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1

Dydak, Sara M. "The Hydraulic Sorting of Light and Heavy Minerals, Heavy-Mineral Concentrations, and Grain Size." W&M ScholarWorks, 1991. https://scholarworks.wm.edu/etd/1539617625.

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2

Eisenmann, Matthew Donnel. "Elutriation Technology in Heavy Mineral Separations." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/35707.

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Hindered-bed separators have been used in several different mineral processing fields for many years. Recent improvements in designs have led to the development of the CrossFlow separator. This new design employs a tangential feed system that has shown promise in several applications. This paper investigates the use of this relatively new technology to upgrade heavy mineral concentrates using Florida type ores. The intended use of this separatory device in this particular application is the removal of gangue quartz from other valuable heavy minerals such as ilmenite, leucoxene, rutile, zircon, and staurolite. The results of two different pilot-scale in-plant testing investigations are discussed. In general, quartz rejections in excess of 80% were achieved while maintaining TiO2 and heavy mineral recoveries above 98% and 99%, respectively. In addition to field test work, two separate unit models have been developed. The first model is an empirical investigation into understanding unit operation and functionality. The second model is a statistical prediction of unit operation based on specific field test work. These models can be used to effectively scale-up a CrossFlow unit for full-scale installation at any Florida heavy mineral sands operation. Emphasis is placed on unit capacity and other operational parameters such as elutriation flowrate and bed level.
Master of Science
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3

Lener, Edward F. "Mineral Chemistry of Heavy Minerals in the Old Hickory Deposit, Sussex and Dinwiddie Counties, Virginia." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/35803.

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The Old Hickory is the largest of a series of Pliocene (?) age heavy mineral sand deposits in Virginia and North Carolina. The high density of heavy minerals allows for selective concentration during transport and deposition. Under the right conditions, placers of considerable size can be formed. The elliptically shaped ore body of the Old Hickory Deposit extends in a North - South direction and is approximately 13 km (8 miles) long and up to 2.5 km (1.5 miles) wide, with an average thickness of 6.5 m (20 feet). The deposit lies along the Fall Zone, where a thin wedge of Cenozoic Coastal Plain sediments unconformably overlies the older rocks of the Piedmont. The principal minerals of economic interest found in the heavy mineral sands at the site are ilmenite (FeTiO3), leucoxene (Fe2-xTi3+xO9+x/2) where x is less than or equal to 2, rutile (TiO2), and zircon (ZrSiO4). An important focus of this study is the alteration of ilmenite by leaching away of iron, which results in enrichment in titanium. Titanium metal is highly valued for its light weight and high strength. In terms of total economic value, however, the use of titanium dioxide pigments for paint, coated paper, and other products is far more important. As the value of the ore is heavily dependent on the titanium content, the weathering process is a matter of considerable interest to the mineral industry. Analysis of ilmenite grains using reflected light microscopy revealed a wide range of alteration textures. Quantitative analysis and mapping of trace elements showed altered areas with enrichment in Ti and depletion in Fe, Mn, Mg, and Cr. It is believed that the weathering process took place in a reducing environment prior to final deposition according to the reaction:
    Fe2+TiO3 + 2H+ --> Fe2+ (aq) + TiO2 + H2O
Reducing environments are found in water-logged soils such as floodplains and other low-lying areas. Repeated cycles of burial and exhumation during transport would have created conditions ideal for the removal of iron from the ilmenite.
Master of Science
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4

Hughes, Nicholas. "Heavy mineral distribution in upland gravel-bed rivers." Thesis, Loughborough University, 1992. https://dspace.lboro.ac.uk/2134/27944.

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The characteristics of gravel-bed river deposits vary according to the complex relationships between hydrological and sedimentological regimes that occur over a range of spatial and temporal scales. This thesis concerns the composition and distribution of fine-grained sediment in British upland rivers; the size fractions which are perhaps the most susceptible, as regards both quantity and quality, to human activity and yet which can yield important information regarding upstream geological characteristics.
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5

Hapugoda, Priyanthi Devika. "Rapid measurement of heavy mineral content in wet-plant streams /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18496.pdf.

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6

De, Villiers Dawid. "Characterisation of heavy mineral sands and soils by radiometry and its use in mineral benefication and agriculture." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6851.

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Thesis (PhD (Physics))--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: Radioactivity is well known and well understood, but its usefulness in industrial applications to optimise processes or increase economic viability is not yet fully utilised by many industries. This study focuses on the measurement of natural radioactivity and its application in heavy mineral separation and vineyard soil classification. The gamma radiometry set-up consisted of a high purity germanium detector, a Marinelli beaker as sample container and associated electronics. It was calibrated for laboratorybased measurements by minimising the background radiation with the use of lead castle and energy and resolution calibrations. Furthermore, detection parameters were optimised; these included the counting time, the selection of gamma rays used for analysis of a sample, the peak area calculation for the detector dead time and the detector efficiency. Given that the samples had different densities and volumes, the detector efficiency had to be corrected for volume and density effects. After implementation of the corrections and optimisations the detection system was tested and found able to accurately measure radioactivity concentrations. The systematic measurement errors for 238U were 5.1 % in the case of the heavy mineral sands and 34.3 % for the vineyard soils, 4.5 % for the 232Th concentrations and 4.7 % for 40K concentrations. Statistical errors were kept below 2 %. The application of radiometry has not been done before at any South African heavy mineral separation plant. For this reason radiometry is suggested as an easier, faster and cheaper alternative to X-ray fluorescence (XRF) for effective implementation of grade control for zircon to improve the cost benefit of the heavy mineral separation process. Zircon is an example of a heavy mineral that is worldwide in demand with a consumption of more than a million tonnes per year. It is used in a wide range of industrial applications and products that include tiles, sanitary ware and plasma displays. South Africa is the second largest producer of zircon in the world and also has the second largest reserve of available zircon, making this mineral a viable source of income for several years to come. Radioactivity, in the form of uranium and thorium, and other impurities such as iron oxide and titanium oxide are found in the crystal lattice of zircon. For it to be a sellable product, the sum of the uranium and thorium concentrations must be less than 500 parts per million for prime or first grade zircon and less than 1000 parts per million for second grade zircon. At present the concentrations of uranium and thorium in zircon concentrates are measured on a whole rock basis by XRF during and at the end of the processing cycle before the final products are ready to be shipped. This is not an ideal situation as the grab samples are taken periodically and are not necessarily representative of the stream or final assignment and has resulted in significant losses by the producer. The solution is to accurately measure the uranium and thorium concentrations fast or immediately, preferably the measurements must be made online and in real time so that processing decisions can be implemented quickly to optimise the final product. Heavy mineral sand samples were obtained from the various separation processes in a Mineral Separation Plant and their 238U and 232Th concentrations determined. The results indicated that the samples’ uranium to thorium ratios together with their total concentrations can be used to differentiate between the samples (i.e. separation processes). The measurement results were compared with those obtained with XRF. The correlations with radiometry were excellent for the uranium (r2 = 0.992), thorium (r2 = 0.998) and total concentrations (r2 = 0.998). Radiometric measurements were also conducted by decreasing the counting time from 3600 s to 1 s to investigate its effect on the accuracy of the results. Correlations between the different times and 3600 s ranged from excellent to good. The obtained results are then used to recommend that radiometry is used in a Mineral Separation Plant to verify that the zircon and zirkwa meet the specifications, to optimise the entrance feed and the other separation processes and to monitor the tailings streams. Finally the practical aspects of the implementation of radiometry are discussed. As a second application was radiometry applied in an agricultural pilot study to demonstrate the applicability of radiometry as a possible useful tool in soil classification. The creation of a vineyard is a long term and expensive investment and its yield and quality will be influenced by many factors such as the type of soil, viticultural preparations and climate. Information on the different soil types in a vineyard is therefore indispensable for the optimisation of land use with respect to vine cultivar, wine quality and production. Soil samples were obtained from Kanonkop, Simonsig and Spier vineyards and their 238U, 232Th and 40K concentrations determined, assuming that fertilisers would have no effect on the results. The difference in 40K concentrations were related to the clay fraction of the soil and demonstrated that the Kanonkop and Simonsig soils are fine-grained and clay-rich compared to the sandy coarse-grained soils of Spier. The uranium and thorium concentrations were indicators of whether the mineralogy of the soil is the same as the underlying bedrock as well as soil maturity. The measurement results were compared with those obtained with XRF. The correlation with radiometry were poor for the uranium concentrations (r2 = 0.314), as many of the samples concentrations were below the XRF detection limit. The correlations were excellent for both thorium (r2 = 0.985) and potassium (r2 = 0.999). As a positive result from the findings of the study was an in-situ measurement performed by Newman et al. for the radiometric mapping of a Simonsig vineyard for soil classification.
AFRIKAANSE OPSOMMING: Radioaktiwiteit is wel bekend en word goed verstaan, tog is die gebruik daarvan in industriele toepassings om prosesses te optimiseer of winsgrense te verhoog nog nie deur baie industrië ten volle benut nie. Hierdie studie fokus op die meting van natuurlike radioaktiwiteit en die toepassing daarvan in swaar mineraal skeiding en wingerd grond klassifikasie. Die gamma radiometrie opstelling het bestaan uit ‘n hoë suiwerheid germanium detektor, 'n Marinelli beker as monster houer en verwante elektronika. Dit was gekalibreer vir laboratorium gebaseerde metings deur die vermindering van die agtergrondstraling met die gebruik van lood kasteel en energie en resolusie kalibrasies. Verder was deteksie parameters geoptimaliseer, dit sluit in die teltyd, die keuse van gammastrale wat gebruik word vir die ontleding van 'n monster, die piek area berekening, die korreksie vir die detektor se dooie tyd en die detektor doeltreffendheid. Gegee dat die monsters van mekaar verskil het in terme van dighteid en volume was dit nodig om die detektor doeltreffendheid te korrigeer vir volume en digtheid effekte. Na die implementering van die korreksies en optimalisasie was die detektor stelsel getoets en was gevind dat radioaktiwiteit konsentrasies akkuraat gelewer kan lewer. Die sistematiese meet foute vir 238U was 5.1 % vir die mineraal sand en 34.3 % vir wingerd grond, 4.5 % vir 232Th konsentrasies en 4.7 % vir 40K konsentrasies. Statistiese foute was onder 2 % gehou. Die toepassing van radiometrie was nog nie voorheen by enige Suid-Afrikaanse swaar mineraal skeidings aanleg gedoen nie. Vir die rede is radiometrie voorgestel as ‘n makliker, vinniger en goedkoper alternatief teenoor XSF vir effektiewe implementering van graad beheer vir zirkon om die koste voordeel van die swaar mineral skeiding proses te verbeter. Zirkon is ‘n voorbeeld van ‘n swaar mineraal wat wêreldwyd in aanvraag is met ‘n verbruik van meer as ‘n miljoen ton per jaar. Dit word in ‘n wye reeks van industriele toepassings en produkte gebruik onder andere teëls, sanitêre ware en plasma skerms. Suid Afrika is die tweede grootste vervaardiger van zirkon in die wêreld en het ook die tweede grootste reserwe van besikbare zirkon. Dit veroorsaak dat die mineraal ‘n lewensvatbare brom van inkomste is vir nog etlike jare. Radioaktiwiteit, in die vorm van uraan en thorium, word tesame met ander onsuiwerhede soos ysteroksied en titaanoksied in zirkon se kristal rooster gevind. Om ‘n verkoopbare produk te wees moet die som van die uraan en thorium konsentrasies minder wees as 500 dele per miljoen vir prima en eerste graad zirkon en minder wees as 1000 dele per miljoen vir tweede graadse zirkon. Huidiglik word die uraan en thorium konsentrasies in die zirkon konsentraat gemeet op ‘n heel gesteente basis met X-straal fluoroskopie (XSF) gedurende en op die einde van die prosesering siklus net voor die finale produk reg is om versend te word. Dit is nie die ideale situasie nie, want die monsters word periodies geneem en is nie noodwendig verteenwoordigend van die stroom of die finale produk nie en het al tot beduidende verliese deur die vervaardiger gelei. Die oplossing is om die uraan en thorium konsentrasies vinnig of onmiddelik te meet, verkieslik moet die metings inlyn en intyds gedoen word om verwerkings besluite vinnig geimplementeer kan word om die finale produk te optimaliseer. Swaar mineraal sand monsters was verkry van die verskeie skeidingsprosesse in ‘n Mineraal Skeidings Aanleg en hul 238U en 232Th konsentrasies bepaal. Die resultate het aangetoon dat die monsters se uraan en thorium verhoudings saam met hul totale konsentrasies gebruik kan word om te onderskei tussen die monsters (oftewel die skeiding prosesse). Die meting resultate was vergelyk met dié verkry met XSF. Die korrelasies met radiometrie was uitstekend vir die uraan (r2 = 0.992), thorium (r2 = 0.998) en totale konsentrasies (r2 = 0.998). Radiometriese metings was ook uigevoer deur die teltyd te verminder van 3600 s tot 1 s om die uitwerking daarvan op die akkuraatheid van die resultate te ondersoek. Korrelasies tussen die verskillende tye en 3600 s het gewissel van uitstekend tot goed. Die bevindinge was dan gebruik om aan te beveel dat radiometrie in a Mineraal Skeidings Aanleg gebruik kan word om te verifeer dat daar aan die zirkon en zirkwa spesifikasies voldoen word, om die begin voer en ander skeidings prosesse te optimaliseer en ook die uitskot strome te monitor. Laastens is die praktiese aspekte van die implementering van radiometrie bespreek. Vir die tweede toepassing was radiometrie toepgepas in ‘n loods studie in die landbou om die toepaslikheid van radiometrie as ‘n moontlike nuttige instrument in grond klassifikasie te demonstreer. Die skepping van ‘n wingerd is ‘n lang termyn en duur belegging waarvan die opbrengs en kwaliteit beinvloed sal word deur vele faktore, onder andere die tipe grond, wynbou voorbereidings en die klimaat. Inligiting oor die verskillende grond tipes in ‘n wingerd is daarom onmisbaar vir die optimalisering van land gebruik in betrekking tot die wingerdstok kultivar, wyn kwaliteit en produksie. Radiometrie is toegepas om te demonstreer die toepaslikheid daaran as ‘n moontlike nuttige instrument in grond klassifikasie. Grondmonsters was verkry vanaf Kanonkop, Simonsig en Spier wingerde en hul 238U, 232Th en 40K konsentrasies bepaal met die aanname dat kunsmis nie ‘n uitwerking op die resultate sou hê nie. Die verskil in 40K konsentrasies was verwant aan die kleifraksie van die grond en het getoon dat die Kanonkop en Simonsig gronde is fyn korrelrig en kleiryk is in vergelyking met die sanderige growwe korrel grond van Spier. Die uraan en thorium konsentrasies het gedui op die samestelling van die grond en ook aangedui watter grond dieselfde is as die onderliggende rots. Die meting resultate was vergelyk met dié verkry met XSF. Die korrelasie met die radiometrie was sleg vir die uraan konsentrasies (r2 = 0.314) aangesien baie van die monster konsentrasies laer was as die XSF deteksie limiet. Die korrelasies was uitstekend vir beide thorium (r2 = 0.985) en kalium (r2 = 0.999). As ‘n positiewe resultaat van die studie se bevindinge was ‘n in-situ meting gedoen deur Newman et al. om ‘n Simonsig wingerd radiomeries te karteer vir grond klassifasie.
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7

Duffin, P. A. "The effect of phytate on mineral bioavailability and heavy metal contaminants." Thesis, University of Surrey, 1989. http://epubs.surrey.ac.uk/595/.

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8

Carelse, Candice. "Mineralogy and provenance of the Namakwa Sands heavy mineral satellite deposits." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71980.

