O potássio (K) é o cátion presente em maior quantidade no citoplasma, atuando em processos enzimáticos e metabólicos vitais para as plantas. Nas raízes, a absorção ocorre na forma livre (K+), e sua biodisponibilidade depende das formas como o elemento se associa ao solo. Não existe limite crítico entre as frações solúveis, trocáveis, não trocáveis e estruturais de K, sendo suas concentrações alteráveis por fatores bióticos e abióticos. Solos oxídicos, situados em ambientes tropicais úmidos, geralmente apresentam baixos teores totais de K, atribuídos tanto ao forte intemperismo nessas regiões quanto aos materiais de origem pobres no nutriente. Os teores disponíveis de K são estabelecidos como referência para diagnósticos e para cálculos de adubações no Brasil. Contudo, existem evidências de que formas não extraíveis por extratores convencionais podem contribuir para a nutrição de plantas, principalmente quando se observa ausência de resposta à adubação potássica em solos com baixos teores disponíveis de K nos quais o processo de coleta de solo e determinação de K foram feitos de modo adequado. Além disso, mesmo em solos muito intemperizados, fontes minerais de K podem ser identificadas por técnicas especiais de difração de raios-X e extração sequencial de K em suas frações minerais. A soja (Glycine max L.) é uma espécie de grande importância econômica e apresenta requerimento elevado de K quando comparada a outras espécies de importância econômica. Objetivou-se avaliar o efeito do material de origem e da mineralogia do solo e suas frações nos atributos químicos e nas formas de K no solo, bem como na nutrição potássica da soja. Este projeto foi realizado com amostras de um Latossolo Vermelho distroférrico (LVdf), oriundas de um experimento iniciado em 1983, em Londrina (PR), para avaliar o efeito de doses de adubo potássico (KCl) na produtividade da soja, em ciclos com restrição e ciclos com acúmulo de K. Com a interrupção da adubação potássica em 2008, as plantas vieram sendo nutridas com o K residual no solo por sete safras. Estudos com efeito residual de K em sistemas de produção tropicais são escassos, principalmente em experimentos de longa duração com solos oxídicos. Com isso, em outubro de 2015 foi reaplicado potássio em metade das parcelas para avaliar do efeito da adubação e da manutenção do efeito residual na mineralogia e formas de K no solo, bem como na nutrição da soja. Foram realizados o mapeamento elementar e a quantificação de K no material de origem (basalto), bem como a identificação e estudo da reserva mineral de K na fração argila do solo por meio de difrações e extrações sequenciais. Foram determinadas as formas trocáveis (resina trocadora de íons e Mehlich-1), não trocáveis e totais de K no solo, além dos teores totais em suas frações separadas. Para fins de fertilidade, foram determinados os demais atributos químicos do solo antes e após a aplicação de K nas subparcelas. Também foram determinados os teores de macronutrientes e micronutrientes, com exceção do níquel (Ni), cloro (Cl) e molibdênio (Mo), em trifólios, partes aéreas e grãos de soja, bem como parâmetros produtivos como massa seca produzida, produtividade e massa de cem grãos. O material de origem e o solo apresentaram baixa reserva de K, sendo que para este último a maior parte do reservatório mineral do nutriente esteve contido na fração argila. A constituição mineralógica do solo apresentou pouca variação, sendo identificados óxidos e hidróxidos como hematita, goethita e gibbsita, filossilicatos 1:1 e 2:1, com e sem hidróxi-Al intercamadas, e outros minerais como quartzo, maghemita e anatásio. Mesmo em avançado estágio de intemperismo, o Latossolo apresentou espécies minerais fontes de K na fração argila. Os extratores de teores trocáveis (Mehlich-1 e resina de troca iônica) extrairam quantidades diferentes de K. A disponibilidade de K e a reaplicação do nutriente após efeito residual, influenciaram os teores de determinados nutrientes em trifólios, partes aéreas e grãos, bem como a produtividade, a massa de grãos e a massa seca de partes aéreas. / Potassium (K) is the cation present in greater quantity in the cytoplasm and acts on enzymatic and metabolic processes vital for plants. The absorption occurs in the roots in the soluble form (K+), and its bioavailability depends on the ways in which the element is associated with the soil. There is no critical limit between soluble, exchangeable, non-exchangeable and structural fractions of K, and its changeable concentrations are affected by biotic and abiotic factors. Oxidic soils located in humid tropical environments generally have low contents of total K, attributed to the strong degree of weathering in these regions and to the parent materials, poor in the nutrient. The levels available K are set as a reference for diagnosis and fertilization calculations in Brazil. However, there are evidence that forms not extractable by conventional