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1
Gosling, Christine. „Co-disposal of rejects from coal and sand mining operations in the Blue Mountains : a feasibility study /“. View thesis, 1999. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030822.133548/index.html.
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2
Cotter-Howells, Jane. „Lead minerals in soils contaminated by mine-waste : implications for human health“. Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/8913.
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3
Bamber, Andrew Sherliker. „Integrated mining, pre-concentration and waste disposal systems for the increased sustainability of hard rock metal mining“. Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/779.
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The integration of automated ore pre-concentration and waste disposal functions into the hard rock metal mining system, prior to treatment by conventional grinding and flotation, is proposed as a novel interpretation of Mine-Mill Integration for improving the economics and environmental impact of exploiting deep, low-grade or otherwise marginal mineral deposits. The proposed approach seeks to reject coarse, barren waste from the ore stream as early as possible in the mining cycle, and safely dispose of it as backfill underground. The concept is proposed as a Lean Manufacturing approach to hard rock mining, as an alternative to improving the economics of mining simply by increasing the mining rate. Lean Manufacturing philosophy seeks to design out overburden, smooth production, and eliminate waste from the system. It is suggested that the introduction of these systems into the hard rock mining process addresses all three of these areas of Lean thinking, and is thus an important approach to be considered for surface or underground mines wishing to simultaneously improve efficiency, economics and environmental performance, thus increasing the life, and the sustainability of the operation. The application of integrated mining, processing and waste disposal systems, where appropriate, is proposed as a strategy for the development of efficient new mining operations, or alternately the expansion of production at existing mines.
Technologies specific to the success of the approach such as automated ore pre-concentration systems, composite fill preparation and delivery systems, as well as continuous mechanized mining methods are explored. The impacts and benefits of applying these integrated technologies to the mining system are defined and quantified through research, testwork, engineering design and systems analysis. Custom geo-metallurgical evaluation tools incorporating mineralogical, metallurgical, geophysical and geotechnical methods have been developed to allow the assessment of ores in terms of their potential for the adoption of the proposed approach. A computerized parametric evaluation model has also been developed to quantify the potential impacts and benefits using data from this testwork. A wide range of case studies have been investigated with positive results, and important conclusions are drawn towards the potential for application of the concept as a generalized case.
4
Mitchell, Paul Brian. „The application of industrial minerals in the control of pollution emanating from metalliferous mine waste“. Thesis, University of Exeter, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293379.
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Waller, Caroline P. „Dispersion of heavy metals and arsenic from mine waste into adjacent farmland in west Cornwall“. Thesis, University of Exeter, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318183.
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6
Lee, Matthew R. „The effects of the disposal of copper mine tailings on littoral meiofaunal assemblages of the Chanaral area of northern Chile“. Thesis, Bangor University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367316.
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7
Gosling, Christine, University of Western Sydney und School of Civic Engineering and Environment. „Co-disposal of rejects from coal and sand mining operations in the Blue Mountains : a feasibility study“. THESIS_XXXX_CEE_Gosling_C.xml, 1999. http://handle.uws.edu.au:8081/1959.7/824.
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This thesis presents details of investigations into the potential for co-disposal of the two rejects from Clarence Colliery and Kable's Transport Sand Mine. Column experiments were undertaken to simulate field conditions. The experiment consisted of: 1/. creating the required co-disposal arrangement and structure in containers 2/. infiltrating water through each container and measuring the rates of infiltration and overflow 3/. measuring the chemical properties of the leachate water. Geotechnical tests of co-disposal pile stability were undertaken using a specially constructed shear box. Results of this study suggest the co-disposal of course coal washery reject from Clarence Colliery with clay tailings from Kable's Transport Sand Mine is a feasible option for managing the generation of acetic drainage. It is recommended that field trials comprise layers of coal reject and clay tailings in a 9:1 ratio. Layering the coal reject with clay tailings creates a semi-permeable barrier which acts to restrict water percolation through the reject as well as reacting with the leachate to increase the leachate pH and adsorb metalsMaster of Engineering (Hons)
8
Chikusa, Chimwemwe Mainsfield. „Pollution caused by mine dumps and its control“. Thesis, Rhodes University, 1994. http://hdl.handle.net/10962/d1005603.
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All mine dumps are a point source of either physical, chemical or both forms of pollution. Physical pollution includes the physical site coverage of the dump, slumping of parts of the dams and dust that may originate from it (air pollution). Chemical pollution from, or related to the mine dumps include the dominant acid drainage (which contains heavy metals), radioactivity, electromagnetic radiation, noise and chemicals released from the mineral processing stage. In one way or the other, exposure to these pollution forms is detrimental to the human health and his environment. It is this fact that urges the public, government and the responsible mining companies to find ways of monitoring the pollution and stopping it, preferably at the source. Where it can not be stopped, techniques of reducing it, or containing it have been, and are still being developed. Personal protection is the priority. Pollution exposure to the general public is minimised as much as possible. Pollution control techniques that employ less expensive, natural, self-sustaining elements suitable for the environment such as wetlands and vegetation are recommended. The artificial short term and often expensive alternatives are of secondary priority. However, choice of which technique to use is based on the merit of each problem, knowing that chemicals act faster but are effective for a short period as compared to the natural systems. Pollution management is the critical part of the whole process. This involves decision making on courses of action and financial allocation on the part of both the polluter and the monitoring department/agent. The ability to effectively manage pollution programmes is achieved these days with the aid of computers. It is emphasised that pollution control should be handled in an integrated, multi-disciplinary approach manner. This is because pollution is a question of life and death, hence every individual remains accountable to it. Keeping the public and the concerned parties educated, informed and welcoming their concerns on the environmental issues related to the mine dumps generated in a mining venture is essential in the modern days of environmental public awareness, or otherwise face the public lath.
9
Rammika, Modise. „An ion imprinted polymer for the determination of Ni (II) ions from mine tailing samples“. Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1004981.