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Thesis (MSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Five areas proximal to the world class Namakwa Sands heavy mineral deposit have been studied and include the farms Houtkraal Remainder Portion 2, Houtkraal Remainder, Geelwal Karoo, Graauwduinen and Rietfontein. These are locally referred to as the satellite deposits and are sub-economic occurrences. The primary objective of the study was to quantify the mineralogy and mineral chemistry, determine the provenance of the heavy mineral suite and draw a comparison between the satellite deposits and the Namakwa Sands deposit from an exploratory point of view. Methodology used to achieve the above objectives included optical microscopy, Scanning Electron Microscope (SEM), Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), Quantitative Evaluation of Minerals by Scanning Electron Microscopy (QEMSCAN), X- Ray Fluorescence (XRF) and Zr-geothermometry of rutile. The five satellite areas contain the same heavy mineral suite but mineral proportions differ. The total heavy mineral population (THM) are diverse and consist of ilmenite and its alteration products (hydrated ilmenite, pseudorutile and leucoxene), magnetite, hematite, spinel, rutile, tourmaline, pyroxene, amphibole, garnet, aluminosilicates, staurolite, corundum, epidote, zircon, monazite and sphene. Ilmenite and garnet are the two most dominant heavy minerals present. The valuable heavy minerals (VHM) suite consists of ilmenite, zircon, rutile and leucoxene. The mineralogy of the satellite areas and chemistry of the ore minerals (rutile, zircon, ilmenite and leucoxene) are similar to the Namakwa Sands deposit. The whole spectrum of ilmenite alteration products (hydrated ilmenite, pseudorutile, and leucoxene) is present and allowed the quantitative use of the alteration index. The indices is low (22-24%) and indicates that the surficial deposits have formed under arid to semi-arid climatological conditions which preserved the pristine character of most of the minerals. This allowed reliable provenance studies using the characteristics of most of the heavy mineral suite, which showed that the minerals were derived from a diversity of source rocks. These included mainly medium to high-grade metamorphites and felsic intrusives of the underlying Mesoproterozoic Namaqualand Metamorphic Complex and a minor contribution from the Neoproterozoic Gariep Supergroup. This relationship indicates a limited transport distance from source to depositional basin. Mineral ratios in particular the THM-VHM relationship showed that the deposits located close to the shoreline such as Geelwal Karoo, Graauwduinen and Rietfontein have a relatively low proportion of valuable heavy minerals whereas those more inland such as Houtkraal Remainder Portion 2 and Houtkraal Remainder are close to unity. Heavy mineral concentration as such is low in the satellite areas and the mechanism to increase the concentration is clearly not only a function of distance from the present shoreline but is also topographically controlled. Steep sided linear depressions channelled the unconsolidated sediments and heavy minerals were upgraded into economic concentrations by aeolian processes. The quality of the valuable heavy minerals in the satellite areas however is similar to those of the adjacent Namakwa Sands deposit. This study has demonstrated that Houtkraal Remainder is the northeasterly continuation of the red aeolian sand (RAS) associated East Mine orebody and offers the best exploration potential.
AFRIKAANSE OPSOMMING: Vyf areas proksimaal aan die Namakwa Sands swaar mineral afsetting is bestudeer en sluit in Houtkraal Remainder, Houtkraal Remainder Portion 2, Geelwal Karoo, Graauwduinen en Rietfontein. Hierdie areas word plaaslik na verwys as satelliet afsettings en is subekonomies. Die hoofdoel van hierdie studie was om die mineralogie en mineral chemie te kwantifiseer, die oorsprong van die swaar mineraal suite te bepaal asook n vergelyking te tref tussen die satelliet areas en die Namakwa Sands afsetting vanuit n verkennende eksplorasie oogpunt. Optiese mikroskopie, SEM, LA-ICP-MS, QEMSCAN, XRF en die Zr-geotermometer van rutiel is gebruik om bostaande doele te bereik. Die vyf satellite areas bestaan uit dieselfde swaar minerale maar mineral proporsies verskil. Die totale swaar mineraal populasie is divers en bestaan uit ilmeniet en ilmeniet se veranderingsprodukte (gehidreerde ilmeniet, pseudorutiel en leukokseen), magnetiet, hematiet, spinel, rutiel, toermalyn, pirokseen, amfibool, granaat, aluminiumsilikate, stauroliet, korund, epidoot, sirkoon, monasiet and sfeen. Ilmenite en granaat is die twee mees dominante swaar minerale teenwoordig. Die waardevolle swaar mineraal populasie bestaan uit ilmeniet, rutiel, sirkoon en leukokseen. Die mineralogie van die satelliet areas en die chemie van die erts minerale (rutiel, sirkoon, ilmeniet en leukokseen) is dieselfde as die van die Namakwa Sands afsetting. Die hele spektrum ilmeniet veranderingsprodukte is teenwoordig en het die kwantitatiewe gebruik van die alterasie indeks toegelaat. Die alterasie indekse is laag (22-24%) en dui aan dat die oppervak afsettings gevorm het tydens droë tot semi droë toestande wat die eertydse karakter van meeste minerale bewaar het. Deurdat die karakter van meeste minerale behoue gebly het, kon provenans studies toegepas word op die swaar mineraal suite. Provenans studies het aangedui dat die swaar minerale afkomstig is van n verskeidenheid van bron gesteentes. Dit sluit in medium tot hoë graad metamorfe gesteentes en felsiese intrusies van die Mesoproterosoïese Namakwaland Metamorfiese Kompleks met n geringe bydrae van die Neo Proterosoïese Gariep Supergroep. Hierdie verhouding dui n beperkte vervoer afstand aan vanaf die bron tot by die afsettings omgewing. Mineraal vehoudings spesifiek die totale swaar mineraal-waardevolle swaar mineraal verhoudings dui aan dat afsettings na aan die kus soos Geelwal Karoo, Graauwduinen en Rietfontien n lae inhoud van waardevolle swaar minerale het teenoor afsettings soos Houtkraal Remainder Portion 2 en Houtkraal Remainder wat meer land in is met verhoudings na aan eenheid. Swaar mineral konsentrasie is laag in die satellite areas en die meganisme verantwoordelik vir die toename in konsentrasie is nie net n funksie van die afstand van die bestaande kuslyn nie maar word ook deur topografie beheer. Steil sydige lineêre depressies kanaliseer die ongekonsolideerde sediment en swaar minerale en word opgradeer tot ekonomiese konsentrasies deur wind prossese. Die kwaliteit van die waardevolle swaar minerale in die satelliet areas is egter dieselfde as die van die aangrensende Namakwa Sands afsetting. Hierdie studie het gewys dat Houtkraal Remainder is die noordelike voortsetting van die Rooi Aeoliese Sand geassosieerde Oos Myn ertsliggam en bied die beste eksplorasie potensiaal.
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9

Berquist, C. R. Jr. "Stratigraphy and heavy mineral analysis in the lower Chesapeake Bay, Virginia." W&M ScholarWorks, 1986. https://scholarworks.wm.edu/etd/1539616565.

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Spatially continuous patterns of heavy mineral distributions in three dimensions characterized the sandy Holocene sediments of the lower Chesapeake Bay. A pilot study using Q-mode factor analysis on data from an earlier study determined mineral assemblages and mineral composition gradients; the gradients suggested that surficial sediments entered the Bay from offshore and from older deposits to the west. Principal components analysis of the same data indicated that the abundances of only 5 out of 21 minerals were adequate to explain most of the mineral variance. The mineralogy of 87 samples from cores defining two geologic cross-sections was added to the pilot study data and formed a new data set of 173 samples and 5 minerals. Q-mode factor analysis gave similar end-member compositions and mineral gradients as compared to the pilot study. Mineral gradients in the cross-sections show offshore sediment rich in amphibole, garnet, and pyroxene has entered the Bay mouth and presently overlies landward-derived sediment rich in zircon and epidote. The gradients depict tube- and tongue-shaped pathways located above paleodrainages. Surficial gradients support the notion of mutually evasive ebb and flood channels in the Bay entrance. Most of the Holocene sediment in the lower Bay appears to have originated from outside the Bay mouth, to include littoral drift from the north. The techniques used in this study may be useful in an attempt to subdivide a massive sandy lithosome by recognizing distinct stratigraphic units of different age or origin. A magnetohydrostatic mineral separator was constructed and tested.
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10

Lynn, Michael David. "The development and distribution of heavy mineral concentrations in alluvial systems." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005549.

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The objective of this review is to summarise the characteristics, significance and evolution of heavy minerals and their accumulations, and to identify the key controls on the development and distribution of heavy mineral concentrations in alluvial systems. These controls can be broadly classified as tectonic setting, geomorphic setting and grain-scale concentrating processes, each of which is discussed. Based on this review, exploration models are developed which are designed to indicate favourable localities for the accumulation of heavy minerals, and trends likely to be exhibited within these accumulations. The models are structured from the broadest scale of target selection, down to the local scale of sample site selection. The major conclusion of this work is that an understanding of process geomorphology is required to develop genetic models of placer development, including a detailed evaluation of climatic fluctuations throughout the Caenozoic. Palaeoplacers such as the Witwatersrand goldfield, are inferred to have formed under similar circumstances of tectonic setting as genetically comparable Caenozoic placers such as those of Otago, New Zealand. The means of preservation of such major basins is however poorly understood.
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11

Wilson, Stephen. "The use of crosslinked casein for the removal of heavy metals from wastewater." Thesis, Federation University Australia, 1986. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/165021.

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This project studies the heavy metal cation adsorption of crosslinked casein, to assess its viability as an alternative means of removing heavy metal ions from the wastewater produced by mining and manufacturing processes.
Masters Degree in Applied Science
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12

Donachie, Kevin James. "Heavy metal accumulation and divalent-cation complexation in the crassulacean plant Kalanchoe daigremontiana." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363672.

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13

Sidhu, Manjinder. "Interactions between heavy metals and mineral nutrients in the moss rhytidiadelphus squarrosus." Thesis, University of Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317966.

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14

Kuhnle, Roger Alan. "Experimental studies of heavy-mineral transportation, segregation, and deposition in gravel-bed streams." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/59601.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1986.
Microfiche copy available in Archives and Science
Vita.
Includes bibliographies.
by Roger Alan Kuhnle.
Ph.D.
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15

Elias, Sílvio José. "Mineralogy and provenance of the TiO₂ - ilmenite heavy mineral sand deposit of Nataka." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/23762.

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The Nataka heavy mineral sand deposit occurs along the northeast Mozambique coastline. It comprises a regional Pleistocene elliptical structure extending from Somalia, passing through Kenya, Tanzania, Madagascar and Mozambique, to Richards Bay in South Africa. The deposit consists of fine- to medium- grained, unconsolidated red sediments, hosting heavy minerals. The deposit mineral assemblage is made up of non-valuable phases comprising mostly magnetite, hematite, chromite, monazite, and the valuable phases dominated by ilmenite (50.91 wt. %), with additional zircon and rutile (9.96 and 3.52 wt. % respectively). The total heavy minerals comprise about 5% volume, of which 2 % are valuable heavy minerals making up about 445 Mt (million tonnes) probable resources. This study focuses on the mineralogical characterization of ilmenite from the Nataka deposit, alongside with sediment provenance. Mineralogical and chemical characterisation of ilmenite undertaken on 32 samples from 16 selected drill holes using a combination of QEMSCAN and EPMA revealed that the ilmenite has undergone different stages of alteration, at distinct environment conditions, yielding products spanning from hydrated ilmenite to leucoxene. The alteration dominantly involved groundwater, which was oxidizing and acidic, hence the predominance of ilmenite-pseudorutile alteration. Long exposure to direct sunshine has been hypothesized as a different process that might have favoured the direct alteration of ilmenite to leucoxene and of pseudorutile to leucoxene, on a smaller scale. The major impurities in the ilmenite are Al and Si, which are enriched in the advanced ilmenite alteration products (leucoxene), where they fill pores and cracks. Chromium impurities occur as discrete grains of chrome spinel. The compositional variety of magnetite, Cr-spinel, tourmaline, zircon and rutile indicate major contribution from granitoid terranes, subjected to granulite metamorphic facies (750 to 1000 :C), and minor contribution from mafic plutonic intrusions. The granitoid field as a sediment source area if analysed in conjunction with zircon ages (1100 – 900 Ma, 900 – 700 Ma, and 650 – 500 Ma), and zircon δ¹⁸O (7.07 ‰) is consistent with preferential sourcing from the proximal Mesoproterozoic Nampula Complex, with some contribution from igneous plutonic rocks from Xixano, Lalamo and Montepuez Complexes.
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16

Shafer, Paula L. "Mineralogic and Geochemical Variations within the Old Hickory Heavy Mineral Sand, Sussex and Dinwiddie Counties, Virginia." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/34073.

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The Old Hickory mine is a world class placer titanium deposit located at the boundary of the Coastal Plain and the Piedmont in Virginia, astride the Sussex-Dinwiddie county line (77°34' W Long, 36°55'N Lat., Cherry Hill Quad). The Old Hickory deposit, discovered in 1987 by C. R. Berquist, was opened as a commercial mine in 1997, and is presently operated by Iluka Resources. Heavy minerals constitute an average of 8% of the sediment, but locally reach concentrations as rich as 60%. The ore minerals, in order of decreasing concentrations, are ilmenite, rutile, and zircon, which are believed to have been derived from weathering of Piedmont and Blue Ridge sources. After fluvial transport to the coast, the ore minerals were redistributed laterally along the coast by longshore currents, and ultimately concentrated by intense wave action, probably generated by large storms. The ores occur over an area of 8 km x 3 km, with ore minerals being found from the surface to up to depths of 12 meters, and appear to occur in at least two distinct ore horizons. This study examines the general ore mineralogy and differences in the mineralogy, grain sizes, secondary textures, and geochemistry of the ore minerals in the two distinct ore zones. Distinguishable differences between the two zones include a slightly coarser grain size, more angular grains of rutile, and a higher percentage of accessory minerals (epidote, garnet, etc) in the younger zone. Approximately 40% of all the ilmenite grains contain exsolution lamellae of hematite, a residual texture from the time of original ilmenite crystallization. Weathering of these ilmenite grains has preferentially dissolved out the hematite while preserving the original texture; thus the weathering increases the titanium content of the ore by removing some of the iron. The weathering also affects the distribution of minor elements such as aluminum, manganese, and chromium. At Old Hickory, the zircon population can be divided into two main types (thin, elongate rounded pink prisms, and short, thicker white to clear prisms) that may represent either multiple source regions or multiple generations of heavy mineral deposition. The variations in grain size, angularity, and rutile content are likely to be mappable and may prove useful in continuing stratigraphic studies, and in distinguishing separate ore zones.
Master of Science
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17

Herath, Dulana Nilupul. "Fire impacts on restored shrublands following mining for heavy minerals near Eneabba, southwestern Australia." Thesis, Curtin University, 2008. http://hdl.handle.net/20.500.11937/556.

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Abstract:
Following mineral-sand mining in the northern sandplains near Eneabba, southwestern Australia, rehabilitation managers have the difficult task of restoring shrubland communities of exceptional plant species richness. Management aims to restore a fully functional and self-sustaining shrubland community with similar vegetation and resilience properties to that of the surrounding natural vegetation. This thesis examines the performance of the restoration program by Iluka Resources Ltd. (and their predecessors) by comparing current vegetation properties and their response to fires on previously mined land versus the surrounding natural shrubland. As biomass accumulates post-restoration, fires will return as a natural disturbance factor and, as a result, a desirable measure of restoration success might include the ability of the postmined lands to recover from disturbance. Pre-burnt plant species diversity, composition, structure and key functional attributes in four mined sites rehabilitated 8 (R8) to 24 (R24) years ago were compared with those of surrounding natural areas classified on the basis of substrate type (low and high sand dunes, shallow sand swales, sand over laterite and sand over limestone). The rehabilitated sites (except R8) had more species (about 140) than natural sites (about 100) with 12–37% species in common with natural sites. Floristic composition was most similar to the local swales and dunes (physically closest).Two strong colonizers, the fire-killed Acacia blakelyi and the fire-tolerant Melaleuca leuropoma, were universally present. Plant densities were about a quarter to half those of natural sites. Fire-resprouters were under-represented. Growth-form distributions were most similar to those of the dunes, with some woody shrubs up to 2.5 m tall present. Greater iron levels and soil hardness (penetrability) were the only soil factors consistently greater in rehabilitated sites. Following experimental fires at the same study sites, species richness fell by 22–41% in rehabilitated sites but increased by 4–29% in natural sites. Species present before fire were reduced by 40–56% in rehabilitated sites and 4–12% in natural sites. Only 42–66% of resprouting species recovered in rehabilitated sites, whereas 96–100% recovered in natural sites. Nonsprouting species recruitment was also lower in rehabilitated (18–57%) than natural (67–85%) sites. Seedling mortality over the first summer after fire was higher in rehabilitated sites (59-86% death of individuals) than in natural sites (14-60%). PCoA ordination showed that fire altered the floristic composition of rehabilitated sites much more than it did in natural sites, mostly attributable to the loss of the extant resprouter species. It was found that the smaller lignotuber size (source of dormant buds) recorded in rehabilitated (vs. natural) resprouters was responsible for their higher post-fire mortality. For equivalent crown size in ten common lignotuberous shrub species, lignotuber circumferences were, on average, 50% smaller at rehabilitated sites.As a result, overall persistence in these species was much lower in rehabilitated (mean of 52% alive, range of 11–93%) versus natural sites (mean of 96%, range of 79–100%), but improved with time since restoration for five of the ten selected species. Apart from differences in the age of the plants (natural sites having much older plants recruited after previous fires), the lower soil penetrability at rehabilitated sites may have restricted lignotuber development. A tradeoff favoring a higher crown volume to lignotuber size ratio was also apparent in nine of the ten species with greater crown volumes (by 37%) and smaller lignotubers (by 36%) in rehabilitated sites. Demographic attributes for six selected woody species were compared between rehabilitated and natural sites (~3-30 years since disturbance) to investigate growth patterns and optimum fire-return intervals. At matched years since restoration or last fire, nonsprouter species in rehabilitated sites grew larger (1.1 to 4.7 times) and produced/stored more viable seeds per plant (1.1 to 10.9 times). Despite older aged individuals in natural sites at matched years since restoration vs. last fire, restored resprouters were larger (1.1 to 3.6 times) and produced/stored more viable seeds (1.1 to 6.9 times). Although greater growth and fecundity rates were recorded in rehabilitated sites, the estimated optimum fire-return interval based on maximum seed production was similar in rehabilitated and natural sites for five out of six species.However, mean fire intervals typical of surrounding natural vegetation near the Eneabba area (13 years over the last 40 years) may not be suitable for rehabilitated minesites at Eneabba, whereby longer initial fire intervals (20–30 years) would better ensure persistence of resprouter individuals via the seedling recruitment strategy and resprouting strategy. Iv My study indicated that the returned vegetation can at present be classified as “rehabilitated” or “partially restored” but not “completely restored” since the original plant diversity, composition, structure, and resilience properties to fire have not yet been achieved. It may not be possible/realistic to achieve complete restoration since mining is such a destructive disturbance type that some complex ecological attributes may take centuries to develop. I discuss six key factors as important in improving the overall restoration success at Eneabba: 1) restoration of a deeper topsoil and looser subsoil profile; 2) collection of appropriate amounts of only local provenance species, mulch and topsoil; 3) control of highly competitive species; 4) management of fertilizer additions; 5) reseeding and replanting in subsequent years after the initial restoration treatments, including after initial fires; and 6) delaying the introduction of management fires until the restored vegetation develops sufficient fire-resilience properties.
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18

Assane, Ali Ossufo. "Distribution of heavy minerals sand in Namalope deposit, Moma district, Mozambique." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1012169.