extractors can contribute to plant nutrition, especially in the absence of response to potassium fertilization in soils with low levels of available K, in which the process of soil sampling and K determination were done properly. Moreover, even in highly weathered soils, mineral sources of K can be identified by diffraction techniques and sequential extraction in soil minerals present in soil fractions with associated K. Soybean (Glycine max L.) is of great economic importance and requires high amounts of K as compared to other species. The objective was to evaluate the effect of parent material and soil mineralogy in the chemical attributes and K forms, as well as on K soybeans nutrition. This project was carried out with samples of an Oxisol, coming from a long-term field experiment started in 1983 at Londrina (state of Paraná), to evaluate the effect of potassium fertilizer rates (KCl) on soybean yield in cycles with either restraint or accumulation cycles of K. With the interruption of potassium fertilization in 2008, plants have been fed by the residual K in the soil for seven crops. Studies with the residual effect of K in tropical production systems are scarce, especially in long-term experiments under Oxisols. Thus, in October 2015 potassium fertilizer was reapplied in half of the plots to evaluate the effect of fertilization and the maintenance of the residual effect on the mineralogy and on the forms of K in the soil as well as in soybean nutrition. Elemental mapping was performed and quantification of the K in the parent material (basalt), as well as the identification and study of the mineral reserve of K in the soil clay fraction by diffractions and sequential extractions. The exchangeable forms (ion exchange resin and Mehlich-1), non-exchangeable and total K in the soil were determined, in addition to the total contents of K in their separate fractions. For fertility purposes, soil chemical properties were determined before and after application of K in subplots. The quantities of macronutrients and micronutrients were determined, with the exception of nickel (Ni), chlorine (Cl) and molybdenum (Mo) in the trefoil, aerial parts, and grains, as well as production parameters as dry mass produced, yield and mass of a hundred grains. The mineralogical composition of the soil had little variation, with oxides/hydroxides such as hematite, goethite, and gibbsite, 1:1 and 2:1 phyllosilicates, with or without hydroxyl-Al interlayers, ans other minerals such as quartz, maghemite, and anatase. The highly-weathered Oxisol presented mineral species containing potassium in the clay fraction. The extractors of exchangeable forms of K (Mehlich-1 and ion-exchange resin) extracted differect amounts os K. The availability of K, as well as the nutrient reaplication after the residual effect, influenced the nutrient contents in trefoils, aerial parts, and grains, as well as yield, grain mass and dry mass of aerial parts.

<p>The primary aim of these coal fired industries for co-disposing fly ash and brine was to use the fly ash as a sustainable salt sink. It is therefore important to study the interaction chemistry of the fly ash-brine systems to fully understand the leaching and mobility of the contaminant species, and to determine the possibility of capturing the salts from the brine solution when fly ash and brine are co-disposed. In order to achieve the aims and objectives of this study, several leaching procedures such as batch reaction tests, long-term fly ash-brine interaction tests, acid neutralization capacity (ANC) tests, up-flow percolation tests and sequential extraction tests were employed. The geochemical modeling software was applied to predict the formation of secondary mineral phases controlling the release of species in the fly ash-brine systems. Several analytical techniques such as x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy-energy dispersion spectroscopy (SEM-EDS), inductively coupled plasma-mass spectroscopy (ICP-MS) and ion chromatography (IC) were applied to characterize the fresh fly ashes, solid residues recovered from the fly ash-brine interaction tests, the brine sample used in this study and the leachate samples in order to determine the chemical and mineralogical compositions and speciation of the waste materials.</p>

