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Características químicas e indicadores de qualidade de solos em sistemas conservacionistas de manejo de longa duração / Soil chemical characteristics and quality index under long-term conservation management systemsViero, Fernando January 2015 (has links)
O plantio direto (PD), associado a plantas de cobertura, pode melhorar os atributos químicos e a qualidade do solo, dependendo do tipo de solo. O objetivo da pesquisa foi avaliar o impacto do PD, associado a diferentes sistemas de cultura, durante longo período (~30 anos) sobre os atributos químicos e indicadores de qualidade de um solo de clima subtropical e de um solo de clima temperado (Estudos I e II), e da influência de sistemas de cultura sobre a eficiência da calagem superficial em PD em um solo de clima subtropical (Estudo III). Nos estudos I e II foram avaliados experimentos instalados em 1985 em Eldorado do Sul (Brasil) e em Concord (EUA) cultivados em PD e preparo convencional (PC). No experimento em Eldorado do Sul foram utilizados três sistemas de cultura: aveia (Avena strigosa)/milho (Zea mays) (A/M), ervilhaca (Vicia sativa)/milho (V/M) e aveia+ervilhaca/ milho+caupi (Vigna unguiculata) (AV/MC), em duas doses de N (0 e 180 kg ha-1). O experimento em Concord foi conduzido com dois sistemas de cultura: milho contínuo e milho-soja (Glycine max)], em três doses de N (0, 80 e 160 kg ha-1). O Estudo III foi conduzido em um experimento instalado em 1983 em PD, sendo avaliados atributos químicos relacionados à acidez do solo antes e dois anos após a calagem (5,0 Mg ha-1) em cinco sistemas de cultura: pousio/M (P/M), A/M, AV/M, AV/MC, LL (Lablab purpureus)+M (LLM), com e sem calagem e em duas doses de N (0 e 180 kg ha-1). As práticas de manejo de longa duração influenciaram os atributos químicos do solo, principalmente, na camada de 0 a 10 cm de profundidade, na qual o PD aumentou, em média, 23 % o teor de C orgânico do solo (COS), 30 % o teor de nitrogênio total (NT) e 100 % o teor de P disponível, em relação ao PC, nos dois solos. O COS e o NT aumentaram na ordem A/M<V/M<AV/MC, enquanto que, o pH, o P disponível e a saturação por bases reduziram na ordem A/M>V/M>AV/MC. O COS e o NT não foram influenciados, mas o pH e a saturação por bases aumentaram na rotação milho-soja. O COS aumentou 5% na dose de 160 kg N ha-1 no solo temperado. A adubação nitrogenada reduziu o pH e a saturação por bases nos dois solos, contudo reduziu 30 % o P disponível no solo subtropical, mas aumentou 20 % no solo temperado. O PD aumentou o estoque e o índice de estratificação (IE) do COS e do C orgânico particulado (COP) e o índice de labilidade (IL) nos dois solos. A inclusão de leguminosas aumentou o IE do COS e COP, e o IL em PD. Os sistemas com leguminosas de cobertura de solo aumentaram a acidificação e a saturação por Al3+ e reduziram a saturação por bases, comparado com sistemas exclusivamente de gramíneas. Após dois anos da calagem superficial o pH foi maior que 5,0 e a saturação por Al3+ foi < 4,0 % até 5 cm, independente do sistemas de cultura, porém, a saturação por bases aumentou para > 50 % até 7,5.cm. As práticas de manejo apresentam comportamento similar entre os diferentes solos, e os sistemas de culturas não influenciaram na eficiência da calagem na camada superficial do solo. / No-till (NT), associated with cover crops, can improve soil chemical properties and quality, which the magnitude of the effects possibly is dependent of soil type. The objective of this research was to evaluate the impact of NT, associated with different cropping systems, cultivated for long-term (~ 30 years) on soil chemical properties and quality indicators of subtropical soil in Southern Brazil and a temperate soil in Midwest US (Studies I and II), and cropping systems influence on liming efficiency in a subtropical soil under long-term NT (Study III). In Studies I and II were used two long-term experiments installed in 1985 in Eldorado do Sul (Brazil) and Concord (US) carried out under NT and conventional tillage (CT). In Brazil, the experiment was composed by three cropping systems: oat (Avena strigosa) / corn (Zea mays) (O/C), vetch (Vicia sativa)/corn (V/C) and oat+vetch/corn+cowpea (Vigna unguiculata) (OV/CC), with two N rates (0 and 180 kg ha-1). In US, the experiment was conducted with two crop rotations: continuous corn and corn-soybean (Glycine max), with three N rates (0, 80 and 160 kg ha-1). The Study III was conducted in a third experiment under NT and assessed soil chemical attributes related to acidity, before and two years after liming (5.0 Mg ha-1), in five cropping systems: fallow/C (F/C), O/C, OV/C,OV/CC, LL (Lablab purpureus)+C LLM), with and without liming and two N rates (0 and 180 kg ha-1). The long-term management effects on soil chemical properties were confined from 0 to 10 cm depth, in which NT system increased, in average, 23 % of soil organic C (SOC), 30 % of total N (TN), 100 % of available P, compared with CT in subtropical and temperate soil. Subtropical cropping systems increased SOC and TN in the order O/C<V/C<OV/CC, while soil pH, available P and base saturation decreased in the order O/C<V/C<OV/CC. Temperate crop rotation had no effects on SOC and TN, but soil pH and base saturation increased in corn-soybean rotation. Nitrogen fertilization increased 5 % of SOC in the N rate of 160 kg ha-1 in temperate soil. Nitrogen fertilization decreased soil pH and base saturation in both soils, but decreased 30% available P in subtropical soil, but increased 20% in temperate soil. No-till increased SOC and particulate organic C (POC) stocks, SOC and POC stratification ratio (SR) and lability index (LI) in both soils. Legume-based cropping systems increased the SOC and POC SR and LI under NT. Besides, legume-based cropping systems increased soil acidification and Al3+ saturation, and decreased base saturation, compared with grass crops. After two years of superficial liming, soil pH increased to >5.0 and Al3+ saturation decreased to <4.0% up to 5 cm, regardless of cropping systems, and base saturation increased to >50% up to 7.5 cm depth. Long-term management practices have similar behavior in the subtropical and temperate soil, and cropping systems has no influence on liming efficiency in topsoil.
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Processos oxidativos avançados para degradação da matéria orgânica do efluente da descontaminação da madeira tratada com arseniato de cobre cromatadoFerreira, Suenni Pires January 2015 (has links)
Nas mais diversas atividades industriais hoje existentes está presente a problemática dos resíduos gerados e seu gerenciamento. Os efluentes líquidos são uma grande fonte de poluição dos recursos hídricos, sendo necessário o controle das condições de seu descarte. Para efluentes contendo poluentes orgânicos uma das alternativas de tratamento que vem sendo muito utilizada é o uso de Processos Oxidativos Avançados - POA’s. Esses processos se baseiam na geração de radicais livres, principalmente o radical hidroxila (HO.), que possui alto poder oxidante e pode promover a degradação de vários compostos poluentes eficientemente. Esses processos têm obtido grande atenção devido ao aumento da complexidade e dificuldade no tratamento de águas residuárias, o que tem sido motivo para a busca de novas metodologias visando a remediação desses rejeitos. Diante disso, o presente trabalho tem por objetivo estudar os processos (POA’s), para a degradação da matéria orgânica em efluente oriundo da descontaminação de madeira tratada com Arseniato de Cobre Cromatado – CCA. Este efluente é gerado através de extração ácida em ciclos de madeira tratada com CCA que foram utilizados como postes tanto de eletricidade como de telefonia. O efluente gerado na extração ácida foi caracterizado através dos parâmetros de pH, Condutividade, Demanda Química de Oxigênio, Carbono Orgânico Dissolvido, Sólidos totais e metais. Após caracterização, o efluente foi submetido aos processos oxidativos avançados de Fotólise, Fotocatálise heterogênea, Eletrólise e Fotoeletrooxidação, a fim de degradar a matéria orgânica. Depois de realizados os processos, o efluente foi caracterizado novamente com os mesmos parâmetros. Pode-se concluir que todos os processos utilizados alcançaram resultados positivos, degradaram a matéria orgânica, mas o processo que obteve melhor rendimento de degradação foi o de Eletrólise que degradou 68% da matéria orgânica presente no efluente. / In the most diverse industrial activities exist today is present the problem of waste generated and its management. Liquid effluents are a major source of pollution of water resources, requiring the control of the disposal conditions. For wastewater containing organic pollutants the use of Advanced Oxidation Processes - POA's has been widely used. These processes are based on the generation of free radicals, especially the hydroxyl radical (HO.), which has high oxidizing power and can promote the degradation of several polluting compounds efficiently. These processes have achieved great attention due to the increasing complexity and difficulty in the treatment of residual waters, which has been the reason for the search of new methods for remediation of these wastes. Therefore, this paper aims to study these