical additives (Fillset, sodium silicate gel). The components of GF are combined and mixed on the surface and transported (by gravity and/or pumping) to the underground mine workings, where the GF can be used for both underground mine support and tailings storage. Thermal (T), hydraulic (H), and mechanical (M) properties are important performance criteria of GF. The understanding of these engineering properties and their evolution with time are still limited due to the fact that GF is a new cemented backfill material. In this thesis, the evolution of the thermal, hydraulic, mechanical, and microstructural properties of small GF samples are determined. Various binder contents of Portland cement type I (PCI) are used. The GF is cured for 3, 7, 28, 90, and 120 days. It is found that the thermal, hydraulic and mechanical properties are time-dependent or affected by the degree of binder hydration index. Furthermore, a relationship is found between the compressive strength and the saturated hydraulic conductivity of the GF samples. The unsaturated hydraulic properties of GF samples have also been investigated. The outcomes show that unsaturated hydraulic conductivity is influenced by the degree of binder hydration index and binder content, especially at low suction ranges. Simple functions are proposed to predict the evolution of air-entry values (AEVs), residual water content, and fitting parameters from the van Genuchten model with the degree of hydration index (α). Furthermore, two columns are built to simulate the coupled thermo-hydro-mechanical (THM) behaviour of GF under drained and undrained conditions. The obtained results from the GF columns are compared with the small samples. It is observed that the mechanical properties, hydraulic properties (suction and water content), and temperature development are strongly coupled. The magnitude of these THM coupling factors is affected by the size of the GF. The findings also show that the mechanical, hydraulic and thermal properties of the GF columns are different from samples cured in plastic moulds.
10

Experimental Study on the Engineering Properties of Gelfill

Abdul-Hussain, Najlaa 29 March 2011 (has links)
Gelfill (GF) is made of tailings, water, binder and chemical additives (Fillset, sodium silicate gel). The components of GF are combined and mixed on the surface and transported (by gravity and/or pumping) to the underground mine workings, where the GF can be used for both underground mine support and tailings storage. Thermal (T), hydraulic (H), and mechanical (M) properties are important performance criteria of GF. The understanding of these engineering properties and their evolution with time are still limited due to the fact that GF is a new cemented backfill material. In this thesis, the evolution of the thermal, hydraulic, mechanical, and microstructural properties of small GF samples are determined. Various binder contents of Portland cement type I (PCI) are used. The GF is cured for 3, 7, 28, 90, and 120 days. It is found that the thermal, hydraulic and mechanical properties are time-dependent or affected by the degree of binder hydration index. Furthermore, a relationship is found between the compressive strength and the saturated hydraulic conductivity of the GF samples. The unsaturated hydraulic properties of GF samples have also been investigated. The outcomes show that unsaturated hydraulic conductivity is influenced by the degree of binder hydration index and binder content, especially at low suction ranges. Simple functions are proposed to predict the evolution of air-entry values (AEVs), residual water content, and fitting parameters from the van Genuchten model with the degree of hydration index (α). Furthermore, two columns are built to simulate the coupled thermo-hydro-mechanical (THM) behaviour of GF under drained and undrained conditions. The obtained results from the GF columns are compared with the small samples. It is observed that the mechanical properties, hydraulic properties (suction and water content), and temperature development are strongly coupled. The magnitude of these THM coupling factors is affected by the size of the GF. The findings also show that the mechanical, hydraulic and thermal properties of the GF columns are different from samples cured in plastic moulds.

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