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The spatial distribution of heavy minerals along the mine paths 2014 and 2015 at the wet concentrate plant B shows an increase of heavy minerals sand concentration northwards and slime contents southwards, and it is commonly associated with depth and grain sorting; the increase of heavy minerals concentration with depth is considered to be from the surface formed by Unit 6 to the bottom of Unit 7. The Unit 82 is characterized by low heavy minerals concentrations and high slime contents declining northwards. The mineral proportion estimation suggests that ilmenite is the most abundant heavy mineral in the entire area followed by zircon, rutile and mozanite, and some accessory minerals such as chromite, kyanite, staurolite, tourmaline, epidote, spinel and quartz. The ilmenite occurrence is divided into ilmenite low (< 53% TiO₂) and high (> 53% TiO₂); the ilmenite high with zircon and rutile shows tendency to increase northwards while ilmenite low increase southwards. Zircon, monazite, rutile, chromite, kyanite and staurolite show low variability, which is probably associated with high resistance of minerals for abrasion during transportation and diagenesis. The depositional model of the Namalope deposit, in the flat area and wet concentrate plant B in particular, suggests deposition in a shallow marine environment associated with regression for deposition of Unit 6, 7 and 9 and transgression during deposition of Unit 82. The spatial distribution of heavy minerals in the Namalope deposit and its environment of deposition are the key points for discovery of new deposits around the Namalope with the same characteristic of mineral assemblage and they are used for mine strategic plans such as update block model and mine design.
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19

Hiraki, Simone Silva [UNESP]. "Tolerância e potencial fitorremediador de Jatropha curcas L. aos metais níquel e cobre." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/141968.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Devido às atividades antrópicas de mineração, descarte inadequado de resíduos, e uso exagerado de pesticidas químicos, problemas de contaminação dos solos por metais pesados têm sido cada vez mais registrados, ocupando áreas agrícolas que poderiam ser utilizadas por culturas alimentares. Dentre as técnicas utilizadas para descontaminar áreas poluídas por metais, existe a fitorremediação, que é uma técnica que utiliza plantas para extrair, ou reter os metais do solo. O pinhão-manso (Jatropha curcas L.) é uma espécie que foi apontada em muitos trabalhos como tolerante à solos de baixa fertilidade e com alta concentração de metais pesados, e graças à essas características, poderia ser utilizada em programas de fitorremediação. No entanto, os dados sobre crescimento, tolerância, acúmulo de metais e alterações na composição mineral da espécie são escassos, necessitando que mais trabalhos sejam realizados a fim de comprovar esse potencial. A fim de analisar o potencial da espécie J. curcas para uso em áreas contaminadas por níquel e cobre, foram realizados seis experimentos aplicando-se 0; 6,5; 13; 30; 70 e 100 mg de Ni Kg-1, e 0; 17,5; 35; 60; 200 e 400 mg de Cu Kg-1 nas fases de germinação, desenvolvimento inicial e em plantas com dois anos de idade. Os resultados obtidos demonstraram que J. curcas tem potencial para revegetar áreas em processo de descontaminação por níquel, por mostrar melhorias na germinação, além de apresentar parâmetros de crescimento pouco afetados, apesar de ser notado um antagonismo à absorção de Mg, Cu e Zn, que poderiam levar à problemas em outras fases do desenvolvimento. A espécie não é indicada para plantio em áreas contaminadas por cobre, apresentando queda da germinação, alta mortalidade na fase jovem e sintomas visuais de toxidez causados por esse metal. Além das alterações no crescimento, a presença de cobre pode reduzir a absorção de N, P e Fe nutrientes essenciais ao desenvolvimento da planta.
Because the human activities of mining, inadequate waste disposal, and exaggerated use of chemical pesticides, soil contamination problems from heavy metals have been increasingly recorded, occupying agricultural land that could be used for food crops. Among the techniques used to decontaminate areas polluted with metals, there is phytoremediation, which is a technique that uses plants to extract or retain metals from soil. The physic nut (Jatropha curcas L.) is a species that was identified in many studies as tolerant of low soil fertility and high concentrations of heavy metals, and thanks to these characteristics, could be used in phytoremediation programs. However, data on growth, tolerance, accumulation of metals and changes in mineral composition of this kind are still scarce, requiring that more studies be carried out to prove that potential. In order to analyze the potential of J. curcas species for use in areas contaminated by nickel and copper, six experiments were carried out by applying 0; 6.5; 13; 30; 70 and 100 mg Kg-1 Ni, and 0; 17.5; 35; 60; 200 and 400 mg Kg-1 Cu phases germination and early development of plants with two years of age. The results showed that J. curcas has potential for Revegetate areas for nickel decontamination process, presents improvements on the germination and the growth parameters are little affected despite being noticed a antagonism the absorption of Mg, Cu and Zn, which could lead to problems in other stages of development. The species is not indicated for planting in copper contaminated areas, showing a drop of germination, high mortality in young stage and visual symptoms of toxicity caused by copper. In addition to the changes in growth, the presence of copper may reduce the absorption of N, P and Fe nutrients essential to plant development.
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20

Hiraki, Simone Silva. "Tolerância e potencial fitorremediador de Jatropha curcas L. aos metais níquel e cobre." Botucatu, 2016. http://hdl.handle.net/11449/141968.

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Orientador: Giuseppina Pace Pereira Lima
Resumo: Devido às atividades antrópicas de mineração, descarte inadequado de resíduos, e uso exagerado de pesticidas químicos, problemas de contaminação dos solos por metais pesados têm sido cada vez mais registrados, ocupando áreas agrícolas que poderiam ser utilizadas por culturas alimentares. Dentre as técnicas utilizadas para descontaminar áreas poluídas por metais, existe a fitorremediação, que é uma técnica que utiliza plantas para extrair, ou reter os metais do solo. O pinhão-manso (Jatropha curcas L.) é uma espécie que foi apontada em muitos trabalhos como tolerante à solos de baixa fertilidade e com alta concentração de metais pesados, e graças à essas características, poderia ser utilizada em programas de fitorremediação. No entanto, os dados sobre crescimento, tolerância, acúmulo de metais e alterações na composição mineral da espécie são escassos, necessitando que mais trabalhos sejam realizados a fim de comprovar esse potencial. A fim de analisar o potencial da espécie J. curcas para uso em áreas contaminadas por níquel e cobre, foram realizados seis experimentos aplicando-se 0; 6,5; 13; 30; 70 e 100 mg de Ni Kg-1, e 0; 17,5; 35; 60; 200 e 400 mg de Cu Kg-1 nas fases de germinação, desenvolvimento inicial e em plantas com dois anos de idade. Os resultados obtidos demonstraram que J. curcas tem potencial para revegetar áreas em processo de descontaminação por níquel, por mostrar melhorias na germinação, além de apresentar parâmetros de crescimento pouco afetados, apesar d... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Because the human activities of mining, inadequate waste disposal, and exaggerated use of chemical pesticides, soil contamination problems from heavy metals have been increasingly recorded, occupying agricultural land that could be used for food crops. Among the techniques used to decontaminate areas polluted with metals, there is phytoremediation, which is a technique that uses plants to extract or retain metals from soil. The physic nut (Jatropha curcas L.) is a species that was identified in many studies as tolerant of low soil fertility and high concentrations of heavy metals, and thanks to these characteristics, could be used in phytoremediation programs. However, data on growth, tolerance, accumulation of metals and changes in mineral composition of this kind are still scarce, requiring that more studies be carried out to prove that potential. In order to analyze the potential of J. curcas species for use in areas contaminated by nickel and copper, six experiments were carried out by applying 0; 6.5; 13; 30; 70 and 100 mg Kg-1 Ni, and 0; 17.5; 35; 60; 200 and 400 mg Kg-1 Cu phases germination and early development of plants with two years of age. The results showed that J. curcas has potential for Revegetate areas for nickel decontamination process, presents improvements on the germination and the growth parameters are little affected despite being noticed a antagonism the absorption of Mg, Cu and Zn, which could lead to problems in other stages of development. The spec... (Complete abstract click electronic access below)
Doutor
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21

Tejan-Kella, Mustapha S. "The development of coastal sandy soil age sequences in Australia : with emphasis on heavy mineral weathering." Title page, abstract and contents only, 1990. http://hdl.handle.net/2440/19587.

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22

Herath, Dulana Nilupul. "Fire impacts on restored shrublands following mining for heavy minerals near Eneabba, southwestern Australia." Curtin University of Technology, Department of Environmental Biology, 2008. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=116352.

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Following mineral-sand mining in the northern sandplains near Eneabba, southwestern Australia, rehabilitation managers have the difficult task of restoring shrubland communities of exceptional plant species richness. Management aims to restore a fully functional and self-sustaining shrubland community with similar vegetation and resilience properties to that of the surrounding natural vegetation. This thesis examines the performance of the restoration program by Iluka Resources Ltd. (and their predecessors) by comparing current vegetation properties and their response to fires on previously mined land versus the surrounding natural shrubland. As biomass accumulates post-restoration, fires will return as a natural disturbance factor and, as a result, a desirable measure of restoration success might include the ability of the postmined lands to recover from disturbance. Pre-burnt plant species diversity, composition, structure and key functional attributes in four mined sites rehabilitated 8 (R8) to 24 (R24) years ago were compared with those of surrounding natural areas classified on the basis of substrate type (low and high sand dunes, shallow sand swales, sand over laterite and sand over limestone). The rehabilitated sites (except R8) had more species (about 140) than natural sites (about 100) with 12–37% species in common with natural sites. Floristic composition was most similar to the local swales and dunes (physically closest).
Two strong colonizers, the fire-killed Acacia blakelyi and the fire-tolerant Melaleuca leuropoma, were universally present. Plant densities were about a quarter to half those of natural sites. Fire-resprouters were under-represented. Growth-form distributions were most similar to those of the dunes, with some woody shrubs up to 2.5 m tall present. Greater iron levels and soil hardness (penetrability) were the only soil factors consistently greater in rehabilitated sites. Following experimental fires at the same study sites, species richness fell by 22–41% in rehabilitated sites but increased by 4–29% in natural sites. Species present before fire were reduced by 40–56% in rehabilitated sites and 4–12% in natural sites. Only 42–66% of resprouting species recovered in rehabilitated sites, whereas 96–100% recovered in natural sites. Nonsprouting species recruitment was also lower in rehabilitated (18–57%) than natural (67–85%) sites. Seedling mortality over the first summer after fire was higher in rehabilitated sites (59-86% death of individuals) than in natural sites (14-60%). PCoA ordination showed that fire altered the floristic composition of rehabilitated sites much more than it did in natural sites, mostly attributable to the loss of the extant resprouter species. It was found that the smaller lignotuber size (source of dormant buds) recorded in rehabilitated (vs. natural) resprouters was responsible for their higher post-fire mortality. For equivalent crown size in ten common lignotuberous shrub species, lignotuber circumferences were, on average, 50% smaller at rehabilitated sites.
As a result, overall persistence in these species was much lower in rehabilitated (mean of 52% alive, range of 11–93%) versus natural sites (mean of 96%, range of 79–100%), but improved with time since restoration for five of the ten selected species. Apart from differences in the age of the plants (natural sites having much older plants recruited after previous fires), the lower soil penetrability at rehabilitated sites may have restricted lignotuber development. A tradeoff favoring a higher crown volume to lignotuber size ratio was also apparent in nine of the ten species with greater crown volumes (by 37%) and smaller lignotubers (by 36%) in rehabilitated sites. Demographic attributes for six selected woody species were compared between rehabilitated and natural sites (~3-30 years since disturbance) to investigate growth patterns and optimum fire-return intervals. At matched years since restoration or last fire, nonsprouter species in rehabilitated sites grew larger (1.1 to 4.7 times) and produced/stored more viable seeds per plant (1.1 to 10.9 times). Despite older aged individuals in natural sites at matched years since restoration vs. last fire, restored resprouters were larger (1.1 to 3.6 times) and produced/stored more viable seeds (1.1 to 6.9 times). Although greater growth and fecundity rates were recorded in rehabilitated sites, the estimated optimum fire-return interval based on maximum seed production was similar in rehabilitated and natural sites for five out of six species.
However, mean fire intervals typical of surrounding natural vegetation near the Eneabba area (13 years over the last 40 years) may not be suitable for rehabilitated minesites at Eneabba, whereby longer initial fire intervals (20–30 years) would better ensure persistence of resprouter individuals via the seedling recruitment strategy and resprouting strategy. Iv My study indicated that the returned vegetation can at present be classified as “rehabilitated” or “partially restored” but not “completely restored” since the original plant diversity, composition, structure, and resilience properties to fire have not yet been achieved. It may not be possible/realistic to achieve complete restoration since mining is such a destructive disturbance type that some complex ecological attributes may take centuries to develop. I discuss six key factors as important in improving the overall restoration success at Eneabba: 1) restoration of a deeper topsoil and looser subsoil profile; 2) collection of appropriate amounts of only local provenance species, mulch and topsoil; 3) control of highly competitive species; 4) management of fertilizer additions; 5) reseeding and replanting in subsequent years after the initial restoration treatments, including after initial fires; and 6) delaying the introduction of management fires until the restored vegetation develops sufficient fire-resilience properties.
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23

Elferink, Lisa. "The cenozoic stratigraphy and associated heavy mineral palaeo-placer deposit on Geelwal Karoo : West Coast, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/21452.

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ENGLISH ABSTRACT: The farm Geelwal Karoo is situated some 16km north of the Olifants River mouth on the West Coast of South Africa and hosts fluvial, marine and aeolian deposits of post-Gondwana age. The oldest basal fluvial succession, unconformably overlies Proterozoic and Palaeozoic basement rocks and is in turn capped by aeolianite and littoral packages representing two transgressive cycles. The fluvial channel clay succession is deposited in shallow bedrock-incised channels, has a wedge-shape and is deposited parallel to the present coastline. The flow direction is along the coast and the northwardtapering, angular, poorly sorted basal vein-quartz lag indicates a northward palaeo-flow direction. Less than 1% total heavy minerals (THM) is found in the matrix of these gravel units and the heavy mineral suite is distinguished by zircon, pseudorutile and kyanite. The channel clay unit is dominated by an upper, mediumgrained quartzose sand and kaolin clay facies, which shows advanced post-depositional weathering. The fluvial unit is correlated with the channel clay unit of Hondeklip Bay and a Cretaceous age is proposed for the initial channel incision. The two shallow marine successions have been correlated with the Late Miocene, Early Pleistocene, +30m and +50m packages respectively. These marine sediments were first described by John Pether (1994) in the Hondeklip Bay area and were named according to their transgressive maxima. They are transgressive successions arranged en echelon down the coastal bedrock gradient, from oldest and highest to youngest. The offshore environment of the +50m package consists of fine silty sand, which is moderately sorted. The mineral assemblage is dominated by quartz and the average THM is 18%. The inshore environment is distinguished by a single poorly sorted basal cobble lag which shows an overall fining upward succession. The beachface environment is composed of medium to fine-grained sand, which is moderate to well-sorted. Mineral diversity is greatest in the inshore and beachface environments and the average THM for these two units is greater than 35%. The +30m package has been extensively eroded due to its lower erosion and outcrops were sporadic along the coast. The +30m offshore sediments are recognised by fine sediments with high concentrations of glauconite and organic matter. The inshore environment is distinguished by numerous poorly sorted pebble lags with fining upward successions. Both the inshore and beachface units have higher feldspar concentrations than the corresponding +50m units. The average THM for these two units is less than 3%. The aeolianite unit, which comprises several distinct units, extends over the entire length of the study area and is characterized by calcrete and red bed horizons. Colour variations in the otherwise homogeneous unit are due to heavy mineral enrichment and/or different degrees of in situ weathering and cementation. The unit is composed exclusively of fine- to medium-grained sand and the THM concentration averages 9%. This unit is composed of more than one generation of aeolian sand and forms part of an aeolian transport corridor which transported sand from the beach to the interior. The oldest unit has been equated with the Upper Miocene Prospect Hill Formation, whereas the more recent yellow dune sand is equated with the Pleistocene Springfontyn Formation. At Geelwal Karoo, only the heavy sand placer in the +50m package was deemed to be of any economic significance. The average THM of this placer was calculated to be 40% and some 150 thousand tons of Tibearing material can be expected from this succession. This relatively small volume of heavy minerals and extensive cementation however, make this placer a less attractive prospect than the neighbouring Namakwa Sands operation.
AFRIKAANSE OPSOMMING: Die plaas Geelwal Karoo is ongeveer 16km noord van die Olifantsriviermond aan die Weskus van Suid- Afrika geleë en het voorkomste van fluviale, marine en eoliese afsettings van post-Gondwana ouderdom. Die oudste eenheid, ‘n basale fluviale eenheid, oorlê Proterosoiëse en Paleosoiëse plaaslike vloer gesteentes wat op hulle beurt weer bedek word deur eoliese en littorale eenhede verteenwoordigene ven twee transgressiewe siklusse. Die fluviale kanaalklei-opeenvolging, afgeset in vlak ingesnyde rotsbedding-kanale, is wigvormig en is afgeset parallel aan die huidige kuslyn in ‘n alluviale waaier-afsetting. Die vloeirigting was langs die kus en die noorwaards toespitsende, hoekige, swak gesorteerde basale aar-kwarts bodemgruis dui op ‘n noordwaards palaeo-vloeirigting. Minder as 1% totale swaarminerale (TSM) is gevind in die tussenmassa van hierdie gruis-eenhede en die swaarmineraal reeks word onderskei deur sirkoon, pseudo-rutiel en kianiet. Die kanaalklei eenheid word oorheers deur ‘n boonste, medium-korrelrige kwarts-bevattende sand en kaolien kleifasies was dui op gevorderde verwering na afsetting. Die fluviale eenheid word gekorreleer met die kleikanaal en ‘n Kryt-ouderdom word voorgestel vir die aanvanklike insnyding van die kanaal. Die twee vlak marine opeenvolgings word gekorreleer met die Laat Mioseen, vroeg Pleistoseen, naamlik die +30m en +50m eenhede onderskeidelik. Die aflandige omgewing van die +50m eenhied bestaan uit matiggesorteerde, fyn slikkerige sand. Die mineraalversameling word oorheers deur kwarts en die gemiddelde TSM is 18%. Die subgetysone word onderskei deur ‘n enkele swak-gesorteerde gruislaag en is oorwegende opwaarts fynerwordend. Die strandomgewing is goed verteenwordige en bestaan uit matig tot goedgesorteerde medium- tot fynkorrelrige sand. Die grootste mineraal-diversiteit kom voor in die subgety- en strandomgewings en die gemiddelde TSM vir hierdie eenhede is hoër as 35%. As gevolg van algemene erosie kom die +30m eenheid sporadies voor. Die aflandige omgeving is herken deur fyn kleierige of slikkerige sedimente met hoe konsentrasies gloukoniet en organiese materiaal. Die subgetysone omgewing is gekenmerk deur verskeie gruislae wat almal opwaarts fynwordend is. Altwee die subgety- en strandomgewings het hoer feldspar konsentrasies as die +50m eenhede. Die gemiddelde THM vir hierdie enhede is minder as 3%. Die eolitiese eenheid, bestaan uit verskeie duidelik-onderskeibare eenhede, beslaan die totale lengte van die studiegebied en word kenmerk deur uitgebreide kalkreet en rooi-laag horisonne. Kleurverskille in die andersins homogene eenheid kan verklaar word in terme van lae swaarmineraal konsentrasies en/of as gevolg wan verskillende grade van in situ verwering en sementering. Die eenheid bestaan uitsluitlik uit fyntot medium-korrelrige sand en het ‘n gemiddelde TSM konsentrasie van 9%. Die eenheid bestaan uit meer as een generasie eoliese sand en maak deel uit van ‘n eoliese vervoersisteem wat sand vanaf die strand na die binneland vervoer het. Die oudste sande in hierdie eenheid is gekorreleer met die Laat Mioseen Prospect Hill Formasie terwyl die meer onlangse geelduin sand vergelyk word met die Pleistoseen Springbokfontein Formasie. By Geelwal Karoo is slegs die +50m eenhede beskou as economies van belang. Die gemiddelde TSM van hierdie swaarmineraal-ertsligaam is bereken op 40% met ‘n verwagte 150 duisend ton Ti-draende material van die opeenvolging. Die relatiewe klein volume swaarminerale en uitgebreide sementering het tot gevolg dat dit ‘n minder aanloklike proposisie is as die aanliggende Namakwa Sands aanleg.
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24

Gungor, Kazim. "Production Of Heavy-media-quality Magnetite Concentrate From Kesikkopru Iron Ore Tailings." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611830/index.pdf.

