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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

Rehabilitation of waste materials near lead and zinc mining sites in Galena, Kansas

Alghamdi, Abdulaziz Ghazi January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / DeAnn R. Presley / The abandoned lead (Pb) and zinc (Zn) mines in the Tri-State Mining District of Kansas, Missouri, and Oklahoma have left a legacy of environmental contamination. The waste materials are highly polluted, not only with Pb and Zn, but also cadmium (Cd), which often co-occurs geologically with Zn. The District includes Galena, Kansas, where mines operated between 1876 and 1970. Because limited information exists concerning these mines, three studies were done to characterize them and to investigate a way to remediate the mine waste materials. In the first study, the physical characteristics of the mine waste materials were determined. Plots at Galena that had been established by researchers in May 2006 were sampled in November 2014, 8.5 years after they had received amendments (combinations of compost, lime, and bentonite). Water content, bulk density, infiltration rate, unsaturated hydraulic conductivity, aggregate stability, and particle size distribution were determined. The physical characteristics were highly variable, and the amendments added 8.5 years earlier had no effect on them, except the wind erodible fraction (fraction <0.84 mm in diameter) which was low on treatments that contained bentonite. Because biosolids had never been applied to the mine waste materials at Galena for remediation, an experiment was done to see their effect on plant growth and availability of heavy metals. In 2014 the plots established in 2006 were sampled and a greenhouse study was set up with sudex [Sorghum bicolor (L.) Moench x S. Sudanese (P.) Staph]. Plants grew in the mine waste materials with and without biosolids, and 110-111 days after planting the roots, shoots, and heads with grain were harvested and analyzed for heavy metals. At the same time, the mine waste materials were analyzed for heavy metals, organic carbon (C), nitrogen (N), and phosphorus (P). Plants grew better with biosolids than without biosolids, and only the plants grown with biosolids produced heads . Plants grown without biosolids were stunted and showed severe heavy metal toxicity. Organic C and P were increased in the mine waste materials after the addition of biosolids. Thus, the biosolids increased organic C and P, and they apparently made the heavy metals less available for plant uptake. Many studies have shown the importance of attic dust in documenting metal pollution from a mine. Attic dust in Galena had never been studied, so in a third experiment, 14 dust samples in Galena were collected from interiors (attics and one basement) of nine different buildings using two methods: sweeping with a brush and vacuuming. Dust samples were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, and Zn), mineralogy using X-ray diffraction (XRD), scanning electron microscopy (SEM) in conjunction with energy dispersive spectroscopy (EDX), and particle size. Concentrations of Cu, Fe, Mn, Ni, and Zn in the dust were higher than in the mine waste materials. The results from XRD agreed with those from the SEM-EDX analysis. About 10% of each dust sample contained particulate matter (PM) with a diameter of less than 10 μm (PM₁₀), which is a health concern.
2

Carbonation of cement-solidified hazardous waste

Lange, Lisete Celina January 1996 (has links)
Solidification technology can be an effective process for treating a variety of difficult to manage waste materials containing heavy metals prior to reuse or disposal. There are numerous commercial solidification techniques spanning a spectrum of technical complexity and cost. The most common methods include those based on cement or cement/pozzolanic materials. These materials, which are used in many solidification processes, make the technology appear simple and inexpensive. However, there are significant challenges to the successful application of this technique. The morphology and chemistry of the solidified waste forms are complex, specially when the waste streams used contain components other than the metals that are likely to be effectively immobilised. Also, the selection of the binder, depends upon an understanding of the chemistry of both the contaminants and the binder itself, to ensure efficient and reliable results. Nevertheless,a number of complex interactions are known to cause significant retardation on normal hydraulic reactions of cement-based materials, causing numerous and controversial problems. In recent years there has been renewed interest in elucidating the binding mechanisms responsible for the fixation of waste species. Carbonation, which is known to affect a wide range of cementitious materials, is a phenomenon observed by many scientists and has received very little attention. The aim of this work has been to investigate the effects of natural and accelerated carbonation on the development of mechanical and microstructural properties of solidified products as well as on the binding of metallic waste components. Particular emphasis was paid to examine the influence of different binders on the properties of carbonated solidified waste forms. The kinetics of the carbonation reaction was thoroughly examined, particularly when mix parameters such as binder/waste type and water content were varied. An examination of the resulting products showed that carbonated solidified waste materials had improved mechanical properties and increased metal binding capacity, when compared to specimens cured in nitrogen or normal atmospheric conditions. Microstructural analysis showed that large amounts of calcite where characteristics of carbonated samples. The increased formation of calcite as a result of carbonation appeared to be directly linked with the development of strength and enhanced metals fixation. NMR and FTIR spectroscopy indicated that carbonation has a significant influence on the hydration of waste forms by increasing the degree of polymerisation of the silicate hydration phases, with a consequent acceleration of the hydration of the cement paste. Examination by SEM analysis confirmed an acceleration of C3S hydration, typified by a de-calcified hydration rims and a matrix of dense calcite intergrowth infilling porosity. Some metals appeared to be incorporated in the silica-rich rims and others in the calcite rich matrix, suggesting precipitation of metal as both carbonates, silicates and complex double-salts. An examination of the kinetic of the carbonation reaction revealed that the reactivity of the different cements was different in the presence of carbon dioxide, and that when metal wastes were added the susceptibility of the paste to react with carbon dioxide increased. In general the results of this work indicate the potential of carbon dioxide for incorporation into the treatment of wastes during solidification. However, further work is necessary to establish the long-term performance of these carbonated waste forms as well as the behaviour of carbon dioxide upon different waste streams.
3

