Due to the complexity of nitrogen dynamics in the soil, tracer techniques are employed to estimate the fate and transport of nitrate in agricultural fields. This study was conducted to examine effects of N fertilization and landscape position on two-dimensional redistribution of bromide in a hummocky landscape, and to identify the landscape position with the greatest potential for solute loss using a dual application of Br- and 15N. The field data on Br- transport was also simulated using the HYDRUS models. The study was carried out near Brandon, Manitoba in 2007 and 2008, using two separate plots denoted as Site-2007 and Site-2008, respectively. The field plot was delineated into three landscape positions as upper (UPP), middle (MID) and lower (LOW) slope. Each landscape position received labelled K15NO3 at the rates of 0, 90 and 135 kg N ha-1, and KBr at the rate of 200 kg Br- ha-1. Site-2007 was seeded to canola while Site-2008 had winter wheat. Soil samples were taken in the fall and the following spring and were analyzed for Br-, NO3-N, total N, and isotope N ratio. Nitrogen fertilization reduced the downward movement of Br- in the soil profile, resulting in a greater lateral movement of Br- compared to the unfertilized plots. The greatest vertical and lateral movement of Br- occurred at the LOW slope. In the dual-tracer experiment, the smallest amounts of Br-, 15N, and NO3-N were measured in the soil at the LOW slope, while the greatest amounts were at the MID slope; indicating that solute loss was: LOW > UPP > MID. In the absence of crop uptake, Br- transport was identical to that of 15N. The simulation study showed that HYDRUS-1D model was inadequate to describe solute transport in the landscape, as HYDRUS-2D/3D reproduced the field data better than HYDRUS-1D. However, the 2D model did not reflect effects of landscape position and N fertility on Br- transport. Overall, the study confirmed the “Campbell hypothesis” which states that proper N fertilization reduces nitrate leaching. The field experiment and model simulation both showed that downward movement is the main pathway of solute loss in the landscape.

When high yield chemimechanical sulphite pulp fibres were suspended in water, both lignin and carbohydrate were leached out of the pulp. The rate of leaching fitted a theory developed previously for the diffusion of macromolecules through the water-swollen fibre wall. The average intrafibre diffusion coefficients for lignin and carbohydrate were several orders of magnitude lower than the free diffusion of these macromolecules in solution. Leaching over a long period indicated a polydispersity of diffusion coefficients. This was related to an increase with time in the molecular weights of macromolecules removed from the fibre. Although the rate of leaching increased markedly with temperature, the diffusion coefficient of lignin decreased, while that of carbohydrate increased by a factor higher than that predicted by the Stokes-Einstein equation. These contrasting results were interpreted in terms of the molecular weights of the diffusing species and hydrogen bonding of carbohydrate to the fibre wall. The rate of leaching decreased with an increase in pulp yield, increasing cationic strength and pH of the wash water, decreasing refining energy, pretreatment of pulp with formaldehyde, and the use of polyethyleneoxide/alum retention aid in the wash water. Decreasing pH of the cooking liquor and the use of anthraquinone in the pulping increased the leaching of lignin but did not affect the leaching of carbohydrate. The effects observed could be related either to swelling or degradation of the fibre wall.

This study was carried out with Beypazari trona ore having a grade about 85 % trona (Na2CO3.NaHCO3.2H2O). The main target of the study is the determination of calcinations and leaching parameters, which are the two main unit operations in the production of soda ash (Na2CO3) from trona ore. Calcination parameters / calcination duration, calcination temperature and particle size were determined by using three different heat treatment systems, namely laboratory type muffle furnace, up draught furnace and microwave oven. As an alternative, wet type microwave-induced calcination which completes the decomposition of trona in solution was also investigated. Thirty minutes of calcination time was sufficient for complete calcination of &amp / #8211 / 6.35 mm trona sample at 175 &deg / C with the muffle furnace. Calcination of trona with microwave treatment was completed in a shorter time. The nature of thermal reactions and structural changes of trona during calcination were elucidated by TG (Thermogravimetry), DTG (Derivative Thermogravimetry), SEM (Scanning Electron Microscope) and XRD (X-ray diffraction) analysis. The effect of heat treatment on grindability, specific surface area and decrepitation of trona were also investigated. In the last stage of the study, leaching parameters / leaching time, leaching temperature and pulp density were determined for both uncalcined and calcined samples. 80 % leach recovery was obtained in 4 minutes for &amp / #8211 / 6.35 mm particle size of uncalcined sample in 25 % pulp density while 100 % leach recovery was reached for the calcined samples under the same conditions.

