Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-08-01T11:55:04Z No. of bitstreams: 1 JoseRaelsonPereiraDeSouza_DISSERT.pdf: 2931697 bytes, checksum: 893ae580fb21bb765e576fb1a24663a9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-08-02T14:19:30Z (GMT) No. of bitstreams: 1 JoseRaelsonPereiraDeSouza_DISSERT.pdf: 2931697 bytes, checksum: 893ae580fb21bb765e576fb1a24663a9 (MD5) / Made available in DSpace on 2017-08-02T14:19:30Z (GMT). No. of bitstreams: 1 JoseRaelsonPereiraDeSouza_DISSERT.pdf: 2931697 bytes, checksum: 893ae580fb21bb765e576fb1a24663a9 (MD5) Previous issue date: 2017-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Este trabalho apresenta o estudo da obten??o e caracteriza??o da reciclagem de alum?nio oriundo de latas de bebida composta pelas ligas de alum?nio AA3004, 5042 e 5182, atrav?s da t?cnica de moagem de alta energia e da metalurgia do p?. As latas foram selecionadas, picotadas e mo?das para obten??o do p? met?lico sob diferentes tempos de moagem (1h, 1h30min e 2h). O p? obtido foi compactado a uma carga de 400 MPa e sinterizado a 600 ?C por duas horas. Para caracteriza??o do p? de alum?nio foram realizadas an?lises em DRX, MEV e EDS, e granulometria a laser; enquanto o material consolidado por sinteriza??o, al?m das an?lises via DRX, MEV e EDS, foi caracterizado tamb?m atrav?s de ensaios de dilatometria, compress?o e microdureza Vickers. Avaliou-se o tamanho das part?culas e sua rela??o com as propriedades da liga de alum?nio. A rota de processamento adotada resultou na compacta??o efetiva do p? de alum?nio proveniente da moagem de latinhas de bebidas, por?m apresentando porosidade, t?pica de metais sinterizados. Observou-se uma grande incid?ncia de precipitados da fase Al6Mn dispersa na matriz Al-alfa (CFC). As amostras apresentaram varia??es em suas propriedades mec?nicas em fun??o do tempo de moagem. A porosidade e a microestrutura da liga podem ter influenciado as propriedades mec?nicas resultando no comportamento discrepante entre a resist?ncia a compress?o.e a microdureza. A resist?ncia a compress?o aumentou de 105 N/mm? com 1h de moagem para 120 N/mm? com 1h30min e diminui para 110 N/mm? com 2h de moagem, mas a ductilidade apresentou pouca varia??o. A dureza foi de 56,43 HV, 66,52 HV e 92,21 HV para os tempos de 1h, 1h30min e 2h, respectivamente. / This work presents the study of the production and characterization of aluminum recycling from beverage cans composed of aluminum alloys AA3004, 5042 and 5182, using high energy grinding and powder metallurgy. The cans were selected, punched and ground to obtain the metallic powder under different milling times (1h, 1h30min and 2h). The obtained powder was compacted at a load of 400 MPa and sintered at 600 ? C for two hours. For characterization of the aluminum powder, XRD, SEM and EDS analyzes were performed, and laser grading; While the material consolidated by sintering, in addition to the analyzes via DRX, SEM and EDS, was also characterized by Vickers dilatometry, compression and microhardness tests. The size of the particles and their relationship to the properties of the aluminum alloy were evaluated. The processing route adopted resulted in the effective compaction of the aluminum powder from the beverage cans mill, but with porosity, typical of sintered metals. A high incidence of precipitates of the Al6Mn phase dispersed in the Al-alpha matrix (CFC) was observed. The samples presented variations in their mechanical properties as a function of milling time. The porosity and microstructure of the alloy may have influenced the mechanical properties resulting in the dissimilar behavior between the compressive strength and microhardness. The compressive strength increased from 105 N / mm? with 1h grinding to 120 N / mm? with 1h30min and decreasing to 110N / mm? with 2h grinding, but the ductility presented little variation. The hardness was 56.43 HV, 66.52 HV and 92.21 HV for the times of 1h, 1h30min and 2h, respectively.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-01T21:11:49Z No. of bitstreams: 1 JulianoAugustoMedeirosDeMenezesEOliveira_DISSERT.pdf: 8358330 bytes, checksum: a0ec67f844a5bacdf6c24e821ebe74d1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-07T19:34:30Z (GMT) No. of bitstreams: 1 JulianoAugustoMedeirosDeMenezesEOliveira_DISSERT.pdf: 8358330 bytes, checksum: a0ec67f844a5bacdf6c24e821ebe74d1 (MD5) / Made available in DSpace on 2017-11-07T19:34:31Z (GMT). No. of bitstreams: 1 JulianoAugustoMedeirosDeMenezesEOliveira_DISSERT.pdf: 8358330 bytes, checksum: a0ec67f844a5bacdf6c24e821ebe74d1 (MD5) Previous issue date: 2017-08-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / As ligas de alum?nio na composi??o eut?tica apresentam como caracter?stica baixa temperatura de fus?o e uma microestrutura complexa formada por constituintes eut?ticos. Elas podem ser aplicadas na ind?stria de fundi??o, por apresentarem adicionalmente alta fluidez e baixa tend?ncia ? forma??o de porosidade e de trincamento a quente. Foram produzidas por fundi??o em areia as ligas eut?ticas do sistema Al-Cu (bin?ria), Al-Cu-Si e Al-Cu-Mg (tern?rias) e Al- Cu-Si-Mg (quatern?ria). As ligas foram analisadas microestruturalmente no estado bruto de fus?o e no estado ap?s tratamento t?rmico de homogeneiza??o ? 495 ?C por at? 24 horas, via Fluoresc?ncia de Raios-X (FRX), Difra??o de Raios-X (DRX) e Microscopia Eletr?nica de Varredura (MEV) com sistema de Energia Dispersiva de Varredura (EDS). Os resultados mostraram a forma??o das principais fases constituintes no estado de equil?brio termodin?mico, a forma??o significativa de constituintes eut?ticos e a forma??o em pequena quantidade de intermet?licos Al5FeSi (plaquetas) e AlFeSiMgCu (escrita chinesa), comumente encontradas devido ? presen?a intr?nseca do ferro como impureza em ligas de alum?nio. / The aluminum alloys in the eutectic composition have a characteristic low melting temperature and a complex microstructure formed by eutectic constituents. They can be applied in the foundry industry, as they additionally present high fluidity and low tendency to the formation of porosity and hot cracking. The Al-Cu (binary), Al-Cu-Si and Al-Cu-Mg (ternary) and Al- Cu-Si-Mg (quaternary) systems were produced by sand casting. The alloys were analyzed microstructurally in the as-cast condition and after homogenizing heat treatment at 495 ? C for until 24 hours, via x-rays fluorescence (FRX), x-rays diffraction (XRD) and scanning electron microscopy (SEM) with dispersive scanning energy system (EDS). The results showed the formation of the main constituent phases in the thermodynamic equilibrium state, the significant formation of eutectic constituents and the formation of a small amount of intermetallic Al5FeSi (platelets) and AlFeSiMgCu (chinese writing), commonly found due to the intrinsic presence of iron as an impurity In aluminum alloys.