<p>The primary aim of these coal fired industries for co-disposing fly ash and brine was to use the fly ash as a sustainable salt sink. It is therefore important to study the interaction chemistry of the fly ash-brine systems to fully understand the leaching and mobility of the contaminant species, and to determine the possibility of capturing the salts from the brine solution when fly ash and brine are co-disposed. In order to achieve the aims and objectives of this study, several leaching procedures such as batch reaction tests, long-term fly ash-brine interaction tests, acid neutralization capacity (ANC) tests, up-flow percolation tests and sequential extraction tests were employed. The geochemical modeling software was applied to predict the formation of secondary mineral phases controlling the release of species in the fly ash-brine systems. Several analytical techniques such as x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy-energy dispersion spectroscopy (SEM-EDS), inductively coupled plasma-mass spectroscopy (ICP-MS) and ion chromatography (IC) were applied to characterize the fresh fly ashes, solid residues recovered from the fly ash-brine interaction tests, the brine sample used in this study and the leachate samples in order to determine the chemical and mineralogical compositions and speciation of the waste materials.</p>

Characterization of phosphorus (P) in organic amendments is essential for environmentally sustainable fertilization of agricultural soils. The sequential chemical extraction (SCE) technique commonly used for P characterization does not provide any direct molecular information about P species. Studies were conducted to characterize P species in organic amendments and amended soils at a molecular level. The SCE was used to fractionate P in organic amendments including biosolids, hog, dairy and beef cattle manures, and poultry litter. The extracts were analyzed for total P and P species using inductively coupled plasma - optical emission spectroscopy (ICP-OES) and solution 31P nuclear magnetic resonance (NMR) spectroscopy, respectively. The relative proportions of P species in intact organic amendments and residues after each extraction, and calcareous soils amended with organic amendments and monoammonium phosphate (MAP) were estimated using the synchrotron-based P 1s X-ray absorption near edge structure (XANES) spectroscopy. The solution 31P NMR provided a detailed characterization of organic P in the non-labile NaOH and HCl fractions of organic amendments, but was limited in characterizing the labile fractions of most of these organic amendments due to their proneness to alkaline hydrolysis. The XANES analysis, however, identified the actual chemical species constituting the labile P that was only characterized as inorganic P or orthophosphates by sequential extraction and solution 31P NMR. In the amended Vertisolic and Chernozemic soils, XANES analysis estimated ‘soluble and adsorbed P’ as the dominant P species. For the Vertisolic soil, both the unamended and soil amended with biosolids and MAP contained hydroxyapatite (HAP). In addition, soil amended with biosolids, hog and dairy manures contained β-tricalcium phosphate (TRICAL), a more soluble CaP than HAP. TRICAL was found in all amended soils except in that amended with hog manure, while HAP was present in appreciable amount only in the control. Overall, the combination of techniques used in these studies improved the understanding of P species in organic amendments and amended soils that would not have been possible with any individual technique. Technological advances in P analysis should therefore be combined with conventional chemical extraction techniques to determine the fate of P in the environment.

Lyophilized pea chloroplasts were extracted in a stepwise manner in an organic solvent (petroleum ether) with increasing polarity which was obtained by addition of small amount of ETOH (0-1 %). Absorption and low temperature fluorescence emission spectra were measured on both the extracted thylakoids and on isolated chlorophylI-protein complexes. Extraction of chlorophyll from the membrane increased (and the ratio of chlorophyl l a/b decreased) with increasing polarity of the solvent. The gel scan revealed that after extraction with petroleum ether, CPa.. was lost from the gel and after extraction with petroleum ether +1 % ETOH only the CPa/b was left together with SDS-free chlorophyll. This shows that the chlorophyll in CPa/b are situated in a less hydrophobic environment than chlorophyll in CPa|| and CPa|. The long wavelength absorbing and emitting chlorophyll fraction associated to CPaj was found to be easily removed from the membrane. This caused a blue shift in the low temperature fluorescence emission peak and in the red absorption peak and it was also accompanied by a decrease in carote-noid absorption in isolated CPa|. It was found in different plant material lacking $-carotene in CPàj that a strong correlation between ß-carotene in CPa. and the existence of the long wavelength chlorophyll in isolated cPa. existed. Based on these data, it was suggested that excited chlorophyll can transfer energy in excess to ß-carotene by a triplet--triplet transfer.A method based on in vivo chlorophyll £ fluorescence was developed for studying photosynthetic capacity in unicellular algae. It was shown that DCMU-induced fluorescence increase was a good measure of photosynthetic capacity in four species of green algae tested.The effect of copper chloride on photosynthetic electron transport and chlorophyl1-protein complexes was studied in spinach chloroplasts. Copper(11) inhibited a PS I i reaction H2O—&gt; DPIP, a PS I reaction Asc/DPIP —&gt; NADP and the overall electron transport H2O —&gt; NAOP to different degrees. Chlorophyll protein complexes were only slightly affected by copper(ll) but with both copper and ascorbate in the reaction media, a rapid membrane destruction occurred. This was probably caused by a free radical reaction catalyzed by copper(ll). / <p>Härtill 4 delarbeten.</p> / digitalisering@umu