Thesis (Ph.D.)--Murdoch University, 2003. / Thesis submitted to the Division of Science and Engineering. Bibliography: leaves 190-209.

Thesis (M.S.)--University of Nevada, Reno, 2005. / "August 2005." Includes bibliographical references (leaves 81-82). Online version available on the World Wide Web.

Thesis (M.S.)--Ohio University, August, 1992. / Title from PDF t.p.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Submitted by GÉSSICA APARECIDA SILVEIRA (gessicasilveira100@hotmail.com) on 2016-01-22T12:21:41Z No. of bitstreams: 1 Dissertação_Gessica_Aparecida_Silveira.pdf: 2697973 bytes, checksum: 0379873e1b58dd16332e3d3e730d4b7b (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-01-25T13:46:57Z (GMT) No. of bitstreams: 1 silveira_ga_me_jabo.pdf: 2697973 bytes, checksum: 0379873e1b58dd16332e3d3e730d4b7b (MD5) / Made available in DSpace on 2016-01-25T13:46:57Z (GMT). No. of bitstreams: 1 silveira_ga_me_jabo.pdf: 2697973 bytes, checksum: 0379873e1b58dd16332e3d3e730d4b7b (MD5) Previous issue date: 2015-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atividades agropecuárias contribuem para a degradação das águas, alterando processos físico-químicos e biológicos, principalmente pela ocupação e uso do solo, por processos de lixiviação e/ou erosão. Os objetivos do presente trabalho foram: avaliar a influência do uso do solo na qualidade da água dos córregos Jaboticabal e Cerradinho e estudar o perfil metabólico da população microbiana da água. As coletas (C1 a C6) foram realizadas bimestralmente (Fev a Dez/2014) em oito pontos (P1 a P8), um deles situado na entrada do município de Jaboticabal, no córrego Cerradinho; outro, próximo à nascente do Córrego Jaboticabal; três pontos localizados em área urbana e os demais, em área rural. Foram determinadas variáveis físicas e químicas e a comparação metabólica da população microbiana das amostras de água foi realizada pela avaliação da capacidade de metabolização de diversas fontes de carbono pelo método EcoPlate (Biolog). Os resultados para oxigênio dissolvido, cloreto, nitrito, nitrato, sólidos totais dissolvidos e turbidez, estão de acordo com os valores estabelecidos na resolução 357/2005 do Conselho Nacional do Meio Ambiente (CONAMA), para corpos d´água classe 2. Em todos os pontos e coletas, o teor de fósforo total (Ptotal) excedeu o limite estabelecido pelo CONAMA. Em pontos próximos de atividades agrícolas ocorreram alterações nos valores de variáveis físicas e de variáveis químicas, observando-se resultados elevados para Ptotal e demanda química de oxigênio. A estatística multivariada auxiliou na interpretação dos resultados, mostrando que as atividades antropogênicas afetam a qualidade da água. O estudo de comparação das populações microbianas pela análise da capacidade de metabolização de diferentes fontes de carbono mostrou que a população microbiana da água parece não estar sendo alterada pelas atividades agrícolas. O perfil metabólico da população bacteriana das amostras não apresentou correlação com a presença das atividades agrícolas, os resultados mostram diferenças entre as coletas, mas não entre os pontos de amostragem. Atividades agropecuárias contribuem para a degradação das águas. Metais incorporados no solo, devido a diferentes manejos, podem ser transportados para as águas superficiais por processos de lixiviação e/ou erosão contaminando-as. Bactérias resistentes a metais podem ser utilizadas em processos de biorremediação. Objetivos: determinar as concentrações de metais traço em dois corpos d´água e no seu sedimento e isolar micro-organismos presentes na água para testes de resistência aos metais. As coletas de água (C1 a C6) foram realizadas bimestralmente (fevereiro a dezembro/2014) em oito pontos (P1 a P8). Um deles situado na entrada do município de Jaboticabal, no córrego Cerradinho; outro, próximo à nascente do Córrego Jaboticabal; três pontos localizados em área urbana e os demais, em área rural. O sedimento foi coletado na C6 nos pontos P3, P4, P6, P7 e P8. Nas amostras de água e sedimento foram determinadas as concentrações de cobre, cádmio, zinco, chumbo, níquel e cromo. Visando relacionar os teores de metais encontrados na água com os presentes no solo do entorno, foram coletadas (em fevereiro e agosto/2014), amostras de solo, em doze pontos (PS1 a PS12): PS1, PS2 e PS3, distantes do córrego Jaboticabal; PS4, PS5 e PS6 em área de plantação; PS7, PS8, PS9, PS10, PS11 e PS12, nas matas ciliares presentes nas imediações do córrego Jaboticabal. Foram isolados 182 micro-organismos das amostras de água e submetidos a testes de resistência aos metais estudados em meio de cultivo contendo diferentes concentrações (1, 2, 3, 4 e 5 mmol L-1) dos metais. Em pontos próximos ao córrego Jaboticabal foi possível observar maiores concentrações de metais no solo que, portanto, pode afetar a qualidade da água por meio de processos de erosão e/ou lixiviação, promovendo aumento da concentração de metais no corpo d’ água. Para a água observou-se reta de tendência com aumento nas concentrações de cádmio, cobre e cromo nos pontos da área agrícola (P6, P7 e P8). No sedimento, as maiores concentrações de metais foram encontradas em área agrícola evidenciando que o córrego está sendo