Made available in DSpace on 2017-07-10T18:08:16Z (GMT). No. of bitstreams: 1 Adriana Simane Camera.pdf: 3567207 bytes, checksum: 8d7a8eda99ee4c4d490c232bcc95cfd2 (MD5) Previous issue date: 2011-02-25 / Fundação Araucária / This work aims to study the reduction of hexavalent chromium to trivalent form through the adsorption process as assessed by the Kβ X-ray emission spectrometry. As adsorbent material activated carbon samples were used, while the resin Amberlite IR 120 was used as an indicator of the presence of Cr(III) in all solutions containing Cr(VI). Preliminar speciation tests were performed previously in solutions containing Cr(VI) in order to analyze the possible reduction to Cr(III) due to the effect of solution pH. A EDTA-based colorimetric speciation method of Cr(III) was applied. Preliminary kinetic Cr adsorption tests were performed at controlled temperature and agitation, achieving the equilibrium at 24 h for activated carbon. Batch single equilibrium Cr adsorption experiments using activated carbon and cation exchange resin materials as adsorbents and 8 mequiv.L-1 of Cr (III) and Cr(VI) ions as adsorvates were performed at pH 3.5 and under controlled temperature and agitation. Adsorbent and Cr reference material samples were pressed in pellets for spectrometric analysis. By using a high-resolution spectrometer of Johann type and a 6.1 keV monochromatic X-ray beam, Kβ X-ray emission spectra of Cr-treated adsorbent and reference material samples were registered by a Si detector, scanning the scattering X-ray by a spherycal bent analyzer around the Kβ1,3 spectral line of metallic chromium. The sample, spherical bent analyzer and detector system was positioned on the Rowland circle in order to scan in high resolution condition, focus the maximum back-scattered X-ray beam on the main detector and built Kβ X-ray emission spectra. As the incident monochromatic X-ray beam is a time-depending function, X-ray intensity that was registrated by detector was monitored and it was normalized to monitor-detector intensity. By setting measurement time of 2-4 h for Cr-treated adsorbent samples and 10-30 min for Cr reference material ones, a complete full scan of Kβ X-ray emission region was performed with enough statistic to observe the sattelite lines of chromium, which suffer a strong influence due to the oxidation state of metal ion and the chemical environment. The Cr-Kβ emission spectra were plotted on the basis of recorded X-ray intensity (y-axis) and spherical bent analyzer (SBA) position (x-axis), performing both the monitor-to-normalized intensity and the converted-to-energy SBA position. Besides this, scattered X-rays on matrix bulk and chromium absorption edge effect were systematically subtracted from Cr-Kβ emission spectra, applying pseudo-physical procedures and consequentely allowing enhancing the weaker sattellites lines of chromium. Main physical characteristic such as energy and intensity of main (Cr-Kβ1,3) and satellite lines (Cr-Kβ2,5 and Cr-Kβ ) for Cr-Kβ emission spectra of Cr treated-adsorbent samples were extracted by gaussian type peak fits and then compared with those of Cr reference materials, allowing to assign the oxidation state of chromium ions adsorbed on activated carbon surface and removed by an ion exchange process on cationic resin surface. In addition, no Cr(VI) reduction in acidic solutions was observed according to the EDTA-based colorimetric speciation result as well as with no presence of Cr(III)-Kβ spectral line pattern in Cr(VI) treated cationic resin samples. Based on Cr-Kβ spectral line analysis, the activated carbon samples treated with Cr(III) and Cr(VI) ions have shown the same spectral line pattern corresponding to the Cr(III) one. Thus, the reduction of Cr(VI) to Cr(III) has occurred by the adsorption process / Este trabalho visa estudar a redução do cromo hexavalente à forma trivalente através do processo de adsorção, avaliada pela espectrometria Kβ de emissão. Amostras de carvão ativado foram utilizados como material adsorvente, enquanto a resina Amberlite IR 120 foi usada como um indicador da presença de Cr(III) em todas as soluções contendo Cr(VI). Testes preliminares de especiação foram realizados em soluções contendo Cr(VI), a fim de analisar a possível redução para Cr(III) devido ao efeito do pH da solução. Foi aplicado o método de especiação colorimétrica de Cr(III), usando como complexante o EDTA. Testes preliminares da cinética de adsorção de íons de Cr foram realizados em batelada a temperatura e agitação controlada, alcançando o equilíbrio em 24 h para o carvão ativado. Foram realizados