The purpose of this study was to characterize the leachate from a landfill in Pennsylvania that had been pretreated by activated sludge and propose the most efficient treatment for this effluent. These samples had been pretreated in a sequencing batch reactor that also was operated to remove nitrogen by nitrification/denitrification. The SBR samples were found to have low BOD, high COD, high TOC and a very low BOD/COD ratio. These SBR decant samples have poor UV transmittance and hence quench UV light. Five treatment methods were evaluated, coagulation, ultrafiltration, combined coagulation/ultrafiltration, combined ultrafiltration/oxidation and combined filtration/fentons. These processes were tested for their ability to remove BOD and TOC and also to evaluate the improvement in UV transmittance. It was found that coagulation; Ultrafiltration and Ultrafiltration combined with coagulation do not work in improving the transmittance properties though there is a significant BOD and TOC removal with these processes. Ultrafiltration combined with oxidation was found to work the best in terms of TOC removal. In this study, four oxidants, KMnO?, H?O?, NaOCl and Fenton's reagent were used. It was observed that Fenton's reagent was capable of removing 90% TOC at a dose of 1g/L each of iron salt and hydrogen peroxide at a pH of 4.5. Since Fentons reagent was found to be the most effective method, hence, efforts were made to optimize the oxidation process with Fenton's. The two parameters which were studied were the initial pH and the chemical dosage. The initial pH was varied from a value of 2.5 to 6.5. The range of iron salt and peroxide dose used was from 0.05 to 0.1 g/L. Additional studies were conducted using samples filtered through a 0.45 um filter and oxidized with Fenton's reagent. The Fenton's process for oxidation of filtrates from the 0.45?m filter was also optimized with respect to pH and chemical dosage to determine the most economical operating conditions. The maximum transmittance of 57% was obtained for an iron dose of 0.075 g/L and a peroxide dose of 0.075 g/L at a pH of 4.5. This is in comparison to the transmittance of unoxidized 1K ultrafiltrate which was found to be 21.5%. There was a significant difference in the performance of 1K and 0.45um filtrates in terms of TOC removal and percentage transmittance. The oxidation process for improving the UV transmittance of leachate can therefore be economically optimized depending upon the desired efficiency by varying the operational parameters. / Master of Science

High total organic carbon (TOC) and low clay content are two criteria to identify the "sweet spots" in shale gas plays. Recently, machine learning has been proved to be effective to estimate TOC and clay from well loggings. The remaining questions are what algorithm we should choose in the first place and whether we can improve the already built models. Automatic machine learning (AutoML) appears as a promising tool to solve those realistic questions by training multiple models and compares them automatically. Two wells with conventional well loggings and elemental capture spectroscopy are selected from a shale gas play to test the AutoML's ability in TOC and clay estimation. TOC and clay content are extracted from the Schlumberger's ELAN interpretation and calibrated to cores. Generalizability is proved in the blind test well and the mean absolute test errors for TOC and clay estimation are 0.23% and 3.77%. 829 data points are used to generate the final models with the train-test ratio of 75:25. The mean absolute test errors are 0.26% and 2.68% for TOC and clay, respectively, which are very low for TOC ranging from 0-6% and clay from 35-65%. The results show the AutoML's success and efficiency in the estimation. The trained models are interpreted to understand the variables effects in predictions. 235 wells are selected through data quality checking and feed into the models to create TOC and clay distribution maps. The maps provide guidance on where to drill a new well for higher shale gas production. / Master of Science / Locating "sweet spots", where the shale gas production is much higher than the average areas, is critical for a shale reservoir's successful commercial exploitation. Among the properties of shale, total organic carbon (TOC) and clay content are often selected to evaluate the gas production potential. For TOC and clay estimation, multiple machine learning models have been tested in recent studies and are proved successful. The questions are what algorithm to choose for a specific task and whether the already built models can be improved. Automatic machine learning (AutoML) has the potential to solve the problems by automatically training multiple models and comparing them to achieve the best performance. In our study, AutoML is tested to estimate TOC and clay using data from two gas wells in a shale gas field. First, one well is treated as blind test well and the other is used as trained well to examine the generalizability. The mean absolute errors for TOC and clay content are 0.23% and 3.77%, indicating reliable generalization. Final models are built using 829 data points which are split into train-test sets with the ratio of 75:25. The mean absolute test errors are 0.26% and 2.68% for TOC and clay, respectively, which are very low for TOC ranging from 0-6% and clay from 35-65%. Moreover, AutoML requires very limited human efforts and liberate researchers or engineers from tedious parameter-tuning process that is the critical part of machine learning. Trained models are interpreted to understand the mechanism behind the models. Distribution maps of TOC and clay are created by selecting 235 gas wells that pass the data quality checking, feeding them into trained models, and interpolating. The maps provide guidance on where to drill a new well for higher shale gas production.