Raman spectroscopy applied to iron oxide pigments from waste materials and earthenware archaeological objects

Legodi, Malebogo Andries 06 June 2008 (has links)
Raman spectroscopy is a vibrational spectroscopic technique. It gives a unique combination of non-destructive analysis, high spatial resolution and phase characterisation. In the current study Raman spectroscopy was used as the primary technique during the study of chemical components in archaeological earthenware samples (i.e. low temperature fired clay pottery) of South African and Chinese origin, and characterisation of iron oxides derived from mill scale. One shard from each of the South African archaeological sites (Rooiwal, Lydenburg, Makahane and Graskop) was analysed by Raman spectroscopy, FT-IR spectroscopy, X-ray fluorescence (XRF) spectroscopy and X-ray diffractometry (XRD). The common features observed were montmorillonite (Mg3(Si,Al)4(OH)2.4.5H2O[Mg]0.35), kaolin (Al2Si2O5(OH)5), quartz (α-SiO2), feldspar (K- and NaAlSi3O8), hematite (α-Fe2O3), calcium silicate (CaSiO3) and illite (KAl4(Si7AlO20)(OH)4). Gypsum (CaSO4.2H2O) and calcium carbonates (CaCO3) were detected in Lydenburg, Makahane and Graskop shards. Amorphous carbon was observed in Lydenburg and Makahane shards while rutile appeared only in Makahane shard. The Lydenburg and Rooiwal shards showed the presence of anhydrite (CaSO4). The Chinese clay samples investigated by Raman spectroscopy were from the J A Van Tilburg museum at the University of Pretoria. The large red shard was recovered from the 1552 Portuguese shipwreck, São João, found around Port Edward, South Africa. Four other shards (two red and two gray) were recovered from the 1622 Portuguese shipwreck, the São João Baptista, found around Kenton-on-Sea off the South African coast. A 19th century Chinese teapot was also analysed. Hematite, kaolin, quartz, amorphous carbon and aluminosilicates were observed in all three red shards. All these components, except quartz, were also observed in the teapot. The gray shards showed the presence of quartz, kaolin, amorphous carbon and aluminosilicates. The pigments identified were hematite (in red samples) and black amorphous carbon (in all samples). Magnetite and goethite were precipitated from mill scale-derived precursors in aqueous media. Hematite was then prepared from the calcination of goethite at 750°C and maghemite from the thermal treatment of magnetite at 200°C. The iron oxides were characterised by Raman spectroscopy, XRD, surface area determination and scanning electron microscopy (SEM). They were generally composed of very small sized particles showing high surface area values. / Thesis (PHD)--University of Pretoria, 2008. / Chemistry / unrestricted
4

An Alternative Future of Spatial Materiality

Kraus, Katharina Sofie January 2016 (has links)
In our practice the choice of materials is mostly driven by practical reasons, aesthetics and a given budget, and it is often applied rather at the end of the process – rarely is it the driver of any design process. What often gets forgotten is that materials can carry an immaterial layer of connotations. This means that materials are not perceived neutrally but are instead always loaded with certain meanings and values we attribute to them which in return can evoke different emotions in us. In my thesis project I explore the effect of analternative design process that uses materials as the point of departure.Through experimental explorations I have produced my own materials and investigated possibilities to use them in a spatial context. I created different scenarios to speculate about the potential these materials could have. Could they become applicable materials for interior and furniture design as well as for being a carrier of meaning?
5