experimentos de adsorção de Cr utilizando carvão ativado e resina de troca catiônica materiais em soluções contendo 8 mequiv L-1 de Cr(III) e Cr(VI) em pH 3,5 e com temperatura e agitação controladas. Foram prensados, em forma de pastilhas, amostras de adsorventes tratados com Cr(III) e (VI), além de materiais de referência de Cr, para análise espectrométrica. Usando um espectrômetro de alta resolução do tipo de Johann e um feixe de raios X monocromático de 6,1 keV, foram registrados, por um detector de Si, espectros de emissão de raios-X Kβ de amostras de material adsorbente tratados com íons de Cr bem como de materiais de referência, fazendo para tanto a varredura em energia dos raios-X espalhados pela amostra em torno da linha espectral principal Kβ do cromo metálico. O conjunto amostra, analisador esfericamente curvado (SBA) e detector foi posicionado sobre um círculo de Rowland, a fim de obter, em condições de alta resolução, a focalização do feixe de raios X retro-espalhados no detector principal e permitindo a construção de espectros de emissão Kβ. Como a intensidade do feixe incidente de raios-X monocromático foi uma função dependente do tempo, a intensidade de raios-X registrada pelo detector foi monitorada e normalizada por aquela registrada pelo detector-monitor. Ao definir o tempo de medição de 2-4 h para amostras adsorvente tratadas com íons de Cr e 10-30 min para os compostos de referência de Cr, uma região completa do espectro de emissão de raios-X foi obtida com estatística suficiente para observar as linhas satélite dos íons de cromo, que sofrem uma forte influência devido ao estado de oxidação do íon metálico e do ambiente químico. Os espectros Kβ foram graficados em intensidade de raios-X contra a posição do analisador curvado (SBA), sendo sistematicamente normalizados a intensidade do detector-monitor e convertendo a posição do SBA em energia. Além disso, o fundo oriundo dos raios X espalhados na amostra e do efeito da borda de absorção do Cr foi subtraído de todos os espectros de emissão Cr-K, destacando assim as linhas satelites de cromo. As características físicas, como a energia e a intensidade, das linhas principais (Cr-Kβ1,3) e linhas satélite (Cr-Kβ2,5 e Cr-Kβ") foram extraídas dos espectros de emissão Cr-K das amostras tratadas com Cr e comparados com os dos materiais de referência, permitindo inferir o estado de oxidação do cromo adsorvido no carvão ativado e os que também foram removidos pela resina catiônica. Além disso, não foi observado a redução do Cr(VI) na solução, de acordo com a ausência das linhas espectrais de Cr(III) em amostras de resina catiônica tratadas com Cr(VI). Baseado na análise das linhas espectrais, as amostras de carvão ativado tratadas com Cr(III) e Cr(VI) têm mostrado o mesmo padrão de linhas espectrais correspondentes ao Cr(III) e portanto, a redução de Cr(VI) para Cr(III) ocorreu durante o processo de adsorção

[pt] A determinação de diferentes níveis de silício e alumínio em petróleo é importante porque pequenas quantidades destes elementos podem produzir efeitos adversos nas refinarias devido à corrosão de equipamento ou afetar a qualidade dos produtos refinados. A espectrometria de fluorescência de raios-X por dispersão de energia (EDXRF) foi utilizada para desenvolver um método para a determinação de Si e Al em petróleo, onde estes elementos se encontram principalmente sob a forma de partículas sólidas de aluminossilicatos dispersas na amostra. Uma vez que os analitos não puderam ser determinados sem interferência diretamente no óleo, a fusão das amostras de petróleo foi realizada utilizando tetraborato de lítio. Em seguida, as amostras fundidas foram colocadas no centro de papéis de filtro de 10 mm de diâmetro, que foi colocado entre duas folhas de filme de polipropileno, para então ser fixado à cubeta para as medições no instrumento. A quantificação foi feita por meio de curvas analíticas no intervalo de concentração de 0 a 40 mg kg(-1) (para ambos os elementos) no material fundido final. O método desenvolvido, não sofreu interferência matriz uma vez que as amostras foram completamente decompostas e, posteriormente secas no substrato. Os resultados para os elementos foram estatisticamente comparáveis com os obtidos por espectrometria de absorção atômica com chama (FAAS). Além disso, os resultados concordaram com os obtidos nas amostras de programas de proficiência da ASTM. Amostras reais de petróleo, fornecidas pela Petrobras, também foram analisadas. As recuperações alcançadas se encontram entre 71 e 100 por cento para as diferentes amostras, o qual pode ser considerado satisfatório devido