Η λεπτομερής ιζηματολογική ανάλυση των αποθέσεων της τομής Μακρυλιά, έδειξε την ύπαρξη τουλάχιστον 5 κύκλων ιζηματογένεσης με αυξανόμενο προς τα πάνω κοκκομετρικό μέγεθος που αναπτύχτηκαν σε ένα περιβάλλον υφαλοκρηπίδας. Η κύρια λιθολογία είναι αμμούχος πηλός και τα ιζήματα μεταφέρθηκαν ως ομογενές αιώρημα. Το ποσοστό του ανθρακικού ασβεστίου είναι χαμηλό και τείνει αυξανόμενο προς τα πιο αδρομερή κλάσματα. Το ποσοστό του οργανικού υλικού έδειξε την παρουσία αρκετών δειγμάτων με αυξημένο οργανικό υλικό προτείνοντας την ύπαρξη εν δυνάμει μητρικών πετρωμάτων για την γένεση υδρογονανθράκων. Η σχέση μεταξύ του ανθρακικού ασβεστίου και οργανικού υλικού είναι κύρια αρνητική προτείνοντας ανοξικές συνθήκες. Η βιοστρωματογραφική ανάλυση έδειξε Πλειοκαινική ηλικία των ιζημάτων που αποτέθηκαν σε εναλλασσόμενες οξικές – ανοξικές συνθήκες. Από τα παραπάνω αποτελέσματα και περνώντας υπόψη τα υπάρχοντα αποτελέσματα των ιζημάτων που περιβάλλουν την περιοχή μελέτης φαίνεται πως οι μελετηθείσες αποθέσεις συγκεντρώθηκαν σε μια ρηχή με ήσυχα νερά ενδο-ορεινή λεκάνη στα περιθώρια της κύριας λεκάνης της Ιεράπετρας. / Detailed sedimentological analysis, in Makrylia cross-section deposits, showed at least five coarsening-upward cycles developed in a shelf environment. The main lithology is sandy silt and sediments transported as homogenous suspension in a low energy environment that deposited in a shallow water basin. Calcium carbonate (CaCO3) is low and tends to increase to the coarse-grained clasts. Organic carbon (TOC) ratio showed the presence of many high content samples in TOC suggesting potential hydrocarbon source rocks. There is mostly a negative relation between CaCO3 and TOC introducing generally anoxic conditions. Biostratigraphy analysis showed a Pliocene age for the studied deposits in alternating conditions with oxic- anoxic events. According to the above results and taking into account previous results from the surrounding sediments it seems that studied deposits accumulated in a shallow, low energy, intra-mountain basin at the margins of the main Ierapetra basin.