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A Ni(II)-dimethylglyoxime ion imprinted polymer {Ni(II)-DMG IIP} was synthesized by the trapping method using the bulk polymerisation format. The structures of the imprinted and non-imprinted polymer were evaluated by infrared spectroscopy and the morphology was observed by scanning electron microscopy. The Ni(II)-DMG IIP was optimised for pH, mass, time and by the uniform design experimental method for the molar ratios of monomer to crosslinker to porogen and template to ligands as well as keeping these parameters constant and varying the quantities of initiator, 2,2'-azobisisobutyronitrile (AIBN). The optimum pH was 8.5, optimum mass was 50 mg, optimum time was 1 min and the optimum molar ratios of crosslinker to monomer, monomer to template and nickel(II) sulfate hexahydrate (NiSO₄.6H₂O) to 4-vinylpyridine to dimethylglyoxime were found to be 3.3:1.0, 0.6:1.0 and 1.0:0.6:3.6 respectively with 30 mg and 8 mL as the optimum amounts of initiator and porogen respectively. Through this optimisation, recovery of Ni(II) was increased from 98 to 100%. Selectivity of the ion imprinted polymer was evaluated by analysing, using an inductively coupled plasma-optical emission spectrometer, for Ni(II) ions that were spiked with varying concentrations of Co(II), Cu(II), Zn(II), Pd(II), Fe(II), Ca(II), Mg(II), Na(I) and K(I) in aqueous samples. Selectivity studies also confirmed that the ion imprinted polymer had very good selectivity characterised by % RSD of less than 5 %. Co(II) was the only ion found to slightly interfere with the determination of Ni(II). The limits of detection and quantification were found to be 3x10⁻⁴ μg/mL and 9x10⁻⁴ μg/mL respectively. The method was evaluated by a custom solution of ground water certified reference material (SEP-3) and sandy soil reference material (BCR-142R) and the concentrations of Ni(II) obtained were not significantly different to the certified ones. The Ni(II)-DMG IIP was then evaluated in aqueous and soil samples where recoveries of 93 to 100% and 98 to 99% respectively were obtained with enrichment factors ranging from 2 to 18 in aqueous and 27 to 40 in soil samples. Finally, the Ni(II)-DMG IIP was used to analyse mine tailings samples and Ni(II) recovery of 99% was obtained with an enrichment factor of 2.
10
Albuquerque, Allwyn J. J. „Geoenvironmental aspects of coal refuse-fly ash blends /“. This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-12042009-020142/.
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11
Basu, Kohinoor. „Feasibility of an Integrated Thin Seam Coal Mining and Waste Disposal System“. Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/9578.
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The depletion of more attractive thicker and easily accessible coal seams in the central Appalachia will direct attention towards the extraction of coal seams thinner than 28 in. This thesis investigates the feasibility of an integrated mining and backfilling system applicable to thin seams. Two conceptual mining systems, namely Auger mining and Self Advancing Miner, have been proposed for this purpose. Both these systems are designed to remotely mine coal from the seams. Several attempts were made in the past to mine coal in a similar fashion but were not very successful due to several problems inherent to thin seams. The lack of effective steering techniques, accurate coal/rock interface and pillar thickness detection techniques were the main shortcomings of the systems. These problems were addressed in the proposed conceptual mining systems. Several coal/rock interface and rib thickness detection techniques currently available in the market or in the prototype stage have been discussed. Recent developments in coal/rock interface detection and direction sensing techniques have good potential in alleviating the previously encountered problems. Sensitivity analyses have been performed to assess the of effect critical mining parameters on the production potential of these systems. The self advancing miner has been found to be more promising than auger mining. Conceptual panels and face layouts for both systems have been included. Two types of filling methods namely pneumatic and hydraulic are considered applicable under thin seam conditions. A backfilling technique using rubber hoses for fill placement can be applied with both methods. Sensitivity analysis have been performed to establish the relationship between face operation cost, filling cost per ton and development cost per foot. Resulting analyses indicate that panel cost per short ton of coal is more sensitive to filling cost than on development cost.Master of Science
12
Roman, Henry James. „The degradation of lignocellulose in a biologically-generated sulphidic environment“. Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1004057.
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South Africa is renowned for its mining industry. The period over which the polluted waters from the existing and abandoned mines will require treatment has driven research into the development of passive treatment systems. These waters are characterised by a low pH, high concentrations of heavy metals, high levels of sulphate salts and low concentrations of organic material. The biological treatment of these waters has been a subject of increasing focus as an alternative to physicochemical treatment. The utilisation of lignocellulose as a carbon source has been restricted by the amount of reducing equivalents available within the lignocellulose matrix. After a few months of near 100% sulphate reduction, it was found that although there was a large fraction of lignin and cellulose remaining, sulphate reduction was reduced to less than 20%. The present study demonstrated that lignocellulose can be utilised as a carbon source for sulphate reduction. It was established that lignocellulose degradation was enhanced under biosulphidogenic conditions and that lignin could be degraded by a sulphate reducing microbial consortium. It was established using lignin model compounds synthesized in our laboratory, that the bonds within the lignin polymer can be cleaved within the sulphidic environment. The presence of cellulolytic enzymes, using CMCase as a marker enzyme, was detected within the sulphate reducing microbial consortium. Based on the results obtained a descriptive model was formulated for the degradation of lignocellulose under biosulphidogenic conditions. It was determined that the initial reduction in sulphate observed using lignocellulose as a carbon source was due to the easily extractable components. The degradation of which resulted in the production of sulphide, which aided in the degradation of lignin, allowing greater access to cellulose. Once the easily extractable material is exhausted, the cycle is halted, unless the sulphide production can be maintained. This is the focus of an ongoing project, testing the hypothesis that an easy to assimilate carbon source added after exhaustion of the easily extractable material, can maintain the sulphide production.
13
Grimes, Janet A. „Economic and system feasibility study of municipal waste stowage in underground coal mines“. Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-05092009-040521/.
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14
Clarke, Anna Maria. „The microbial ecology of sulphidogenic lignocellulose degradation“. Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1008181.