à dificuldade em se determinar esses elementos. Os limites de quantificação (10 vezes o desvio-padrão, n=10) encontrados para o Si e Al no petróleo foram de 0,7 e 1,1 mg kg(-1), respectivamente, mostrando o potencial do método proposto para a determinação de amostras com valores mais elevados destes elementos. / [en] It is important to determine silicon and aluminum at different levels in crude oils because of trace amounts of these elements may produce adverse effects in oil refining either by causing corrosion or by contaminating and affecting the quality of the refined products. Energy dispersive X-ray fluorescence spectrometry (EDXRF) was used to enable a reliable method for determination of Si and Al in crude oil, where these elements are found mainly in the form of solid aluminosilicate particles dispersed in the sample. Since the analytes could not be determined directly in the oil without interference, the fusing the crude oil samples was made using lithium tetraborate. Then, the fused samples were placed in the center of 10 mm diameter filter paper that were sandwiched between two polypropylene film foils and attached to the instrument cell for measurements. Quantification was made by using analytical curves in the concentration range from 0 to 40 mg kg (-1) (for both elements) in the final fused material. The method developed did not suffer from matrix effect once the sample matrix was completely decomposed and the sample solution dried in the substrate before measurements. The results for the elements were statistically comparable to the ones obtained by flame atomic absorption spectrometry (FAAS). In addition, for proficiency test samples, the results were in accordance to the ones reported by ASTM proficiency programs. Real samples of oil provided by Petrobras Company also were analyzed. Recoveries were achieved between 71 and 100 percent for different samples, which can be considerable satisfactory because of the difficulty in determine those elements. The limits of quantification (10 times the standard deviation. N = 10) found for silicon and aluminum in the oil were of 0.7 and 1.1 mg kg (-1), respectively, showing the potential of the proposed method to screen for samples with higher amounts of these elements.

The elemental analysis of soil is useful in forensic and environmental sciences. Methods were developed and optimized for two laser-based multi-element analysis techniques: laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS). This work represents the first use of a 266 nm laser for forensic soil analysis by LIBS. Sample preparation methods were developed and optimized for a variety of sample types, including pellets for large bulk soil specimens (470 mg) and sediment-laden filters (47 mg), and tape-mounting for small transfer evidence specimens (10 mg). Analytical performance for sediment filter pellets and tape-mounted soils was similar to that achieved with bulk pellets. An inter-laboratory comparison exercise was designed to evaluate the performance of the LA-ICP-MS and LIBS methods, as well as for micro X-ray fluorescence (μXRF), across multiple laboratories. Limits of detection (LODs) were 0.01-23 ppm for LA-ICP-MS, 0.25-574 ppm for LIBS, 16-4400 ppm for µXRF, and well below the levels normally seen in soils. Good intra-laboratory precision (≤ 6 % relative standard deviation (RSD) for LA-ICP-MS; ≤ 8 % for µXRF; ≤ 17 % for LIBS) and inter-laboratory precision (≤ 19 % for LA-ICP-MS; ≤ 25 % for µXRF) were achieved for most elements, which is encouraging for a first inter-laboratory exercise. While LIBS generally has higher LODs and RSDs than LA-ICP-MS, both were capable of generating good quality multi-element data sufficient for discrimination purposes. Multivariate methods using principal components analysis (PCA) and linear discriminant analysis (LDA) were developed for discriminations of soils from different sources. Specimens from different sites that were indistinguishable by color alone were discriminated by elemental analysis. Correct classification rates of 94.5 % or better were achieved in a simulated forensic discrimination of three similar sites for both LIBS and LA-ICP-MS. Results for tape-mounted specimens were nearly identical to those achieved with pellets. Methods were tested on soils from USA, Canada and Tanzania. Within-site heterogeneity was site-specific. Elemental differences were greatest for specimens separated by large distances, even within the same lithology. Elemental profiles can be used to discriminate soils from different locations and narrow down locations even when mineralogy is similar.