Characterization of phosphorus (P) in organic amendments is essential for environmentally sustainable fertilization of agricultural soils. The sequential chemical extraction (SCE) technique commonly used for P characterization does not provide any direct molecular information about P species. Studies were conducted to characterize P species in organic amendments and amended soils at a molecular level. The SCE was used to fractionate P in organic amendments including biosolids, hog, dairy and beef cattle manures, and poultry litter. The extracts were analyzed for total P and P species using inductively coupled plasma - optical emission spectroscopy (ICP-OES) and solution 31P nuclear magnetic resonance (NMR) spectroscopy, respectively. The relative proportions of P species in intact organic amendments and residues after each extraction, and calcareous soils amended with organic amendments and monoammonium phosphate (MAP) were estimated using the synchrotron-based P 1s X-ray absorption near edge structure (XANES) spectroscopy. The solution 31P NMR provided a detailed characterization of organic P in the non-labile NaOH and HCl fractions of organic amendments, but was limited in characterizing the labile fractions of most of these organic amendments due to their proneness to alkaline hydrolysis. The XANES analysis, however, identified the actual chemical species constituting the labile P that was only characterized as inorganic P or orthophosphates by sequential extraction and solution 31P NMR. In the amended Vertisolic and Chernozemic soils, XANES analysis estimated ‘soluble and adsorbed P’ as the dominant P species. For the Vertisolic soil, both the unamended and soil amended with biosolids and MAP contained hydroxyapatite (HAP). In addition, soil amended with biosolids, hog and dairy manures contained β-tricalcium phosphate (TRICAL), a more soluble CaP than HAP. TRICAL was found in all amended soils except in that amended with hog manure, while HAP was present in appreciable amount only in the control. Overall, the combination of techniques used in these studies improved the understanding of P species in organic amendments and amended soils that would not have been possible with any individual technique. Technological advances in P analysis should therefore be combined with conventional chemical extraction techniques to determine the fate of P in the environment.

O presente estudo teve como objetivo avaliar o teor de Cu, Cr, Ni, Zn, Pb, Mn, Al e Fe e sua partição geoquímica em sedimentos da bacia hidrográfica do rio dos Sinos, Sul do Brasil. Esta bacia apresenta elevada densidade populacional e industrial, especialmente dos setores de metalurgia, galvanoplastia, siderurgia, petroquímica e curtumes. As concentrações totais de metais, determinadas por espectroscopia de fluorescência de raios X, e as concentrações nas fases dos sedimentos, determinadas através da aplicação do esquema de extração sequencial BCR-701 proposto pelo Community Bureau of Reference, da Comunidade Europeia, utilizando ICP/OES, foram avaliadas nos sedimentos com granulometria <63 μm. Também foram considerados os teores extraídos através de uma solução de HCl 0,5 mol/L nesta fração dos sedimentos. Os resultados na região industrializada e com alta densidade populacional mostraram um aumento nas concentrações totais, para Cu, Cr, Zn e Pb, e nas frações potencialmente móveis para os metais Cu, Cr, Zn e Ni extraídos sequencialmente. O Cr destacou-se especialmente no arroio Portão, apresentando uma concentração total de 1286 mg/kg, devido à influência de curtumes localizados nesta região. Os sedimentos também foram caracterizados através de espectroscopia de reflectância, método rápido e não destrutivo de caracterização dos diferentes materiais, na região entre 400 e 2500 nm. Nos espectros de reflectância das amostras avaliadas observou-se que as principais feições espectrais são resultantes das absorções decorrentes da água, das ligações Al-OH e dos teores de ferro presentes. Ainda ficou evidenciada a influência da granulometria, dos teores de ferro e matéria orgânica sobre os espectros de reflectância resultantes. Não foi possível observar as feições espectrais decorrentes dos metais pesados, provavelmente devido às altas concentrações de ferro observadas nas amostras e devido ao fato destes metais apresentarem as suas feições espectrais nas mesmas regiões de comprimento de onda onde ocorrem as