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Acid mine drainage is a well known environmental pollutant, not only in South Africa, but throughout the world, and the use of microbial processes in the treatment of these wastes has been the subject of investigation over past decades. Lignocellulose packed-bed reactors have been used in passive treatment systems, and, although effective initially, they show early decline in performance while the packing material remains largely un-utilized. Little is known about this phenomenon which remains a severe constraint in the development of efficient passive mine water treatment systems. It has been proposed that the degradation pathways of the complex lignocellulose substrate may be limited in some way in these systems during the manifestation of this effect. This study has addressed the problem using a molecular microbial ecology methodology in an attempt to relate trophic functions of the microbial population to the physico-chemical data of the system. A field-scale lignocellulose packed-bed reactor located at Vryheid Coronation Colliery (Northern Kwa-Zulu Natal province, South Africa) was monitored for six years and the results showed the classic profile of performance decline related to a slowdown in sulphate reduction and alkalinity production. The reactor was decommissioned , comprehensive samples were collected along the depth profile and the microbial populations investigated by means of 16S rRNA gene methodology. The population was found to include cellulolytic Clostridia spp., CytophagaIFlavobacterlBacteroidetes, Sphingomonadaceae and as yet uncultured microorganisms related to microbiota identified in the rumen and termite gut. These are all known to be involved as primary fermenters of cellulose. Oesulphosporosinus was present as sulphate reducer. A comparison of substrata sampling and population distribution suggested that spatial and temporal gradients within the system may become established over the course of its operation. Based on these findings, a laboratory-scale reactor was constructed to simulate the performance of the packed-bed reactor under controlled experimental conditions. The laboratory-scale reactor was operated for 273 days and showed comparable performance to that in the field in both biomolecular and physicochemical data. Clearly defined trophic niches were observed. These results suggested that a sequence of events does occur in lignocellulose degradation over time. Based on the spatial and temporal column studies, a descriptive model was proposed to account for these events. It was found that fermentative organisms predominate in the inlet zone of the system using easily extractable compounds from the wood, thus providing feedstock for sulphate reduction occurring in the succeeding compartments. Production of sulphide and alkalinity appears to be involved in the enhancement of lignin degradation and this, in turn, appears to enhance access to the cellulose fraction. However, once the readily extractables are exhausted, the decline in sulphide and alkalinity production leads inexorably to a decline in the overall performance of the system as a sulphate reducing unit operation. These observations led to the proposal that with the addition of a limited amount of a readily available carbon source, such as molasses, in the initial zone of the the reactor, the ongoing generation of sulphide would be sustained and this in turn would sustain the microbial attack on the lignocellulose complex. This proposal was tested in scale-up studies and positive results indicate that the descriptive model may, to some extent, provide an account of events occurring in these systems. The work on sustaining lignocellulose degradation through the maintenance of sulphate reduction in the initial stages of the reactor flow path has led to the development of the Degrading Packed-bed Reactor concept and that, has subsequently been successfully evaluated in the field.
15
Drysdale, Karen. „Geochemistry of a buried marine mine tailings deposit, Howe Sound, British Columbia“. Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28982.
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One hundred surface sediment samples and two 30 cm cores were collected from Howe Sound, British Columbia, a deep (≈280 m) fjord with a restricted inner basin into which mine tailings had been dumped for 75 years. The abundances of major elements Si, Al, Ti, Fe, Mg, Ca, Na, K, C, N, and P, and minor elements Ba, Co, Cr, Cu, Mn, Ni, Pb, Rb, Sr, V, Y, Zn, and Zr were determined as well as nutrient and trace metal concentrations in porewater from the two cores.
The solid-phase data suggest that the inner basin sediments are dominated by Squamish River-derived feldspars, while the outer basin is characterized more by quartz and Fe and Mg minerals, which enter the southernmost portion of the fjord via estuarine circulation from Georgia Strait. Although Fe, Cu, Pb, Zn, and Ba are still enriched in sediments near the tailings outfall, the lapse of 13 years since cessation of tailings deposition has apparently resulted in reduced metal levels throughout much of the rest of the inlet due to ongoing dilution by natural sedimentation. Profiles of these metals with depth show that the tailings deposit proper is buried by ≈14 cm of natural sediment in the deep central portion of the inner basin.
Porewater analysis of the two cores revealed that active bacterial remobilization of organic matter is occurring at both locations; although the organic carbon content of the outer basin is greater than that in the inner basin, sulphate-reduction is more intense in the latter due to the higher sedimentation rate. Despite this, dissolved sulphides were nearly absent in porewaters, leading to the conclusion that authigenic pyrite precipitation is removing some of the dissolved Fe. Dissolved Cu and Zn are enriched in surficial porewaters of both the outer and inner basins (i.e. Cu = 215 and 132 nmol/L, respectively, and Zn = 32 µmol/L and 1.6 /µmol/L), but decrease rapidly within the top 2-3 cm, suggestive of active removal by some mechanism. Dissolved Pb concentrations were low (<3 nmol/L) in both cores, and did not show any surface enrichment. These data suggest that a strongly reducing environment such as is found at depth in natural sediments inhibits the release of some labile metals which may be contained within them.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
16
Albuquerque, Allwyn J. „Geoenvironmental aspects of coal refuse-fly ash blends“. Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/46095.
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The separate land disposal of coal refuse and fly ash presents difficulties throughout
the Appalachian region, both in terms of disposal costs per acre and in terms of its potential
environmental impacts on soil, ground water, revegetation, and slope stability. The purpose
of this study was to determine how fly ash addition to coal refuse would impact on certain
geotechnical properties of the refuse disposal piles, and whether the refuse-fly ash blends
would be suitable as co-disposed materials. Accordingly, the compaction, permeability and
shear strength characteristics of the refuse-fly ash blends were experimentally determined for
varying fly ash percentages. The compaction test results indicated that, with increasing fly
ash, the maximum dry density of these blends marginally decreased. The permeability test
results showed that the permeability of the test specimens progressively decreased with the
increase in fly ash. The shear strength results demonstrated that the addition of fly ash did
not significantly influence the shear strength of the refuse. The critical factor of safety
determined during slope stability analysis revealed that the tested slope geometries were
stable for long term, drained conditions (using the STABGM computer program). The volume change analysis determined that there was a minimal expansion in the volume of
refuse when it was blended with fly ash. However, it may be noted that all the stated results
depend on a number offactors, including the nature of the refuse and fly ash used. Therefore,
these findings would be specific to bulk blends of coal refuse and fly ash only. In general,
this study indicates that fly ash can be beneficially reused with respect to the geotechnical
properties evaluated. Co-disposal of fly ash and coal refuse may be a reasonable alternative
to present disposal methods.
Master of Science
17
Stewart, Barry R. „Physical and chemical properties of coarse coal refuse from Southwest Virginia“. Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41626.
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Coarse coal refuse is difficult to reclaim due to high potential acidity and coarse fragment content, low water holding capacity, low fertility, and other problems. Little is known about coal refuse properties, particularly as they relate to revegetation potential. This study was undertaken to determine the physical and chemical properties of composite samples from 27 coal waste piles of varying age. Selected physical and chemical properties varied widely across this sample set. The mean coarse fragment (>2mm) content of these materials was 60%. The average texture of the fine (<2mm) fraction was a sandy loam with 15% clay. The mean water retention difference, between 0.03 MPa and 1.5 MPa of soil moisture tension, on a whole sample basis was 0.08 g water/g refuse. The pH values varied from 8.3 to 3.0, and the older piles generally had lower pH values than the more recent piles. The saturated paste electrical conductivity (EC) was higher in the younger coal waste materials. Total elemental analysis revealed that Si, Al, Fe, and K were the most abundant elements in these materials. The mineralogy of three selected samples was found to be dominated by quartz in the sand and silt fraction and mica in the clay fraction. The physical factor most limiting to plant growth was found to be low water holding capacity. Low pH was found to be the chemical factor most limiting to plant survival. These findings indicate that some refuse piles may be suitable for direct seeding, but many will require heavy lime and/or organic treatments.Master of Science
18
Alarcon, Leon Edgardo. „Pyrite weathering and lithium (Li?) transport under unsaturated flow conditions in model and mine-tailing systems“. University of Western Australia. School of Earth and Geographical Sciences, 2005. http://theses.library.uwa.edu.au/adt-WU2006.0011.