O presente trabalho teve como objetivo avaliar a eficiência de pós-filtros adsorvedores constituídos de Carvão Ativado Granular (CAG) na remoção de compostos orgânicos precursores e na formação de subprodutos da desinfecção, em particular dos trialometanos (THM) na Estação de Tratamento de Água Alto da Boa Vista (ETA ABV), abastecida por reservatórios de água bruta com elevado grau de eutrofização. Os ensaios foram conduzidos em ETA Piloto composta por tanque de reservação de água filtrada, ozonizador, tanque de reservação de água ozonizada e 4 pós-filtros adsorvedores, sendo duas unidades dotadas de CAG de origem mineral e duas unidades dotadas de CAG de origem vegetal. Os filtros foram operados em paralelo, sendo que duas colunas foram alimentadas com água filtrada da ETA ABV (Filtro F3 CAG de origem mineral e Filtro F4 CAG de origem vegetal) e as outras duas alimentadas com água filtrada e ozonizada (Filtro F1 CAG de origem mineral e Filtro F2 CAG de origem vegetal). A avaliação da remoção de compostos orgânicos precursores e formação de subprodutos da desinfecção foi feita através de análises de carbono orgânico total (COT), UV-254 nm e formação de THM. A análise dos resultados gerados de julho de 2007 a dezembro de 2008 permitiu concluir que 93% do THM é formado nas primeiras 24 horas de contato da amostra com o cloro, simulando a pós cloração e pós alcalinização da ETA ABV. O processo de oxidação por ozônio não foi efetivo na remoção de THM instantâneo, visto que a média dos 38 valores de THM instantâneo para a água filtrada (17,8 ± 5,6 g/L) foi igual a média obtida para o THM instantâneo na água ozonizada. A remoção de THM pelos filtros de CAG foi mais significativa nos primeiros três meses de operação do sistema, apresentando remoção de 80% para os filtros com CAG de origem mineral e 70% para os filtros com CAG de origem vegetal, a partir do quarto mês de operação do sistema a remoção de THM caiu para um valor médio de 34%, o que mostra uma iminente saturação do leito adsorvedor. Os pós-filtros adsorvedores constituídos de CAG de origem mineral apresentaram melhor comportamento com respeito a remoção de THM e COT quando comparado com os pós-filtros dotados de CAG de origem vegetal. / The main purpose of this work was to evaluate the performance of a Granular Activated Carbon (GAC) post-filter adsorbers in the removal of organic precursors and in the formation of disinfection byproducts, especially trihalomethanes (THM) in Alto da Boa Vista Water Treatment Plant (ABV WTP), which takes raw water from a highly eutrophized reservoirs. The tests was conducted on a Pilot WTP composed of filtered water tank, ozonator, ozonized water tank, and four post-filter adsorbers: two units with mineral GAC media and two units with vegetal GAC media. The filters were operated in parallel, with two columns fed with filtered water from ABV WTP (F3 Filter mineral GAC and F4 Filter vegetal GAC) and the other fed with ozonized water (F1 Filter mineral GAC and F2 Filter vegetal GAC). The evaluation of the removal of organic precursors and the formation of disinfection byproducts was made through analysis of Total Organic Carbon (TOC), UV-254 nm and THM formation. The results generated from July 2007 to December 2008 showed that 93% of THM is formed in the first 24 hours of contact with the chlorine in the sample, simulating the post chlorination and post alkalinization of ABV WTP in samples of filtered water, ozonized water, and post-filter adsorbers effluent. Ozone oxidation process was not effective in removing THM. Was found the same instantaneous THM values in the filtered water (17.8 g/L± 5.6 g/L) and in the ozonized water. During the first three months of post-filter adsorber operation, THM removal efficiencies were around 80% for F1 and F3 (mineral GAC media) and around 70% for F2 and F4 (vegetal GAC media). After four months of operation, THM removal efficiencies decreased to 34% average value, thus indicative of GAC saturation. Regarding THM and TOC removal efficacy, the mineral GAC performed better than the vegetal GAC.

Os radiofármacos são definidos como preparações farmacêuticas contendo um radionuclídeo em sua composição, são administrados intravenosamente em sua maioria, e, portanto, o cumprimento dos princípios de Boas Práticas de Fabricação (BPF) é essencial e indispensável à tais produtos. A validação de limpeza é um requisito das BPF e consiste na evidência documentada que demonstra que os procedimentos de limpeza removem os resíduos a níveis pré-determinados de aceitação, garantindo que não haja contaminação cruzada. Uma simplificação da validação dos processos de limpeza é admitida, e consiste na escolha de um produto, denominado de \"pior caso\" ou worst case, para representar a limpeza de todos os equipamentos da mesma linha de produção. Uma das etapas da validação de limpeza é o estabelecimento e validação do método analítico para quantificação do resíduo. O objetivo deste estudo foi estabelecer o pior caso para a validação de limpeza dos equipamentos de produção de reagentes liofilizados-RL para marcação com 99mTc, avaliar a utilização do teor de carbono orgânico total (COT) como indicador de limpeza dos equipamentos