feições do ferro. / The present study aimed to evaluate the content of Cu, Cr, Ni, Zn, Pb, Mn, Al, and Fe as well as their geochemical partitioning in sediments of the Sinos river basin in southern Brazil. This basin has a high population density and a great number of industries, especially metallurgy, electroplating works, steel mills, petrochemicals, and tanneries. The total metal concentrations, determined by X-ray fluorescence, and the concentrations in the sediment phases, determined by applying the BCR-701 sequential extraction method proposed by the Community Bureau of Reference of the European Community, using ICP/OES, were evaluated in the sediment fraction <63 μm. The contents extracted by a solution of 0.5 mol/L HCl were also considered in this fraction. Results in the industrialized and densely populated region showed an increase in the total concentrations for Cu, Cr, Zn, and Pb, and in the potentially mobile fractions for the sequentially extracted metals Cu, Cr, Zn and Ni. Cr stood out particularly in the Portão stream, showing a total concentration of 1,286 mg/kg, due to the influence of tanneries in this region. The sediments were also characterized by reflectance spectroscopy, a rapid and nondestructive method for characterization of different materials, in the region between 400 and 2500 nm. The reflectance spectra of the samples showed that the main spectral features are the result of the absorptions due to water, Al-OH bonds and contents of iron. The influences of particle size, organic matter and mineral composition on the absorption features and on the reflection coefficient of the spectra were also evidenced. It was not possible to observe the spectral features resulting from metals, probably due to high iron concentrations observed in the samples, and because these metals make their spectral features on the same wavelength regions where there are the iron spectral features.

Orientador: Wanderley José de Melo / Banca: Cássio Hamilton Abreu Júnior / Banca: Jorge de Lucas Júnior / Resumo: Rico em matéria orgânica e nutrientes, o lodo de esgoto tem despertado interesse na utilização agrícola com o intuito de substituir total ou parcialmente o uso de adubos minerais. Embora a utilização agrícola seja uma alternativa para sua disposição final, o lodo de esgoto pode conter elevadas concentrações de metais pesados, que são elementos potencialmente tóxicos às plantas, aos animais e aos homens, exigindo assim, uma avaliação cuidadosa da sua aplicação continuada ao solo. Nesse sentido, objetivou-se com este estudo avaliar os efeitos da aplicação do lodo de esgoto complementado com K por onze anos consecutivos em Latossolo Vermelho distrófico na produtividade do milho, no fornecimento de nutrientes à cultura, na concentração de Ba, Cd, Cr e Pb na folha para diagnose foliar, planta inteira (parte aérea + raiz) e nos grãos de milho, na distribuição de Ba, Cd, Cr e Pb no perfil do solo e na distribuição dos mesmos metais nas frações do solo (solúvel+trocável, adsorvida à superfície, matéria orgânica, óxidos de manganês, óxidos de ferro amorfo, óxidos de ferro cristalino e residual). O experimento foi desenvolvido em condições de campo, utilizando-se o delineamento experimental em blocos casualizados com 4 tratamentos e 5 repetições. Os tratamentos foram: T1= testemunha (sem lodo de esgoto e com fertilização mineral), T2= 5, T3= 10 e T4= 20 t ha-1 de lodo de esgoto, base seca, complementado com K. As amostras de folha para fins de diagnose foliar, solo, planta inteira e grãos foram obtidas, respectivamente, aos 60, 68, 80 e 123 dias após a emergência das plantas. A utilização do lodo de esgoto complementado com K, por onze anos consecutivos, em Latossolo Vermelho distrófico como fertilizante para a cultura do milho proporcionou produtividade superior a obtida com a fertilização mineral e também, ótima condição nutricional para as ... (Resumo completo,clicar acesso eletrônico abaixo) / Abstract: Rich in organic matter and nutrients, sewage sludge has attracted attention for agricultural use in order to fully or partially replace the use of mineral fertilizers. Although agricultural use is an alternative to its final disposal, sewage sludge may contain high concentrations of heavy metals that are potentially toxic to plants, animals and men, and thus requiring a careful assessment for continuous application to the soil. In this sense, this study aimed to evaluate the effects of eleven annual applications of sewage sludge supplemented with K to a Typic Hapludox to maize productivity, nutrient supply to the plants, Ba, Cd , Cr and Pb concentration in maize diagnosis leaf, plant (aerial part + root) and grains, Ba, Cd, Cr and Pb distribution in the soil profile and the metals distribution in the soil fractions (soluble+exchangeable, surface adsorbed, organic matter, manganese oxides, amorphous iron oxides, crystalline iron oxides and residual fraction). The experiment