Lithological core logging is a subjective and time consuming endeavour which could possibly be automated, the question is if and to what extent this automation would affect the resulting core logs. This study presents a case from the Zinkgruvan Zn-Pb-Ag mine, Bergslagen, Sweden; in which Classification and Regression Trees and K-means Clustering on the Self Organising Map were applied to X-Ray Flourescence lithogeochemistry data derived from automated core scan technology. These two methods are assessed through comparison to manual core logging. It is found that the X-Ray Fluorescence data are not sufficiently accurate or precise for the purpose of automated full lithological classification since not all elements are successfully quantified. Furthermore, not all lithologies are possible to distinquish with lithogeochemsitry alone furter hindering the success of automated lithological classification. This study concludes that; 1) K-means on the Self Organising Map is the most successful approach, however; this may be influenced by the method of domain validation, 2) the choice of ground truth for learning is important for both supervised learning and the assessment of machine learning accuracy and 3) geology, data resolution and choice of elements are important parameters for machine learning. Both the supervised method of Classification and Regression Trees and the unsupervised method of K-means clustering applied to Self Organising Maps show potential to assist core logging procedures.

The main focus areas of this master thesis include the writing of a literature review, which contains an overview and segregation of pigments which are used in the preparation of cosmetic products. The thesis is focused on the properties and characterization of pigments for use in cosmetology. The following focus is on legislation, more specifically on pigments that the cosmetic industry allows, limits and does not allow. The main part of this thesis is an overview of methods for the characterization of pigments. The practical part deals with the characterization of particles of selected cosmetic pigments by applying methods for determination of color, elemental and phase composition, particle size and morphology. The thesis is concluded by evaluation of the achieved results.

Ernst Alexander hat sich sowohl als experimentell als auch theoretisch äußerst fähiger Assistent von Georg von Hevesy im Institut für Physikalische Chemie der Universität Freiburg um die Entwicklung der Röntgenfluoreszenzanalyse verdient gemacht, habilitiert und wurde 1933 kurz nach seiner Ernennung zum Privatdozenten entlassen. Er ging an die Hebräische Universität Jerusalem, wo er das Arbeitsgebiet Experimentalphysik mit einer Institutswerkstatt aufgebaut, wesentliche Beiträge zur Röntgenstrukturanalyse geleistet und als Hochschullehrer fähige Wissenschaftler hervorgebracht hat. Während der kriegerischen Auseinandersetzungen stellte er Ersatzteile erst für die britische und dann für die israelitische Armee her. Ungeachtet seiner In Freiburg und in Jerusalem erbrachten Leistungen waren 1956 Institutsdirektor R. Mecke und der Dekan bei der Beurteilung seines Wiedergutmachungsantrages nicht bereit, ihm einen positiven Verlauf seiner akademischen Laufbahn zu bescheinigen, wenn er in Deutschland seine Arbeit hätte fortsetzen können. / Ernst Alexander was an assistant of George de Hevesy in the institute of physical chemistry of the university in Freiburg. He was a skillful experimenter with broad knowledge. He has done important contributions in the development of x-ray fluorescence analysis and has been qualified to give lectures at the university. In 1933 shortly after his appointment as lecturer he was dismissed. He went to the Hebrew University of Jerusalem, where he founded the laboratory of experimental physics with a workshop, where he dealt with x-ray structural analysis. During the war he produced spare parts for the British and later for the Israeli army. In 1956 he applied for reparation, but the head of the institute, R.Mecke and the dean did not accept that he would obtain a professorship if he must not leave Germany.

No description available.