The palaeoecological development of alum mire since early Eneolithic on the basis of the results of macro-remains, pollen, and chemical analysis. The developement of local vegetation and nearest surrounding area was studied.

The Caledonian alum shales of Sweden host a vast number of economically interesting metals. In Fetsjön, Västerbotten, the shales contain significant amounts of rare-earth elements, vanadium, molybdenum and uranium. As metals with a multitude of high-technological applications, the former rare-earth elements (REEs) are particularly attractive in a world where the supply may be exhausted as the demand continuously increase while new deposits are not being discovered fast enough. Meanwhile, the latter uranium notably constitutes as an unwanted secondary product during the extraction of rare-earth elements. As the mineral association of the REEs in Fetsjön is unknown, the intent of this study is to analyze and thus determine their mineralogical expression. The assumed REE-bearing mineral apatite was confirmed to host the rare-earths in the Fetsjön shales after microscopy and spectrometry analyses.

The treatment of water for human consumption results in the production of residual waste flows that vary depending on source waters and water treatment technologies. Water treatment plant residual waste is defined as a pollutant that requires treatment either on site or through other means. Due to strict and evolving regulatory requirements, treatment of water treatment plant residual waste several common methods of disposing of water plant residuals exist including discharge to surface waters, discharge to sanitary sewers, and sanitary landfill disposal of dewatered wastes. Although originally discharged to the neighboring City Reservoir, the Carbondale Water Treatment Plant (CWTP) conducted an initial study to determine if plant residual waste could be treated at one of the City’s two wastewater treatment plants. No negative impacts were identified as part of this study and infrastructure was put in place to divert CWTP residual waste from the City Reservoir to the Carbondale Southeast Wastewater Treatment Plant (SEWWTP). This study focused on accessing and quantifying any impacts of Carbondale Water Treatment Plant (CWTP) residual solids sewer discharge on biological treatment processes, effluent water quality, and sludge production at the SEWWTP. The Carbondale SEWWTP treats raw water influent through a number of physical and biological processes including screening, clarification, nitrification/denitrification, and aeration. Of the tests run as part of this study daily samples were collected of SEWWTP influent, mixed liquor, return sludge, and effluent and measured for changes in pH, biochemical oxygen demand (BOD), solids, sludge volume index (SVI), dissolved oxygen (DO), and nitrogen. No significant changes were documented other than percent BOD removal did improve after the introduction of the residuals. Anions were also tested weekly. Samples were collected from the SEWWTP’s oxidation ditch to monitor biological life using biological activity reaction tests (BART) for nitrifying, denitrifying, and heterotrophically active bacteria. BART testing showed no decline in biological activity and increased populations of denitrifying bacteria. Additionally, both metals and acute toxicity of SEWWTP effluent were tested by outside testing facilities to confirm that CWTP residual solids sewer discharge did not interfere with discharge limits established as part of the plant’s permits. No significant changes were observed during testing but plant staff did indicate that more extensive cleaning of the basins was implemented post-introduction. Overall, the case study confirmed that the treatment of CWTP residual solids sewer discharge did not negatively impact treatment processes at the SEWWTP and is sustainable.