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ABSTRACT PRODUCTION OF HEAVY-MEDIA-QUALITY MAGNETITE CONCENTRATE FROM KESiKKÖ
PRÜ
IRON ORE TAILINGS Gü
ngö
r, Kazim M. Sc. Department of Mining Engineering Supervisor: Prof. Dr. M. Ü
mit Atalay May 2010, 91 pages The aim of this research was to investigate the possibility of the production of a magnetite concentrate which is suitable for preparation of heavy media from iron ore tailings of Gü
ncem Mining Company magnetic separation facility. During the study, three different tailings named as low grade, medium grade and high grade with 5.91 % Fe3O4, 19.06 % Fe3O4 and 37.06 % Fe3O4, respectively, were used. Mineralogical analyses of test samples showed that magnetite and hematite were the major ore minerals while pyrite and chalcopyrite were found in trace amounts. Actimolite, tremolite, epidote, chlorite, quartz, calcite, and dolomite were the gangue minerals. The effects of feed particle size and applied magnetic field intensity on the Fe3O4 grade and recovery of concentrate were examined throughout magnetic concentration tests. The highest grade magnetite concentrate with 79.98% Fe3O4 content was obtained with 65.42% recovery from 100% -75 micron size feed at 1000 Gauss magnetic field intensity from high grade tailing.
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25

Bernier, Marc A. "Geomorphology and shallow overburden elemental and heavy mineral studies in southwestern Gaspésie, Quebec - possible aids to gold exploration." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61981.

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26

Thomas, Alice. "Paleocene strata of the London Basin : an integrated analysis of grain-size, heavy mineral and tourmaline geochemistry characteristics." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432333.

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27

Van, Der Westhuizen Asriel. "Provenance of alluvial diamonds in Southern Africa : a morphological and mineral chemistry study of diamonds and related heavy minerals from the Vaalorange system and the West Coast." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20155.

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Thesis (PhD)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The discovery of lucrative diamond deposits along the west coast of Southern Africa about 1200 kilometres from the Kimberley region during the period 1908 to 1927, gave rise to a number of different theories with respect to their possible provenance. These included the transportation of diamonds from unknown sources in southern Namibia by south-flowing rivers, hidden on- and off-shore kimberlites along the coast, and transportation by west-bound rivers from the hinterland. Subsequent research has shown that the latter is the only plausible theory. The discovery of marine and coastal diamond deposits as far south as the Olifants River estuary showed that the Vaal-Orange drainage in its current form could not have been the only conduit for diamonds to the coast, and the drainage evolution of southern Africa was interpreted as comprising essentially the following two main palaeo-fluvial systems active in the formation of the world's only known diamond mega-placer deposit:  The Karoo River with its headwaters similar to those of the modern Orange and Vaal Rivers and entering the Atlantic Ocean via the present-day Olifants River;  The Kalahari River that drained southern Botswana and followed the route of the modern-day Molopo River, entering the Atlantic Ocean in the vicinity of the present Orange River mouth. An important shortcoming of the above model is that it could not account for the fact that diamond distribution along the west coast shows a marked increase in grade and average stone size at the estuaries of all the major rivers draining from the escarpment to the Atlantic between the Olifants and the Orange Rivers. The presence of fluvial diamond deposits along the courses of the Buffels, Swartlintjies, Spoeg, Horees and Groen Rivers confirms that the increased grade and diamond size at their estuaries is not a function of large bays and rougher bottom topography associated with the rivers, although these could have contributed to this phenomenon. This proves that the catchments of the rivers between the Olifants and Orange Rivers also had access to diamondiferous debris, although they were not in contact with these two major drainages. A number of researchers proposed that diamonds liberated from pre-Karoo kimberlites were moved from their primary hosts to the south-western parts of the subcontinent by Dwyka glacials. From the above it is clear that nearly a century after the discovery of diamonds along the west coast of southern Africa consensus regarding their origin had not been reached. The aim of this study was therefore to establish a model explaining the most likely sources and distribution history of the more important alluvial diamond deposits in southern Africa. The methodology comprised a study of 1878 diamonds collected from 25 alluvial and two kimberlitic sources for comparison with known similar data from 12 kimberlitic populations in southern Africa. The diamond study was supplemented by a study of sedimentary clasts from bulk gravel samples taken along the Middle and Lower Orange River as well as Scanning Electron-microscope (SEM) Analyses of garnet grains and zircon geochronology. The evidence from the study does not support the postulated existence of a former Karoo River. The surface features of diamonds, notably brown spots indicating – in the context of southern Africa - liberation from pre-Karoo kimberlites, as well as the results of Fourier Transform Infrared analyses revealed that the populations at Kwaggaskop along the Sout River, previously considered an erosion remnant of the Lower Karoo River and those occurring south of Brandvlei and Van Wyksvlei in the valley of the Sak River, previously considered to have been reworked from the Middle Karoo River, differ profoundly from each other. In addition, the surface feature studies and Fourier Transform Infrared Analyses clearly show major distinctions between the diamond populations from the Sout River-Olifants River estuary and those from the Kimberley kimberlite province which was said to have supplied diamonds in large quantities to the Olifants River estuary via the postulated Karoo River. Furthermore the idea of a palaeo-Gamoep River playing a significant role in the transportation of diamonds to the west coast is favoured by the presence of brown-spotted diamonds and diamonds with Platelet Preservation Indices revealing severe platelet destruction that could be traced through Bosluispan in the Koa River valley, the Buffels River valley, the Buffels River estuary and to the shallow marine environment north of the Buffels River. Zircon geochronology confirmed the role of the Orange River in the denudation of the sub-continent. With respect to the drainage evolution and diamond distribution in southern Africa the results of this study indicate a complex diamond dispersal model that differs in some respects from prevailing theories. It shows that diamonds liberated from pre- Karoo kimberlites in the north-eastern part of the sub-continent were initially moved in a south-westerly direction by pre-Karoo drainages, then by Dwyka glaciers and ice sheets. Ultimately, after liberation from exhumed glacial and fluvial deposits and together with diamonds subsequently liberated from Jurassic and Cretaceous kimberlites, Cretaceous and younger drainages provided the transport toward the Atlantic Ocean where the diamonds were concentrated along shorelines and in bedrock trap sites. Significant quantities did not reach the coast, but were locked up in fluvial sediments in erosion remnants like terraces, karstic depressions and other segments of palaeo-channels along the way. The presence of diamonds with FTIR characteristics reminiscent of those from Orapa and Jwaneng in the Orange River deposits as well as in a raised marine terrace in southern Namaqualand and in marine deposits north of Concession 12A, also negates the possible existence of a palaeo-Kalahari River, unless it was a very young system that did not interrupt the south-bound dispersal of Botswana diamonds during the Late Oligocene-Early Miocene. The study also included microscopic examination of a parcel of diamonds from the enigmatic Skeleton Coast deposits, north-western Namibia. These results confirmed the conclusion based on geological and geomorphic grounds that these diamonds cannot be linked to the Oranjemund deposits, while their surface features showed that pre-Karoo sources comprise the most likely provenance for the Skeleton Coast diamonds. Thus the combination of FTIR analyses and surface feature studies of diamonds, zircon geochronology and SEM analyses of garnets allowed the formulation of a revised model for the distribution of alluvial diamonds and the drainage history of the sub-continent since the Middle Cretaceous, while the study of sedimentary clasts confirmed the repeated occurrence of high energy fluvial conditions – especially evident in the palaeo-Orange River sediments – that contributed to the high percentage of gem stones in the surviving alluvial diamond populations due to the destruction of poor quality diamonds.
AFRIKAANSE OPSOMMING: Die ontdekking van ryk alluviale diamantafsettings aan die suider-Afrikaanse weskus, meer as 1200 kilometer van die Kimberley-omgewing af tussen 1908 en 1927, het 'n aantal teorieë omtrent moontlike provenansgebiede vir hierdie afsettings tot gevolg gehad. Dit het gewissel van die suidwaartse vervoer van diamante vanaf bronne in suidelike Namibië, diamantdraende kimberliete in die kusvlaktes of op die vastelandstoep onder huidige seevlak, tot die vervoer van diamante deur weswaarts-vloeiende riviere vanuit die binneland. Geen ontdekkings wat eersgenoemde teorie kon ondersteun is in Namibië gemaak nie. Verder, namate meer gevorderde navorsingsresultate aan die lig gekom het, het dit duidelik geword dat kimberliete wat weg van 'n antieke kraton geleë is, grootliks sonder diamante is, en gevolglik het die idee van nabygeleë diamantdraende kimberliete in die kusvlakte of op die seebodem as bron, onaanvaarbaar geword. Grootskaalse wes- tot suidweswaartse vervoer van diamante het gevolglik die enigste aanvaarbare alternatief gebied. Die ontdekkiing van aan- en aflandige mariene afsettings tot so ver as suid van die Olifantrsrivier het getoon dat die Vaal-Oranjestelsel in sy huidige vorm nie die enigste vervoerkanaal vir diamante na die weskus kon wees nie. Die dreineringsgeskiedenis van suidelike Afrika was gevolglik vertolk aan die hand van twee voorgestelde groot oer-rivierstelsels, naamlik: - Die Karoorivier met sy bolope naastenby soortgelyk aan dié van die moderne Oranje- en Vaalriviere, en wat langs die huidige Olifantsrivier uitgemond het; - Die Kalaharirivier wat die suide van Botswana gedreineer het, en min of meer die roete van die huidige Moloporivier gevolg het, met sy monding baie naby aan dié van die moderne Oranjerivier. 'n Belangrike tekortkoming in bogenoemde model is die feit dat dit nie 'n verduideliking bied vir die volgende feit nie: Diamant-produksiedata van die Suid-Afrikaanse weskus toon 'n skielike toename in graad (karaat per 100 ton) en gemiddelde steengrootte van diamante by die monding van al die belangrike riviere tussen die Olifants- en Oranjeriviere, wat vanaf die platorand na die Atlantiese Oseaan dreineer. Die feit dat fluviale diamantvoorkomste in die valleie van die Bufffels-, Swartlintjies-, Spoeg-, Horees- en Groenriviere aangetref word, bevestig dat hierdie verskynsel nie net aan die teenwoordigheid van kus-inhamme en ruwer vloertopografie wat met die riviermondings geassosiëer is, toegeskryf kan word nie, alhoewel dit wel „n bydrae tot hierdie waarneming kon maak. Dit bevestig dat hierdie riviere wel in hul opvang-gebiede ook toegang tot diamanthoudende puin gehad het, sonder enige kontak met die Olifants- of Oranjeriviere. 'n Aantal navorsers het die gedagte geopper dat diamante wat uit voor-Karoo kimberliete vrygestel was, deur bewegende ysplate en/of gletsers vanaf hul provenansgebiede na die suidweste van die subkontinent vervoer is. Uit die voorafgaande paragrawe is dit duidelik dat, ongeveer ʼn eeu ná die ontdekking van diamante langs die suider-Afrikaanse weskus, daar nog nie eenstemmigheid bereik is oor die oorsprong van hierdie diamante nie. Die doel van hierdie studie was gevolglik die daarstelling van „n model wat „n aanvaarbare verduideliking bied vir die verspreiding en afsetting van sommige voorkomste van spoeldiamante in suidelike Afrika soos tans waargeneem. Vir hierdie doel is 1878 diamante afkomstig vanuit 25 alluviale en twee kimberlietvoorkomste ondersoek. Die resultate is vergelyk met soortgelyke inligting wat bekend is vir diamantpopulasies vanuit 12 suider-Afrikaanse kimberliete. Die diamantstudie is aangevul met die ondersoek van spoelklippe vanuit gruismonsters wat langs die Middel- en Benede Oranjerivier versamel is asook Skanderings-elektron Mikroskoop-analises (SEM) van granaatkorrels en sirkoon-geokronologie. Die resultate van hierdie studie ondersteun nie die hipotese van „n eertydse Karoorivier nie. Die teenwoordigheid van bruin spikkels op diamante wat – in die konteks van die geologiese geskiedenis van suidelike Afrika – vrystelling vanuit vóór- Karoo kimberliete impliseer, asook die resultate van FTIR-analises dui op „n komplekse model wat „n alternatief bied vir bestaande sienswyses. Dit toon dat die diamantpopulasies by Kwaggaskop langs die Soutrivier wat veronderstel was om die Benede Karoorivier te verteenwoordig, en dié wat suid van Brandvlei en Van Wyksvlei in die vallei van die Sakrivier aangetref word en veronderstel was om afkomstig te wees uit die Middel Karoorivier, drasties van mekaar verskil. Dit openbaar ook beduidende verskille tussen die diamantpopulasies van die Olifantsriviermonding en dié van die Kimberley-omgewing waarvandaan die veronderstelde Karoorivier groot hoeveelhede diamante aan die Sout-Olifantsrivier sou gelewer het. Verder verskaf die teenwoordigheid van diamante met bruin spikkels en diamante met eienskappe wat toon dat hul stikstofplaatjies vernietig is, „n skakel tussen Bosluispan in die vallei van die Koarivier en die seegebied noord van die Buffelsrivier, via die Buffelsriviervallei en die Buffelsriviermonding, en hierdie feite ondersteun gevolglik eerder die voorstel dat groot hoeveelhede diamante deur die paleo-Gamoeprivier na die weskus vervoer is. Die teenwoordigheid van diamante met FTIR-kenmerke soortgelyk aan dié van Orapa en Jwaneng in die Mid-Oranje afsettings, 'n mariene terras in die suide van Namakwaland en in mariene konsessies noord van Seegebied 12A, opponeer ook die gedagte van 'n paleo-Kalaharirivier, tensy laasgenoemde 'n baie jong stelsel was wat nie die suidwaartse beweging van Botswana-diamante gedurende die Laat Oligoseen tot Vroeg Mioseen verhinder het nie. Die resultate van die sirkoon-geokronologie het die rol van die Oranjerivier in die afplatting van die subkontinent bevestig. Die volgende model tree uit bogenoemde waarnemings na vore: diamante wat in die noordooste van die subkontinent uit kimberliete met „n voor-Karoo inplasingsouderdom vrygestel is, is aanvanklik suidweswaarts vervoer deur voor-Karoo riviere. Daarna is die diamante deur gletsers en ysplate gedurende die Dwyka-tydperk, en uiteindelik ná vrystelling vanuit ontblote glasiale en paleo-fluviale afsettings tesame met diamante wat intussen vanuit Jura- en Krytouderom kimberliete vrygestel is, deur die dreineringstelsels in die Kryt-tydperk en later, verder suidweswaarts vervoer. Sommige het onderweg in fluviale sedimente (terrasse, karstholtes en ander reste van paleokanale) agtergebly, terwyl „n beduidende hoeveelheid tot in die Atlantiese Oseaan vervoer is waar hulle deur mariene prosesse in ou strandlyne en bodemrots opvangstrukture gekonsentreer is. Die studie het ook die mikroskopiese ondersoek van 'n pakkie diamante afkomstig vanuit die enigmatiese afsettings aan die noordelike Skedelkus van Namibië ingesluit. Op grond van geologiese en geomorfologiese getuienis word die afleiding gemaak dat die Skedelkusdiamante nie met die Oranjemund-afsettings verbind kan word nie, terwyl die mikroskopiese oppervlakteksture toon dat bronne met 'n voor-Karoo inplasingsouderdom die mees waarskynlike provenans vir hierdie diamante is. Die kombinasie van FTIR-analises en oppervlaktekstuur-studies van diamante, sirkoongeokronologie en SEM-analises van granate het die formulering van „n hersiene model vir die subkontinent se dreineringsgeskiedenis sedert die Middel-Kryttydperk en diamantverspreiding moontlik gemaak terwyl die studie van sedimentêre klaste getoon het dat hoë-energietoestande, waardeur diamante van swak gehalte vernietig sou word, herhaaldelik voorgekom het, veral in die paleo-Oranjerivier. Die afleiding word gemaak dat hierdie aspek „n bydrae gelewer het tot die hoë persentasie juweelstene in die oorblywende alluviale diamantpopulasies.
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28

Bayuseno, Athanasius Priharyoto. "Mineral phases in raw and processed municipal waste incineration residues towards a chemical stabilisation and fixation of heavy metals /." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=98018777X.