processes (POA's) for the degradation of organic matter in the effluent coming from the decontamination of wood treated with CCA - chromated copper arsenate. This effluent is generated by cycles of acid extraction of wood treated with CCA which were used as both telephone and electricity poles. The effluent generated by the acid extraction was characterized by the parameters pH, conductivity, chemical oxygen demand, dissolved organic carbon and metals. After characterization, the effluent was subjected to advanced oxidation processes photolysis, heterogeneous photocatalysis, Electrolysis and photoelectrooxidation (which are the three processes together) in order to degrade organic matter. After the effluent treatment, the solution was again characterized by the same parameters. It can be concluded that all the processes used have achieved positive results, degradeding organic matter, but the process that showed the best performance degradation was the electrolysis with 68% less organic matter.
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THE PROPERTIES OF NATURAL ORGANIC MATTER (NOM) AFFECT THE IMPACT OF NON-FUNCTIONALIZED AND FUNCTIONALIZED MULTI-WALLED CARBON NANOTUBES (MWCNTS) ON TOMATO PLANTS (SOLANUM LYCOPERSICUM)Jasim, Nuralhuda Aladdin 01 December 2013 (has links)
Due to the high specific surface area and aspect ratio (length to diameter ratio, or L/D) of carbon nanotubes, they tend to bind strongly through the van der Waals interactions prevailing among tubes. Thus, they agglomerate and settle in water to form large conglomerates. The adsorption of natural organic matter (NOM) or surfactants onto raw multi-walled carbon nanotubes (MWCNTs) was shown to effectively enhance the dispersibility and stabilization of MWCNTs. The two kinds of dispersants used were humic acid and peptone. Also, two functionalized MWCNTs (-OH and -COOH functional groups) were also dispersed in humic acid (HA) to evaluate the effect of surface property on CNT biological interactions. Based on the dynamic light scattering (DLS) analyses, the use of surfactants increased the steric hindrance as well as the charge repulsion between adjacent CNT particles, thereby enhancing their suspension. HA and peptone sorption onto the surface of MWCNTs can cover their hydrophobic surfaces and help stabilize CNTs. Furthermore, hydroxyl modification of MWCNTs resulted in stable dispersions in water containing HA at 10 and 1000mg/L, while COOH-MWCNT suspensions displayed stable dispersion with lower negative surface charges solely at 100g/L. While, TEM images agreed with the DSL analysis that HA-stabilized MWCNTs were well-dispersed compared to pep-stabilized MWCNTs. Both f-MWCNT types showed a significant reduction in agglomerates as compared to the non-functionalized one. It was noted that the dispersion state as well as the surface properties of both MWCNTs and f-MWCNTs plays an effective role in the potential toxic effects of CNTs. Decreases in the growth rate, chlorophyll index, water uptake, dry weight, and root elongation rate along with a rise in mortality were detected as an indication of phyto-toxicity in both the pep-MWCNT suspensions at 1000mg/L and the peptone control seedlings in contrast to the seedlings treated with pep-MWCNTs at 10 and 100mg/L doses . This was an indicator for the presence of suspended MWCNTs as well as their unstable dispersion in the water column. However, the interaction between the HA-CNTs and the plants improved development in terms of water uptake, growth rate, chlorophyll index, dry weight and root elongation rate due to their well- dispersed stability in water. There were no differences among the f-MWCNT, MWCNT and HA plant groups in terms of their quantum yield and chlorophyll content. While the f-MWCNTs significantly enhanced the plants' growth, water transpiration, and dry root and shoot weight as compared to the non-functionalized MWCNTs. It appeared that exposure to OH-MWCNTs improved the development of tomatoes in terms of water uptake, root elongation rate, and growth rate as well as light- and dark-adaptation, whereas COOH-MWCNTs and non-functionalized MWCNTs were apparently toxic in terms of root leakage and dark-adaptation. Overall, our results suggest that the surface properties of CNTs associated with their dispersion stability specify their influence on the growth of tomato plants. Moreover, the nature of the dispersant agent itself plays an active role in the toxicity of MWCNTs on tomatoes. Our investigation indicated that there is a significant correlation between the toxicity of unfunctionalized MWCNTs and f-MWCNTs and the toxicity of the dispersant agent.
