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Aspects of aquatic CO photoproduction from CDOMStubbins, Aron Paul January 2002 (has links)
No description available.
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Uranium associations and migration behaviour at the Needle's Eye natural analogue site in SW ScotlandXu, Xiaolu January 2015 (has links)
This thesis investigated uranium (U) migration behaviour at the Needle‟s Eye natural analogue site, located close to Southwick Water, South West Scotland. The results of this study are important for the prediction of U behaviour in the far-field environments of nuclear waste repositories over long time-scales. The Needle‟s Eye natural analogue site was selected because the processes involved in U mobilisation, the direction of water flow and the extent of retention of uranium in peaty soils had already been identified. To this end, previous results demonstrated that groundwater passing through the mineralisation oxidized U and transported it to the peaty area, where 80-90% of the released U has been retained. Sequential extraction of the peaty soils indicated that more than 90% of the solid phase U was bound to the organic fraction. However, in-depth characterisation of U associations within the soil porewaters and the peaty soils at this site was lacking. Therefore, the processes controlling the migration of uranium within this organic-rich system were the main focus of this study. There were five sampling trips carried out from 2007-2011, in which cave drip waters, bog waters and surface soil and soil core samples were selectively collected for analysis by a range of methods described below. The cave drip waters emerging from the mineralisation were oxidizing and slightly alkaline (7.6-7.8), U was mainly in truly dissolved (<3 kDa) forms (Ca2UO2(CO3)30, CaUO2(CO3)32- and UO2(CO3)22-). It is known that the formation of the ternary Ca-UVI-CO3 complexes inhibits the reduction of U and so it is likely that it is UVI that is present within the peaty soils and their associated porewaters. Sampling trip 1 quantified the U concentrations in cave waters and soil core porewaters. By 30 m from the cave, U concentrations in the soil porewaters had decreased by a factor of ~10. Ultrafiltration fractionated the colloidal fraction (3 kDa-0.2 μm) into large (100 kDa-0.2 μm), medium (30-100 kDa) and small (3-30 kDa) colloidal fractions. It was found that U was mainly associated with the large colloid (100 kDa-0.2 μm) but, with increasing distance from the mineralisation, the U distribution became bimodal with both large and small fractions being equally important. Iron (Fe) was exclusively associated with the large colloid fraction in the peaty soil porewaters. Gel electrophoresis and gel filtration, applied to study the interactions of U (and other elements) with humic substances (HS), showed that the associations were quite uniform with increasing depth of the cores and increasing distance from the U mineralisation. Uranium (and other elements including Fe) was associated with the largest humic molecules. Sampling trip 2 involved collection of three more soil cores and ultrafiltration again fractionated the total dissolved porewater into large, medium and small colloids. This time, the truly dissolved (<3 kDa) fraction was also analysed. Again, U was mainly associated with the large colloidal (100 kda-0.2 μm) fraction. With increasing distance and increasing depth, U was still predominantly associated with the large colloidal fraction, but the importance of the truly dissolved (<3 kDa) phase could not be neglected. At the same time, Fe was also mainly associated with the large colloidal fraction. The remainder of the experimental work on samples from trip 2 focused on determining the importance of U associations with both Fe and humic components of the solid phase. Sequential extraction of the whole soil mainly targeted different iron phases and found that U was mainly released in the sodium acetate and sodium dithionite solutions, which indicated U was associated with (i) Fe carbonates; and (ii) crystalline Fe oxides (e.g. goethite, hematite, and akaganetite). However, very little Fe was extracted in the “carbonate-bound” fraction and separate experiments showed that U was not associated with Fe carbonates but instead had been released from the surfaces of HS and humic-bound Fe surfaces. XRD spectroscopy showed that mineral compositions