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[Truncated abstract] As mineral deposits continue to be mined, the non economic gangue materials such as sulphides (e.g. pyrite) that are extracted as part of the ore body or overburden are deposited within the waste rock and/or milled tailings. As a result of natural weathering processes, these reactive materials represent a potential hazard to surrounding environments. A major consequence, resulting from mine-waste impoundments containing sulphidic materials, relates to the offsite movement of low pH leachates containing elevated concentrations of metal ions posing a contamination threat. The processes and mechanisms acting in the formation of acid mine drainage (AMD) are highly variable and, to a high extent, controlled by climatic conditions as the main driver of water flow and wetness of the system which in turn determines the availability of oxygen as well as water for pyrite weathering. In particular, this thesis is based on the hypothesis that in semiarid and arid climates the acid production may be water … The experiments were repeated at different water contents ranging from 0.24 to 0.33 cm3 cm-3. Breakthrough curves (BTC) of Li+, K+, Ca2+, Mg2+, Na+ and pH were measured and described with models of different complexities. This included the use of a simple linear and non-linear isotherms for Li+ alone, a binary Li+ - K+ ion exchange, and a complete multicomponent chemical equilibrium description of ion transport. The latter, by including dissolution of primary minerals which released base cations such as Mg2+, Ca2+ and K+ explained some of the elution patterns of base cations for which the Li+ - K+ exchange was the dominant process. Furthermore, under unsaturated water flow conditions, retardation of Li+ increased with decreasing water content. Thus solute mobility in mafic rock tailings appears to decrease under strongly unsaturated water flow conditions.
19
Stewart, Barry Robert. „Physical and chemical properties of coarse coal refuse from Southwest Virginia“. Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03142009-040755/.
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20
Golela, Mhlangabezi Tolbert. „Effect of microbial consortium on the biokinetic test for assessing acid rock drainage potential“. Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2754.
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Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018.Acid rock drainage (ARD) is one of the most severe environmental challenges currently faced by the mining industry worldwide. ARD is formed from the oxidation of sulphide-bearing minerals, particularly pyrite, in the presence of water and oxygen. ARD generation is accelerated by the presence of naturally occurring iron and sulphur-oxidizing micro-organisms, which regenerate leaching agents that facilitate sulphide mineral oxidation. ARD pollution is characterized by a high concentration of metals and sulphates in solution, low pH and a high salt content (salinity) in the environment, contaminating soil and groundwater. In South Africa, ARD is a major challenge in the gold and coal mining industries, where millions of tons of sulphide waste rock and overburden are generated and discarded. Characterization of these waste materials is required to develop an appropriate disposal strategy to minimise the risk of pollution and the generation of ARD. Potential ARD generation prediction from waste rock depends on the precise characterization of ARD potential using Biokinetic tests. Commonly used ARD prediction methods are static and long-term kinetic tests. Static tests provide data for a worst-case scenario focussing on strong acid chemical leaching potential to give an overall acid forming potential of a sample. Such kinetic tests provide data illustrating the rate of the net acid generation capacity of mine waste. However, these tests are capital intensive and time-consuming and fail to provide adequate information on the effect of micro-organisms on the overall net acid generation capacity of mine waste. The Biokinetic test reported herein and developed at the University of Cape Town, focusses on addressing a worst case scenario provided by static tests in a cost-effective manner and reduced time frames provided for by conventional kinetic tests. This test primarily provides relative rates of ARD generation in the presence of micro-organisms within 90 days. However, the Biokinetic test is at the developmental stage and thus far, has not been consistently used for different waste ores to determine a standardised approach. Therefore, the aim of this study was to investigate the effects of microbial consortia and to develop a standardisation approach for the test for ARD formation potential using gold-bearing and copper-bearing waste rock. Additionally, to refine the Semi-continuous Biokinetic test simulation, a flow-through system where there is minimal seepage in the waste deposit, was also developed. The sulphur content of the gold and copper-bearing samples used in this study was between 2.3 and 3.15%, respectively. These waste rock samples were found to be potentially acid- forming. In the Biokinetic test, finely milled waste rock samples were slurrified, inoculated with consortia and cultured under standard bioleaching conditions. Leaching and acidification rates were monitored.
21
Lapuente, Pérez Joaquin de. „Apodemus sylvaticus como centinela de fuentes de contaminación complejas“. Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668296.