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GEOCHEMISTRY OF THERMALLY ALTERED COALS AND ORGANIC-RICH SHALES: THE IMPACT OF RAPID HEATING ON PHYSICAL AND CHEMICAL PROPERTIES OF ORGANIC MATTERRahman, Mohammad W. 01 August 2014 (has links)
Igneous intrusion can change the geochemical and petrographic properties of sedimentary organic matter (such as coals and organic-rich clays or shales) including vitrinite reflectance, maceral petrographic composition, mineralogy, stable isotope composition, trace element composition, and bulk geochemistry. Igneous intrusions into coals and organic-rich rocks may have contributed to global warming in the geologic past by causing the release of greenhouse gases. Evidence for the release of large amounts of thermogenic CH4 from the organics would include significant;13Corg enrichment in the residual organic matter. However, 13Corg of thermally altered organic matter in coals and shales adjacent to intrusions often show negative shifts and, in some cases, ambiguous or positive trends. Previous studies have evaluated 13Corg of bulk samples rather than that of individual components, or macerals. As different macerals have different isotopic compositions, maceral-specific trends may be masked by variations in maceral composition of the whole-coal samples. It is important to explain the evolution of different geochemical and petrographic signatures in coals, coals macerals, and organic-rich sedimentary rocks close to an intrusion. This study evaluates the following three hypotheses: (1) thermally altered coals show different geochemical trends compared with coals that have undergone normal burial maturation; (2) if a large-scale release of 13C-depleted thermogenic CH4 resulted from intrusion of the coal, then it should have produced 13C-enriched coal and vitrinite macerals (the most abundant components of the coal) adjacent to the intrusion due to the release of light gases; and (3) 13Corg gets heavier with the increase in heat alteration approaching an intrusion due to the release of isotopically light gases. The current study reports petrographic, bulk geochemical (proximate, and ultimate), 13Corg data (whole-coal/shale samples and vitrinite macerals separated via density-gradient centrifugation, (DGC)), density data (vitrinite macerals), and Rock-Eval pyrolysis data for occurrences of thermally altered Springfield (No. 5) Coal (Pennsylvanian), Danville (No. 7) Coal (Pennsylvanian), and an organic-rich shale in the southern part of the Illinois Basin. Petrographic analysis shows an increase in vitrinite reflectance (Rm) from background levels of 0.55% up to ~4.80% in the Springfield (No. 5) Coal, 0.66% to 4.40% in the Danville (No. 7) Coal, and 0.71% to 4.78% for organic-rich shale; a loss of liptinite macerals, formation of isotropic coke and, at the intrusion contact, even development of fine-grained mosaic anisotropic coke texture. Volatile matter (VM) content decreases and fixed carbon (FC) content, ash, and mineral matter increase approaching the coal/intrusion contact. Carbon increases whereas nitrogen, hydrogen, and oxygen decrease approaching the intrusions. The presence of carbonate minerals (confirmed by X-ray diffraction and petrographic analysis) has a significant impact on proximate and ultimate data. However, even after removal of carbonates, trends for VM vs. vitrinite reflectance, %C vs. Rm, and H vs. C do not follow typical trends associated with normal burial coalification. Approaching the contacts, free oil content (S1), remaining hydrocarbon potential (S2), carbon dioxide from pyrolysis of the organic matter (S3), and hydrogen (HI) and oxygen (OI) indices decrease whereas thermal maturity (Tmax, ⁰C) increases. In addition, HI vs. VM, S2 vs. Rm, and Tmax vs. Rm diverge from pathways seen in previous studies. Trends in most of the Rock-Eval parameters in the organic-rich shale studied here are less clear due to the degree of variation in organic matter content, but a clear increase in thermal maturity (Tmax, C) is