were in reasonable agreement with the sequential extraction results and SEM-EDX analysis indicated that U in the soil was generally not present in crystalline form, as only two particles with high U content were found after 4-hour searching. Exhaustive extraction of HS showed that >90% U was associated with organic substances, in agreement with previous work and novel experiments involving gel electrophoresis in conjunction with sequential extraction was used to study the relationships between U, Fe and the HS. It was demonstrated that ~20-25% U was weakly held by the HS or at humic-bound Fe surfaces, ~45% was incorporated into crystalline Fe oxides which were intimately associated with HS and the remainder was in the form of strong U-CO3-humic complexes. In sampling trip 3, U migration behaviour in the soil porewaters was the focus. A 30-m transect line, comprising seven0-5 cm soil samples, starting at the cave and passing through the peaty area towards the Southwick Water, was established. Soil porewaters from these surface soils were fractionated into colloidal (3 kDa-0.2 μm) fraction and truly dissolved (<3 kDa) phase. There was a major change in U speciation, from Ca2UO2(CO3)3 0,CaUO2(CO3)32- and UO2(CO3)22- in the truly dissolved fractions of waters close to the cave to a predominant association with the highly coloured colloidal fractions as soon as the boggy area was reached. With distance through the boggy area, it was clear that the colloidal U was being incorporated into the solid phase since porewater concentrations had decreased ~100-fold by 30 m from the cave. Ultrafiltration in conjunction with acetate extraction was then used to extract U from the porewater colloids isolated from a soil core (20 m from cave). In the organic-rich portion of the core (0-30 cm), ~60-70% U was colloidally associated and ~85-95% of this U was extracted from the colloidal fraction. This indicated that the interactions between U and the porewater colloids were weak. In sampling trip 4, U associations in the porewater colloids were still the main focus. Gel filtration of porewater colloids confirmed that U, Fe and humic colloids were intimately associated. It was concluded that although U in the cave drip water was mainly in truly dissolved forms, weak U----humic/Fe colloids were formed immediately when U entered the peaty area. In sampling trip 5, results for soil core porewaters showed that Fe in the whole core was mainly in the form of FeII. Thus strongly reducing conditions prevailed through the core which was situated within the peaty area. Combining the results from the five sampling trips, three zones within the peaty area were distinguished. Zone I was characterised by extremely high concentrations of dissolved HS and this was where the change in U speciation from dissolved to colloidal forms took place. Zone II contained most of the soil cores collected during this study and was characterised by strongly reducing conditions and moderate concentrations of HS. Colloidal U was removed to the solid phase as waters flow through this area. Zone III marks the transition to the saltmarsh. Focusing on Zone II, a conceptual model of U behaviour was developed: upon entering the peaty area, U is weakly held by very large humic-Fe colloids. These colloids are removed to the solid phase and over time the associations of U are transformed; some becomes incorporated into stable humic-bound crystalline oxides as a result of redox cycling of Fe, some becomes strongly complexed to HS and the remainder is weakly held by the HS and/or humic-bound Fe surfaces. The crystalline Fe oxides were transformed to Fe sulfides below 30 cm depth but the associated U was not transferred to these sulfides. Instead the weak associations became more important. In the wider context, since only UVI forms soluble complexes with acetate, UVI does not appear to be reduced even under the strongly reducing conditions encountered within waterlogged organic-rich soils. Initial interactions between UVI and porewater colloids appear to be weak but stronger interactions such as incorporation into Fe phases and complexation by HS occur once the colloids and associated U are removed to the solid phase. Waterlogged organic-rich soils appear to be a long-term sink for U but changing climatic conditions leading to the drying out of such soils may ultimately release U in association with smaller, more mobile organic-rich colloids.