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La entrada en el medioambiente de xenobióticos, procedentes de la actividad humana, que son biológicamente activos y de difícil eliminación, representa un grado de estrés que, a menudo, resulta inaceptable por los organismos y que con, demasiada frecuencia, se eleva a nivel del ecosistema. Es, por tanto, necesario realizar una vigilancia activa de las fuentes de contaminación conocidas para detectar, de la manera más rápida y fiable posible, las señales de alarma que envían los ecosistemas. Los animales denominados centinelas, a su vez, por su capacidad de integrar la información del hábitat, tanto en el espacio como en el tiempo, pueden actuar como señales de alarma ecológica temprana. Por otro lado, para evaluar el impacto de los peligros por sustancias químicas en los ecosistemas, se han establecido modelos regulatorios que permiten predecir el grado a la que los organismos estarán expuestos, para finalmente evaluar el riesgo. Este abordaje estandarizado, a menudo, ha construido sus algoritmos en base a los valores límites establecidos en ensayos, en condiciones controladas, con modelos de experimentación conocidos. Sin embargo, dada la dotación enzimática, la fisiología o la flora intestinal específica de cada especie y las propiedades toxicocinéticas de los compuestos químicos expuestos, las respuestas pueden variar, por lo que, la extrapolación de los efectos tóxicos de unos organismos a otros debe ser conocida. Para ello, se ha propuesto, por un lado, al ratón de campo, Apodemus sylvaticus, como centinela de contaminación ambiental de tipo crónica, difusa y compleja, por su ubicuidad, su prospección del hábitat y su tolerancia a los contaminantes. Con este objetivo se caracterizó, mediante biomarcadores de exposición y de efecto, al ratón de campo en tres depósitos controlados de residuos de diferentes orígenes y en zonas agrícolas donde se habían vertido lodos de depuradora como fuente de nutrientes. Por otro lado, se utilizó a Apodemus sylvaticus como modelo de experimentación en mesocosmos, a fin de comprender y comparar la respuesta a la exposición de xenobióticos conocidos, con el fin de integrar y mejorar la capacidad predictiva de los modelos. Los resultados han permitido confirmar que el ratón de campo, Apodemus sylvaticus, es capaz de integrar información de la contaminación ambiental mediante el estudio de biomarcadores exposición y de efecto, ya que la exposición a fuentes de contaminación de diversos orígenes produjo una respuesta cuantitativa y diferencial entre las diversas zonas de estudio. De igual manera, Apodemus sylvaticus, ha aportado información relevante sobre los tipos de efectos observados tras la exposición a un tóxico polar o a un toxico de carácter lipofílico, en estudios en mesocosmos, al ser comparado con Mus musculus domesticus, como modelo experimental conocido. Por tanto, podemos concluir que el ratón de campo, Apodemus sylvaticus, es un modelo fiable como centinela de contaminación ambiental, capaz de integrar de manera cuantificable la exposición a xenobióticos.The release of xenobiotics into the environment, derived from human activity, which are biologically active and difficult to eliminate, represents a degree of stress that is, often, unacceptable to organisms and which, too often, rises to the level of ecosystem. It is, therefore, necessary to carry out an active surveillance of known sources of contamination in order to detect, as fastest and most reliable as possible, the alarm signals sent by the ecosystems. Animals called sentinels because of their ability to integrate habitat information, both in space and time, can act as early ecological warning signals. On the other hand, to assess the impact of the chemical hazards on ecosystems, regulatory models have been established that allow predicting the degree to which organisms will be exposed, to finally assess the risk. However, the responses may vary between species. To this end, it has been proposed, the wood mouse, Apodemus sylvaticus, as a sentinel of chronic, diffuse and complex environmental pollution. With this objective, the wood mouse was characterized, through biomarkers of exposure and effect, in three controlled landfills from different origins and in agricultural areas where sewage sludge had been discharged as a source of nutrients. On the other hand, Apodemus sylvaticus was used as experimental model in mesocosms, in order to understand and compare the response to the exposure of known xenobiotics. The results have confirmed that the wood mouse, Apodemus sylvaticus, is capable of integrating information of the environmental contamination through the study of exposure and effect biomarkers, since the exposure to contamination of different origins produced a quantitative and differential response between the different areas of study. Similarly, Apodemus sylvaticus, has provided relevant information on the types of effects observed, after the exposure to a polar toxic or a lipophilic toxic, in the study in mesocosmos, when it is compared against Mus musculus domesticus, as a known experimental model. Therefore, we can conclude that the wood mouse, Apodemus sylvaticus, is a reliable model as sentinel of environmental contamination, capable of quantitatively integrating exposure to xenobiotics.
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Van, den Berg Mader J. „Western limb tailings reclamation project“. Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-07272005-100249.
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Moore, Bronwyn Ann. „Investigation into the technical feasibility of biological treatment of precious metal refining wastewater“. Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002013.
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The hydrometallurgical refining of platinum group metals results in large volumes of liquid waste that requires suitable treatment before any disposal can be contemplated. The wastewater streams are characterized by extremes of pH, high inorganic ion content (such as chloride), significant residual metal loads and small amounts of entrained organic compounds. Historically these effluents were housed in evaporation reservoirs, however lack of space and growing water demands have led Anglo Platinum to consider treatment of these effluents. The aim of this study was to investigate whether biological wastewater treatment could produce water suitable for onsite reuse. Bench-scale activated sludge and anaerobic digestion for co-treatment of an acidic refinery waste stream with domestic wastewater were used to give preliminary data. Activated sludge showed better water treatment at lab scale in terms of removal efficiencies of ammonia (approximately 25%, cf. 20% in anaerobic digestion) and COD (70% cf. 43% in digestion) and greater robustness when biomass health was compared. Activated sludge was consequently selected for a pilot plant trial. The pilot plant was operated on-site and performed comparably with the bench-scale system, however challenges in the clarifier design led to losses of biomass and poor effluent quality (suspended solids washout). The pilot plant was unable to alter the pH of the feed, but a two week maturation period resulted in the pH increasing from 5.3 to 7.0. Tests on algal treatment as an alternative or follow-on unit operation to activated sludge showed it not to be a viable process. The activated sludge effluent was assessed for onsite reuse in flotation and it was found that there was no significant difference between its flotation performance and that of the process water currently used, indicating the effluent generated by the biological treatment system can be used successfully for flotation. Flotation is the method whereby minerals refining operations recover minerals of interest from ore through the addition of chemicals and aeration of the ore slurry. Target minerals adhere to the bubbles and can be removed from the process.
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Hai, Qu, Sun PiaoYi und Li Xiang. „Waste disposal and renewable resources“. Thesis, Högskolan Kristianstad, Sektionen för hälsa och samhälle, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-10871.
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Purpose/aim: The purpose of this dissertation is to find out the effect of waste disposal on environment and to explore the effect of renewable resources on economy. We use some data to test and verify the existence of effects. Design/methodology/approach: We use our questionnaires to collect data, and analyze the data in statistical tests. We use case studies to find examples to verify the significance of waste classification and renewable resources as well as the problems in main cities of China. Findings: The analysis shows that we need to focus on waste classification education, if we want to apply it in real life. The best way to use renewable resource more widely is to aquire government support. If we can carry out waste classification better, we can make use of more renewable resources. Originality/value: The value of this paper is that we prove that using waste classification and renewable resource can increase economic growth rate and protect the environment. It is also important because economic growth brings about the reduction of environment quality. When the environment quality decreases, the economic level will also decrease.
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Thomas, Roger Henri. „Factors influencing household hazardous waste disposal“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0034/MQ27067.pdf.
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Leung, Kin-keung Kenneth, und 梁健強. „Management and disposal of clinical waste“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31253775.
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Leung, Kin-keung Kenneth. „Management and disposal of clinical waste /“. Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18733992.
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Davison, Nigel. „The geochemistry of radioactive waste disposal“. Thesis, Aston University, 1987. http://publications.aston.ac.uk/9698/.