This study was carried out as a bachelor's thesis at KTH Royal Institute of Technology during the spring of 2023, investigating the correlation between the color with the concentration of various metal and metalloids (MMs) in the soil of Marinduque, The Philippines. With a history of mineral exploitation, notably copper and gold, the island has faced persistent environmental challenges, exemplified by the catastrophic waste spills in 1993 and 1996 that contaminated the Boac and Mogpog Rivers. These incidents have left lasting consequences on the environment and human health. The research methodology involved an analysis of soil samples collected from Marinduque, using portable equipment such as Olympus Vanta X-Ray Fluorescence (XRF), color scanning using the Nix Pro 2 Color Sensor, followed by data processing through MATLAB version R2023a. The latter involved statistical methods such as Pearson correlation and p-value, which produced correlation coefficients and identified which correlations were statistically significant. The correlations yielded were those between varying MMs concentrations in the soil and CIE L*a*b* soil color parameters across different municipalities in Marinduque. These correlations offer insights into potential causal relationships between arsenic (As), iron (Fe), lead (Pb), manganese (Mn) and zinc (Zn), and soil discoloration. Based on correlations between MMs concentrations and soil color, future studies can encompass a broader range of soil assessment and contamination risks analysis, thus offering valuable guidance to local communities and authorities in devising effective strategies for mitigating MMs pollution in the natural environment. / Denna studie utfördes som en kandidatuppsats vid Kungliga Tekniska högskolan (KTH) under våren 2023 och undersökte korrelationer mellan färg, metalloid- och metallkoncentrationer i marken på Marinduque, Filippinerna. Med en historia av mineralutvinning, särskilt koppar och guld, har ön stått inför pågående miljöutmaningar, såsom katastrofala avfallsutsläpp som förorenat floderna Boac och Mogpog. Dessa händelser har lämnat långvariga konsekvenser för miljön och människors hälsa. Forskningsmetoden omfattade en analys av jordprover från Marinduque, med användning av laboratorieutrustning som röntgenfluorescens (XRF), färgskanning med Nix Pro 2 Color Sensor, följt av databehandling genom MATLAB version R2023a. Den senare involverade statistiska metoder som Pearson-korrelation och p-värde, vilka genererade korrelationskoefficienter och identifierade vilka korrelationer som var statistiskt signifikanta. De erhållna korrelationerna var mellan varierande metallkoncentrationer i jorden och CIE L*a*b* markfärgsparametrar inom olika kommuner på Marinduque. Dessa korrelationer ger insikter i potentiella kausala samband mellan arsenik (As), järn (Fe), bly (Pb), mangan (Mn) och zink (Zn), samt jordfärg. Baserat på korrelationer mellan metalloid- och metallkoncentrationer i mark och markfärg kan framtida studier täcka en bredare räckvidd av risker för markförorening, och därmed erbjuda värdefull vägledning till lokala samhällen och myndigheter för att utveckla effektiva strategier för att minska förorening av tungmetaller i den naturliga miljön.

Submitted by Eunice Novais (enovais@uepg.br) on 2018-06-28T19:18:21Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Talita Rosas Ferreira.pdf: 3918159 bytes, checksum: 3af8401f079b1540a49f10a3f6fd3b2d (MD5) / Made available in DSpace on 2018-06-28T19:18:21Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Talita Rosas Ferreira.pdf: 3918159 bytes, checksum: 3af8401f079b1540a49f10a3f6fd3b2d (MD5) Previous issue date: 2018-04-23 / No presente estudo, foram investigados os efeitos da calagem superficial sobre: os atributos químicos, as propriedades de interação com a radiação e a estrutura (sistema poroso) de um Cambissolo Háplico alumínico. A estrutura do solo foi analisada em escala micrométrica, considerando monólitos (8×8×8 cm) e pequenos agregados do solo (2-4 e 1-2 mm de diâmetro). O experimento consistia de cinco faixas, uma delas em área de pasto, considerada como referência (REF) e representando as condições do solo antes da implementação do sistema de plantio direto (SPD), e as demais, sob SPD, receberam as seguintes doses de calcário: 0 (C0), 10 (C10), 15 (C15) e 20 (C20) t ha-1 aplicadas na superfície do solo. A coleta das amostras se deu aos trinta meses após o procedimento de calagem, nas camadas 0-10 cm (A) e 10-20 cm (B). Os atributos químicos do solo foram caracterizados de acordo com procedimentos experimentais padrões e a composição de óxidos do solo, obtida por meio de análise de espectroscopia de fluorescência de raios X (FRX), foi usada para o cálculo do coeficiente de atenuação de massa do solo (μm), por meio do código computacional XCOM, para as energias de ≈ 60 keV (241Am) e ≈ 662 keV (137Cs). Os valores de μm foram utilizados para calcular as demais propriedades de interação da radiação com o solo e para simular as variações causadas na densidade (D) e porosidade total (Pt) do solo. Para a análise da estrutura do solo, foram utilizadas imagens 3D de microtomografia computadorizada de raios X (μTC), com resolução espacial de 60 μm (monólitos), e de μTC utilizando radiação síncrotron (μTC-RS), com resolução espacial de 1,64 μm (agregados). A visualização, processamento e análise das imagens foram realizadas com o software Avizo Fire. Foram determinadas as seguintes propriedades micromorfológicas e geométricas: porosidade baseada na imagem (P’), número de poros (NP), distribuições de P’ e NP em função de intervalos de