utilizados na fabricação dos RL, validar o método para determinação de CONP (carbono orgânico não purgável/volátil) e realizar testes de recuperação com o produto escolhido como pior caso. A escolha do produto pior caso baseou-se no cálculo de um índice denominado \"índice para pior caso - Worst Case Index (WCI)\", utilizando informações de solubilidade dos fármacos, dificuldade de limpeza dos equipamentos e taxa de ocupação dos produtos na linha de produção. O produto indicado como pior caso entre os RL foi o MIBI-TEC. Os ensaios de validação do método foram realizados utilizando-se um analisador de carbono modelo TOC-Vwp acoplado a um amostrador automático modelo ASI-V, ambos da marca Shimadzu&reg e controlados por software TOC Control-V Shimadzu&reg. Foi utilizado o método direto de quantificação do CONP. Os parâmetros avaliados na validação do método foram: conformidade do sistema, robustez, linearidade, limites de detecção (LD) e de quantificação (LQ), precisão (repetibilidade e precisão intermediária), e exatidão (recuperação) e foram definidos como: 4% acidificante, 2,5 mL de oxidante, tempo de integração da curva de 4,5 minutos, tempo de sparge de 3,0 minutos e linearidade na faixa de 40-1000 μgL-1, com coeficiente de correlação (r) e soma residual dos mínimos quadrados (r2) > 0,99 respectivamente. LD e LQ para CONP foram 14,25 ppb e 47,52 ppb, respectivamente, repetibilidade entre 0,11 4,47%; a precisão intermediária entre 0,59 a 3,80% e exatidão entre 97,05 - 102,90%. A curva analítica para Mibi mostrou-se linear na faixa de 100-800 μgL-1, com r e r2 > 0,99, apresentando parâmetros similares aos das curvas analíticas de CONP. Os resultados obtidos neste estudo demonstraram que a abordagem do pior caso para validação de limpeza é um meio simples e eficaz para diminuir a complexidade e morosidade do processo de validação, além de proporcionar uma redução nos custos envolvidos nestas atividades. Todos os resultados obtidos nos ensaios de validação de método CONP atenderam as exigências e especificações preconizadas pela norma RE 899/2003 da ANVISA para considerar a metodologia validada. / Radiopharmaceuticals are defined as pharmaceutical preparations containing a radionuclide in their composition, mostly intravenously administered, and therefore compliance with the principles of Good Manufacturing Practices (GMP) is essential and indispensable. Cleaning validation is a requirement of the current GMP, and consists of documented evidence, which demonstrates that the cleaning procedures are able to remove residues to pre-determined acceptance levels, ensuring that no cross contamination occurs. A simplification of cleaning processes validation is accepted, and consists in choosing a product, called \"worst case\", to represent the cleaning processes of all equipment of the same production area. One of the steps of cleaning validation is the establishment and validation of the analytical method to quantify the residue. The aim of this study was to establish the worst case for cleaning validation of equipment in the radiopharmaceutical production of lyophilized reagent (LR) for labeling with 99mTc, evaluate the use of Total Organic Carbon (TOC) content as indicator of equipment cleaning used in the LR manufacture, validate the method of Non-Purgeable Organic Carbon (NPOC), and perform recovery tests with the product chosen as worst case.Worst case products choice was based on the calculation of an index called \"Worst Case Index\" (WCI), using information about drug solubility, difficulty of cleaning the equipment and occupancy rate of the products in line production. The products indicated as worst case was the LR MIBI-TEC. The method validation assays were performed using carbon analyser model TOC-Vwp coupled to an autosampler model ASI-V, both from Shimadzu&reg, controlled by TOC Control-V software. It was used the direct method for NPOC quantification. The parameters evaluated in the validation method were: system suitability, robustness, linearity, detection limit (DL) and quantification limit (QL), precision (repeatability and intermediate precision), and accuracy (recovery) and they were defined as follows: 4% acidifying reagent, 2.5 ml oxidizing reagent, 4.5 minutes integration curve time, 3 minutes sparge time and linearity in 40-1000 μgL-1 range, with correlation coefficient (r) and residual sum of minimum squares (r2) greater than 0.99 respectively. DL and QL for NPOC were 14.25 ppb e 47.52 ppb respectively, repeatability between 0.11 and 4.47%; the intermediate precision between 0.59 and 3.80% and accuracy between 97.05 and 102.90%. The analytical curve for Mibi was linear in 100-800 μgL-1 range with r and r2 greater than 0.99, presenting similar parameters to NPOC analytical curves. The results obtained in this study demonstrated that the worst-case approach to cleaning validation is a simple and effective way to reduce the complexity and slowness of the validation process, and provide a costs reduction involved in these activities. All results obtained in NPOC method validation assays met the requirements and specifications recommended by the RE 899/2003 Resolution from ANVISA to consider the method validated.