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29

LESSA, MARCUS PAULO FOURNIER. "STUDY OF EFFECT FOR APLICATION TO A HUMIC COMPOUND OF MINERAL SOURCE ON HEAVY METALS PRESENTS IN SEWAGE SLUDGE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5924@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Com base no procedimento EPA-3050B, estudou-se o teor de metais (Cd, Cr, Cu, Ni, Pb, e Zn) em lodos de esgoto da CETESB. Foram analisadas duas amostras e os resultados obtidos foram (Cd =3,4 ; Cr =367,5 ; Cu =263,0 ; Ni=290,6 ; Pb =91,5 ; Zn =1324,9 mg/ kg) para primeira amostra e (Cd =3,0 ; Cr =332,2 ; Cu =190,5 ; Ni=274,6 ; Pb =82,5 ; Zn =1284,2 mg/ kg) para segunda amostra, resultados estes inferiores aos descritos pela CETESB para amostras de lodo da mesma estação de tratamento. Dada uma potencial utilização deste material como adubo agrícola, foi determinada a fração disponível destes metais. Com exceção do níquel (25%), uma fração pequena dos metais estudados encontra-se na forma assimilável pelas plantas (< 20%), com base no procedimento descrito pela EMBRAPASolos (extração com DTPA). Os efeitos de uma eventual utilização de composto húmico mineral (CHM) como aditivo ao lodo, visando uma redução na fração assimilável de metais, foi estudada em função da quantidade de CHM aplicado e do pH da solução final. Os resultados obtidos demonstraram que o CHM possui um poder de complexação para os metais semelhante ao do DTPA e que, sua aplicação ao lodo de esgoto, teria, na realidade um efeito de potencializar a fração disponível de certos metais como o zinco.
Based on the EPA-3050B procedure, the concentration of metals (Cd, Cr, Cu, Ni, Pb and Zn) in sludge source at CETESB studied. Two samples were analyzed and the results obtained were (Cd =3,4 ; Cr =367,5 ; Cu =263,0 ; Ni=290,6 ; Pb =91,5 ; Zn =1324,9 mg/ kg) and (Cd =3,0 ; Cr =332,2 ; Cu =190,5 ; Ni=274,6 ; Pb =82,5 ; Zn =1284,2 mg/ kg). These concentrations were below those descried by SABESP for sludge samples measured in the same treatment station. Due to the potential utilization of these materials as manure in agriculture, the disposal fraction of these metals was determined. Except nickel (25%), a little fraction of metals studied is assimilated by plants (< 20%), base on the procedure already descried by EMBRAPA- Solos (extraction with DTPA). The effect of an eventual utilization to humic mineral compound (HMC), as additive in sludge, aiming the reduction of the assimilated fraction of metals, were studied in function of both, the amount of HMC applied and the final pH of the solution. The results obtained showed that HMC has a complexation potential for metals similar to DTPA and that, its application in sludge, has in fact, a potential effect on the disposal fraction of metals such as zinc.
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30

Sinuka, Sikhulule. "Heavy mineral characterization and provenance interpretation of the Ecca Group of geological formations in Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/2911.

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The aim of the research focuses on characterizing heavy mineral assemblages and interpretation of the provenance of the Ecca Group of in the Eastern Cape Province, South Africa. In South Africa, the Ecca Group outcrops extensively in the Main Karoo Basin. Mudstone, siltstone, sandstone, minor conglomerate and coal are the major constituent lithologies within the group. For descriptive purposes, the Ecca is categorized into three different geographical areas: the southern area, the western and northwestern area and the northeastern area. Six of the sixteen geological formations, namely the Prince Albert, Whitehill, Collingham, Ripon, Fort Brown, Waterford and Koonap Formations are present in the study area and are best exposed in road cuttings. For purposes of comparison, the underlying Witteberg Group, the Dwyka (which has Formation status here), and the overlying Koonap Formation of the Beaufort Group, are included in the study. This study is motivated by the relatively little information that is available on the heavy minerals of the Ecca Group, and that research of this nature had not been undertaken in the study area before. Another contributing motivation was to determine whether heavy mineral assemblages could be used to identify formations of the Ecca Group and for correlating between different localities in accordance with studies done elsewhere. Additionally, diagnostic heavy mineral assemblages could aid with stratigraphic selection of future boreholes in the Ecca Group. Heavy minerals are natural provenance tracers because of their stable nature and hydrodynamic behaviour. They are both non-opaque and opaque, with apatite, epidote, garnet, rutile, staurolite, tourmaline and zircon being good examples of non-opaque grains while ilmenite and magnetite are the most common opaques. Heavies are either derived from stable minor accessory minerals or from abundant but unstable mafic components of the host rock. They are very useful in interpreting the provenance due to the fact that some minerals are diagnostic of certain source rocks. However, sediments are exposed to several factors (conditions) such as weathering, erosion, breakage due to abrasion, mixing and recycling during transportation from the source to the depositional area. This implies that there are parameters other than the parent lithology that determine their final composition.
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31

Ochoa, Felipe Lamus. "Análise de minerais pesados aplicada ao mapeamento geológico na Bacia Paraíba." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-08012011-003004/.

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O mapeamento geológico dos depósitos siliciclásticos aflorantes nas bacias marginais do nordeste brasileiro tem gerado um alto volume de designações estratigráficas ainda abertas às discussões. No intuito de subsidiar a resolução deste problema cartográfico foi escolhida a parte emersa da Bacia Paraíba, mais especificamente as sub-bacias Alhandra e Mirirí. Para isto foi realizada a caracterização mineralógica e petrográfica dos arenitos cenozóicos da Bacia Paraíba, com vistas a identificação de critérios discriminadores entre os diversos depósitos siliciclásticos aflorantes. Derivado deste processo é acrescentado o reconhecimento das áreas fontes desses arenitos e suas implicações na evolução do Cenozóico da Bacia Paraíba. Análises laboratoriais incluíram análises granulométricas, de minerais pesados e morfológica de grãos em 134 amostras de superfície e subsuperfície. Foram estudadas também 5 seções delgadas para testar a petrografia sedimentar como ferramenta no auxílio do mapeamento geológico. A identificação dos minerais pesados transparentes foi feita através microscópio petrográfico, com quantificação dos principais minerais transparentes (100 grãos/lâmina), além de várias contagens independentes (100 grãos/lâmina) das relações transparentes/opacos, do par rutilo/zircão e sobre as formas e grau de arredondamento de zircão e turmalina. Em superfície foram mapeadas como unidades siliciclásticas de base para topo a Formação Barreiras (Mioceno), Depósitos Pós-Barreiras I (Neopleistoceno) e Depósitos Pós-Barreiras II (Holoceno). Em subsuperfície, o furo estudado atravessa toda seção cenozóica e mesozóica, inclusive as unidades basais da bacia, as formações Beberibe e Itamaracá. A mineralogia acessória é dominada por minerais opacos com porcentagens superiores a 60% em todas as unidades. Em toda sucessão cenozóica, as assembléias de minerais transparentes são muito homogêneas e apresentam como minerais principais zircão, turmalina, cianita e rutilo e, subordinadamente, estaurolita, andaluzita, topázio e anfibólios cálcicos. Ocorrem como traços sillimanita, epidoto, monazita e granada. Em subsuperfície, no entanto, na unidade basal é reportada a existência de granada como mineral principal. A análise de formas de zircão e turmalina permitiu diferenciar, tanto em superfície como em subsuperfície, os depósitos estudados. Em termos gerais, existe um maior grau de arredondamento das formas de zircão e turmalina na direção do topo das unidades. Os dados de petrografia, ainda que poucos, apontam diferenças texturais, composicionais e inclusive diagenéticas entre os arenitos aflorantes na bacia. Esta ferramenta mostrou-se promissora para a caracterização das unidades da bacia. A mineralogia acessória em superfície não permite diferenciar as unidades aflorantes, mas, em subsuperfície, mostra que a Formação Beberibe tem uma assinatura de granada que a caracteriza muito bem e permite concluir, de maneira categórica, que esta unidade não aflora na área estudada. Os resultados do estudo de formas em zircão e principalmente em turmalina permitem diferenciar as unidades aflorantes pelo grau de arredondamento dos grãos, o que evidencia uma reciclagem sedimentar inclusive das unidades cretáceas. Este dado é reproduzível em subsuperfície, onde as categorias euédricas concentram-se nas unidades basais. Assim, considera-se que as principais fontes para os depósitos cenozóicos são resultantes do retrabalhamento de unidades sedimentares preexistentes, e subordinadamente, de fontes primárias relacionadas às rochas metamórficas da Zona Transversal da Província Borborema.
The geologic mapping of siliciclastic deposits which outcrop in the marginals basins of Brazilian northeast have generated a high volume of stratigraphic designations that are opened to actual discussions. In order to solve this cartographic problem, the emerging part of the Paraiba basin was chosen, specifically the sub-basins of Alhandra and Mirirí. For this reason were realized the mineralogic and petrographic characterizations of the Cenozoic sands and sandstones of the Paraiba Basin, with the purpose of identifying the discriminating criteria between the diverse siliciclastic deposits. Additionally were realized the recognition of the sandstones´ source areas and its implications in the evolution of the Paraíba Basin in the Cenozoic times. The laboratory analysis included heavy minerals, granulometric, morphology from grains in 134 surface and subsurface samples. Five thin sections were studied to testify the sedimentary petrography as a tool for geological mapping. The identify of heavy minerals was done under petrographic microscope for species descriptions, with counting of 100 grains per slide. Several independent counts (100 grains/slide) of the ratio transparent/opaque, the rutile/zircon index and shape and grain roundness of the zircon and tourmaline were also done. On the geological mapping, the siliciclastic units were considered, from the base to the top, Barreiras Formation (Miocene), deposits Post-Barreiras I (Neopleistocene) and deposits Post-Barreiras II (Holocene). On subsurface, the drill hole studied crosses through the whole Cenozoic and Mesozoic stratigraphy of the basin, including the basal units (Beberibe and Itamaracá formations). The accessory mineralogy is dominated by opaque heavy minerals with higher percentages than 60% in all units. In the whole Cenozoic succession, the assembly of transparent heavy minerals is very homogeneous and is essentially composed by zircon, tourmaline, kyanite and rutile, containing also staurolite, andalusite, topaz and calcic amphibole subordinately. Sillimanite, epidote, monazite and garnet occur as a trace minerals. Otherwise, on subsurface, garnet is reported as a principal mineral in the basal unit. The analysis of zircon and tourmalines shapes allowed to distinguish all the studied deposits. In general, the grade of roundness in grains of zircon and tourmaline increases to the top of succession. The petrografic data showed textural, compositional and diagenetic differences between the cropping out sands - sandstones of the basin. This tool seemed to be a promising to characterize the stratigraphic units of Paraíba Basin. The accessory mineralogy permitted to distinguish the Beberibe Formation, which is well characterized by the presence of garnet. On the other hand, the absence of garnet in the described sandstones let to conclude the Beberibe Formation not exposed in the mapped area. The data from shape studies in grains of zircon and tourmaline allowed to differentiate the cropping out units by the roundness grade, evidencing a sedimentary recycling, including the Cretaceous units. This data is reproducible on subsurface samples where the euedrical categories are concentrated on the basal units. At last, the main sources of the Cenozoic deposits are considered to be reworked preexistence sedimentary units, and subordinately, the primary sources comprise the metamorphic rocks from Transversal Zone of Borborema Province.
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32

Coddington, Kacee. "The role of heavy minerals in the thermal maturation of the woodford shale, Anadarko Basin, Oklahoma." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/16941.

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Master of Science
Department of Geology
Matthew W. Totten
Shales are generally regarded as organic rich source and seal rocks that are unworthy of the amount of research that has been given to their coarser-grained counterparts, even though shales comprise nearly two-thirds of Earth’s sedimentary record (Potter et al., 1980). The Woodford Shale is acknowledged as a prolific source rock across much of Oklahoma and the midcontinent (Lambert, 1990). Up to 8% world's original hydrocarbon reserves are estimated to have been sourced by the Woodford and its equivalents (Fritz et al., 1991). Study of the heavy-mineral fraction in sedimentary rocks is important because it can indicate provenance and some of the diagenetic changes that occur in sedimentary rocks. This goal of this study is to describe the heavy-mineral fraction of eight Woodford Shale samples from the Greater Anadarko Basin of Oklahoma, and determine whether or not the constituents that make up the heavy-mineral fraction have any impact on the process of thermal maturity within source rocks. This study utilizes a method designed to efficiently separate the heavy-mineral fraction of shale samples. Scanning electron microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) are used in this study to identify mineralogy, grain size, composition and shape. Mineral distributions in the samples have been determined from point counting. The weight percent of the heavy mineral fraction was calculated for each of the samples. This was then compared to their location within the basin, depth, vitrinite reflectance and total organic carbon (TOC). We found that as the thermal maturity increase, the weight percent of heavy minerals also increases. Pyrite (FeS₂) was the most abundant heavy mineral found in the Woodford samples used in this study. From analyzing the different forms of pyrite, it was found that as thermal maturity increases, framboidal pyrite alters to euhedral pyrite.
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33

Kishimoto, Angelica Mariko Naka. "Hydraulic Performance and Chemical Compatibility of Mineral Barriers to Mitigate Natural Contamination from Excavated Rocks." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188879.

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34

Boekhoud, Karina. "Risk and reliability of exploration methods used to define a heavy mineral sand deposit in Kwa-Zulu Natal, South Africa." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/25876.

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The objective of the treatise is to review the sample methodology and the exploration methods at a heavy mineral sands deposit. The level of confidence and the risk associated with the resource calculations will be established based on the sample methodology. Two drilling methods used at Hillendale are compared statistically and visually. It is clear from the comparison that the Wallis Aircore (WAC) method is significantly better than the Reverse Circulation (RCN) method. This is evident also when comparing results of the two methods with the recovery from the mined out areas. The WAC drilling method reduces the risk of downhole contamination due to the change in the drilling method allowing air to be forced back in an inner tube after the sample is collected compared to the air blowout of the RCN method. The WAC method reduces the variability introduced in the sample collection as compared to the RCN method. The average calculated value (for total heavy minerals (THM) and Ilmenite) of the global population for the two methods is similar. The reduced variability in the sample population of the WAC method results in a lower population being required for the confidence interval about the mean at a 95% confidence level. The lower number of required samples results in a lowering of project cost. Blockmodels created from the two drilling methods are compared statistically (mode, median, standard deviation). The global mean of the input data compares well with the global mean of the estimated blockmodel. In reconciling the resource blockmodels with actual production data, the variability as introduced by the RCN drilling method is clear. The WAC drilling information produces a blockmodel with an acceptable level of variance (deviation of the geological model from the actual values obtained during mining) as defined by Hillendale mine management of less than 10%. This is determined by reconciling the estimated geological blockmodel for a specific mined out area against the actual tonnages and plant recovery values achieved in the same area. Ultimately, because the drill spacing is standard in the mining operation under study, the required confidence in the mean might not be achieved by either of the two drilling methods in certain portions of the mine, but the results from the WAC method will be closer to the reality than the RCN method with the same number of drillholes. Three main risks are identified in the sample methodology; they have a high probability to occur or have a high cost impact. The risk inherent in sampling and analysis is the most important of the risks identified in this study. The risk can be effectively reduced by implementing a quality assurance and quality control programme (QAQC). The other high risks are introduced by the drilling method and drillhole spacing. The risk can be reduced by continuous improvement and keeping up to date with new developments in the industry such as improved drilling techniques and by improved knowledge of the ore-body. The knowledge will help in understanding the risk - It may become clear in the text how this can reduce the risk. In conclusion, the improvement and implementation of systems such as improved drilling technique and quality assurance and quality control programmes enables one to establish an acceptable confidence level in the resource calculation as well as reducing the inherent risk to an acceptable level for future decisions. Copyright
Dissertation (MSc)--University of Pretoria, 2012.
Geology
unrestricted
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35

Harris, Mark Anglin. "Some organic amendments for heavy metal toxicity, acidity and soil structure in acid-sulphate mine tailings /." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phh3148.pdf.

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36

Tavakkoli, Osgouei Yashar. "An Experimental Study On Steam Distillation Of Heavy Oils During Thermal Recovery." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615574/index.pdf.

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Thermal recovery methods are frequently used to enhance the production of heavy crude oils. Steam-based processes are the most economically popular and effective methods for heavy oil recovery for several decades. In general, there are various mechanisms over steam injection to enhance and have additional oil recovery. However, among these mechanisms, steam distillation plays pivotal role in the recovery of crude oil during thermal recovery process. In this study, an experimental investigation was carried out to investigate the role of various minerals present in both sandstone and carbonate formations as well as the effect of steam temperature on steam distillation process. Two different types of dead-heavy crude oils were tested in a batch autoclave reactor with 30 % water and the content of the reactor (crude oil, 10 % rock and mineral). The results were compared as the changes in the density, viscosity and chemical composition (SARA and TPH analyses) of heavy crude oil. Five different mineral types (bentonite, sepiolite, kaolinite, illite and zeolite) were added into the original crude oil and reservoir rocks to observe their effects on the rheological and compositional changes during steam distillation process. Analysis of the results of experiments with Camurlu and Bati Raman heavy crude oils in the presence of different minerals such as Bentonite, Zeolite, Illite, Sepiolite, and Kaolinite in both sandstone and limestone reservoir rocks indicate that steam distillation produces light end condensates which can be considered as solvent or condensate bank during steam flooding operation. It was also illustrated that minerals in reservoir formations perform the function of producing distilled light oil compounds, resulting in enhancement of heavy crude oils recovery in steam flooding. Measurements showed that the remaining oil after steam distillation has higher viscosity and density. On the other hand, the effect of steam distillation is more pronounced in limestone reservoirs compared to sandstone reservoirs for the given heavy crude oil and steam temperature. Among the five different minerals tested, kaolinite found to be the most effective mineral in terms of steam distillation.
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37

Van, Andel Tjeerd Hendrik. "Provenance, transport and deposition of Rhine sediments : a heavy mineral study on river sands from the drainage area of the Rhine /." Ann Arbor (Mich.) : UMI, 1995. http://catalogue.bnf.fr/ark:/12148/cb37462487r.

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38

Mobricci, Cassiano Augusto de Nadai [UNESP]. "Adubação mineral, esterco de curral e lodo de esgoto no desenvolvimento inicial do cafeeiro." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/86363.