Recycled Materials Relational Database: Design and Implementation Aspects

McDonald, Rory Morgan 25 June 2004 (has links)
Although there has been a rise in the use of recycled materials in highway and geotechnical systems, many tons of potentially useful industrial and domestic by-products are still being discarded in the United States each year. While extensive research has been conducted to investigate the use of recycled materials in engineering applications, the dissemination of the findings is often limited. The problem is compounded by the lack of a single resource containing relevant engineering and environmental characteristics of each material; the tendency of the researchers to publish their findings in technical reports rather than archived publications; and the wide discrepancies among local and state environmental regulations and acceptability. A relational database is proposed as a method to improve implementation of recycled material research. A comprehensive review is conducted on data available for a wide variety of recycled materials and their usage in highway and geotechnical applications. Mechanical and environmental data and information from case histories are organized into approximately 10 tables in a relational database management system. More than 30 parameters, including engineering properties, availability and cost, are recorded for 23 materials in a highly-organized compendium. Through a simple user interface, a vast amount of data can be sorted to implement a recycled material program based on historic and current data. The DBMS is updatable and the design is amendable to account for future expansion.
6

Materialavfall som resurs : En studie av hur man samarbetar i en region för hållbar utveckling

Johnsson, Lina, Korfitsen, Katarina January 2013 (has links)
The concept of sustainable development has been pervasive in recent years and many organizations choose to implement sustainability and adapt their activities accordingly. The purpose of this study have been to explore how a collaboration on the use of waste materials may look to analyze what influences cooperation. A case study has been carried out examining a Swedish state regional project aimed at creating partnerships between actors and utilizing textile waste with the help of design. The study was conducted using qualitative methods and the collection of data has been done through interviews and by examining documents. The results show that there are seven key factors that affect cooperation: expectations, commitment, internal communication, a strong non-profit actor, individual treatment, personal networks and the diversity of actors. The discussion addresses that the project has been publicly funded and suggests that further research may focus on the logistics and marketing of redesign.
7

Stabilization of marginal soils using recycled materials

Carreon, Delfin G 01 June 2006 (has links)
Marginal soils, including loose sands, soft clays, and organics are not adequate materials for construction projects. These marginal soils do not possess valuable physical properties for construction applications. The current methods for remediation of these weak soils such as stone columns, vibro-compaction, etc. are typically expensive. Waste materials such as scrap tires, ash, and wastewater sludge, offer a cheaper method for stabilizing marginal soils. As an added benefit, utilizing waste materials in soil stabilization applications keeps these materials from being dumped into landfills, thereby saving already depleting landfill space. Included in this report is an extensive investigation into the current state of research on waste and recycled materials in construction applications. Also included is an investigation on actual implementation of this research in construction projects. Upon completion of this investigation, an effort was made to determine waste materials specific to the state of Florida (waste roofing shingles, municipal solid waste ash, waste tires, and paper mill sludge) that could be used in stabilizing marginal soils through soil mixing techniques. Changes in the engineering properties of soils as a result of adding these waste materials were studied and recommendations on implementing these effects into construction applications are offered.
8

An?lise de argamassas com substitui??o parcial do cimento Portland por cinza residual de lenha de algaroba / Analysis de mortars with partial replacement of Portland cement by residual algaroba wood ASH