seen. There are no significant changes in 13Corg in the whole-coal samples (WCM) of the Springfield (No. 5) Coal (-25.28 / to -24.88 /), Danville (No. 7) whole coals (-25.37 / to -24.76 /), and in the DGC-separated vitrinites (-25.33 / to -24.96 /) of the Springfield (No. 5) Coal approaching the intrusion. However, the organic-rich shale transect shows a 1.31 / positive shift in 13C (from -25.06 / to -23.87 /) approaching the intrusion. DGC-separated vitrinite densities range from 1.268 g/mL in the unaltered coal to 1.523 g/mL at the coal/intrusion contact. For the vitrinite concentrates, density shows a clear correlation with Rm, %Cdaf, Hdaf, H/C, TOC, and 13Corg. These geochemical data suggest that these coals may have followed a different maturation track because of the geologically rapid heating associated with the intrusive event. It is also suggested here that the natural coke textures produced by such rapid geological heating may differ from those observed for metallurgical cokes produced under standard industrial coking conditions. Typically, in an industrial coke oven, a coal of this initial rank (Ro = ~ 0.6%) would produce an isotropic coke, rather than the fine-grained circular anisotropic coke seen here. The development of this texture may reflect differences due to heating rates or, alternatively, may indicate "pre-heating" of the coal during the intrusion event. Changes in the isotopic signatures are not of a magnitude that would be expected if significant thermogenic CH4 had been generated by the intrusive event. Moreover, there is no petrographic evidence for condensed or immobilized thermal products due to rapid pyrolysis (12C-rich pyrolytic carbon) close to the intrusion. These geochemical and petrographic data suggest there was only minimal CH4 generation associated with the rapid heating of the coals and organic-rich sedimentary rocks by the intrusion. In addition, there is no evidence for 13C-depleted condensed gas or pyrolytic carbon at the intrusion contact that could have moderated the isotopic signature. These data agree with previously reported data from this laboratory (Rahman et al., 2014, in review) and others (Gröcke et al., 2009; Yoksoulian, 2010) that indicate no clear evidence for large-scale CH4 generation due to the rapid heating or igneous intrusion in coals or sedimentary rocks.
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Soil-Climate Feedbacks: Understanding the Controls and Ecosystem Responses of the Carbon Cycle Under a Changing ClimateReynolds, Lorien 27 October 2016 (has links)
Soil organic matter (SOM) decomposition and formation is an important climate feedback, with the potential to amplify or offset climate forcing. To understand the fate of soil carbon (C) stores and fluxes (i.e., soil respiration) under future climate it is necessary to investigate responses across spatial and temporal scales, from the ecosystem to the molecular level, from diurnal to decadal trends. Moreover, it is important to question the assumptions and paradigms that underlie apparently paradoxical evidence to reveal the true nature of soil-climate feedbacks. My dissertation includes research into the response of soil respiration in Pacific Northwest prairies to warming and wetting along a natural regional climate gradient (Chapter II), and then delves deeper into the mechanisms underlying SOM decomposition and formation, examining the temperature sensitivity of SOM decomposition of prairie soils that were experimentally warmed for ~2 yr, and a forest soil in which litter-inputs were manipulation for 20 yr (Chapter III), and finally testing soil C cycling dynamics, including mineral-associated C pools, decomposition dynamics, and the molecular nature of SOM itself, under litter-manipulation in order to understand the controls on SOM formation and mineralization (Chapter IV).
This dissertation includes previously published and unpublished coauthored material; see the individual chapters for a list of co-authors, and description of contributions.