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スギ落葉有機組成分の生分解(第2報) 2年および3年経過リターの組成分について川上, 日出國, KAWAKAMI, Hidekuni, 坂野, 弘美, BANNO, Hiroharu, 沓名, 重明, KUTUNA, Sigeaki 03 1900 (has links) (PDF)
農林水産研究情報センターで作成したPDFファイルを使用している。
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Desenvolvimento de metodologia para extração de substâncias húmicas de turfas utilizando se hidróxido de potássioRosa, André Henrique [UNESP] January 1998 (has links) (PDF)
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rosa_ah_me_araiq.pdf: 516521 bytes, checksum: f4c7ea7ac1bc51926aee3818d09347f1 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Substâncias Húmicas (SH), extraídas de turfa sob diferentes condições foram caracterizadas com o objetivo de se desenvolver nova metodologia de extração com elevado rendimento, baixo teor de cinzas e sem grandes alterações estruturais. Parâmetros como: tempo, temperatura, atmosfera de extração, razão solo/extrator, granulometria do solo, extrator e sua concentração foram avaliados e mostraram ter grande influência no processo. Pelos estudos feitos e resultados obtidos pode-se concluir para a amostra estudada que: 1 - a extração alcalina das substâncias húmicas utilizando-se hidróxido de potássio aumenta o rendimento e diminui o teor de contaminantes inorgânicos co-extraídos em relação ao procedimento utilizando hidróxido de sódio; 2 - a concentração do extrator influencia muito no rendimento, teor de cinzas, razão E4/E6, razão AH/AF e composição elementar das substâncias húmicas extraídas; 3 - 4 horas de extração são suficientes para extrair praticamente toda matéria orgânica presente na amostra; 4 - a razão solo/extrator não exerce influência no teor de matéria orgânica extraída, entretanto, a diminuição dessa razão eleva o teor de contaminantes inorgânicos no extrato húmico; 5 - espectros na região do infravermelho e visível mostraram que o aumento da temperatura de extração causa mudanças estruturais nos ácidos húmico e fúlvico... / Humic Substances (HS), extracted from the peat under different conditions were characterised with the aim of developing a methodology of extraction with high yields, low contents of ashes and without big structural alterations. Parameters such as: time, temperature, extraction atmosphere, soil/extractor ratios, soil granulemetry, extractor and its concentration were evaluated and showed to have great influence on the process. By the studies done and results obtained we can conclude to the studied sample that: 1. the alkaline extraction from the humic substances using potassium hydroxide increase the yields and reduce the contents of inorganic contaminator co-extracted in relation to the procedure that uses sodium hydroxide; 2. the concentration of the extractor influences very much on the yields, contents of ashes, E4/E6 ratios, AH/AF ratios and elementary composition of the extracted humic substances; 3. four hours of extraction are enough to extract almost all the organic material present in the sample; 4. the soil/extractor ratios does not exert any influence on the contents of the extracted organic material, however, the decrease of this ratio increases the contents of inorganic contaminator in the humic extract; 5. spectres in the region of the infrared and visible showed that the increase of temperature of extraction provokes structural changes in the humic and fulvic acids. It was also verified that the reduction of the contents of humic acid and elevation of the fulvic acid extracted with the increase of temperature; 6. the nitrogen atmosphere minimises the oxidation of the humic and fulvic acids during the extraction. The increase in time of extraction of the humic substances in the absence of nitrogen favours the oxidative processes; ...(Complete abstract, click electronic access below)
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Crescimento e sobrevivência de juvenis de jundiás (Rhamdia quelen) em diferentes concentrações de ácido húmico, em ph ácido. / Development and survival of juvenile silver catfish (Rhamdia quelen) challenged by acidic ph at different concentrations of humic acid.Costa, Sílvio Teixeira da 27 July 2012 (has links)
Humic acid is an organic substance identified in black waters, used as growth
promoter and confers protection against environmental contamination by metals. The
objective of this study was to evaluate survival and growth of juvenile silver catfish
Rhamdia quelen exposed to different concentrations of humic acid at acidic pH, observing the
morphological effects in the gills and erythrocytes. In the first experiment, juveniles were
exposed to two pH (5.5 and 6.5) with concentrations (0, 10, 25 and 50 mg.L-1) of humic acid
(CAT: H1 0.675-2 Aldrich® - humic acid sodium salt) for 40 days. In the second study the
histological and morphometric parameters of gills of juveniles exposed to these treatments