volume, comprimento, alongamento, formato, conectividade e tortuosidade dos poros (monólitos); e: P’, distribuições de P’ e NP em função de intervalos de volume, conectividade, tortuosidade e dimensão fractal (agregados). Complementarmente, a composição elementar dos agregados do solo foi avaliada por meio de medidas de FRX. Na maioria dos casos, os efeitos da calagem concentraram-se na camada A, onde houve melhora nos atributos químicos e, portanto, no grau de acidez do solo, bem como houve aumento nas propriedades de interação da radiação em função das doses de calcário. O aumento nas propriedades de interação da radiação foi mais acentuado para a energia de ≈ 60 keV em relação a ≈ 662 keV e, no primeiro caso, as mudanças causadas em μm promoveram variação considerável na D e Pt do solo, demonstrando a relevância do estudo. A exemplo dos efeitos da calagem sobre o sistema poroso de monólitos do solo, na camada A, ressalta-se o aumento de P’ e do número de poros em que o poro principal foi separado, os quais foram identificados como sendo mais alongados e mais conectados devido à calagem. A calagem promoveu ainda alterações no arranjo dos poros separados, em ambas as camadas, com a formação de poros cilíndricos na direção horizontal, o que pode ser atribuído ao estímulo da atividade da fauna do solo. Para os agregados de solo, na camada A, a porcentagem de cálcio foi elevada a um valor mais alto em agregados de 1-2 mm em comparação com aqueles de 2-4 mm, em função das doses de calcário. A calagem afetou negativamente a estrutura de pequenos agregados do solo, diminuindo a P’ e aumentando a tortuosidade de poros para agregados de 1-2 mm. Além disso, a calagem reduziu a dimensão fractal em agregados de ambas as classes de tamanhos, em acordo com o fato de que, com a calagem, poros maiores foram substituídos por poros menores em agregados de 1-2 mm, conforme análises de natureza quantitativa e qualitativa. / In the present study, effects of surface liming on: chemical attributes, soil-radiation interaction properties and the structure (porous system) of a Dystrudept soil were investigated. The soil structure was analyzed in micrometric scale, considering monoliths (8×8×8 cm) and tiny aggregates (2-4 and 1-2 mm in diameter). The trial consisted of five stripes, one of them under pasture, considered here as reference (REF), representing the soil conditions before the no-till system (NTS) implementation, and the remaining, under NTS, received the following lime rates: 0 (C0), 10 (C10), 15 (C15) and 20 (C20) t ha-1 on the soil surface. Samples were collected thirty months after the liming procedure, at the 0-10 cm (A) and 10-20 cm (B) soil layers. The soil chemical attributes were characterized according to standard experimental procedures and the soil oxide composition, obtained by X-ray fluorescence spectroscopy (XRF), was used for the calculation of the soil mass attenuation coefficient (μm), by means of the computer code XCOM, for the energies of ≈ 60 keV (241Am) amd ≈ 662 keV (137Cs). The μm values were used to calculate the remaining soil-radiation interaction properties and to simulate variations caused on soil density (D) and total porosity (Pt). For the soil structure analysis, 3D images of X-ray computed microtomography (μCT), with spatial resolution of 60 μm (monoliths), and 3D images of synchrotron radiation based X-ray computed microtomography (SR-μCT), with spatial resolution of 1,64 μm (aggregates) were used. The image visualization, processing and analysis were performed in the Avizo Fire software. The following micromorphological and geometrical properties were determined: image-based porosity (P’), number of pores (NP), distributions of P’ and NP as function of volume intervals, length, elongation, shape, connectivity, and tortuosity of pores (monoliths); and: P’, distributions of P’ and NP as function of volume intervals, connectivity, tortuosity, and fractal dimension (aggregates). Additionally, the elemental composition of the soil aggregates was evaluated by XRF. In the majority of cases, liming effects were concentrated at layer A, where there was an improvement of soil chemical attributes and, therefore, of soil acidity level, as well as there was an increase in the soil-radiation interaction properties as function of lime rates. The increase in soil-radiation interaction properties was more accentuated for the energy of ≈ 60 keV in relation to ≈ 662 keV and, in the former case, the μm variation promoted considerable variation in D and Pt, demonstrating the relevance of the study. Highlighted instances of liming effects on the porous system of the soil monoliths, at layer A, were an increase in P’ and in the number of pores into which the main soil pore was separated, which were identified as being longer and more connected due to liming. Moreover, liming promoted changes in the arrangement of the separated pores, at both soil layers, with the formation of cylindrical pores in the horizontal orientation, which can be attributed to stimulation of the soil fauna activity. Regarding the soil aggregates, at layer A, calcium was raised to a higher percentage in aggregates of 1-2 mm when compared to those of 2-4 mm, as function of the lime rates. Liming affected negatively the structure of the soil tiny aggregates, decreasing P’ and increasing the tortuosity of pores for 1-2 mm aggregates. Besides, liming decreased the fractal dimension in aggregates from both size classes, in accord to the fact that, with liming, larger pores were replaced by smaller ones in 1-2 mm aggregates, as both quantitatively and qualitatively analyzed.