O presente trabalho teve como objetivo avaliar a eficiência de pós-filtros adsorvedores constituídos de Carvão Ativado Granular (CAG) na remoção de compostos orgânicos precursores e na formação de subprodutos da desinfecção, em particular dos trialometanos (THM) na Estação de Tratamento de Água Alto da Boa Vista (ETA ABV), abastecida por reservatórios de água bruta com elevado grau de eutrofização. Os ensaios foram conduzidos em ETA Piloto composta por tanque de reservação de água filtrada, ozonizador, tanque de reservação de água ozonizada e 4 pós-filtros adsorvedores, sendo duas unidades dotadas de CAG de origem mineral e duas unidades dotadas de CAG de origem vegetal. Os filtros foram operados em paralelo, sendo que duas colunas foram alimentadas com água filtrada da ETA ABV (Filtro F3 CAG de origem mineral e Filtro F4 CAG de origem vegetal) e as outras duas alimentadas com água filtrada e ozonizada (Filtro F1 CAG de origem mineral e Filtro F2 CAG de origem vegetal). A avaliação da remoção de compostos orgânicos precursores e formação de subprodutos da desinfecção foi feita através de análises de carbono orgânico total (COT), UV-254 nm e formação de THM. A análise dos resultados gerados de julho de 2007 a dezembro de 2008 permitiu concluir que 93% do THM é formado nas primeiras 24 horas de contato da amostra com o cloro, simulando a pós cloração e pós alcalinização da ETA ABV. O processo de oxidação por ozônio não foi efetivo na remoção de THM instantâneo, visto que a média dos 38 valores de THM instantâneo para a água filtrada (17,8 ± 5,6 g/L) foi igual a média obtida para o THM instantâneo na água ozonizada. A remoção de THM pelos filtros de CAG foi mais significativa nos primeiros três meses de operação do sistema, apresentando remoção de 80% para os filtros com CAG de origem mineral e 70% para os filtros com CAG de origem vegetal, a partir do quarto mês de operação do sistema a remoção de THM caiu para um valor médio de 34%, o que mostra uma iminente saturação do leito adsorvedor. Os pós-filtros adsorvedores constituídos de CAG de origem mineral apresentaram melhor comportamento com respeito a remoção de THM e COT quando comparado com os pós-filtros dotados de CAG de origem vegetal. / The main purpose of this work was to evaluate the performance of a Granular Activated Carbon (GAC) post-filter adsorbers in the removal of organic precursors and in the formation of disinfection byproducts, especially trihalomethanes (THM) in Alto da Boa Vista Water Treatment Plant (ABV WTP), which takes raw water from a highly eutrophized reservoirs. The tests was conducted on a Pilot WTP composed of filtered water tank, ozonator, ozonized water tank, and four post-filter adsorbers: two units with mineral GAC media and two units with vegetal GAC media. The filters were operated in parallel, with two columns fed with filtered water from ABV WTP (F3 Filter mineral GAC and F4 Filter vegetal GAC) and the other fed with ozonized water (F1 Filter mineral GAC and F2 Filter vegetal GAC). The evaluation of the removal of organic precursors and the formation of disinfection byproducts was made through analysis of Total Organic Carbon (TOC), UV-254 nm and THM formation. The results generated from July 2007 to December 2008 showed that 93% of THM is formed in the first 24 hours of contact with the chlorine in the sample, simulating the post chlorination and post alkalinization of ABV WTP in samples of filtered water, ozonized water, and post-filter adsorbers effluent. Ozone oxidation process was not effective in removing THM. Was found the same instantaneous THM values in the filtered water (17.8 g/L± 5.6 g/L) and in the ozonized water. During the first three months of post-filter adsorber operation, THM removal efficiencies were around 80% for F1 and F3 (mineral GAC media) and around 70% for F2 and F4 (vegetal GAC media). After four months of operation, THM removal efficiencies decreased to 34% average value, thus indicative of GAC saturation. Regarding THM and TOC removal efficacy, the mineral GAC performed better than the vegetal GAC.