were analyzed. The third study evaluated the effect of different pH (3.8, 4.0, 4.2 and 7.0) and
the concentrations of humic acid previously described on survival and erythroid morphology
of juvenile silver catfish. Silver catfish showed greater weight, length, biomass, feed intake,
and specific growth rate when exposed to pH 6.5 without the presence of humic acid. The
gills of silver catfish exposed to pH 5.5 at 50 mg.L-1 of humic acid presented higher filament
length, width of the lamellae, thickness of the epithelium of gill filament, lower distance
between the lamellae, cell proliferation and increase in chloride gill respiratory surface area
GRSA. There was also proliferation of chloride cells and increase in chloride cells fractional
area (CCFA) of juveniles exposed to pH 5.5 at 50 mg L-1 humic acid. Survival of juveniles
was impaired at pH 3.8 and pH 4.0, and the higher the concentration of humic acid, the lower
the survival. Silver catfish exposed to pH 7.0 showed higher erythrocyte are than those
exposed to pH 3.8, 4.0 or 4.2. The presence of humic acid caused an opposite effect,
increasing red cells diameter in fish exposed to higher concentrations (50 mg.L-1). No changes
in plasma Na+, K+, but at pH 3.8 the plasma levels of Cl- were lower than at neutral pH and
this effect was potentiated by the increase of humic acid levels. Thus, it is concluded that the
presence of synthetic humic acid in water is harmful to the developing juvenile catfish, the
higher the concentration of humic acid in water, the higher is the water barrier and blood-cell
proliferation chloride, changing the gill morphology of juvenile catfish, hematological
parameters of juvenile silver catfish are also altered by the presence of synthetic humic acid,
which could compromise adaptation and survival of this species in acidic pH, the humic acid
protects against the juvenile catfish ionorregulatórios negative effects of exposure the acidic
pH. / O ácido húmico é uma substância orgânica identificada nas águas pretas, já utilizada
como promotor de crescimento e que confere proteção contra a contaminação ambiental por
metais. O objetivo deste estudo foi verificar a sobrevivência e o crescimento de juvenis de
jundiá Rhamdia quelen em concentrações distintas de ácido húmico em pH ácido,
observando os efeitos morfológicos nas brânquias e nos eritrócitos. No primeiro manuscrito,
os juvenis foram expostos a dois pH (5,5 e 6,5) em concentrações (0, 10, 25 e 50 mg L-1) de
ácido húmico, por 40 dias. No segundo manuscrito, foram analisados os aspectos histológicos
e morfométricos das brânquias dos juvenis expostos a esses tratamentos ao final de 40 dias de
experimento. O terceiro manuscrito avaliou a sobrevivência e o efeito na morfometria
eritróide de juvenis de jundiá expostos a pH distintos (3,8; 4,0; 4,2 e 7,0) e nas concentrações
de ácido húmico já citadas. Após ao experimento, os juvenis de jundiás apresentaram maior
peso, comprimento, bioamassa, consumo de ração e taxa de crescimento específico quando
expostos ao pH 6,5 sem a presença de ácido húmico. As brânquias dos jundiás expostos ao pH
5,5 em 50 mg L-1 de ácido húmico apresentaram maior comprimento dos filamentos, largura
das lamelas e da espessura do epitélio do filamento branquial, menor distanciamento entre as
lamelas, proliferação de células de cloreto e aumento na área de superfície respiratória GRSA.
Também se verificou proliferação das células de cloreto e aumento na área fracional das
células de cloreto (CCFA) dos juvenis expostos ao pH 5,5 em 50 mg L-1 de ácido húmico. A
sobrevivência dos juvenis foi comprometida em pH 3,8 e pH 4,0, diminuindo esta
sobrevivência em quanto maior foi a concentração de ácido húmico adicionado ao meio
ambiente. Jundiás expostos ao pH 7,0 apresentavam área eritrocitária maior que os peixes
expostos aos pH 3,8; 4,0 ou 4,2. Já a presença do ácido húmico causou um efeito contrário,
fazendo com que os eritrócitos de peixes expostos às maiores concentrações (50 mg L-1)
tivessem maiores diâmetros. Não há alteração nos níveis plasmáticos de Na+, K+, porém em
pH 3.8 os níveis plasmáticos de Cl- foram menores que em pH neutro e esse efeito foi
potencializado pelo aumento da concentração de ácido húmico. Assim, conclui-se que a
presença do ácido húmico sintético na água é prejudicial para o desenvolvimento de juvenis
de jundiá; quanto maior a concentração de ácido húmico na água, maior é a barreira águasangue
e a proliferação de células de cloreto, alterando a morfologia branquial de juvenis de
jundiá; os parâmetros hematimétricos de juvenis de jundiás também são alterados pela
presença do ácido húmico sintético, podendo comprometer a adaptação e sobrevivência desta
espécie em pH ácido; o ácido húmico protege juvenis de jundiá contra os efeitos
ionorregulatórios negativos da exposição ao pH ácido.