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The present study attempted to identify the significant parameters which affect radionuclide migration from a low level radioactive waste disposal site located in a clay deposit. From initial sorption studies on smectite minerals, increased Kd with decreasing initial cation concentration was observed, and three sorption mechanisms were identified. The observation of anion dependent sorption was related to the existence of a mechanism in which an anion-cation pair are bound to the clay surface through the anion. The influence of competing cations, typical of inorganic groundwater constituents, depended on: (1) Ni/Co:Mn+(Mn+ = competing cation) ratio, (2) nature of M^n+, (3) total solution ionic strength. The presence of organic material in groundwater is well documented, but its effect on cation sorption has not been established. An initial qualitative investigation involving addition of simple organic ligands to Ni(Co)-hectorite samples demonstrated the formation of metal complexes in the clay interlayers, although some modified behaviour was observed. Further quantitative examination involving likely groundwater organic constituents and more comprehensive physical investigation confirmed this behaviour and enabled separation of the organic compounds used into two classes, according to their effect on cation sorption; (i) acids, (ii) amine compounds. X-ray photoelectron spectroscopy, scanning electron microscopy and Mossbauer spectroscopy were used to investigate the nature of transition metal ions sorbed onto montmorillonite and hectorite. Evidence strongly favoured the sorption of the hexaaquo cation, although a series of sorption sites of slightly different chemical characteristics were responsible for broadened peak widths observed in XPS and Mossbauer investigations. The surface sensitivity of XPS enabled recognition of the two surface sorption sites proposed in earlier sorption studies. Although thermal treatment of Fe^3+/Fe^2+-hectorite samples left iron atoms bonded to the silicate sheet structure, Mossbauer evidence indicated the presence of both ferric and ferrous iron in all samples.
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Carolus, Vernon. „Waste and waste management in Breede Valley district“. Thesis, Cape Peninsula University of Technology, 2007. http://hdl.handle.net/20.500.11838/784.
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Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2007The waste management that is taking place in the Breede Valley district focus mainly on disposal and end-of-pipe solutions. This approach resulted in serious negative impacts on the environment and human health. Improper waste management practices have become a major source of concern due to the risk associated with poor waste management in the area. Indiscriminate dumping of waste at street corners is very common. The basic waste management processes of collection, transport, segregation and [mal disposal appear to be very inefficient and inadequate. The objective of this study was to determine the composition of the waste stream as well as public awareness, attitudes and behaviours towards current and alternative waste management practices. A waste assessment study was conducted to determine the amount of waste generated by the different communities, as well as how much and what of the recyclables can be taken out of the waste stream by recycling. For this study data was obtained by formulation of questionnaires for businesses, communities and medical practitioners, as well as an interview with the Engineering Department of the Breede Valley Municipality about the current waste management situation in the area. From the data obtain from businesses, communities and medical facilities, it is clear that public participation, partnership, education and awareness is essential for effective integrated waste management. This study revealed that waste management practices are inefficient, uncontrolled and fragmented. This investigation shows that there is a huge difference between the different communities in terms of the volume of waste generation. The study also shows that waste related legislation is outdated and fragmented and there is no enforcement by municipal officials. The major Issues and challenges that affect the management of waste. include its organisational structure and lack of waste minimisation plans.
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Maiden, Benjamin Gaylord. „Geographic implications of public policy : the siting of noxious facilities /“. The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487266011225094.
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Rezaee, Mohammad. „SUSTAINABLE DISPOSAL OF COAL PROCESSING WASTE STREAMS“. UKnowledge, 2015. http://uknowledge.uky.edu/mng_etds/26.
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Modern coal preparation facilities incorporate a wide array of solid-solid and solid-liquid separation processes for rejecting mineral matter to meet market specifications. The coarse mineral matter is typically placed into engineered refuse piles whereas the fine refuse is either stored in impoundments or co-disposed with the coarse refuse. The discharge water from the refuse material represents an environmental concern due to the potential release of trace elements, and the subsequent elevation of total dissolved solids and conductivity. The research findings reported in this dissertation addresses sustainable coal processing waste disposal through using strategies aimed at minimizing the environmental impacts. To provide an accurate and inexpensive method to assess the potential environmental effects of a given waste material, a conductivity screening-level test was modified to incorporate the impact of particle surface area. The test was used on various waste streams as well as the particle size and density fractions of each waste stream to identify environmentally sensitive components that can be separated from the bulk and isolated to prevent negative environmental impacts. The results were subsequently evaluated for long term mobility of trace elements under different disposal scenarios: (i) static leaching tests designed to simulate the quiescent conditions in a stable impoundment, and (ii) a dynamic test to simulate waste materials exposed to the atmosphere in variable wet/dry storage conditions. The results indicated that liberating, separating and isolating the highest density fractions (>2.68 SG) which represents less than 5% of the coal refuse materials results in significant abatement of total dissolved solids and conductivity. Required modifications of the coal processing plants were suggested to segregate and subsequently isolate the environmentally sensitive fractions from the remaining refuse material.
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Shadras, Mohammad Reza. „Solid waste disposal in eastern Mediterranean countries“. Thesis, London South Bank University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332217.
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Tong, Cheuk-kei. „Municipal waste management in Shanghai, 1866-1949“. Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B41634032.
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Čepanko, Violeta. „Investigation of fermented waste and technologies of disposal“. Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100628_092621-12161.
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Object of the work – the fermented solid waste (substrate) and liquid (filtrate) fractions and their technologies of disposal. The key aim of this work is to analyse and evaluate the possibilities of using fermented wastes (sewage sludge, swine and poultry manure, fruit and vegetable waste, and grain) for fertilisation, composting and incineration taking into account their elementary composition and a level of pollution with heavy metals. Carry out an evaluation of gaseous pollutant (NOx) emissions from the process of incineration through the employment of a digital model.Tyrimų objektas – fermentuotų atliekų kietoji (substratas) ir skystoji (filtratas) frakcijos bei jų panaudojimo technologijos. Darbo tikslas – išnagrinėti bei įvertinti fermentuotų atliekų (nuotekų dumblo, kiaulių ir vištų mėšlo, vaisių su daržovėmis bei žliaugto) panaudojimo tręšimui, kompostavimui bei deginimui galimybes atsižvelgiant į jų elementinę sudėtį ir užtaršos lygį sunkiaisiais metalais. Atlikti šių atliekų deginimo proceso metu išsiskiriančių dujinių teršalų (NOx) įvertinimą naudojant skaitinį modelį.
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Leung, Carolina, und 梁碧芬。. „A review of the 1989 waste disposal plan“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31254329.