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Geoquímica e petrografia orgânica da formação Santana, Bacia do Araripe, Nordeste do BrasilMenezes, Jorge Danine de Oliveira January 2017 (has links)
A Bacia do Araripe, conforme Brito Neves et al. (2000), está inserida na unidade geotectônica da Província Borborema, abrangendo os estados do Ceará, Pernambuco e Piauí. Este trabalho buscou identificar possíveis intervalos potencialmente geradores da Formação Santana (Aptiano-Albiano) na Bacia do Araripe, a partir de técnicas de geoquímica e petrografia orgânica para caracterizar dez amostras de campo, referentes a folhelhos orgânicos provenientes deste intervalo estratigráfico. Os valores de COT indicam que todas as amostras possuem mais que o mínimo de carbono orgânico necessário para geração de hidrocarbonetos, a partir de 1 % em massa. Foram encontrados valores no pico S2 que variam de 7,44 a 13,56 mg HC/g de rocha para os Membros Crato e Romualdo (base e topo da Formação estudada), conferindo-lhes um potencial petrolífero bom e muito bom, respectivamente. No Membro intermediário, Ipubi, há um acréscimo na produção de hidrocarbonetos rumo ao seu topo estratigráfico, mas ocorre também a amostra com mais pobre potencial petrolífero, a amostra 9, com valor de S2 de 0,05 mg HC/g de rocha. O tipo de querogênio é classificado como tipo II para os Membros Crato e Romualdo, e tipos I, II e III para o Membro Ipubi. Os valores de ICE variam entre 3.0 a 4.0 (Robertson Research Limited), e de Tmax (361 a 433 ºC), permitindo classificar as amostras como imaturas a marginalmente maturas, conforme classificação de Peters & Cassa (1994) Foram encontradas vitrinitas apenas no Membro Ipubi, indicando material imaturo com 0,29 – 0,48% Rrandom, e baixo grau de maturação 0,60% Rrandom na amostra 2. A petrografia sob luz refletida mostra que as amostras 2, 3 e 9 estão contaminadas por betumen, interferindo nos valores de índice de produção, além de reflectância da vitrinita para a amostra 9. Análises de DRX mostram que o quartzo é o mineral mais abundante nas amostras, seguido pela esmectita e calcita, por vezes gipso, pirita e ilita e raramente caolinita. A petrografia sob luz transmitida, indica a matéria orgânica amorfa, como sendo o principal componente do querogênio estudado, seguido por fitoclastos e palinomorfos. A Análise elementar das razões atômicas de N, C, H e S, apontam os maiores valores nas amostras 5 a 8 (Membro Ipubi), podendo relacioná-las também aos maiores valores de COT e pertencentes a querogênio do tipo I, o menor valor dos parâmetros supracitados ocorre na amostra 9, a única que possui querogênio do tipo III. Os valores intermediários encontrados nas amostras 1 a 4 e 10, coincidem com amostras referentes a querogênio do tipo II. O intervalo em que se observa maior predominância destas condições está localizado no topo do Membro Ipubi, englobando as amostras 5 a 8. Foi determinado, a partir das análises realizadas, que este grande intervalo é caracterizado como o maior potencial gerador de petróleo identificado neste trabalho, apesar das amostras analisadas estarem imaturas. / The Araripe Basin, according to Brito Neves et al. (2000), is inserted in the geotectonic unit of the Borborema Province, covering the states of Ceará, Pernambuco and Piauí. This study aimed to identify possible potentially generating intervals of the Santana Formation (Aptian-Albian) in the Araripe Basin, from geochemical techniques and organic petrography to characterize ten samples field, referring to organic shales from this stratigraphic interval. The COT values indicate that all samples have more than the minimum of organic carbon required for generation of hydrocarbons, from 1% by mass. The S2 values ranging from 7.44 to 13.56 mg HC / g of rock for the Crato and Romualdo Members (base and top of the study Formation), giving them a good petroleum potential and very good, respectively. In the intermediate member, Ipubi, there is an increase in production of hydrocarbons toward its top stratigraphic, but also occurs the sample with poorer oil potential, the sample 9, with a value of S2 0.05 mg HC / g rock. The type of kerogen is classified as type II for Members Crato and Romualdo, and types I, II and III to the Member Ipubi. SCI values range from 3.0 to 4.0 (Robertson Research Limited), and Tmax (361-433 °C), allowing classifying the samples as immature to marginally mature, as Peters & Cassa classification (1994). Vitrinitas were found only in the Member Ipubi indicating immature material with from 0.29 to 0.48% Rrandom