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Desenvolvimento de metodologia para extração de substâncias húmicas de turfas utilizando se hidróxido de potássio /Rosa, André Henrique. January 1998 (has links)
Resumo: Substâncias Húmicas (SH), extraídas de turfa sob diferentes condições foram caracterizadas com o objetivo de se desenvolver nova metodologia de extração com elevado rendimento, baixo teor de cinzas e sem grandes alterações estruturais. Parâmetros como: tempo, temperatura, atmosfera de extração, razão solo/extrator, granulometria do solo, extrator e sua concentração foram avaliados e mostraram ter grande influência no processo. Pelos estudos feitos e resultados obtidos pode-se concluir para a amostra estudada que: 1 - a extração alcalina das substâncias húmicas utilizando-se hidróxido de potássio aumenta o rendimento e diminui o teor de contaminantes inorgânicos co-extraídos em relação ao procedimento utilizando hidróxido de sódio; 2 - a concentração do extrator influencia muito no rendimento, teor de cinzas, razão E4/E6, razão AH/AF e composição elementar das substâncias húmicas extraídas; 3 - 4 horas de extração são suficientes para extrair praticamente toda matéria orgânica presente na amostra; 4 - a razão solo/extrator não exerce influência no teor de matéria orgânica extraída, entretanto, a diminuição dessa razão eleva o teor de contaminantes inorgânicos no extrato húmico; 5 - espectros na região do infravermelho e visível mostraram que o aumento da temperatura de extração causa mudanças estruturais nos ácidos húmico e fúlvico...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Humic Substances (HS), extracted from the peat under different conditions were characterised with the aim of developing a methodology of extraction with high yields, low contents of ashes and without big structural alterations. Parameters such as: time, temperature, extraction atmosphere, soil/extractor ratios, soil granulemetry, extractor and its concentration were evaluated and showed to have great influence on the process. By the studies done and results obtained we can conclude to the studied sample that: 1. the alkaline extraction from the humic substances using potassium hydroxide increase the yields and reduce the contents of inorganic contaminator co-extracted in relation to the procedure that uses sodium hydroxide; 2. the concentration of the extractor influences very much on the yields, contents of ashes, E4/E6 ratios, AH/AF ratios and elementary composition of the extracted humic substances; 3. four hours of extraction are enough to extract almost all the organic material present in the sample; 4. the soil/extractor ratios does not exert any influence on the contents of the extracted organic material, however, the decrease of this ratio increases the contents of inorganic contaminator in the humic extract; 5. spectres in the region of the infrared and visible showed that the increase of temperature of extraction provokes structural changes in the humic and fulvic acids. It was also verified that the reduction of the contents of humic acid and elevation of the fulvic acid extracted with the increase of temperature; 6. the nitrogen atmosphere minimises the oxidation of the humic and fulvic acids during the extraction. The increase in time of extraction of the humic substances in the absence of nitrogen favours the oxidative processes; ...(Complete abstract, click electronic access below) / Orientador: Julio Cesar Rocha / Coorientador: Maysa Furlan / Banca: Clóvis Augusto Ribeiro / Banca: Antonio Salvio Mangrich / Mestre
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FraÃÃes hÃmicas em luvissolos sob diferentes sistemas agroflorestais no municÃpio de Sobral - CE / The humic fractions of a Luvissol under different agroforestry systems in the city of SobralGislane Mendes de Morais 07 October 2007 (has links)
InvestigaÃÃo desenvolvida em sistemas agroflorestais que estÃo sendo testados no semi-Ãrido cearense, comparativamente a um sistema de cultivo convencional da regiÃo, identificou o aumento dos teores das fraÃÃes Ãcidos fÃlvicos (FAF) e hÃmicos (FAH). Estes resultados estÃo associados Ãs condiÃÃes em que houve revolvimento do solo como acontece nos sistemas agrossilvipastoril e convencional, o que podem ser atribuÃdos a uma possÃvel conversÃo da fraÃÃo humina em Ãcidos fÃlvicos e hÃmicos. Para testar essa hipÃtese, o presente trabalho objetivou caracterizar as fraÃÃes hÃmicas
do Luvissolo, dos seguintes tratamentos: Agrossilvipastoril (AGP), Silvipastoril (SILV),
Cultivo Intenso em Pousio (CIP), Mata Nativa 1 (MN1) e Mata Nativa 2 (MN2), nas profundidades 0 â 6 e 6 â 12 cm. Foram realizadas caracterizaÃÃes das fraÃÃes Ãcidos
fÃlvicos e hÃmicos atravÃs das anÃlises termogravimÃtricas, elementar, ultravioletavisÃvel e infravermelho. Os resultados de todos os tratamentos analisados indicaram que os Ãcidos hÃmicos mostraram-se mais resistentes que os Ãcidos fÃlvicos. Analisando os tratamentos, o SILV apresentou fraÃÃes hÃmicas menos resistente do que os outros tratamentos estudados. O tratamento AGP apresentou fraÃÃes hÃmicas mais humificadas, podendo ser mais recalcitrante. Este fato pode estar relacionado, devido o tratamento AGP sofrer impacto pelo manejo adotado, o que nÃo acontece no tratamento