was developed under field conditions, using a randomized block design with 4 treatments and 5 replications. The treatments want: T1= control (no sewage sludge and with mineral fertilization), T2= 5, T3= 10 and T4= 20 t ha-1 sewage sludge, dried basis, complemented with K. The samples of diagnosis leaf, soil, plants and grains were obtained at 60, 68, 80 and 123 days after seedling emergence, respectively. The sewage sludge supplemented with K utilization for eleven consecutive years to a Typic Hapludox provided maize productivity similar to that achieved with mineral fertilizers and also promoted optimal nutritional condition for the plants, confirming its potential as a source of agricultural nutrients. The rates of 10 and 20 t ha-1 sewage sludge supplemented with K increased soil Ba, Cr and Pb concentration in the topsoil (0-0.10 m), but did not affect Cd. The tested sewage sludge rates did not increase Cd, Cr and ... (Complete abstract click electronic access below) / Mestre

O presente estudo teve como objetivo avaliar o teor de Cu, Cr, Ni, Zn, Pb, Mn, Al e Fe e sua partição geoquímica em sedimentos da bacia hidrográfica do rio dos Sinos, Sul do Brasil. Esta bacia apresenta elevada densidade populacional e industrial, especialmente dos setores de metalurgia, galvanoplastia, siderurgia, petroquímica e curtumes. As concentrações totais de metais, determinadas por espectroscopia de fluorescência de raios X, e as concentrações nas fases dos sedimentos, determinadas através da aplicação do esquema de extração sequencial BCR-701 proposto pelo Community Bureau of Reference, da Comunidade Europeia, utilizando ICP/OES, foram avaliadas nos sedimentos com granulometria <63 μm. Também foram considerados os teores extraídos através de uma solução de HCl 0,5 mol/L nesta fração dos sedimentos. Os resultados na região industrializada e com alta densidade populacional mostraram um aumento nas concentrações totais, para Cu, Cr, Zn e Pb, e nas frações potencialmente móveis para os metais Cu, Cr, Zn e Ni extraídos sequencialmente. O Cr destacou-se especialmente no arroio Portão, apresentando uma concentração total de 1286 mg/kg, devido à influência de curtumes localizados nesta região. Os sedimentos também foram caracterizados através de espectroscopia de reflectância, método rápido e não destrutivo de caracterização dos diferentes materiais, na região entre 400 e 2500 nm. Nos espectros de reflectância das amostras avaliadas observou-se que as principais feições espectrais são resultantes das absorções decorrentes da água, das ligações Al-OH e dos teores de ferro presentes. Ainda ficou evidenciada a influência da granulometria, dos teores de ferro e matéria orgânica sobre os espectros de reflectância resultantes. Não foi possível observar as feições espectrais decorrentes dos metais pesados, provavelmente devido às altas concentrações de ferro observadas nas amostras e devido ao fato destes metais apresentarem as suas feições espectrais nas mesmas regiões de comprimento de onda onde ocorrem as feições do ferro. / The present study aimed to evaluate the content of Cu, Cr, Ni, Zn, Pb, Mn, Al, and Fe as well as their geochemical partitioning in sediments of the Sinos river basin in southern Brazil. This basin has a high population density and a great number of industries, especially metallurgy, electroplating works, steel mills, petrochemicals, and tanneries. The total metal concentrations, determined by X-ray fluorescence, and the concentrations in the sediment phases, determined by applying the BCR-701 sequential extraction method proposed by the Community Bureau of Reference of the European Community, using ICP/OES, were evaluated in the sediment fraction <63 μm. The contents extracted by a solution of 0.5 mol/L HCl were also considered in this fraction. Results in the industrialized and densely populated region showed an increase in the total concentrations for Cu, Cr, Zn, and Pb, and in the potentially mobile fractions for the sequentially extracted metals Cu, Cr, Zn and Ni. Cr stood out particularly in the Portão stream, showing a total concentration of 1,286 mg/kg, due to the influence of tanneries in this region. The sediments were also characterized by reflectance spectroscopy, a rapid and nondestructive method for characterization of different materials, in the region between 400 and 2500 nm. The reflectance spectra of the samples showed that the main spectral features are the result of the absorptions due to water, Al-OH bonds and contents of iron. The influences of particle size, organic matter and mineral composition on the absorption features and on the reflection coefficient of the spectra were also evidenced. It was not possible to observe the spectral features resulting from metals, probably due to high iron concentrations observed in the samples, and because these metals make their spectral features on the same wavelength regions where there are the iron spectral features.