and low degree maturity 0.60% Rrandom the sample 2 The petrographic under reflected light shows that samples 2, 3 and 9 are contaminated with bitumen, interfering with the production index values, and the vitrinite reflectance for sample 9. XRD analysis shows that quartz is the most abundant mineral in the samples, followed by the smectite and calcite sometimes gypsum, pyrite and illite and kaolinite rarely.The petrographic under transmitted light, indicates the amorphous organic material as the main component of kerogen studied, followed by phytoclasts and palinomorphs. The Analysis of the atomic ratios of N, C, H and S, indicate the highest values in samples 5-8 (Member Ipubi), associated also to higher TOC values and belonging to Type I kerogen, the lowest value the above parameters occurs in the sample 9, the one that has the type III kerogen. Intermediate values found in samples 1 to 4 and 10 matching samples related to type II kerogen. The interval in which there is a predominance of these conditions is located at the top of the Member Ipubi, encompassing the samples 5 to 8. It was determined from the analyzes carried out, this long interval is characterized as the greatest potential for generating oil identified in this work although of the samples are immature.
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Dynamika půdního uhlíku a vybraných půdních charakteristik v subpovodích modelového území Stropnice / Dynamism of soil carbon and selective soil characteristics in model landscape Stropnice subcatchmentsBODLÁK, Lubomír January 2011 (has links)
The aim of the theses was to describe soil organic matter changes in model landscape Stropnice subcatchments that have different biotopes and agricultural and forest management.Particular aims were: 1) to determine the link between landuse, soil environment changes and catchment matter losses. 2)to experimentally prove the water regime impact on carbon and other substances losses during and between vegetation seasons.
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Caracterização de fertilizantes orgânicos e organominerais fluidos / Characterization of organic and organomineral fluid fertilizersDanielle Xanchão Dominguez 18 January 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O uso de fertilizantes orgânicos e organominerais fluidos têm crescido bastante no mundo e também no Brasil, nas últimas duas décadas. Esse rápido crescimento da demanda por esses produtos levou o Ministério da Agricultura, Pecuária e Abastecimento a buscar novas metodologias para a verificação da qualidade dos mesmos. Este trabalho tem como objetivo obter informações sobre a natureza desses fertilizantes, avaliando metodologias existentes e testando novos métodos, visando contribuir para o desenvolvimento de um protocolo de controle de qualidade a ser adotado pelo Ministério da Agricultura e pelas empresas produtoras. Em uma primeira etapa, os fertilizantes foram caracterizados por meio de análises físicas e químicas conforme os métodos de rotina previstos na legislação. Adicionalmente, foram avaliados diferentes métodos de determinação de carbono, além do fracionamento das substâncias húmicas presentes nas amostras de fertilizantes, e posterior determinação do teor de carbono nas frações ácido húmico e fúlvico. Por meio da titulação potenciométrica, fez-se a especiação, identificação e quantificação dos grupos funcionais mais reativos presentes nas amostras. Na segunda etapa do trabalho, purificaram-se os ácidos húmicos de 15 amostras de fertilizantes. Após esse procedimento foi realizada a caracterização dos ácidos húmicos por espectrometria no infravermelho (FTIR) e por análise elementar (CHN). Os fertilizantes avaliados apresentaram grande variação em relação aos atributos analisados. Foram Observadas variações acentuadas em relação aos teores de carbono orgânico e carbono total, como também na qualidade dos compostos orgânicos presentes nos fertilizantes, o que deve refletir na sua eficiência agronômica. Pela correlação entre os métodos utilizados, observou-se a possibilidade de substituição de métodos de difícil execução, por métodos simplificados de baixo custo, permitindo sua aplicação em análises de rotina. Novos estudos, abrangendo um maior espectro de amostras, devem ser conduzidos para que se possam determinar parâmetros para os diferentes atributos químicos e físicos desses produtos, subsidiando tecnicamente a legislação. / The use of organic and organic-mineral fertilizers has grown fastly in the world and also in Brazil in the last two