Several studies in high-latitude catchments have demonstrated the importance of near-stream riparian zones as hydrogeochemical hotspots with a substantial influence on stream chemistry. An adequate representation of the spatial variability of riparian-zone processes and characteristics is the key for modeling spatio-temporal variations of stream-water quality. This thesis contributes to current knowledge by refining landscape-analysis techniques to describe riparian zones and by introducing a conceptual framework to quantify solute exports from riparian zones. The utility of the suggested concepts is evaluated based on an extensive set of hydrometric and chemical data comprising measurements of streamflow, groundwater levels, soil-water chemistry and stream chemistry. Standard routines to analyze digital elevation models that are offered by current geographical information systems have been of very limited use for deriving hydrologically meaningful terrain indices for riparian zones. A model-based approach for hydrological landscape analysis is outlined, which, by explicitly simulating groundwater levels, allows better predictions of saturated areas compared to standard routines. Moreover, a novel algorithm is presented for distinguishing between left and right stream sides, which is a fundamental prerequisite for characterizing riparian zones through landscape analysis. The new algorithm was used to derive terrain indices from a high-resolution LiDAR digital elevation model. By combining these terrain indices with detailed hydrogeochemical measurements from a riparian observatory, it was possible to upscale the measured attributes and to subsequently characterize the variation of total organic-carbon exports from riparian zones in a boreal catchment in Northern Sweden. Riparian zones were recognized as highly heterogeneous landscape elements. Organic-rich riparian zones were found to be hotspots influencing temporal trends in stream-water organic carbon while spatial variations of organic carbon in streams were attributed to the arrangement of organic-poor and organic-rich riparian zones along the streams. These insights were integrated into a parsimonious modeling approach. An analytical solution of the model equations is presented, which provides a physical basis for commonly used power-law streamflow-load relations. / At the time of doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press; Paper 4: Manuscript. / Swedish Research Council (VR, grant no. 2005-4289)

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2017-12-05T12:41:21Z No. of bitstreams: 1 PGCS15MA124.pdf: 1312847 bytes, checksum: 750d88452b24e573464fff88790dbef6 (MD5) / Made available in DSpace on 2017-12-05T12:41:21Z (GMT). No. of bitstreams: 1 PGCS15MA124.pdf: 1312847 bytes, checksum: 750d88452b24e573464fff88790dbef6 (MD5) Previous issue date: 2015-05-15 / The soil organic matter (SOM) is formed by a set of chemical compounds which have different decomposition rates and products of these processes result as the main source of sulfur, phosphorus and nitrogen into the soil. Because of its great importance to the ground, it is of utmost importance to quantify MOS content. Its composition consists of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P) and sulfur (S), among others, it is difficult to determine its content. Most analytical techniques measure only carbon and estimate the MOS by a conversion factor. The study aimed to develop an analytical method for quantification of soil organic matter by means of a colorimetric method based on image analysis. The proposed method used the carbon oxidation process of Walkley-Black methodology and the resulting solutions were inserted into spectrophotometer cells for a smart phone equipped with a digital camera with a CCD detector (charge coupled device) register the images. These were treated with ImageJ software and the image of each solution has been selected from an area in which 100x100p were extracted RGB intensities (Red, Green and Blue colors, designs, especially for 8-bit data). We analyzed the RGB values and its relations with the MOS concentrations, resulting that the RED channel showed the best relationship with the organic matter content. The data were modeled by a linear regression (ARED = 0.1222 MOS - 0.1621; R² = 0.9934 and p <0.05) and it was possible to build a model that relates the color intensity with concentration. The proposed method showed accuracy of approximately 71% using a standard soil sample (LUFA Speyer - type 2.2), similar to the result obtained with the method currently used (Walkley-Black) which was 74% / A matéria orgânica do solo (MOS) é formada por um conjunto de compostos químicos que possuem diferentes taxas de decomposição, e os produtos desses processos resultam como fontes principais de enxofre, fósforo e nitrogênio para o solo. Devido a sua grande importância para o solo, é de extrema importância a quantificação do teor da MOS. Como a sua composição consiste em carbono (C), hidrogênio (H), oxigênio (O), nitrogênio (N), fósforo (P) e enxofre (S), dentre outros, torna-se difícil a determinação do seu teor. A maioria das técnicas analíticas mensuram apenas carbono e estimam a MOS por um fator de conversão. A pesquisa teve por objetivo o desenvolvimento de uma metodologia analítica para quantificação de