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Leung, Carolina. „A review of the 1989 waste disposal plan /“. Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21301712.
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Sizer, Calvin Gregory. „Minor actinide waste disposal in deep geological boreholes“. Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/41595.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2006.Includes bibliographical references (leaves 63-65).
The purpose of this investigation was to evaluate a waste canister design suitable for the disposal of vitrified minor actinide waste in deep geological boreholes using conventional oil/gas/geothermal drilling technology. The nature of minor actinide waste was considered, paying particular attention to nuclides whose decay energy and half lives were of relative significance to the minor actinide waste as a whole. Thermal Analysis was performed based on a reference borehole design, by Ian C. Hoag. The strategy of the thermal analysis is aimed at finding peak temperatures within the configuration, paying particular attention to the heat transfer under deep geological conditions in the air gap between the canister and the borehole. A first order economic analysis was made to compare the designed canister emplacement costs to that of intact spent fuel. The results of this analysis show that three minor actinide nuclides dominate heat generation after ten years cooling: Cm-244, Am-241, and Am-243 account for 97.5% of minor actinide decay heat. These three nuclides plus Np-237 account for 99% of the minor actinide mass. The thermal analysis was based on an irretrievable canister design, consisting of a 5 meter long synroc waste form, with minor actinides loaded to 1% wt, an outer radius of 15.8 cm and inner annular radius of 8.5 cm. Filling the annulus with a vitrified technetium and iodine waste form was found to be feasible using a multi-stage emplacement process. This process would only be required for three of the fifty boreholes because technetium and iodine have low heat generations after 10 years cooling. The suggested borehole waste form has a maximum centerline temperature of 349C. The costs of drilling boreholes to meet the demand of 100,000MT of PWR waste are estimated to be 3.5% of the current nuclear waste fund, or about $9.6/kg of original spent fuel.
by Calvin Gregory Sizer.
S.B.
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Akoitai, Samson Arthur. „Arsenic in leachates from mine waste rocks“. Thesis, University of Canterbury. Chemistry, 2000. http://hdl.handle.net/10092/5969.
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This research dealt with the leaching of arsenic containing waste rocks from a proposed gold mine site at Reefton, New Zealand. Then it established the acidity and concentrations of Fe, sulfate, As(V) and As(III) released as a result of leaching experiments which simulated the weathering process. It also determined the arsenic concentrations that were released from old mine workings into the Devils Creek sediments catchment and concentrated into sediments. The Devils Creek catchment is located downstream from the proposed mine.
Acid mine drainage (AMD) results from oxidation of sulfide bearing rocks and deposits (e.g. FeS and FeS2). It is characterised by elevated concentrations of sulphate and iron and low pH. As(V) and As(III) may also be a component in AMD from the oxidation of FeAsS. Biologically As(III) is considered the more toxic form.
Methods were developed for the measurement of arsenic species (As(V) and As(III)) in leachates derived from mine waste rocks. These were applied to freshwater samples and sediment extracts. These included:
• A field method for the on-site fractionation of arsenic in fresh waters using XAD-4 and Chelex-Fe(III) resins. In this two-step process the XAD-4 resin was used to isolate and pre-concentrate natural organic matter (NOM) and therefore the arsenic fraction associated with it through iron bound to the NOM. In the second step Fe(III) modified Chelex 100 resin was used to selectively preconcentrate As(V) from water samples. Thus the combined method achieved discrimination between free and bound fractions of As(V) and the separation of As(V) from As(IU).
• A flow injection analysis protocol based on spectrophotometric detection was modified to increase its sensitivity for measurement of arsenic species in leachates derived from waste rocks. The method was effective for the determination of arsenate. Arsenite was measured by prior oxidation with iodate.
Study on the Devils Creek catchment established the existing baseline levels of arsenic in the fresh water and sediments. The water contains high levels of arsenic. Most of the arsenic in Devils Creek water is soluble. As(V) is the predominant species of which a minor fraction (13-28%) is bound to NOM. It was also established that arsenic was associated with Fe and A1 rich phases in the Devils Creek sediments. Due to the high accumulated arsenic load in the sediments, further uptake of arsenic from the water column is no longer viable because potential binding sites in the sediments have been saturated.
Leaching simulation on mine basic waste rocks (GB 13) and an acidic sandstone were conducted using a variety of leach ants applicable to the field, then quantifying the Fe, As(III), As(V), heavy metals and acidity in the leachates. It was established that the sandstone rock had the greater potential to produce acid mine drainage (AMD). Its leachates give a high acidity (pH 2.9-3.4) compared to leachates of the GB 13 waste rock which have a weakly basic pH of7.2. The dominant arsenic species in leachates of both rock types is As(V). The concentrations of arsenic, soluble Fe and heavy metals leached from the sandstone were greater than those leached from GB 13.
The interactions of arsenate with other components of AMD and natural organic matter were examined. It was established that ferrihydrite semi-quantitatively and rapidly removes arsenate from solution. The arsenate adsorption is inhibited by competing ions in the following order: sulfate> FA ≡ HA. Complexes of HA-Fe(III) and FA-Fe(III) bind arsenate as 1:1 complexes through the Fe(III).
Investigations were made on the use of limestone for the control of arsenic in mine waste rock leachates. It was established that where acidic leachate contacts limestone the pH rises as a result of neutralisation reactions. Subsequently there is a precipitation of Fe(III) and retention of As(V) on the Fe(OH)3. As (III) is oxidised by Fe3+(aq) and Fe(OH)3. On contact with the limestone surface, As (III) is also retained and oxidised. Fe(III) impurities in the limestone are responsible for the uptake of both As(V) and As(III). Insoluble calcium arsenates or arsenites are not formed.
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Liu, Ka-man. „Kitchen solid waste“. Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41549430.
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Kuhn, Eloise M. R. „Microbiology of fly ash-acid mine drainage co-disposal processes“. Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
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The waste products acid mine drainage formed during coal mining and fly ash from coal burning power generation, pose substantial environmental and economic problems for South Africa. Eskom has developed a remediation system employing alkaline fly ash to neutralize and precipitate heavy metals from toxic acidic acid mine drainage streams. The aim of this study was to assess the microbial diversity in and microbial impact on this remediation system.
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Kwan, Woon-yin Patrick. „Policy review on domestic waste management in selected places“. access abstract and table of contents access full-text, 2007. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?ma-sa-b22107149a.pdf.
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Thesis (M.A.)--City University of Hong Kong, 2007."A capstone project submitted in partial fulfillment of the requirements for the Master of Arts in Public Policy and Management at City University of Hong Kong." Title from PDF t.p. (viewed on Oct. 12, 2007) Includes bibliographical references.