O presente estudo teve como objetivo avaliar o teor de Cu, Cr, Ni, Zn, Pb, Mn, Al e Fe e sua partição geoquímica em sedimentos da bacia hidrográfica do rio dos Sinos, Sul do Brasil. Esta bacia apresenta elevada densidade populacional e industrial, especialmente dos setores de metalurgia, galvanoplastia, siderurgia, petroquímica e curtumes. As concentrações totais de metais, determinadas por espectroscopia de fluorescência de raios X, e as concentrações nas fases dos sedimentos, determinadas através da aplicação do esquema de extração sequencial BCR-701 proposto pelo Community Bureau of Reference, da Comunidade Europeia, utilizando ICP/OES, foram avaliadas nos sedimentos com granulometria <63 μm. Também foram considerados os teores extraídos através de uma solução de HCl 0,5 mol/L nesta fração dos sedimentos. Os resultados na região industrializada e com alta densidade populacional mostraram um aumento nas concentrações totais, para Cu, Cr, Zn e Pb, e nas frações potencialmente móveis para os metais Cu, Cr, Zn e Ni extraídos sequencialmente. O Cr destacou-se especialmente no arroio Portão, apresentando uma concentração total de 1286 mg/kg, devido à influência de curtumes localizados nesta região. Os sedimentos também foram caracterizados através de espectroscopia de reflectância, método rápido e não destrutivo de caracterização dos diferentes materiais, na região entre 400 e 2500 nm. Nos espectros de reflectância das amostras avaliadas observou-se que as principais feições espectrais são resultantes das absorções decorrentes da água, das ligações Al-OH e dos teores de ferro presentes. Ainda ficou evidenciada a influência da granulometria, dos teores de ferro e matéria orgânica sobre os espectros de reflectância resultantes. Não foi possível observar as feições espectrais decorrentes dos metais pesados, provavelmente devido às altas concentrações de ferro observadas nas amostras e devido ao fato destes metais apresentarem as suas feições espectrais nas mesmas regiões de comprimento de onda onde ocorrem as feições do ferro. / The present study aimed to evaluate the content of Cu, Cr, Ni, Zn, Pb, Mn, Al, and Fe as well as their geochemical partitioning in sediments of the Sinos river basin in southern Brazil. This basin has a high population density and a great number of industries, especially metallurgy, electroplating works, steel mills, petrochemicals, and tanneries. The total metal concentrations, determined by X-ray fluorescence, and the concentrations in the sediment phases, determined by applying the BCR-701 sequential extraction method proposed by the Community Bureau of Reference of the European Community, using ICP/OES, were evaluated in the sediment fraction <63 μm. The contents extracted by a solution of 0.5 mol/L HCl were also considered in this fraction. Results in the industrialized and densely populated region showed an increase in the total concentrations for Cu, Cr, Zn, and Pb, and in the potentially mobile fractions for the sequentially extracted metals Cu, Cr, Zn and Ni. Cr stood out particularly in the Portão stream, showing a total concentration of 1,286 mg/kg, due to the influence of tanneries in this region. The sediments were also characterized by reflectance spectroscopy, a rapid and nondestructive method for characterization of different materials, in the region between 400 and 2500 nm. The reflectance spectra of the samples showed that the main spectral features are the result of the absorptions due to water, Al-OH bonds and contents of iron. The influences of particle size, organic matter and mineral composition on the absorption features and on the reflection coefficient of the spectra were also evidenced. It was not possible to observe the spectral features resulting from metals, probably due to high iron concentrations observed in the samples, and because these metals make their spectral features on the same wavelength regions where there are the iron spectral features.