No description available.

This history of the Rockbridge Alum Springs near Lexington, Virginia, covers the entire development of the spa from 1790 through its rapid growth and popularity in the nineteenth century, its final death in 1919, its restoration in the 1940's, and its present state in the 1970's. The Cult of the Spa was an important social element in the South during the nineteenth century, and the Springs of Virginia served the nation with their various health-giving waters and their social opportunities. Rockbridge Alum Springs developed from a small, one-hotel enterprise, into a sprawling establishment with two major hotels, several smaller hotels and numerous cabins, serving at its height almost 1,000 people. In the 1850's, and again in the 1880's, it was second in popularity only to the White Sulphur Springs, however, its fame has generally long been forgotten. The effects of the Civil War, the death of the Age of Belledom and the coming of the automobile so changed southern society that, along with ninety percent of the spas, the Rockbridge Alum Springs met its death after the turn of the century. The Alum, however, was partially restored in 1940 as the owners hoped to turn it into a wild life refuge and a retreat for scientists. Although its nature had changed, the Alum has been fortunate enough to survive, while many other watering places have long since been absorbed into the earth. / Master of Arts

Past research regarding complexed iron has focused on the resistance to and kinetics of oxidation by O₂(aq) and the extent of stabilization. The 0.45 um filter was typically used to differentiate between dissolved and particulate iron. This research investigated Fe(II) oxidation by free chlorine and ClO₂ in the presence of DOC by varying the pH, DOC to Fe ratios, DOC sources, oxidant dosages, and contact time. Complexed iron removal by alum coagulation with and without oxidant addition was also examined. Particulate, colloidal, and soluble iron were differentiated by the use of 0.2 um filters and 100K ultrafilters. Ultrafiltration and oxidation studies revealed that, at the DOC-to-iron ratios used for this research, not all of the Fe(II) in solution was actually complexed. Thus, oxidation studies represented the oxidation of uncomplexed Fe(II) to Fe(III), which was then complexed by the higher molecular weight DOC. Results indicated that particulate iron formation (as defined as retention by a 0.2 um filter) was a function of the DOC source and oxidant used for testing. The formation of colloidal iron (as defined by retention on 100K ultrafilter) due to oxidation was dependent upon the initial DOC-to-iron ratio and the DOC source. A correlation between DOC adsorption to iron oxide solids and the solution pH, initial DOC-to-iron ratio, and the oxidant used was also evident. Complexed Fe(II) was removed from solution by alum coagulation. Oxidant addition to alum coagulation was necessary to effectively remove uncomplexed Fe(II) (in the presence of DOC) from solution. / Master of Science

Soil columns of predominantly Peawick and Slagle soils had various amounts of alum residuals, lime and plant nutrients incorporated into the topsoil. A weekly dose of rainwater was applied to each column over a six month period. Leachate and soil constituents were analyzed to evaluate migration of specific constituents from the alum residuals through the soil profile and into the groundwater. Soil analysis indicated little, if any, migration of metals from the alum residuals occurred. Metal constituents found within the leachate appear to have originated from the soil rather than the alum residuals. Of the measured anions, nitrate - nitrogen was the only component which had increasing concentrations within the leachate. Much, if not all, of the nitrate can be attributed to the plant nutrients incorporated into the topsoil and disturbance of the topsoil. Nitrate and zinc were the only components that consistently degraded the leachate quality beyond Virginia Water Control Boards' Groundwater Standards, but were within observed ranges of non-sludge amended soil columns. Groundwater contamination is not likely as a result of land application of alum residuals up to a loading of four percent. / Master of Science

Previous research has shown that crop land application of alum sludge can be a valuable method of residuals disposal and has been demonstrated to cause no adverse effects on soil properties and crop yields. Studies have shown that with good soil management practices essential plant macronutrient levels can be maintained to support good crop growth. This study investigated the application of water treatment residuals in both field studies and greenhouse pot studies in order to determine the effects on soils properties and crop yields. Alum sludge collected from the Blacksburg-Christiansburg-VPI Water Authority and Radford Water Treatment Plant was land applied in the Spring of 1992. Two separate crop rotations, corn followed by wheat, were grown and harvested during the two-year field study. A greenhouse pot study using lettuce and radish plants was initiated in the Spring of 1993. Soil and plant tissue samples were collected and analyzed for the field and greenhouse studies. Harvest yields were also carefully monitored and recorded. The results of the laboratory analysis provided information on nutrient concentrations in soil and uptake by plants, and also soil and plant tissue elemental accumulations. Alum and PACI sludge at loading rates of up to 2.5% had no negative impacts on wheat yield. The growth study using lettuce and radish plants concluded that residual additions at low levels improved crop yield and that residual aging prior to land application was essential for good yield. / Master of Science