42
Wilson, Bruce Gordon. „Systems modelling of municipal solid waste collection operations /“. *McMaster only, 2001.
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Lai, Wai-hing. „Solid waste management in Hong Kong“. Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41013104.
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44
Adkins, Dawn Marie. „A comparison perceived and calculated risk for a low-level radioactive waste disposal facility“. Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/19683.
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Hoag, Christopher Ian. „Canister design for deep borehole disposal of nuclear waste“. Thesis, (5 MB), 2006. http://handle.dtic.mil/100.2/ADA473223.
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Thesis (M.S. in Nuclear Science and Engineering)--Massachusetts Institute of Technology, 2006."May 2006." Description based on title screen as viewed on June 1, 2010. DTIC Descriptor(s): Boreholes, Radioactive Wastes, Disposal, Canisters, Thermal Properties, USSR, Diameters, Thickness, Stability, Permeability, Environments, Corrosion, Drilling, Flooding, Storage, Reactor Fuels, Nuclear Energy, Barriers, Emplacement, Internal, Fuels, Igneous Rock, Geothermy, Drills, Hazards, Performance (Engineering), Water, Theses, Granite, Steel, Containment (General). Includes bibliographical references (p. 122-125). Also available in print.
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Taiyabi, Asif A. „A multi-attribute analysis of nuclear waste disposal alternatives“. Master's thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-02022010-020127/.
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McKeown, Christopher. „A model approach to radioactive waste disposal at Sellafield“. Thesis, University of Glasgow, 1997. http://theses.gla.ac.uk/2588/.
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Sellafield in West Cumbria is the potential site of a repository for radioactive, Intermediate Level Waste (ILW). The proposed repository lies at 650 m beneath the ground surface to the west of the 1000 m uplands of the Lake District. The fractured Borrowdale Volcanic Group (BVG) host rock is overlain by a sequence of Carboniferous and Permo-Triassic sediments. Fresh, saline and brine groundwaters exist in the subsurface. Upward trending fluid pressure gradients have been measured in the area of the potential repository site. Steady-state, 2-D simulations of fluid flow were undertaken with the OILGEN code. Topographically driven flow dominates the regional hydrogeology. Subsurface fluid flow trended persistently upwards through the potential repository site. The dense brines to the west of the site promoted upward deflection of groundwaters. The groundwater flow rate through the potential repository site was dependent upon the hydraulic conductivity of the BVG. Calibration of the model was achieved by matching simulated subsurface pressures to those measured in-situ. Emergent repository fluids could reach the surface in 15,000 years. The measured BVG hydraulic conductivity is up to 1000 times too high to be simply declared safe. Geochemical simulations, with Geochemist's Workbench?, showed natural BVG groundwaters display redox disequilibrium. The in-situ Eh is most probably +66 mV. Pyrite, absent from rock fractures, would not enforce a reducing -250 mV Eh. Steel barrels and alkaline cement are intended to geochemically retain 2.5x106 kg of uranium. Simulations of repository cement/BVG groundwater interactions produced pH 10 at 80°C but no change in the +66 mV Eh. Steel barrel interactions produced an alkaline fluid with Eh -500 mV. Uranium solubility in the high pH repository near field was as high as 10-2.7 M, regardless of steel interactions. Uranium solubility adjacent to the repository (pseudo near field) was controlled by Eh; ranging from 10-13 M in the presence of steel, to 10-2.7 M with no steel. Uranium retention is controlled only by steel barrel durability. Oxidising, natural BVG groundwater will enhance steel barrel destruction. Distant from repository (far field) uranium solubility was 10-5.4 M if Eh was as measured in-situ. Thermodynamic data variations affect the calculation of uranium solubility; uranium near field solubility can be as high as 10-1.4 M. Uranium solubilities in near-field high pH groundwater could be more than 600 times greater than the 10-5.5 M used by the UK Nirex Ltd. in their safety case simulations.
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West, J. M. „Geomicrobiological aspects of the deep disposal of radioactive waste“. Thesis, Edinburgh Napier University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379139.
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Heffner, Heather Ann. „Analysis of post-use hypodermic needle medical waste disposal“. Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131158/unrestricted/heffner%5Fheather%5Fa%5F200405%5Fms.pdf.
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Hoag, Christopher Ian. „Canister design for deep borehole disposal of nuclear waste“. Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/41269.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, June 2006.Includes bibliographical references (p. 122-125).
The objective of this thesis was to design a canister for the disposal of spent nuclear fuel and other high-level waste in deep borehole repositories using currently available and proven oil, gas, and geothermal drilling technology. The canister is suitable for disposal of various waste forms, such as fuel assemblies and vitrified waste. The design addresses real and perceived hazards of transporting and placing high-level waste, in the form of spent reactor fuel, into a deep igneous rock environment with particular emphasis on thermal performance. The proposed boreholes are 3 to 5 km deep, in igneous rock such as granite. The rock must be in a geologically stable area from a volcanic and tectonic standpoint, and it should have low permeability, as shown in recent data taken from a Russian deep borehole. Although deep granite should remain dry, water in flooded boreholes is expected to be reducing, but potentially corrosive to steel. However, the granite and plug are the containment barrier, not the canister itself. The canisters use standard oil drilling casings. The inner diameter is 315.32mm in order to accommodate a PWR assembly with a width of 214mm. At five meters tall, each canister holds one PWR assembly. The canister thickness is 12.19mm, with an outer diameter of 339.7mm. A liner can extend to the bottom of the emplacement zone to aid in retrievability. The liner has an outer diameter of 406.4mm and a thickness of 9.52mm. The standard drill bit used with a liner of this size has an outer diameter of 444.5mm. Sample calculations were performed for a two kilometer deep emplacement zone in a four kilometer deep hole for the conservative case of PWR fuel having a burnup of 60,000 MWd/kg, cooled ten years before emplacement.
(cont.) Tensile and buckling stresses were calculated, and found to be tolerable for a high grade of steel used in the drilling industry. In the thermal analysis, a maximum borehole wall temperature of 2400C is computed from available correlations and used to calculate a maximum canister centerline temperature of 3370C, or 3190C if the hole floods with water. Borehole repository construction costs were calculated to be on the rate of 50 $/kg spent fuel, which is competitive with Yucca Mountain construction costs. Recommendations for future work on the very deep borehole concept are suggested in the areas of thermal analysis, plugging, corrosion of the steel canisters, site selection, and repository economics.
by Christopher Ian Hoag.
S.M.