O fósforo (P) é um nutriente essencial para o crescimento das plantas. Milhões de toneladas de P são aplicados aos solos anualmente. No entanto, apenas uma pequena fração do P aplicado com fertilizantes é aproveitada nas lavouras no ano de aplicação, bem como a eficácia do fertilizante fosfatado diminui com o tempo. Para melhorar a nossa compreensão dos mecanismos, a esta resposta do P no campo, este trabalho visa estudar a migração desse elemento em solos tropicais brasileiros (Latossolo vermelho e Latossolo amarelo) tratados com três tipos de fertilizantes: fosfato monoamônico (MAP), o polímero revestido de fosfato monoamônio (MAPP) e fosfato organomineral (OMP) em um experimento de placa de Petri. Fluorescência de Raios X por Reflexão Total (TXRF) foi usada para determinar o fluxo difusivo P a distâncias radiais diferentes (entre 0 e 7,5 mm, entre 7,5 e 13,5 mm, 13,5 e 25,5 mm e entre 25,5 e 43 mm) a partir do grânulo de fertilizante. As análises usando TXRF foram realizadas no Laboratório Nacional de Luz Síncrotron (LNLS), em Campinas, São Paulo, na linha de Fluorescência de Raios X (Beamline D09B). Depois de um período de cinco semanas, a concentração total de P, Ca e Al foram obtidas e comparadas analisando o tipo de solo/textura, o pH e o respectivo extrator de P, que nesse estudo foram usados o Mehlich 1 e água régia. De forma geral, concluiu-se que 80,0 % de fósforo proveniente dos fertilizantes usados nessa proposta ficaram concentrados em distâncias menores que 10 mm do ponto de aplicação dos fertilizantes, independentemente do tipo de solo, do pH e da respectiva textura. Em relação à utilização da técnica TXRF, o sistema foi eficiente, dentre outras características, na discriminação dos picos de fósforo dos picos de enxofre, principalmente nas amostras de solo usadas a partir da extração com Mehlich 1. Destaca-se isso, pois os raios X característicos desses elementos são muitos próximos. / Phosphorus is an essential nutrient for plant growth. Million of tones of P are applied to the soils annually. However, only a small fraction of the P applied with fertilizers is taken up by crops in the year of application, and the effectiveness of any residual P fertilizer declines with time. To improve our understanding of the mechanisms underlying this response to P in the field, this work aims to study the migration of this element in Brazilian tropical soils (red and yellow Oxisol) treated with three types of fertilizers: monoammonium phosphate (MAP), polymer coated monoammonium phosphate (MAPp) and Organomineral phosphate (OMP) in a Petri dish experiment. Total Reflection X-Ray Fluorescence (TXRF) was used to determine the P diffusive flux at different distances (0 - 7.5, 7.5 13.5, 13.5 25.5 and 25.5 43 mm) from granular fertilizer. TXRF analyses were performed at the X-Ray Fluorescence Beamline D09B at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, São Paulo. After a period of five weeks, the total concentration of P, Ca and Al were obtained and compared by analyzing the type/soil texture, pH, and the respective extractor P, this study used the Mehlich 1 and aqua regia . In general, it was found that 80.0 % of phosphorus from the fertilizer used in this proposal were concentrated in distances smaller than 10 mm from the point of application of fertilizers , regardless of the soil type , pH, and its texture. Regarding the use of TXRF technique , the system was efficient , among other features , the breakdown of phosphorus peaks of the sulfur peaks , especially in the soil samples used from the extraction with Mehlich 1. It is noteworthy that, as the rays X characteristic of these elements are very close.