Melo, Fellipe C?sar Andrade Costa 27 December 2012 (has links)
Made available in DSpace on 2014-12-17T14:48:13Z (GMT). No. of bitstreams: 1 FellipeCACM_DISSERT.pdf: 1867444 bytes, checksum: bdeaf70a3884fde7d06961686d3bb1db (MD5) Previous issue date: 2012-12-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / With the increase in cement consumption, it has quickly become one of the inputs most consumed by mankind over the last century. This has caused an increase in CO2 emissions, as cement production releases large quantities of this gas into the atmosphere. Adding this fact to the growing consciousness of environmental preservation, it has led to a search for alternatives to cement to complement its derivatives, in the form of waste materials like the ashes. This research aimed to analyze the properties of mortars in fresh and hardened state with partial replacement of Portland cement by residual algaroba wood ash (CRLA) potteries produced by the state of Rio Grande do Norte. The CRLA was collected and sieved, where part of it was ground and characterized in comparison with that just sifted, being characterized according to its chemical composition, grain size, fineness, density, bulk density and index of pozzolanic activity. It was found that the wood ash does not act as pozzolan, and grinding it has not changed its characteristics compared to those just sifted, not justifying its use. Two traces were adopted for this research: 1:3 (cement: fine sand) and 1:2:8 (cement: hydrated lime: medium sand); both in volume, using as materials the CRLA just sifted, CP II F-32 Portland cement, CH-I hydrated lime, river sand and water from the local utility. For each trace were adopted six percentages of partial replacement of cement for wood ash: 0% (control) 5%, 7%, 10%, 12% and 15%. In the fresh state, the mortars were tested towards their consistency index and mass density. In the hardened state, they were tested towards their tensile strength in bending, compressive strength and tensile adhesion strength, and its mass density in the hardened state. The mortar was also analyzed by scanning electron microscopy and X-ray diffraction. Furthermore, it was classified according to NBR 13281 (2005). The results showed that up to a content of 5% substitution and for both traces, the residual algaroba wood ash can replace Portland cement without compromising the mortars microstructure and its fresh and hardened state / Com o aumento do seu consumo, o cimento se tornou rapidamente um dos insumos mais consumidos pela humanidade no ?ltimo s?culo. Isso desencadeou um aumento das emiss?es de CO2, uma vez que a produ??o do cimento libera na atmosfera grandes quantidades deste g?s. Somando este fato ao crescente pensamento da preserva??o ambiental, passou-se a buscar alternativas ao cimento, na forma de res?duos, para complementar os seus derivados, sendo uma delas as cinzas. Este trabalho teve como objetivo analisar as propriedades, no estado fresco e endurecido, de argamassas com substitui??o parcial do cimento Portland pela cinza residual de lenha de algaroba (CRLA) produzida pelas olarias do RN. A CRLA foi recolhida e peneirada, onde parte dela foi mo?da e caracterizada em compara??o com a apenas peneirada, sendo caracterizadas quanto a sua composi??o qu?mica, granulometria, finura, massa espec?fica, massa unit?ria e ?ndice de Atividade Pozol?nica. Avaliou-se que a cinza n?o atua como pozolana e que ela mo?da pouco variou em rela??o a apenas peneirada, injustificando seu uso. Adotou-se para este trabalho dois tra?os, sendo 1:3 (cimento : areia fina) e 1:2:8 (cimento : cal : areia m?dia), ambos em volume, usando-se como materiais a CRLA apenas peneirada, o cimento Portland CP II F-32, a cal hidratada CH-I, areia de rio e ?gua da concession?ria local. Para cada tra?o foram adotados percentuais de substitui??o parcial do cimento pela cinza, sendo eles 0% (refer?ncia), 5%, 7%, 10%, 12% e 15%. No estado fresco, as argamassas foram ensaiadas com rela??o ao seu ?ndice de consist?ncia e ? densidade de massa. No estado endurecido, foram ensaiadas com rela??o ? sua resist?ncia ? tra??o na flex?o, ? compress?o e de ader?ncia ? tra??o, e ? sua densidade de massa no estado endurecido. Elas foram tamb?m analisadas por microscopia eletr?nica de varredura e por difra??o de Raios-X. Al?m disso, as argamassas foram classificadas conforme a NBR 13281 (2005). Os resultados encontrados mostraram que, at? um teor de 5% de substitui??o e para ambos os tra?os, pode-se substituir o cimento pela cinza residual de lenha de algaroba sem comprometer as argamassas microestruturalmente e no seu estado fresco e endurecido
9

Possibilities and Limitations of using Production Waste PET and PES materials in Additive Manufacturing (3D Printing Technology)

Gopathi, Pranay, Surve, Pratik January 2017 (has links)
No description available.
10

Environmental Enhancement Gone Awry: Characterization of an Artificial Reef Constructed From Waste Vehicle Tires

Morley, Danielle M. 01 January 2009 (has links)
In 1967, Broward County, Florida resource managers initiated a project to construct an artificial reef to enhance recreational fishing using waste vehicle tires. An estimated two million unballasted tires were bundles and deployed in bundles approximately 1.8km offshore in 21m of water on sandy substrate separating the middle and outer reef tracts, running parallel to the coast. Over time, bindings on the tire bundles failed and the tires became mobile with normal currents and high energy storms. The tires have apparently moved extensively, travelling kilometers from their original location to beaches and deeper waters offshore. It has also been reported that loose tires have physically damaged benthic reef fauna on the natural reef. Due to this damage, a large-scale removal plan of the tires has been initiated. To assess damage and evaluate effectiveness of tire removal, an examination of existing biota was accomplished. Live corals were absent on the middle reef edge, buried by tires but were present on the tires themselves. When compared to the impacted middle reef edge (tires present), adjacent natural reef control sites (tires absent) exhibited significantly lower fish abundance and species richness. Removal of the tires will directly reduce the abundance of fishes and affect the corals in the area. Future studies will evaluate the loss of these resources relative to the gain in reduced impact to the natural reef.

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