SILV. Confirmando a hipÃtese de que o ambiente solo em sistemas de manejo que sofrem intensa perturbaÃÃo està sendo degradado. / Investigations about agroforestry systems, which has been carried out in the arid region in Ceara, Brazil, comparatively to a conventional tillage system in the same area, showed an increase in the concentration of fulvic fraction (FAF) and humic acid (FAH) fractions. These results are related to the conditions in which soil was plowed similar to what is usually done in agrosilvopastoral and conventional systems, which might be attributed to a possible conversion of the humin fraction into FAF and FAH. To address to this hypothesis, a field experiment was carried out aiming to characterize the humic fractions of a Luvissol, over the following treatments: Agrosilvopastoral system (AGP), Silvopastoral system (SILV), Fallow conventional tillage (CIP), Native forest 1 (MN1) and Native forest 2 (MN2), at the depths of 0 to 6 and 6 to 12 cm of the soil. Termogravimetric, elemental, visible-ultraviolet and infrared analyses were utilized to characterize FAF and HAF in the soil samples. The results showed humic acids to be more resistant than fulvic acids. Silvopastoral system had its FAH less resistant in comparison to the others. The AGP had the FAH more humified, which may be more recalcitrant. This finding might be related, due to the AGP to overgo impact by the adopted management, what does not take place in the SILV, so that it might confirm the hypothesis that soil environment overgoing intense disturb might be under degradation.
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Remoção de substâncias húmicas no processo de filtração em múltiplas etapas precedido de oxidação com ozônio / Humic substances removal in the multistage filtration system-MSF preceded rust with ozoneAlmeida, Hélio da Silva 30 November 2001 (has links)
No presente trabalho foi investigada a remoção de substâncias húmicas na Filtração em Mútiplas Etapas - FiME, com aplicação de ozônio antecedendo o processo de filtração lenta. A instalação piloto era constituída de um pré-filtro dinâmico operado com taxa de 18 m/dia, um pré-filtro de escoamento vertical ascendente operado com taxa de 12 m/dia e dois filtros lentos trabalhando com taxas de filtração iguais a 4 m/dia, com diferentes composições dos leitos filtrantes, sendo um somente de areia e o outro de areia e carvão ativado granular disposto como camada \"sanduíche\" entre duas camadas de areia, e sistema de ozonização. Foi injetada solução de substância húmica na água efluente do pré-filtro vertical ascendente, preparada a partir da turfa retirada de uma área localizada no município de Luís Antônio, para proporcionar aumento de cor verdadeira na água. A eficiência das unidades filtrantes, na remoção de matéria orgânica foi avaliada pela determinação de cor verdadeira, carbono orgânico dissolvido, absorvância a 254 nm e oxigênio consumido. O resultados obtidos mostraram que o filtro lento 1, com carvão ativado, foi superior na remoção de matéria orgânica nas duas carreiras desenvolvidas e que não houve diferença entre os filtros lentos quanto a remoção de Escherichia coli, bactérias heterotróficas, sólidos suspensos totais e ferro total. Fortes correlações entre cor verdadeira e absorvância foram identificadas na carreiras de filtração. O mesmo ocorreu só na carreira 3 entre carbono orgânico dissolvido e absorvância e entre COD e oxigênio consumido. / The current research was carried out investigate the removal of humic substances in the multistage filtration system - MSF, with ozone application upstream slow sand filters. The pilot plant was compose by one dynamic roughing filter operated at a filtration rate of 18 m/day, one upflow roughing filter with filtration rate of 12 m/day and two slow sand filters, both operated with filtration rate of 4 m/day, with different \"filtering beds\"; one with sand only and another with sand and granular activated carbon, disposed as a \"sandwich\" layer between two sand layers, and the ozonation system. Solution of humic substance was injected in the effluent water from the upflow roughing filter, which was prepared using turf extracted from Luís Antônio County, to provide a raise in the real color of the water. The efficiency of the filtering units in the remotion of organic matter was evaluated by using the following parameters: true color, dissolved organic carbon, Uv - absorbance at 254 nm and the consumed oxygen. The results show that the slow sand filter 1, with activated carbon, was better for the removal of organic matter in the two runs carried out and that there were no differences between the slow sand filters in the removal of Escheyichia Coli, heteroph bacteria, total suspended solids. Strong correlation between true color and UV - absorbance was identified in run 1. The same occurred in run 3, relating the dissolved organic carbon and UV - absorbance and between DOC and consumed oxygen.