matéria orgânica do solo por meio de um método colorimétrico baseado em análise de imagens. O método proposto utilizou o processo de oxidação de carbono da metodologia Walkley-Black e as soluções resultantes foram inseridas em celas espectrofotométricas para que um smartphone equipado com uma câmera digital, com um detector CCD (charge coupled device), registre as imagens. Estas foram tratadas com o software ImageJ e na imagem de cada solução foi selecionado uma área de 100x100p no qual extraíram-se as intensidades RGB (Red, Green e Blue, modelos de cores, especialmente para dados de 8 bits). Analisou-se os valores RGB e suas relações com as concentrações de MOS, resultando que o canal RED apresentou a melhor relação com o teor de matéria orgânica. Os dados foram modelados por meio de uma regressão linear (ARED = 0,1222 MOS – 0,1621; R² = 0,9934 e p < 0,05) e assim foi possível a construção de um modelo que relaciona a intensidade de cor com a concentração. O método prposto apresentou exatidão de aproximadamente 71% usando uma amostra de solo padronizada (LUFA Speyer – tipo 2.2), similar ao resultado obtido com o método usado atualmente (Walkley-Black) que foi de 74%

No Rio Grande do Sul, são escassos os estudos relacionados à identificação e à caracterização de minerais pedogênicos em ampla escala, bem como aqueles que tratam da influência da mineralogia nos aspectos físicos e químicos dos solos. O sistema solo é resultado da combinação de fatores que atuaram ao longo do tempo geológico, fato evidente no estado do Rio Grande do Sul devido a expressiva variabilidade de classes de solos em seu território. Nesse sentido, o estudo objetivou caracterizar a composição mineralógica de solos formados nas diferentes regiões fisiográficas do Rio Grande do Sul e definir combinações físicas, químicas e mineralógicas responsáveis pela adsorção de fósforo nesses solos. Para tal, foram selecionadas 60 amostras representativas de oito classes de solos de pedoambientes oxidados e com distintos graus de intemperização. As amostras foram previamente coletadas sob vegetação natural na camada de 0 a 20 cm de profundidade. Na fração TFSA, foram realizadas análises físicas (granulometria, área superficial específica, suscetibilidade magnética), químicas (carbono orgânico total, teor de óxidos de ferro pedogênicos e óxidos de baixa cristalinidade, teor de fósforo remanescente) e mineralógicas (difratometria de raio x, estimativa dos minerais por área e largura a meia altura). Os dados foram analisados por correlações de Pearson. Os resultados mostraram ampla variação mineralógica devido aos distintos materiais de origem, influenciando a granulometria, ASE e SM. Os valores de COT mostraram relação positiva com os teores de argila e negativa, principalmente, com os teores de Prem, interferindo nos fenômenos de sorção dos solos. Os teores de Fed aumentaram conforme o incremento de argila nos solos e os teores de Feo foram baixos, ambos devido ao avançado estágio de intemperização dos solos. Na fração argila, predomina a caulinita associada a diferentes proporções de argilominerais 2:1 e óxidos de ferro. A adsorção de fósforo apresenta relação expressiva com os teores de argila, de óxidos de ferro, de carbono orgânico total e, consequentemente, com a área superficial específica do solo. / There are few studies in Rio Grande do Sul making relations with the identification and characterization of pedogenic minerals on a large scale, as well as those that establish the influence of mineralogy on physical and chemical aspects of the soil. The soil system is a result of combination of factors that acted over geological time, an evident fact in Rio Grande do Sul state of due to significant variability of soil classes on his territory. Therein, the study intent to characterize the mineralogical composition of soils formed in distinct geographical regions of Rio Grande do Sul and define physical, chemical and mineralogical combinations responsible for phosphorus adsorption in these soils. However, we selected 60 representative samples of eight soil classes of oxidics pedoenvironments and with distinct degrees of mineral weathering. The samples were previously collected under natural vegetation in the 0 to 20 cm deep. In TFSA fraction, were performed physical (soil texture, specific surface area, magnetic susceptibility), chemical (total organic carbon, content of pedogenic (Fed) and low cristalinity (Feo) iron oxides, remaining phosphorus content (Prem)) and mineralogical analyzes (X ray diffraction, estimation per area and width at half height of minerals). Data were analyzed by Pearson correlations. The results showed wide mineralogical variation due to different parent materials, influencing the soil texture, SSA and MS. The TOC values were closely related with the clay fraction and negative relationship, especially with the levels of Prem, interfering in soil sorption phenomena. The Fed contents increased with the clay fraction and Feo contents were low, both due to the advanced soil stage of weathering. The clay fraction had predominantly kaolinite associated with different ratios of 2: 1 clay minerals and iron oxides. The phosphorus adsorption shows a significant relationship with the clay fraction, iron oxides, total organic carbon and, consequently, with the specific surface area of the soil.