impactado. Os micro-organismos isolados mostraram capacidade de se desenvolver mesmo na maior concentração estudada (5 mmol L-1) em proporções diferentes: para Zn (62,1%) e Pb (92,9%), Cd (32,4%) e Ni (29,7%), Cu (0,5%) e Cr (0%). Dos isolados resistentes 35 se desenvolveram em meio com quatro metais (Cd, Zn, Pb e Ni), mas apenas 1 isolado apresentou resistência aos cinco metais (Cu, Cd, Zn, Pb e Ni). Os microrganismos isolados precisam ser identificados e poderão ser utilizados em processos de biorremediação. / Farming activities contribute significantly to water degradation through alterations in physico-chemical and biological properties, which are mainly derived from land use and occupation as well as processes such as leaching and/ or erosion. This paper focused on assessing the influence of soil use on the water quality of surface waters of Jaboticabal and Cerradinho streams and study the metabolic profile of microbial communities found in this water body. Sampling dates (C1 to C6) were carried out bimonthly (from February to December of 2014) at eight different points (P1 to P8). One of these areas was set at the entrance of Jaboticabal city in Cerradinho stream. Another point lies near the source of the Jaboticabal stream. Three points were set within the urban area and the others within the rural area of Jaboticabal. Water physical and chemical variables were assessed. Moreover, we compared the ability of microorganisms to metabolize different sources of carbon using the Ecoplate method (Biolog). The results on dissolved oxygen, chloride, nitrite, nitrate, total dissolved solids and turbidity are in accordance with standards established by resolution number 357/ 2005 of the National Council on the Environment (CONAMA) for class 2 water bodies. The concentration of total phosphorus (TP) exceeded the limit value set by the CONAMA. We also noted significant changes on physical and chemical variables in areas near agricultural activities such as alterations of TP and chemical oxygen demand. Multivariate statistics assisted on data interpretation and showed the influence of human activities on water quality. Furthermore, the comparisons among microbial communities via study of metabolization of various carbon sources proved that farming activities have not affected the population structures. Therefore, the bacterial metabolic profile had no association with farming practices; however, the results showed differences among sampling dates, but not referring to the sampling points. Agricultural activities contribute to the degradation of the water bodies. Metals incorporated into the soil, due to different management, can be transported to the surface waters through the processes of lixiviation and / or erosion, contaminating them. Bacteria which are resistant to metals can be used in the bioremediation processes. Objectives: To determine the concentrations of trace metals in two a bodies of water and its sediment and isolate micro-organisms present in the water for testing their resistance to metals. The water sampling dates (C1 to C6) were carried out bimonthly (from february to december of 2014) at eight different points (P1 to P8). One of these areas was set at the entrance of Jaboticabal city in Cerradinho stream. Another point lies near the source of the Jaboticabal stream. Three points were set within the urban area and the others within the rural area of Jaboticabal. The sediment was sampling dates in C6 in the points P3, P4, P6, P7 and P8. For the water and sediment samples were determined the concentrations of copper, cadmium, zinc, lead, nickel and chromium. Aiming to relate the the levels of metals found in water with the ones present in the soil from the surroundings, were collected (in february and august / 2014), samples of the soil in twelve points (PS1 to PS12): PS1, PS2 and PS3, far from the stream Jaboticabal; PS4, PS5 and PS6 in plantation areas; PS7, PS8, PS9, PS10, PS11 and PS12,in riparian forests present in the stream nearby. 182 micro-organisms from the samples were isolated in the water samples and tested for resistance to the metals in culture media containing different concentrations(1, 2, 3, 4 and 5 mmol L-1) of metals. At points near the stream it was possible to observe higher metal concentrations in soil, therefore, may affect the quality of water through erosion and / or leaching, promoting increased concentration of metals in the body of water. For the water, the trend was observed with the increase in the concentrations of cadmium, copper and chromium in points of the agricultural area (P6, P7 and P8). In the sediment, the highest concentrations of metals were found in agricultural areas, showing that the stream is being impacted. The micro-organisms isolated showed the same ability to grow even in the highest concentration studied (5 mmol L-1) in different proportions: for Zn(62.1%) and Pb (92.9%), Cd (32.4%) and Ni (29.7%), Cu (0.5%) and Cr (0%). From the 35 isolated resistant organisms developed in medium with four metals (Cd, Zn,Pb and Ni), but only one isolate was resistant to the five metals (Cu,Cd, Zn, Pb and Ni). The microorganisms need to be identified and will be able to be used in bioremediation processes.