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[en] EXTRACTION OF HUMIC SUBSTANCES FROM TAILINGS OF MINERAL COAL BENEFICIATION: ALTERNATIVE METHODS AND CHARACTERIZATION FOR POSSIBLE APPLICATIONS / [pt] OBTENÇÃO DE SUBSTÂNCIAS HÚMICAS A PARTIR DO REJEITO DE CARVÃO MINERAL: MÉTODOS ALTERNATIVOS E CARACTERIZAÇÃO VOLTADA PARA POSSÍVEIS APLICAÇÕESRENZON DANIEL COSME PECHO 13 March 2019 (has links)
[pt] Este trabalho tem como objetivo principal utilizar um rejeito do processo de concentração de carvão mineral (RJ) como fonte de substâncias húmicas, em particular, do ácido húmico (AH). Para atingir o objetivo a pesquisa foi dividida em três etapas: a obtenção, a caracterização e a aplicação do AH. Na primeira etapa, foram utilizados três métodos diferentes de funcionalização da amostra: o processo químico (PQ), a eletrólise (ELE) e o uso de autoclave (PRESS), previamente ao procedimento de extração das substâncias húmicas (SH), em particular, do ácido húmico (AH). Observou-se que, em termos de recuperação em massa nas condições operacionais estabelecidas, o método de processo químico (PQ) foi o mais eficiente resultando 20,2 porcento de AH e 3,8 porcento para AF-Like. Na segunda etapa, estudou-se a caracterização química (acidez fenólica, acidez total, acidez pelos grupos carboxílicos, pH, CTC e cinza), espectroscópica (FTIR, RMN de 13C e ICP-OES), análise elementar, análise térmica (TGA) e análise estrutural (MEV - EDS) dos ácidos húmicos produzidos. Observou-se certa semelhança entre os AH s extraídos do solo e o AH obtido neste trabalho, com a diferença deste ser muito aromático, o grau de aromaticidade mostrou-se muito elevado (em torno de 60 porcento em relação a 15 porcento do solo). Além disso, as características em relação ao CTC foram relevantes, pois variou de 22 a 44 Cmolckg elevado a -1. Este valor é considerado moderadamente alto em relação ao valor médio de 25 Cmolckg elevado a -1 do CTC, oriundo dos solos brasileiros. Os resultados obtidos por espectroscopia de FTIR e de RMN de 13C indicaram que a funcionalização do rejeito de carvão mineral (RJ) por qualquer um dos métodos de obtenção é relativamente baixa (de 5,0 a 9,7 porcento C-carboxílico) em comparação aos AH proveniente dos solos. Os resultados comparativos apresentaram similaridade nas características estruturais e físicas, observadas pela microscopia eletrônica de varredura. Na terceira etapa foi realizado um estudo preliminar sobre a capacidade do AH, obtido pelo método PQ de reter o chumbo, contido em solução sintética (1000 mgL elevado a -1). Constatando-se uma eficiência de 98 porcento na adsorção deste elemento quando se utilizou uma razão de 1:1(1g AH:1g Pb) e vazão de 0,06 mL/min. / [en] This work aims to evaluate the use of a concentration coal tailing (RJ) as a source of humic substances, particularly humic acid (HA). To achieve the goal the research was divided into three steps: obtaining, characterization and application of HA.In the first step three different methods of functionalization of the sample were tested prior to the HA extraction procedure: chemical process (PQ), electrolysis (ELE) and the using of an autoclave (PRESS). It was observed that in terms of mass recovery and within established operating conditions, the method of chemical process (PQ) result was the most efficient, with 20.2 percent and 3.8 percent of AH to AF-Like, respectively.In the second step, it was studied the physical and chemical properties of the humic acids produced: phenolic acidity, total acidity, the acidity of carboxyl groups, pH, CTC and gray, spectroscopy (FTIR, 13C NMR and ICP - OES), elemental analysis, thermal analysis (TGA) and structural analysis (SEM - EDS). There were some similarities with the AH s extracted from the soil with the difference being the degree of aromaticity which is very high (around 60 percent compared to 15 percent of the soil). Moreover, the relevant features were the CTC, which ranged 22 - 44 Cmolckg to the power of -1. This value is considered moderately high in relation to the approximate mean value of 25 Cmolckg to the power of -1 CTC , originated from Brazilian soil. The results obtained from FTIR spectroscopy and 13C NMR indicated that functionalization of the coal tailing (RJ), by any of the methods is relatively low (5.0 - 9.7 percent C-carboxylic acid) compared to AH from soil. Also showed similar structural and physical characteristics, as observed by scanning electron microscopy. In the third stage, a preliminary study on the retention capacity of the lead contained in synthetic (1000 ppm) solution by the AH obtained by the chemical processes method was performed. It was found an efficiency of 98 percent adsorption of the element when using a ratio of 1:1 (AH 1g : 1g Pb) and flow rate of 0.06 ml/min.