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Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-27Bitstream added on 2014-06-13T19:07:32Z : No. of bitstreams: 1 mobricci_can_me_fca.pdf: 653879 bytes, checksum: e715f421035a5c18fd6084a839fdc6d7 (MD5)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
O lodo de esgoto (LE) é um resíduo do tratamento das águas servidas, sejam domésticas, industriais ou agroindustriais, contendo níveis de matéria orgânica, macro e micronutrientes fundamentais para a fertilidade do solo. O presente trabalho teve como objetivo estudar o comportamento de plantas de café, comparando a utilização de lodo de esgoto, esterco de curral curtido (EC) e adubação mineral, avaliando-se o desenvolvimento das plantas, alterações na fertilidade do solo e o estado nutricional das plantas, bem como o acúmulo de metais pesados que pudessem atingir concentrações fitotóxicas para o solo e às plantas manejadas com as diferentes doses de lodo de esgoto. O experimento foi instalado em vasos de 20 litros preenchidos com LATOSSOLO VERMELHO. Foi utilizado o cultivar de café Tupi, linhagem IAC 1669-33 como planta indicadora. Constituiu de nove tratamentos e oito repetições, totalizando 72 plantas. Foram avaliados a cada dois meses os parâmetros de altura das plantas e diâmetro da copa. Depois de 12 meses foi avaliada a composição química das folhas fisiologicamente maduras, visando determinar N, P, Ca, Mg, S, Cu, Fe, Mn e Zn e Mo e os metais pesados As, Cd, Cr, Hg, Pb, Ni e Se. No mesmo período foram retiradas amostras de solo das parcelas, onde quatro amostras simples foram homogeneizadas, secas ao ar e peneiradas para posteriormente ser retirada uma amostragem composta para se determinar os nutrientes. As médias das características foram avaliadas pelo quadro de análise de variância (ANAVA) e regressão linear múltipla e comparadas pelo Teste de Tukey a um nível de 5% de significância. Os resultados comprovam a eficiência do lodo de esgoto no fornecimento de nutrientes às plantas de café, principalmente, N, P, Ca, Mg, Mo, Cu, Zn e na redução da acidez ativa e potencial dos solos. A elevação do pH e o aumento dos teores de 2 matéria orgânica...
The sewage sludge is a residue of served water treatment (domestic, industrial or agoindustrial water), with organic material levels and basic macro and micronutrients for the soil fertility. This work had the aim of studying the behavior of coffee plants, comparing the sewage sludge, corral manure and mineral fertilization usage, evaluating the plants development, soil fertility alterations and plants nutritional state, as well the accumulation of heavy metal which could reach biotoxic concentrations for the soil and plants treated with the different doses of sewage sludge. The experiment had been installed in 20 liters vases filled with RED LATOSSOIL. It had been used Tupi Coffee, ancestry IAC 1669-33 as indicator plant. The experiment had been constituted of 9 treatments and 8 replications, totaling 72 plants. The biometrics parameters of plants had been evaluated in each 2 months, as plants height, cop diameter. After 12 months, the chemical compound of physiological mature leaves had been evaluated, aiming to determine N, P, Ca, Mg, S, Cu, Fe, Mn Zn, Mo and the heavy metals As, Cd, Cr, Hg, Ni, Pb and Se. In the same period, soil samples had been removed from the plots, in which 4 simple samples had been homogenized, dried in air and sifted, and later, compound samples had been removed to determine the nutrients. The averages of the characteristics had been evaluated by the variation analysis chart (ANAVA) and multiple linear regression and compared by the Tukey Test, with 5% significance level. The results prove the efficiency of sewage sludge to provide nutrients to coffee plants, mainly N, P, Ca, Mg, Mo, Cu, Zn and reduce the active and potential acidity of soils. The pH elevation and organic material tenors increase provided by the sewage sludge and corral manure treatments conduced a smaller mobility of heavy metals in soils and leaves, 4 not reaching critical levels to the environment or to the coffee plants.
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39

Brennan, Michael Brendan. "The genesis of ilmenite-rich heavy mineral deposits in the Bothaville/Delmas area, and an economic analysis of titanium, with particular reference to the Dwarsfontein deposit, Delmas district." Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1005561.

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A number of ilmenite-rich heavy mineral deposits occur along the northern margin of the intracratonic Karoo basin, and are hosted by the fluvio-deltaic Middle Ecca Group. Coastal reworking of delta front sands within a regressive, microtidal shoreline may be considered as a depositional model for the development of the heavy mineral deposits. An economic analysis of titanium suggests long term positive demand, and sustained high prices for this commodity. An evaluation of the Dwarsfontein ilmenite-rich heavy mineral deposit, using available data, indicates how important it is for deposits of this type to be situated close to an upgrading plant or export harbour.
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40

Firme, Lucia Pittol. "Produção de madeira e elementos potencialmente tóxicos no sistema solo-eucalipto tratado com lodo de esgoto." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-11122009-152455/.

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O lodo de esgoto aplicado em sistemas florestais pode aumentar a produção de madeira e manter a sustentabilidade do ecossistema. Porém, faltam pesquisas para avaliar o aproveitamento dos nutrientes do lodo e para definir um manejo adequado para sua aplicação ao solo usando complementação via adubo mineral, sem causar prejuízos ao sistema solo-planta pelos elementos potencialmente tóxicos que podem estar presentes no lodo. O objetivo do presente tratabalho foi avaliar os efeitos das doses de lodo de esgoto e das doses de adubos nitrogenados e fosfatados sobre a produção de matéria seca e a produtividade de madeira, aos 43 meses após o plantio, e os teores de Cu, Fe, Mn, Zn, Cd, Cr, Ni e Pb no sistema solo-eucalipto-serapilheira. Um experimento foi conduzido em área comercial da Suzano, em Itatinga - SP, aplicando 4 doses de lodo (0; 7,7; 15,4 e 23,1 Mg ha-1, base seca), 4 doses de adubo nitrogenado (0; 46,9; 95,1 e 142 kg ha-1) e 4 doses de adubo fosfatado (0; 27,7; 55,9 e 84 kg ha-1, P2O5) em delineamento em blocos casualizados, em esquema fatorial 4x4x4 e com duas repetições. Devido ao baixo teor de potássio (K) no lodo, foi aplicado 175 kg ha-1 de K2O em todas as parcelas. Os teores dos elementos potencialmente tóxicos nas amostras de solo e planta foram determinados por ICP-MS (espectrometria de massa com plasma). Aos 4 e 34 meses após o plantio, as amostras de solo foram coletadas nas camadas de 0-0,10; 0,10-0,20 e 0,20-0,40 m de profundidade. Os elementos foram extraídos das amostras de solo por solução de DTPA e por digestão com ácidos (HNO3 + HCl) em microondas. Os elementos potencialmente tóxicos foram extraídos das amostras de folhas, aos 4 e 43 meses após o plantio, das amostras de lenho e casca e das amostras de folha e galho das árvores colhidas aos 43 meses, e das amostras de serapilheira, aos 46 meses após o plantio, pela digestão com ácidos (HNO3 + H2O2) em microondas. A altura e o diâmetro na altura do peito (DAP) das árvores foram medidos aos 43 meses após o plantio para determinar o volume de madeira com casca. A aplicação dos fertilizantes minerais nitrogenado e fosfatado não alterou os teores dos elementos potencialmente tóxicos no solo e na planta. Os teores de Cu, Fe, Mn, Zn, Cd, Cr, Ni e Pb no solo e na planta aumentaram com as doses de lodo aplicadas. Além disso, também o acúmulo dos elementos na biomassa total (lenho, casca, folha e galho) e na biomassa total de serapilheira aumentou em função das doses de lodo. A aplicação de lodo aumentou a produção de matéria seca de lenho, casca, folha e galho, e combinado ou não com adubo nitrogenado e, ou, fosfatado, aumentou o volume de madeira com casca de 139 a 177 m3 ha-1, em comparação ao adubo NPK que produziu 150 m3 ha-1. O lodo de esgoto não causou a contaminação do sistema solo-planta. A dose 7,7 Mg ha-1 de lodo, recomendada pelo critério de N, reduziu a aplicação com adubo nitrogenado e fosfatado em 100 e 66 %, respectivamente, associado com aumento de 8 % no volume de madeira com casca, em relação ao adubo NPK convencional
The application of sewage sludge in forest systems can increase wood production and maintain the sustainability of ecosystems. However, researches are lacking to evaluate the potential of nutrients occurring in the sewage sludge and to define adequate mangement systems for its application on soil using mineral fertilizer supplements without causing harmful effects on the soil-plant system due to potential toxic elements which may occur in this residue. The objective of this study was to evaluate the effects of different sewage sludge doses and different doses of nitrogen and phophate mineral fertilizers on dry matter content and wood production 43 months after planting as well as on the Cu, Fe, Mn, Zn, Cd, Cr, Ni e Pb contents in the soil-eucalyptus-litter system. An experiment was carried out in a commercial area of Suzano, Itatinga, SP by applying 4 doses of sewage sludge (0; 7,7; 15,4 e 23,1 Mg ha-1, dry base), 4 doses of nitrogen fertilizer (0; 46,9; 95,1 e 142 kg ha-1), 4 doses of phosphate fertilizer (0; 27,7; 55,9 e 84 kg ha-1 P2O5), in a randomized block design, in factorial design of 4x4x4, with two repetitions. Due to low contents of potassium (K) in the sewage sludge, 175 kg ha-1 of K2O was applied at all plots. The contents of potential toxic elements in soil and plant samples were determined by using by ICP-MS (inductively coupled plasma mass spectrometry) After 4 and 34 months of planting, soil samples were taken in the 0-0,1; 0,1-0,2 e 0,2-0,4 m layers. The elements were extracted from soil samples by using DTPA solution and digested with acids (HNO3 + HCL) in a microwave. Potential toxic elements in leaf samples, after 4 and 43 months of planting, in wood and bark samples and in leaf and branch samples of felled trees after 43 months, as well as in litter samples after 46 months were digested with acids (HNO3 + H2O2) in a microwave. The height and the diameter at breast height (DBH) of the trees were measured after 43 months of planting to determine the volume of wood with bark. After application of mineral nitrogen and phosphate fertilizer no changes in the contents of potential toxic elements in soil and plant were found. However, the contents of Cu, Fe, Mn, Zn, Cd, Cr, Ni and Pb in soil and plant increased with increasing doses of sewage sludge applied. Moreover, also the accumulation of elements in the total biomass (wood, bark, leaves and branches) and in the litter fraction increased as a function of the doses. The application of sewage sludge increased the dry matter content of wood, bark, leaves and branches and, combined with or without nitrogen fertilizer e/ou phosphate fertilizer, increased the volume of wood with bark from 139 to 177 m3 ha-1, compared to conventional NPK fertilization with a production of 150 m3 ha-1. Sewage slugde application did not cause a contamination of the soil-plant system. A dose of 7,7 Mg ha-1 of sewage sludge reduced the application of mineral nitrogen and phosphate fertilizer about 100% and 66%, respectively, associated with an increase of 8 % of the volume of wood and bark compared to conventional NPK fertilization
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41

Mobricci, Cassiano Augusto de Nadai 1977. "Adubação mineral, esterco de curral e lodo de esgoto no desenvolvimento inicial do cafeeiro /." Botucatu : [s.n.], 2006. http://hdl.handle.net/11449/86363.

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Orientador: Hélio Grassi Filho
Banca: Leandro Borges Lemos
Banca: Carlos Henrique dos Santos
Resumo: O lodo de esgoto (LE) é um resíduo do tratamento das águas servidas, sejam domésticas, industriais ou agroindustriais, contendo níveis de matéria orgânica, macro e micronutrientes fundamentais para a fertilidade do solo. O presente trabalho teve como objetivo estudar o comportamento de plantas de café, comparando a utilização de lodo de esgoto, esterco de curral curtido (EC) e adubação mineral, avaliando-se o desenvolvimento das plantas, alterações na fertilidade do solo e o estado nutricional das plantas, bem como o acúmulo de metais pesados que pudessem atingir concentrações fitotóxicas para o solo e às plantas manejadas com as diferentes doses de lodo de esgoto. O experimento foi instalado em vasos de 20 litros preenchidos com LATOSSOLO VERMELHO. Foi utilizado o cultivar de café Tupi, linhagem IAC 1669-33 como planta indicadora. Constituiu de nove tratamentos e oito repetições, totalizando 72 plantas. Foram avaliados a cada dois meses os parâmetros de altura das plantas e diâmetro da copa. Depois de 12 meses foi avaliada a composição química das folhas fisiologicamente maduras, visando determinar N, P, Ca, Mg, S, Cu, Fe, Mn e Zn e Mo e os metais pesados As, Cd, Cr, Hg, Pb, Ni e Se. No mesmo período foram retiradas amostras de solo das parcelas, onde quatro amostras simples foram homogeneizadas, secas ao ar e peneiradas para posteriormente ser retirada uma amostragem composta para se determinar os nutrientes. As médias das características foram avaliadas pelo quadro de análise de variância (ANAVA) e regressão linear múltipla e comparadas pelo Teste de Tukey a um nível de 5% de significância. Os resultados comprovam a eficiência do lodo de esgoto no fornecimento de nutrientes às plantas de café, principalmente, N, P, Ca, Mg, Mo, Cu, Zn e na redução da acidez ativa e potencial dos solos. A elevação do pH e o aumento dos teores de 2 matéria orgânica... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The sewage sludge is a residue of served water treatment (domestic, industrial or agoindustrial water), with organic material levels and basic macro and micronutrients for the soil fertility. This work had the aim of studying the behavior of coffee plants, comparing the sewage sludge, corral manure and mineral fertilization usage, evaluating the plants development, soil fertility alterations and plants nutritional state, as well the accumulation of heavy metal which could reach biotoxic concentrations for the soil and plants treated with the different doses of sewage sludge. The experiment had been installed in 20 liters vases filled with RED LATOSSOIL. It had been used Tupi Coffee, ancestry IAC 1669-33 as indicator plant. The experiment had been constituted of 9 treatments and 8 replications, totaling 72 plants. The biometrics parameters of plants had been evaluated in each 2 months, as plants height, cop diameter. After 12 months, the chemical compound of physiological mature leaves had been evaluated, aiming to determine N, P, Ca, Mg, S, Cu, Fe, Mn Zn, Mo and the heavy metals As, Cd, Cr, Hg, Ni, Pb and Se. In the same period, soil samples had been removed from the plots, in which 4 simple samples had been homogenized, dried in air and sifted, and later, compound samples had been removed to determine the nutrients. The averages of the characteristics had been evaluated by the variation analysis chart (ANAVA) and multiple linear regression and compared by the Tukey Test, with 5% significance level. The results prove the efficiency of sewage sludge to provide nutrients to coffee plants, mainly N, P, Ca, Mg, Mo, Cu, Zn and reduce the active and potential acidity of soils. The pH elevation and organic material tenors increase provided by the sewage sludge and corral manure treatments conduced a smaller mobility of heavy metals in soils and leaves, 4 not reaching critical levels to the environment or to the coffee plants.
Mestre
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42

Franco, Ademir. "Aplicação de lodo de esgoto em cana-planta como fonte de nitrogênio e fósforo e seu impacto ambiental." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/64/64134/tde-18122009-111046/.

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O potencial do uso agrícola do lodo de esgoto decorre da presença de matéria orgânica e de nutrientes de plantas, principalmente o nitrogênio e fósforo, constituintes de maior valor agrícola no lodo. No entanto, faltam pesquisas para adequar as doses complementares de adubos nitrogenado e fosfatado a serem aplicadas em área agrícola tratada com lodo. Não obstante aos benefícios evidentes da aplicação do lodo na agricultura, elementos potencialmente tóxicos (Ag, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Th, Tl, U, V, e Zn) podem estar presentes no lodo de esgoto e contaminar o ambiente e a cadeia alimentar. O objetivo do presente trabalho foi avaliar os efeitos de doses de lodo de esgoto e de adubos minerais nitrogenado e fosfatado sobre as propriedades químicas do solo e a produtividade, características tecnológicas, estado nutricional e elementos potencialmente tóxicos, como efeito direto, na cana-planta e, como efeito residual, na primeira soqueira. Foi instalado um experimento em área comercial de cultivo de cana-planta (no município de Capivari, Estado de São Paulo, Brasil), em setembro de 2005. Foram aplicadas quatro doses de lodo (0; 3,6; 7,2 e 10,8 t ha-1, base seca), de N (0, 30, 60 e 90 kg ha-1) e de P2O5 (0, 60, 120 e 180 kg ha-1), correspondentes a 0, 33, 66 e 100% do N e P recomendados para a cultura. (as dose de lodo foram calculadas com base no teor do N-disponível), em delineamento em blocos casualizados, em esquema fatorial, com duas repetições. Para avaliar o efeito residual do lodo, após a colheita da cana-planta, foram aplicados 120 kg ha-1 de N e 140 kg ha-1 de K2O, em todas as parcelas. A cana-planta foi colhida em setembro de 2006 e a cana-soca em outubro de 2007. A aplicação dos fertilizantes minerais nitrogenado e fosfatado alterou somente as variáveis de produtividade e teores de N e P no solo e na planta. Para as demais variáveis, em alguns casos, foi observado o efeito do lodo. A aplicação de lodo no plantio da cana, combinado ou não com adubo nitrogenado e/ou fosfatado, aumentou a produtividade de colmos de 84 a 118 t ha-1, sem alterar a qualidade tecnológica da cana-de-açúcar, em relação ao adubo NPK convencional, que produziu 91 t ha-1 de colmo. A aplicação do lodo de esgoto resultou em incremento no teor de C-orgânico, na camada de 0-0,2 m de profundidade. O tempo de persistência do lodo no solo foi superior a 360 dias. Os teores de P no solo aumentaram com a aplicação do lodo e do adubo fosfatado, passando de classe muito baixa para média. O fornecimento de N pelo lodo resultou em aumento do teor de N no solo e na planta. A aplicação do lodo resultou em aporte, em torno de três vezes a quantidade de Cd no solo anterior a aplicação do lodo, para o Zn, o aporte foi de 76%, o que refletiu em maiores teores dos elementos no solo e na partes da planta analisadas (folha, colmo e caldo). Foi observado aumento nos teores de Ag, Cd, Cu, Hg, Ni, V e Zn no solo e na cana-planta, e, como efeito residual, aumento nos teores de Ag, Cd, Hg e Zn no solo e na cana-soca com as doses de lodo. Concluiu-se que a aplicação do lodo de esgoto, na cana-planta, dentro dos critérios técnicos (Resolução CONAMA nº 375) promove: como efeito direto na cana-planta, melhoria da fertilidade do solo, pelo aumento no teor de C-orgânico e fornecimento de N e P; redução no uso de fertilizantes nitrogenado e fosfatado, respectivamente, em 100% e 30%; aumento da produtividade de colmo e de açúcar, sem alterar a qualidade tecnológica; e como efeito residual, na cana-soca, o aumento da produtividade de colmos em 12% e da produtividade de açúcar em até 11%; e não contaminação do ambiente canavieiro, solo e planta, por Ag, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Th, Tl, U, V, e Zn
The potential agricultural use of the sewage sludge is due to their organic matter and nutrients contents, mainly nitrogen and phosphorus, the most important constituint. However, there is a lack of research to adequate the nitrogen and phosphate fertilizer doses to be applied in agricultural fields treated with this residue. Despite the evident benefits of the agricultural use of the sludge in the sugarcane crop, potential toxic elements (Ag, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Th, Tl, U, V and Zn) can be in the sewage sludge and contaminate the environment and the food chain. The objective of this study was to evaluate the effect of levels of sewage sludge and mineral sources of nitrogen and phosphorus in the chemical proprieties, productivity and technological characteristics, nutritional state and potential toxic elements, as direct effect, in cane-plant and, as residual effect, in the first cane-ratoon. The field study was initiated in September 2005, in a commercial production area planted with cane-plant (municipality of Capivari, São Paulo State, Brazil). Four doses of sewage sludge (0, 3.6, 7.2 and 10.8 t ha-1, dry base), of nitrogen (0, 30, 60 and 90 kg ha-1) and of P2O5 (0, 60, 120 and 180 kg ha-1), corresponding to 0, 33, 66 and 100 % of N and P recommended to crop (N doses from sludge was calculated based in N-available), were applied in randomized block design, in factorial design, with two replications. To evaluate the residual effect of the sludge, after the harvest of cane-plant, 120 kg ha-1 of N and 140 kg ha-1 of K2O were applied in all the parcels. The cane-plant cane was harvested on September 2006 and the cane-ratoon was harvested on October 2007. The nitrogen and phosphorus fertilizer only modified the productivity and N and P contents in the soil and plants. In some cases, there were sludge effects. The sludge application in the cane planting combined with or without nitrogen and/or phosphate fertilizer, increased the stalk yield from 84 up to 122 t ha-1, with no alteration on the technological quality of the sugarcane, when compared with the application of NPK fertilizer alone, which stalk yield was 91 t ha-1. It was observed an increment of the C-organic content up to 0-0.2 m depth. The period of the sludge in the soil was more than 360 days. The P contents in soil increased with the application of both, sludge and the phosphorus fertilizer, changing from the very low to middle class. The sludge resulted in an increase of the N concentration, in three times the Cd background and 76% of Zn background in the soil, increasing their plant contents (leaf, stalk and juice). The sludges doses increased the Ag, Cd, Cu, Hg, Ni, V and Zn in soil and cane-plant as direct effect and the Ag, Cd, Hg and Zn content in soil and cane-ratoon as residual effect. The agricultural use of sewage sludge in cane-plant crop, following the criteria (Resolução CONAMA n 375), resultes: as direct effect in cane-plant, improve the soil fertility due to the increase of C-organic content and N and P supplied; reduce the use of N and P mineral fertilizer in 100% and 30%, respectively; increment the stalk and sugar yield, without modifying the technologic quality; and as residual effect, the increment the stalk yield in 12% and sugar yield in 11%; in cane-ratoon; and no contamination of sugarcane environment, soil and plant, by Ag, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Th, Tl, U, V, e Zn
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43

Kahn, Henrique. "Caracterização e desenvolvimento de processo de beneficiamento do minério primário de Pitinga (AM) - criolita, estanho, zircônio, nióbio, ítrio e terras raras." Universidade de São Paulo, 1991. http://www.teses.usp.br/teses/disponiveis/3/3134/tde-20042017-091600/.