Resumo: Uma possibilidade para a recuperação de metais a partir de minerais com baixos teores ou de rejeitos industriais é a utilização da lixiviação com micro-organismos. A biolixiviação é o processo de oxidação bacteriana de sulfetos metálicos contendo metais de valor (por exemplo, níquel, cobre ou zinco), os quais são liberados para a solução, seguida da recuperação por técnicas metalúrgicas convencionais. Estudos de biolixiviação de concentrados de sulfetos minerais em tanques agitados e, sobretudo em pilhas, têm sido desenvolvidos em escala piloto e comercial. Entretanto, poucos trabalhos têm sido realizados sobre o aproveitamento de rejeitos minerais de processos convencionais, tais como flotação ou fusão em forno "flash", por rotas biotecnológicas. O objetivo deste trabalho foi recuperar níquel e cobre de rejeitos industriais, provenientes de processo de flotação e de fusão, utilizando bactérias, especialmente da espécie Acidithiobacillus ferrooxidans ou pelo uso de soluções ácidas, em escala de laboratório. Também foram realizados experimentos de biolixiviação de um sulfeto de níquel (pentlandita) para avaliar o processo de solubilização do metal. Conjuntamente, outros experimentos foram realizados com a finalidade de se obter novas linhagens isoladas a partir destes rejeitos minerais. Suas diferenças fisiológicas foram avaliadas. A partir dos experimentos com os rejeitos encontrou-se que com a escória foi possível obter 13% de níquel e 8 % de cobre em solução após 14 dias de lixiviação biológica. Com soluções ácidas, em pH 0,5 e 1,0, as recuperações foram de 56% de níquel e 24% de cobre em pH 0,5 enquanto que em pH 1,0 as concentrações foram de 21% e 12% de niquele e cobre, respectivamente. Para a recuperação de níquel e cobre deste rejeito sugere-se a lixiviação ácida e não bacteriana. Com a lama as porcentagens... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Bacterial leaching is a feasible to recover metals from minerals with low grade or from mine wastes using microorganisms. The bioleaching process is the bacterial oxidation of valuables metals bearing sulphide minerals (e.g. nickel, copper or zinc), which are released to the solution, followed by conventional recovered by metallurgical techniques. Studies on bioleaching of sulphide minerals concentrates in stirred tanks and, particularly, in heaps, have been developed on pilot and commercial scales. However, few studies have been undertaken on using of mineral wastes from conventional processes such as flotation or flashing smelting through biotechnological routes. This work aims at recovering nickel and copper from industrial wastes such as flotation tailings and slag using bacteria, especially Acidithiobacillus ferrooxidans species, or using acid solutions at laboratory scale. Experiments were also accomplished for nickel sulfide bioleaching to evaluate the metal dissolution process, for comparison purpose. Other experiments were also carried out to obtain new strains isolated from mineral waste to study the physiological differences between them. After 14 days of bioleaching of slag it was possible to extract 13% of nickel and 8% of copper in solution while with acid solutions the extractions were 56% of nickel and 24% of copper at pH 0.5 and 21% and 12% at pH 1.0, respectively. For the metals solubilization from the slag it is suggested the acid leaching instead of bioleaching. With the flotation tailings the recoveries of nickel and copper were 23% e 16% at pH 0.5 or 1.0 while after 14 days with bioleaching the concentrations in solution were 46 % and 17% for nickel and copper. These results show that the flotation tailings can be treated with biological leaching for a higher recovery of metals. The studies of nickel sulfide bioleaching with different bacterial species reached only... (Complete abstract click electronic access below) / Orientador: Oswaldo Garcia Júnior / Coorientador: Denise Bevilaqua / Banca: Maria Lucia Gosales da Costa Araújo / Banca: Ana Teresa Lombardi / Banca: Wilson Cervi da Costa / Banca: Luis Gonzaga Santos Sobral / Doutor

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