No Rio Grande do Sul, são escassos os estudos relacionados à identificação e à caracterização de minerais pedogênicos em ampla escala, bem como aqueles que tratam da influência da mineralogia nos aspectos físicos e químicos dos solos. O sistema solo é resultado da combinação de fatores que atuaram ao longo do tempo geológico, fato evidente no estado do Rio Grande do Sul devido a expressiva variabilidade de classes de solos em seu território. Nesse sentido, o estudo objetivou caracterizar a composição mineralógica de solos formados nas diferentes regiões fisiográficas do Rio Grande do Sul e definir combinações físicas, químicas e mineralógicas responsáveis pela adsorção de fósforo nesses solos. Para tal, foram selecionadas 60 amostras representativas de oito classes de solos de pedoambientes oxidados e com distintos graus de intemperização. As amostras foram previamente coletadas sob vegetação natural na camada de 0 a 20 cm de profundidade. Na fração TFSA, foram realizadas análises físicas (granulometria, área superficial específica, suscetibilidade magnética), químicas (carbono orgânico total, teor de óxidos de ferro pedogênicos e óxidos de baixa cristalinidade, teor de fósforo remanescente) e mineralógicas (difratometria de raio x, estimativa dos minerais por área e largura a meia altura). Os dados foram analisados por correlações de Pearson. Os resultados mostraram ampla variação mineralógica devido aos distintos materiais de origem, influenciando a granulometria, ASE e SM. Os valores de COT mostraram relação positiva com os teores de argila e negativa, principalmente, com os teores de Prem, interferindo nos fenômenos de sorção dos solos. Os teores de Fed aumentaram conforme o incremento de argila nos solos e os teores de Feo foram baixos, ambos devido ao avançado estágio de intemperização dos solos. Na fração argila, predomina a caulinita associada a diferentes proporções de argilominerais 2:1 e óxidos de ferro. A adsorção de fósforo apresenta relação expressiva com os teores de argila, de óxidos de ferro, de carbono orgânico total e, consequentemente, com a área superficial específica do solo. / There are few studies in Rio Grande do Sul making relations with the identification and characterization of pedogenic minerals on a large scale, as well as those that establish the influence of mineralogy on physical and chemical aspects of the soil. The soil system is a result of combination of factors that acted over geological time, an evident fact in Rio Grande do Sul state of due to significant variability of soil classes on his territory. Therein, the study intent to characterize the mineralogical composition of soils formed in distinct geographical regions of Rio Grande do Sul and define physical, chemical and mineralogical combinations responsible for phosphorus adsorption in these soils. However, we selected 60 representative samples of eight soil classes of oxidics pedoenvironments and with distinct degrees of mineral weathering. The samples were previously collected under natural vegetation in the 0 to 20 cm deep. In TFSA fraction, were performed physical (soil texture, specific surface area, magnetic susceptibility), chemical (total organic carbon, content of pedogenic (Fed) and low cristalinity (Feo) iron oxides, remaining phosphorus content (Prem)) and mineralogical analyzes (X ray diffraction, estimation per area and width at half height of minerals). Data were analyzed by Pearson correlations. The results showed wide mineralogical variation due to different parent materials, influencing the soil texture, SSA and MS. The TOC values were closely related with the clay fraction and negative relationship, especially with the levels of Prem, interfering in soil sorption phenomena. The Fed contents increased with the clay fraction and Feo contents were low, both due to the advanced soil stage of weathering. The clay fraction had predominantly kaolinite associated with different ratios of 2: 1 clay minerals and iron oxides. The phosphorus adsorption shows a significant relationship with the clay fraction, iron oxides, total organic carbon and, consequently, with the specific surface area of the soil.