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Os estudos visando o aproveitamento dos minerais de interesse econômico associados ao Granito Madeira, Pitinga, AM, foram subdivididos em três etapas. A primeira etapa compreendeu a realização de estudos de caracterização tecnológica, com um detalhado estudo mineralógico enfocando a forma de ocorrência e granulometria de liberação dos minerais de interesse. Foi identificado pela primeira vez a presença de criolita, mineral raro, cujo valor agregado supera o conjunto de todos os demais minerais de interesse econômico. Verificou-se que a granulometria de liberação dos minerais pesados era muito distinta; valores de 80% são observados para a zirconita acumulada abaixo de 0,595 mm, para a cassiterita abaixo de 0,297 mm e para os minerais de nióbio abaixo de 0,149 mm. A segunda etapa compreendeu, essencialmente, a realização de estudos de desenvolvimento de processo de concentração dos minerais pesados, incluindo ensaios de concentração densitária e separações eletrostática e magnética. Foram estabelecidas as características dos concentrados passíveis de serem obtidos e suas respectivas recuperações metalúrgicas, bem como definido um fluxograma de beneficiamento a ser confirmado em escala piloto. A terceira etapa teve por enfoque principal o desenvolvimento de uma rota de processo para a concentração da criolita, a qual, embora ainda não otimizada, é sumariada a seguir: - deslamagem dos rejeitos da concentração densitária, seguido de flotação aniônica direta, mediante a utilização de \"tal oil\" como coletor e amido de milho e como processor; - remoagem do concentrado \"rougher\" a menos 0,074 mm, em circuito fechado com classificação, seguido de flotação reversa do concentrado \"rougher\" remoído, com coletor catiônico, Armacflote MIC-66 (marca Akzo); - descoleta do concentrado da flotação catiônica, seguido de flotação aniônica com sulfonato de petróleo, Aero 840 (marca Cyanamid), para a separação entre a criolita e os demais minerais de flúor portadores de cálcio; - separação magnética de alta intensidade via úmida, \"WHIMS\", do concentrado da última etapa de flotação (com 0,5% a 0,7% de Fe203), visando minimizar os teores de ferro; - lixiviação clorídrica do produto não-magnético, com a redução suplementar dos teores de ferro, atingindo valores de 0,16 a 0,20% de Fe203.
Studies at the Pitinga primary ore envolved three stages. The first one consisted of detailed mineralogical studies emphasizing the occurrence patterns and the degree of liberation of the minerals in the granitic ground ore. Cryolite in the Pitinga ore was then identified for the first time. The liberation sizes for heavy minerals are quite distinct; a liberation degree of 80% was observed for zircon accumulated under 0,595 mm for cassiterite under 0,297 mm and for niobium minerals under 0,149 mm. The second stage comprised essentially mineral dressing studies to concentrate the heavy minerals. Discontinuous gravity concentration, electrostatic and magnetic separation tests were performed to establish the characteristics of the mineral concentrates and their recoveries, as well as to define a plant flowsheet to be confirmed in continuous pilot plant tests. The definition of a mineral processing route for cryolite concentration was the main object of the last stage. The following sequence of procedures, to be further investigated, was established: - disliming of gravity concentration taillings, followed by direct anionic flotation of fluorine minerals, using tall oil as collector and starch as depressant; - regrinding of the rougher concentrate to minus 0,074 mm, in a closed circuit with classification, followed by reverse cationic flotation to remove silicates, with Armacflote MIC-66 (Akzo trade mark); - remotion of the cationic collector and subsequence anionic flotation with petroleum sulfonate as collector (Aero 840, Cyanamid trade mark), to separate cryolite from the other fluorine minerals and small amounts of silicates; - wet high intensity magnetic separation (WHIMS) on the obtained flotation concentrate; - dilute hydrochloric acid leaching of the non-magnetic product from WHIMS to reduce the iron contamination levels to around 0,16% to 0,25% Fe203.
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44

Zhang, Xiaojing. "Tectonic Evolution of Taimyr in the Late Paleozoic to Mesozoic from Provenance and Thermochronological Evidence." Doctoral thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-119046.

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The Taimyr Peninsula is a key element in the circum-Arctic region and represents thenorthern margin of the Siberian Craton. The Taimyr Peninsula is a late Paleozoic fold andthrust belt and preserves late Paleozoic through Mesozoic siliciclastic sedimentarysuccessions and providing an ideal location to investigate the Paleozoic to Mesozoictectonic evolution associated with the Uralian orogeny, the Siberian Trap magmatism andopening of Amerasia Basin within a circum-Arctic framework. Multiple methods areadopted, including petrography, heavy mineral analysis and detrital zircon U-Pbgeochronology for provenance investigation, apatite fission track dating for revealingthermal history and balanced cross section for understanding the deformation style ofTaimyr.The results of this thesis indicate that the Late Carboniferous to Permian sediments ofsouthern Taimyr were deposited in a pro-foreland basin of the Uralian orogen during theUralian orogeny. In the Triassic, the siliciclastic deposits still show a strong Uraliansignature but the initiation of Siberian Trap-related input begins to be significant. Erosionof the Uralian orogen has reached a deep metamorphic level. By Late Jurassic andCretaceous time, the deposition setting of southern Taimyr is an intracratonic basin.Erosion and input from Uralian sources waned while greater input from SiberianTrap-related rocks of the Taimyr region dominated. The Taimyr Peninsula underwent atleast three cooling and uplifting episodes: 280 Ma, 250 Ma and 220 Ma, corresponding tothe Uralian orogeny, the Siberian Traps and the late Triassic transpression.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: In press. Paper 3: Manuscript. Paper 4: Manuscript.

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Farias, Júlia Gomes. "CARACTERIZAÇÃO BIOQUÍMICO-FISIOLÓGICA DE GENÓTIPOS DE BATATA (Solanum tuberosum) CULTIVADOS EM SOLOS COM ACÚMULO DE COBRE." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/4848.

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Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul
Soils cultivated with grapevines and with a history of cupric fungicide application may accumulate copper, which may be toxic to plants. The ecotoxicological effects of copper (Cu) are a global concern; comparatively there is a lack of information relating phytotoxicity of heavy metals in plants with nutritional efficiency. This work aimed to study the process of stress induced by Cu excess, effect on the mineral nutrients distribution, and to define predictors of Cu toxicity in different tissues of potato genotypes, differing in the efficiency of use and response to phosphorus (P). Plants grown in vineyards soils with different levels of Cu (2.2, 5, 36.3, 67, 95.7, 270.5 and 320.70 mg kg-1) during periods of fall and spring growing season, in a greenhouse. Tissue Cu concentration was dependent on the external Cu level and the higher concentrations were observed in root and stolon tissues and most of absorbed Cu was accumulated in tubers. During the fall growing season, plants pre-classified as not efficient but responsible to P had the highest sensitivity to Cu excess in growth and nutritional terms. These responses included plants without expanded leaves and without tubers production, while genotypes pre-classified as efficient in the use of P were able to expand leaves and to produce tubers in all tested soils. During the fall growing season, there was an increase of malondialdehyde (MDA) concentration in leaves during the plant cycle in all tested soils. In addition, during the spring growing season, the concentrations of MDA and H2O2 were slightly different between the samples. The genotypes pre-classified as efficient and responsive to P showed a greater increase in H2O2 concentration in soils with high Cu, while genotype pre-classified as non-efficient and responsive to P showed a higher increase of H2O2 treatment with deficit P. In general, the enzymes tested, including ascorbate peroxidase, superoxide dismutase and catalase activities were increased with increasing external Cu. However, our results provide evidence that the antioxidant system was not sufficient to prevent biological damage by ROS in high concentrations of Cu, resulting in deleterious effects. Concentrations of P and Cu were highly correlated with Cu toxicity in Cambi soils, while Fe and K were more correlated in Ultisols. In addition, our data suggest the use of medians and apex leaves to investigate toxicity of Cu in potato plants. This study presents evidence of non-competitive uptake of Cu and Fe for the potato plants, and that the P efficiency of use confers greater tolerance to Cu excess.
Solos cultivados com videiras e com longo histórico de aplicação de fungicidas cúpricos tendem a acumular cobre (Cu), podendo este atingir níveis tóxicos às plantas. Os efeitos ecotoxicológicos do Cu são uma preocupação global, entretanto existe uma carência de informações relacionando fitointoxicação por metais pesados com eficiências nutricionais em plantas. Este trabalho teve como objetivo estudar o processo de estresse induzido por excesso de Cu, efeito na distribuição de nutrientes minerais, bem como definir preditores para toxicidade de Cu em diferentes tecidos vegetais de genótipos de batata, diferindo quanto a eficiência de uso e resposta ao fósforo (P). As plantas foram cultivadas em solos de vinhedos com diferentes níveis de Cu (2,2, 5, 36,3, 67, 95,7, 270,5 e 320,70 mg kg-1) durante os períodos de safra e safrinha em casa de vegetação semi-climatizada. O aumento da concentração de Cu em tecidos de plantas foi dependente da concentração externa de Cu, sendo as concentrações mais elevadas observadas em tecidos da raiz e estolão e maior parte de Cu absorvidofoi acumulado em tubérculos. Durante a safrinha, as plantas pré-classificadas como não eficientes mas responsivas ao P apresentaram a maior sensibilidade ao excesso de Cu em termos de concentração de nutrients e de crescimento. Estas respostas incluíram plantas sem folhas expandidas e sem produção de tubérculos, enquanto genótipos pré-classificados como eficientes no uso de P foram capazes de expandir folhas e produzir tubérculos em todos os solos testados. Durante a safrinha, houve um aumento na concentração de malondialdeído (MDA) nas folhas durante o ciclo da planta em todos os solos testados. Já no período de safra, as concentrações de MDA e H2O2 foram ligeiramente diferentes entre as coletas. Além disso, os genótipos pré-classificados como eficientes e não responsivos ao P apresentaram maior incremento na concentração de H2O2 em solos com alto Cu, enquanto o genótipo pré-classificado como não eficiente e responsivo a P apresentou maior incremento de H2O2 no tratamento com déficit de P. Em geral, as enzimas testadas, incluindo ascorbato peroxidase, superóxido dismutase e catalase, tiveram aumento na atividade com o aumento do Cu externo. Entretanto, nossos resultados fornecem evidências de que o sistema antioxidante não é suficiente para evitar danos biológicos mediados por ROS em altas concentrações de Cu, que resulta em efeitos deletérios. Concentrações de P e Cu apresentaram alta correlação com toxidez de Cu em Cambisolos, enquanto Fe e K foram mais correlacionados em Argisolos. Além disso, os nossos dados sugerem a utilização de folhas apicais e medianas para investigação da toxicidade de Cu em plantas de batata. Este estudo apresenta evidências de absorção não-competitiva de Cu e Fe por plantas de batata; e que a eficiência do uso de P confere maior tolerância ao excesso de Cu.
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46

Pontoni, Ludovico. "Accumulation and colloidal mobilization of trace heavy metals in soil irrigated with treated wastewater." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1144/document.

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La réutilisation des eaux usées traitées pour l’irrigation est globalement acceptée et pratiquée pour faire face à la pénurie d'eau et économiser les ressources de haute qualité. Bien que cette pratique présente des avantages indéniables et contribue à un usage plus durable de l'eau douce, elle n’est pas exempt de problèmes liés à l'impact potentiel sur la qualité des sols récepteurs et sur les cultures de micropolluants contenus dans l'eau réutilisée. Parmi ces polluants, les métaux lourds (ML) en concentrations traces jouent un rôle primordial en raison de leur présence systématique dans l'eau utilisée et de leur persistance une fois libéré dans l'environnement. Le devenir des ML dans les sols peut difficilement être prédit parce que les mécanismes de mobilité à travers les sols sont extrêmement variés et liés à des phénomènes simultanés et très complexes impliquant différents équilibres chimiques. Les ML, comme beaucoup d'autres contaminants, ne sont pas seulement partagé entre la phase immobile (le sol) et les phases mobiles présentes dans l'eau. En effet, les colloïdes et les nanoparticules agissent comme une troisième phase mobile, avec leurs propres propriétés rhéologiques et des vitesses de migrations qui leur sont propres. Ce dernier aspect a été l'un des principaux objectifs d’étude de la thèse. Plusieurs essais expérimentaux ont été menés en irriguant un sol standard selon l'Organisation de coopération et de développement économiques (OCDE) avec une eau usés traités réel et / ou synthétiques, contenant des ML en concentrations traces. Pour chaque test, un sol spécifique (avec différentes teneurs en matière organique) et des eaux usées traitées de composition différente (avec différentes concentrations en métaux traces, de salinité, de la teneur en matière organique pour les eaux usées synthétiques, ou des eaux usées traitées réelles) ont été choisi afin d'évaluer les effets des conditions différentes sur le devenir global des ML. L'augmentation de la matière organique du sol de 2,5 à 10% a linéairement amélioré la mobilité des Cd, Cu et Ni avec une augmentation de la mobilité maximum de 35,6, 43,7 et 49,19% pour le Cd, Cu et Ni, respectivement. Pour la plupart des expériences, les ML ont été capturés dans la couche superficielle du sol (0,5 à 1 cm). Néanmoins, des pics de contamination ont été détectés à des profondeurs différentes dans les couches plus profondes du sol. L’étude de la composition des lixiviats montre des variations de concentrations fonction du métal étudié et des caractéristiques du sol et des eaux usées. Des pics de métaux dans le lixiviat sont apparus en même temps que la libération de la matière et / ou la libération de silicates organiques, ce qui démontre l'implication significative des colloïdes dans le transport des métaux. La concentration en sodium (20 mM) a été démontrée un impact fort sur la réduction de la mobilisation colloïdale et que plus de 95% du métal apporté a été détecté dans la couche superficielle du sol en dépit de sa teneur en matière organique. La salinité affiche donc des effets significatifs. L'irrigation avec des eaux usées traitées présentant une très haute teneur en Ca et Mg (111 et 134 mg / L, respectivement) a abouti à la libération moyenne plus élevée de silicium à partir de la matrice inorganique du sol (8,2 mg / L) par rapport à la faible salinité des eaux usées artificielle (1,9 mg / L). Par conséquent, la mobilisation ultérieure de Cd, Cu, Ni et Zn a été observée lorsque le sol a été irrigué avec des eaux usées traitées réelles. Une caractérisation spectroscopique avancée des lixiviats a été réalisée pour identifier les agrégats colloïdaux libérés par le sol dans le but d’en déterminer leur nature, leurs propriétés chimiques et leur état d'agrégation
Reuse of treated wastewater for agricultural purposes is worldwide accepted and practiced to face water scarcity and save high quality resources. Although such practice has undoubtable advantages and is certainly more sustainable respect to the use of fresh water, it is not exempt from severe concerns related to the potential impact on the receiving soil and on the crops of potentially harmful pollutants contained in the reused water at trace levels. Among these pollutants, trace heavy metals (HMs) play a primary role due to their spread presence in the used water and to their persistence once released in the environment. The fate of HMs in the soils can be hardly predicted as mechanisms of mobility through soils are extremely diverse and related to highly complex simultaneous phenomena and chemical equilibria. HMs, in fact, as many other contaminants, are not only partitioned between the solid immobile and the water mobile phases. Indeed, colloids and nanoparticles act as a third mobile phase, with their own rheological properties and velocity. This latter aspect has been one of the main focus of the thesis. In details the thesis describes the results of several experiments conducted irrigating the OECD standard soil with real and/or synthetic wastewater, containing HMs in trace. For each test a specific soil (e.g. varying the organic matter content) and wastewater composition (e.g. varying the metals concentration, the salinity, the organic matter content, or testing real treated wastewaters) has been chosen in order to evaluate the effects of different conditions on the overall HMs fate. The increase of soil organic matter from 2,5 to 10% linearly enhanced the mobility of Cd, Cu and Ni up to a maximum mobility increase of 35.6, 43.7 and 49.19 % for Cd, Cu and Ni, respectively. In most experiments metals accumulated in the top soil layer (0.5 - 1 cm). Nevertheless peaks of contamination were detected at different depths in the soil deeper layers and at different leaching time in the leachates depending on the metal and on the soil and wastewater characteristics. Peaks of metals in the leachate appeared simultaneously with release of organic matter and/or release of silicates, demonstrating outstanding involvement of colloids in metals transport. Sodium concentration (20mM) decidedly reduced colloidal mobilization whereas more than 95 % of the influent metal was detected in the top layer despite the soil organic matter content. Salinity displayed different effects. The irrigation with real treated wastewater with quite high content of Ca and Mg (111 and 134 mg/L, respectively) resulted in higher average release of silicon from the soil inorganic matrix (8.2 mg/L) compared to the low salinity artificial wastewater (1.9 mg/L). Consequently higher mobilization of Cd, Cu, Ni and Zn was observed when the soil was irrigated with real treated wastewater. An advanced spectroscopical characterization of the leachates was performed to identify such colloidal aggregates. The observation of 3D excitation-emission matrix demonstrated in all the leachates samples the presence of fulvic (230-450 nm ex-em fluorescence area) and humic (330-445 nm ex-em) substances. In this context, a novel analytical method was developed to quantify phenolic substances in soil matrices allowing the monitoring of humic matter migration in soil profiles. The novel method was more accurate and more precise respect to the traditional one, allowing to obtain higher recovery of total phenols in peat soil (15.5 % increase) with a decrease of the coefficient of variation (30.1% decrease). Organic water soluble colloids were extracted from the peat used to prepare the OECD standard soil and characterized. Results of size exclusion chromatography highlighted the supramolecular structure of the extracted organic matter. Such structure was further confirmed through fluorescence and 1H-NMR spectroscopy
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47

Su, Lingcheng. "Soil contamination and plant uptake of metal pollutants released from Cu(In, Ga)Se₂ thin film solar panel and remediation using adsorbent derived from mineral waste material." HKBU Institutional Repository, 2018. https://repository.hkbu.edu.hk/etd_oa/552.