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Remoção de substâncias húmicas no processo de filtração em múltiplas etapas precedido de oxidação com ozônio / Humic substances removal in the multistage filtration system-MSF preceded rust with ozoneHélio da Silva Almeida 30 November 2001 (has links)
No presente trabalho foi investigada a remoção de substâncias húmicas na Filtração em Mútiplas Etapas - FiME, com aplicação de ozônio antecedendo o processo de filtração lenta. A instalação piloto era constituída de um pré-filtro dinâmico operado com taxa de 18 m/dia, um pré-filtro de escoamento vertical ascendente operado com taxa de 12 m/dia e dois filtros lentos trabalhando com taxas de filtração iguais a 4 m/dia, com diferentes composições dos leitos filtrantes, sendo um somente de areia e o outro de areia e carvão ativado granular disposto como camada \"sanduíche\" entre duas camadas de areia, e sistema de ozonização. Foi injetada solução de substância húmica na água efluente do pré-filtro vertical ascendente, preparada a partir da turfa retirada de uma área localizada no município de Luís Antônio, para proporcionar aumento de cor verdadeira na água. A eficiência das unidades filtrantes, na remoção de matéria orgânica foi avaliada pela determinação de cor verdadeira, carbono orgânico dissolvido, absorvância a 254 nm e oxigênio consumido. O resultados obtidos mostraram que o filtro lento 1, com carvão ativado, foi superior na remoção de matéria orgânica nas duas carreiras desenvolvidas e que não houve diferença entre os filtros lentos quanto a remoção de Escherichia coli, bactérias heterotróficas, sólidos suspensos totais e ferro total. Fortes correlações entre cor verdadeira e absorvância foram identificadas na carreiras de filtração. O mesmo ocorreu só na carreira 3 entre carbono orgânico dissolvido e absorvância e entre COD e oxigênio consumido. / The current research was carried out investigate the removal of humic substances in the multistage filtration system - MSF, with ozone application upstream slow sand filters. The pilot plant was compose by one dynamic roughing filter operated at a filtration rate of 18 m/day, one upflow roughing filter with filtration rate of 12 m/day and two slow sand filters, both operated with filtration rate of 4 m/day, with different \"filtering beds\"; one with sand only and another with sand and granular activated carbon, disposed as a \"sandwich\" layer between two sand layers, and the ozonation system. Solution of humic substance was injected in the effluent water from the upflow roughing filter, which was prepared using turf extracted from Luís Antônio County, to provide a raise in the real color of the water. The efficiency of the filtering units in the remotion of organic matter was evaluated by using the following parameters: true color, dissolved organic carbon, Uv - absorbance at 254 nm and the consumed oxygen. The results show that the slow sand filter 1, with activated carbon, was better for the removal of organic matter in the two runs carried out and that there were no differences between the slow sand filters in the removal of Escheyichia Coli, heteroph bacteria, total suspended solids. Strong correlation between true color and UV - absorbance was identified in run 1. The same occurred in run 3, relating the dissolved organic carbon and UV - absorbance and between DOC and consumed oxygen.
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