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The Cu(In,Ga)Se2 (CIGS) thin-film solar panels (TFSPs) are widely used in integrated photovoltaic (PV) and solar power systems because of their perfect PV characteristics and ductility. However, the semiconductor layers of these panels contain potentially toxic metals. In this study, the potential environmental pollution arisen by CIGS TFSP treated as construction trash at the end of their useful life was examined. Acid extraction was used to simulate leaching toxicity followed by burying CIGS TFSP material in different soils, namely a synthetic soil, a Mollisol, and an Oxisol, to determine whether metal pollutants might be released into the soil. A vegetable, Brassica parachinensis L. H. Bariley (VegBrassica), was selected to grow in these polluted soils to investigate the uptake of metals and their bioaccumulation. The simulative remediation of contaminated soils was carried out using a remediation module created by the combination of activated carbon and modified mineral waste material (MMWM) in this research. The activated carbon derived from the waste biomass material was produced by an environmental friendly method, and the MMWM was obtained through a thermal dehydroxylation treatment. The physiochemical properties of MMWM, with focusing on mineral phase transformation, were related to the changes in surface morphology due to dehydroxylation occurred during the process of thermal treatment of MMWM samples, and the adsorption performances of metal (lead, Pb) and organic compound (methyl orange, MO) onto this newly modified MMWM were studied. Furthermore, an end-of-life treatment method was designed and proposed for harmless disposal of CIGS TFSP. Various metals, including Pb, zinc (Zn), nickel (Ni), chromium (Cr), gallium (Ga), copper (Cu), indium (In) and aluminum (Al) were found to be released into the soil and caused contamination when scrapped end-of-life CIGS TFSP were buried, and the rates of metal release changed with the variations of both the amounts of CIGS TFSP material in the soil and the soil properties. The increases in concentrations of heavy metals such as Zn, Cu, Ni, Ga, Pb, In, and Cr were correlated with the amounts of CIGS TFSP material added in soils. The Pollution Index and the Nemerow Contamination Index calculated from our results confirmed that, when buried, the CIGS TFSP material polluted the soil. Plants grew well in the synthetic soil and the Mollisol, but those in the Oxisol showed prominent signs of chlorosis and died after 30 days. The bioaccumulation factor (BF) and concentration of Zn were 3.61 and 296 mg/kg, respectively in VegBrassica grown in the synthetic soil with 10% (200 g to 2 kg of soil) of added CIGS TFSP, while the BF and concentration of In were 3.80 and 13.72 mg/kg, respectively in VegBrassica grown in the Mollisol, indicating that bioaccumulation occurred. The thermally treated MMWM samples showed morphological transformation mainly on surface based on the scanning electron microscopy (SEM) observations, and an increasing trend in BET specific surface area (SSA) from 120 to 500 ℃ followed by a decreasing trend up to 1000 ℃. Thermal modification had successfully improved Pb adsorption capacity up to 515 mg/g, corresponding to MMWM modified at 600 ℃ with an SSA of 6.5 m2/g. The MO adsorption capacity was also improved after thermal treatment of MMWM, which performed the best adsorption of 87.6 mg/g at 400 ℃. The adsorption of Pb and MO were mainly chemisorption and monolayer coverage, as pseudo-second-order model and Langmuir equation displayed good relationships of correlation for Pb and MO adsorption data. It is therefore indicated that the newly designed soil remediation modules could significantly remove metals from the contaminated soils. In summary, c
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48

Florentino, Antonio Leite. "Fertilidade do solo, nutrição mineral, produtividade e metais pesados em plantações de eucalipto com efeito residual de lodo de esgoto." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/64/64134/tde-11112016-112849/.

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Os novos paradigmas no setor agrícola almejam a busca por alternativas de maior equilíbrio à entrada e saída de energia do ecossistema. Há muita discussão quanto a reciclagem de lodo de esgoto (LE) pela aplicação no solo, seja pelos aspectos positivos, como fonte de nutrientes às plantas, em especial o fósforo, e condicionador de solo, ou pelos aspectos negativos, com a presença de metais pesados, compostos orgânicos tóxicos e patógenos. Nesta pesquisa foram realizados dois estudos. No primeiro, em Itatinga-SP, objetivou-se avaliar o efeito residual de lodos de esgoto úmido (LU) e lodo seco (LS), aplicados por ocasião do plantio do eucalipto na 1ª rotação de cultivo, nas doses de 10, 20 e 30 t ha 1, sobre a fertilidade do solo (LVAd), a nutrição mineral, a produtividade e nos teores e acúmulos de metais pesados no solo e nos compartimentos aéreos de plantas de eucalipto, aos 45 meses de idade, durante a 3a rotação de cultivo, cerca de 12 anos do resíduo no solo. No segundo, em Itatinga e Angatuba-SP, objetivou-se avaliar a qualidade do solo quanto aos teores de metais pesados em áreas tratadas com diferentes tipos e doses de LE e cultivadas com plantas de eucalipto, entre 10 a 17 anos do resíduo no solo (LVAd, LVd e RQo). Os LEs foram oriundos de ETEs de Jundiaí-SP, Barueri-SP e São Paulo-SP. Em ambos os estudos, os tratamentos foram: fertilização mineral (FM), controle e doses e tipos de LE. Os delineamentos foram em bloco ao acaso, com 8 tratamentos e 3 repetições, no primeiro, e com 5 tratamentos e 4 repetições. Os resultados do primeiro estudo demonstram que houve efeito residual de LU e LS em relação ao manejo de FM, principalmente, em doses mais altas, no aumento da fertilidade do solo (sobretudo, MO, SB, CTC, P, Ca, S, Cu e Zn), nutrição mineral e estoque de nutrientes (em destaque, P, Ca, Cu e Zn), produção (volume de madeira, biomassa aérea e de folhedo depositado no solo) e os teores de metais pesados (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Se e Zn) não evidenciaram contaminação do solo e nem toxicidade ao eucalipto. No segundo, houve efeito residual de LE em relação ao manejo de FM nos atributos do solo e nos teores de metais pesados, principalmente, em doses mais altas. Ainda no segundo estudo, de modo geral, houve efeito residual dos LEs no aumento de MO, SB, H+Al, CTC e V% e os teores de As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Se e Zn no solo, em geral, permaneceram abaixo dos valores de prevenção. Todavia, houve relação entre as doses de aplicação do lodo e os teores de metais pesados no solo, ou seja, quanto maior a dose, maiores foram os teores residuais dos metais pesados, sendo tal efeito, mais incrementado nos solos arenosos. Concluiu-se que há efeito residual de LE em relação ao manejo de fertilização mineral com aumento da fertilidade, nutrição, produtividade e os teores de metais pesados não evidenciaram contaminação do solo e nem toxidez no eucalipto
The new paradigms in the agricultural sector aim to search for alternatives with more balance to the input and output of energy in the ecosystem. There is a lot of discussion about the recycling of sewage sludge (SS), for the positive aspects, as a source of plant nutrients, especially phosphorus, and soil conditioner, as well as for the negative aspects, such as the presence of heavy metals, organic toxic compounds and pathogens. Two studies were carried out in this research. In the first, at Itatinga-SP, the objective was to evaluate the residual effect of humid sewage sludge (HS) and dry sludge (DS), both applied to a eucalyptus plantation in the first rotation with the doses of 10, 20, 30 t ha-1, on the soil fertility (LVAd), mineral nutrition, productivity and amount and accumulation of heavy metals in both the soil and aboveground compartments of the eucalyptus, at 45 month age, during the 3rd rotation, with around 12 years of residues in the soil. In the second study, at Itatinga and Angatuba-SP, the objective was to evaluate the quality of the soil regarding to heavy metals contents in areas treated with different types and doses of SS and cultured with eucalyptus trees, with 10-17 years of residues in the soil (LVAd, LVd e RQo). The used SS came from the sewage treatment plant of Jundiaí-SP, Barueri-SP e São Paulo-SP, respectively. In both studies the treatments were; mineral fertilization (MF), control and doses and types of SS. The experimental design was in randomized blocks, with 8 treatments and 3 replicates, in the first, and with 5 treatments and 4 repetitions, in the second. The results from the first study showed that there was residual effect of both HS and DS in comparison with MF, especially in high doses, in the increase of soil fertility (mainly OM, SB, CTC, P, Ca, S, Cu and Zn), mineral nutrition and the stock of nutrients (mainly P, Ca, Cu e Zn), production (wood, aboveground biomass and litterfall) and heavy metal contents (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Se and Zn) did not showed soil pollution nor toxicity for eucalyptus. In the second study, there was residual effect of SS in comparison with MF when we observed soil properties and heavy metal contents, especially in high doses. Also in the second study, there was a residual effect of SS in the increase of OM, SB, H+Al, CEC and V% e the contents of As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Se and Zn in the soil that, in general, were below the values of prevention. There was also relation between the doses of SS and the contents of soil heavy metals, i.e, the higher the dose, the higher the contents of residual heavy metals. This effect was higher in sandy soils. It was concluded that there was a residual effect of SS in comparison with MF with an increase in soil fertility, nutrition, productivity. Heavy metal contents did not showed soil pollution nor toxicity for eucalyptus
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49

Silva, Júnior Flavio Manoel Rodrigues da. "Atividade mutagênica em solos sob a influência de rejeitos de carvão." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/13841.

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O solo é um compartimento ambiental altamente complexo e, em razão do crescimento populacional acelerado e da intensa atividade industrial e agrícola, tem sofrido com a contaminação de substâncias de origens diversas. Entre as principais atividades que contribuem para a perturbação da qualidade dos solos estão as atividades de geração de energia pela queima de combustíveis fósseis, como o carvão mineral. Dentre as substâncias presentes nos rejeitos do carvão queimado em usinas termelétricas estão compostos orgânicos e metais pesados que interagem com o material genético, produzindo mutações e acarretando prejuízos em nível de organismo (como as neoplasias), mas também em níveis maiores de organização biológica (como a perda de diversidade genética em populações). Estudos de avaliação do potencial mutagênico em amostras de solo são escassos, principalmente investigando a ação de mutágenos de origem inorgânica. Além disso, estudos de mutagênese em solos sob a influência de rejeitos de carvão têm sido pouco abordados na literatura. Desta forma, os objetivos deste trabalho foram: (i) testar um protocolo para avaliação de atividade mutagênica em extratos inorgânicos e orgânicos de solo; (ii) avaliar a presença e o perfil dos compostos mutagênicos em solos sob a influência de cinzas de carvão e (iii) investigar as rotas ambientais para dispersão dos compostos mutagênicos na área de estudo. Para atingir estes objetivos, processos de extração de compostos orgânicos e inorgânicos de solo foram testados quanto a sua eficiência em extrair da amostra compostos potencialmente mutagênicos frente a linhagem de Salmonella typhimurium que detecta erro no quadro de leitura (TA98). Os protocolos mais eficientes foram utilizados para os testes com diferentes amostras de solo sob a influência de rejeitos de carvão utilizando diversas linhagens, na ausência e presença de ativação metabólica (fração S9 mix). Os resultados de mutagênese associados aos resultados da caracterização química de compostos orgânicos e metais indicaram que os contaminantes presentes nas cinzas de carvão podem se dispersar com facilidade para áreas adjacentes. Essa abordagem de estudo permitiu relacionar a presença de determinadas classes de compostos com diferentes danos no DNA e inferir distintas rotas ambientais de dispersão para esses compostos. A realização deste trabalho ressalta a importância de estudos em matrizes ambientais complexas, em especial solos contaminados, que buscam integrar os dados de mutagênese e utilizá-los sob uma perspectiva ecológica.
Soil is a highly complex environmental compartment that has suffered contamination by substances from multiple sources mainly due to fast population growth and intense industrial and agricultural activity. Among the main activities that affect soil quality are power generation activities that use fossil fuels, such as mineral coal. Among the several compounds present in coal ashes that are employed in coal-fired power plants are substances that interact with the genetic material, causing mutations and/or damage at the individual level (like neoplasias) but also at higher levels of biological organization (like loss of genetic diversity in populations). There are few studies on the mutagenic potential of soil samples, especially those that investigate the action of mutagens from inorganic sources. Moreover, studies of mutagenesis in soils under the influence of coal-fired power plants have rarely been reported in literature. Thus, this work aimed at: (i) testing a protocol for the evaluation of mutagenic activity in inorganic and organic extracts from soil samples; (ii) evaluating the presence and the profile of mutagenic compounds in soils under the influence of coal ashes and (iii) investigating environmental routes of dispersion of mutagenic compounds in the study area. In order to achieve these aims, extraction processes for inorganic and organic compounds were tested concerning their efficiency to extract compounds potentially mutagenic to the specific Salmonella typhimurium strain that detects frameshift mutagens (TA98). The most efficient protocols were further utilized for the tests with different soil samples under the influence of coal-fired power plant using several strains, in absence and presence of metabolic activation (S9 mix fraction). Mutagenesis results associated with the chemical characterization of the organic compounds and metals indicated that contaminants present in coal ashes can be easily dispersed to adjacent areas. This approach allowed relating the presence of certain classes of compounds to specific damages in DNA and inferring distinct dispersion routes for these compounds. This work highlights the importance of studies concerning complex environmental matrices, specially contaminated soils, which seek the integration of mutagenesis data and their use from an ecological perspective.
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50

Zhou, Zhe. "Fe(II)-catalyzed transformation of ferrihydrite associated with natural organic matter." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6670.

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The association between natural organic matter (NOM) and iron (Fe) minerals was widely found in soil and sediments and has been shown to impact the fate of Fe minerals and NOM. Ferrihydrite, a ubiquitous Fe mineral, serves as important sink for NOM and rapidly transforms to secondary Fe minerals in the presence of Fe(II). The associated NOM has been found to influence the Fe(II)-catalyzed ferrihydrite transformation pathway, but it remains unclear how various NOM affects this transformation and the implication. This study specifically investigates how different species of NOM affect Fe(II)-catalyzed ferrihydrite transformation under different C/Fe ratios. A series of Fe isotope tracer experiments were conducted to measure Fe atom exchange and electron transfer between aqueous Fe(II) and ferrihydrite in the presence of diverse NOM species. The fate of Ni during Fe(II)-catalyzed transformation of NOM-Fh coprecipitate was also investigated. Ferrihydrite was found less susceptible to Fe(II)-catalyzed transformation with increasing C/Fe ratio and fulvic acids and Suwannee River NOM (SRNOM) in the coprecipitates need lower C/Fe ratio than humic acids to completely inhibit formation of secondary Fe minerals. At C/Fe ratios where ferrihydrite transformed to secondary minerals, goethite was dominant in ferrihydrite coprecipitated with humic acids, whereas lepidocrocite was favored in ferrihydrite coprecipitated with fulvic acids and SRNOM. Adsorbed SRNOM may be more inhibitive than coprecipitated SRNOM on Fe(II)-catalyzed ferrihydrite transformation under similar C/Fe ratios. Despite no secondary mineral transformation at high C/Fe ratios, Mössbauer spectra indicated electron transfer still occurred between Fe(II) and ferrihydrite coprecipitated with fulvic acid and SRNOM. In addition, isotope tracer experiments revealed that a significant fraction of structural Fe(III) in the ferrihydrite mixed with the aqueous phase Fe(II) (~85%). After reaction with Fe(II), Mössbauer spectroscopy indicated some subtle changes in the crystallinity, particle size or particle interactions in the coprecipitate. The effect of coprecipitated SRNOM on Ni(II) distribution during Fe(II)-catalyzed ferrihydrite transformation was investigated with adsorbed Ni(II) and coprecipitated Ni(II). Ni(II) adsorbed on ferrihydrite was more resistant to acid extraction after Fe(II)-catalyzed transformation and suggested that structural incorporation of Ni into secondary Fe minerals occurred. With coprecipitated SRNOM, ferrihydrite did not transform to secondary minerals in the presence of Fe(II) but extensive Fe atom exchange between aqueous Fe(II) and structural Fe(III) still occurred. Limited change in Ni stability was observed, suggesting there was only small portion of Ni redistributed in the presence of Fe(II). Pre-incorporated Ni(II) in Ni-SRNOM-Fh coprecipitate was partially released (6-8 %) in the presence of Fe(II), but the distribution of remaining Ni(II) in the solid did not change measurably. Our observation suggests that the presence of SRNOM limited the redistribution of Ni most likely because of limited transformation of ferrihydrite to secondary minerals.
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