decades. This fast increase in the demand for these products took the Ministry of Agriculture to search new methodologies for the verification of their quality. This work has objective of obtaining information on the nature of these fertilizers, by evaluating existing methodologies and testing new ones, contributing to the development of a quality control protocol to be adopted by the Ministry of Agriculture and the producing companies. In a first stage, the fertilizers were characterized by means of physical and chemical analyses as the foreseen methods of routine in the legislation. Additionally, different methods of carbon determination were evaluated, beyond the humic substances fractionation in the samples of fertilizers, and posterior determination of the carbon in the humic and fulvic fractions. The most reactive functional groups in the samples were identified and quantified by potentiometric titration. The humic acids of fifteen fertilizer samples were extracted and purified. The humic acids were characterized by infrared spectrometry (FTIR) and elemental analysis (CHN). The evaluated fertilizers presented a large variation in relation to the analyzed characteristics. Large variations in relation to the levels of organic carbon and total carbon were observed, as well as in the quality of organic compounds in fertilizers that was reflected in its agronomic efficiency. By the correlation between the used methods, it was observed the possibility of substitution of methods of difficult execution for simplified methods of low cost allowing their application in routine analyses. New studies including a more representative set of samples must be carried out in order to determine parameters for the different chemical and physical attributes of these products given technical subsides to the legislation.
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Origem e composição da matéria orgânica particulada no complexo estuarino-lagunar de Mundaú-Manguaba utilizando lipídios como marcadores moleculares / Origin and composition of particulate organic matter in the estuarine-lagoon complex Mundaú-Manguaba using lipids as molecular markersTalitha Lopes Ferreira da Costa 23 March 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O Complexo Estuarino Lagunar Mundaú-Manguaba está sofrendo um processo acelerado de degradação ambiental devido a muitas atividades antrópicas como crescimento urbano desordenado, processamento de cana-de-açúcar, pecuária, efluentes industriais e domésticos. O objetivo deste trabalho é avaliar a composição e distribuição do material particulado em suspensão através de traçadores geoquímicos orgânicos para identificar as fontes potenciais e os padrões de mistura da matéria orgânica no CELMM durante duas campanhas: uma realizada no período seco e a outra no período úmido. As amostras de água foram coletadas na superfície (< 1 m de profundidade), utilizando garrafas de vidro de 4L de capacidade. Os n-alcoois, esteróis e ácidos graxos foram extraídos por Soxhlet e analisados por cromatografia em fase gasosa acoplada a espectrometria de massas. Considerando os resultados obtidos, constatou-se que há uma predominância de matéria orgânica autóctona em ambos os períodos de amostragem no sistema em questão. Contudo, também foi observada a presença de fontes alóctonas e antrópicas, tendo estas uma menor influência durante o período seco. / The Mundaú-Manguaba estuarine lagoon system is located in Maceió, Alagoas, Brazil. This region has been suffering an accelerated process of environmental degradation through many antropic activities like urban growth, sugar-cane processing, cattle breeding, industrials waste and sewage. The aim of this work is to evaluate the suspended particulate matter composition and distribution with organic geochemistry markers to identify the potential sources and mixing processes in the system during the wet and the dry period. The water samples were collected at the surface (<1m of depth), using a 4L glass bottle. Lipids were extracted by Soxhlet and quantified by gas chromatography-mass spectrometry. Considering the obtained results, a predominance of autochthonous sources of organic matter was established for the system. However, the presence of alochthonous and anthropic also was observed with lower influence during the dry period.
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Fluxo de carbono orgânico particulado e dissolvido no estuário do rio Barra Grande em Vila Dois Rios, Ilha Grande, RJ. / Particulate and dissolved organic carbon flux in the estuary of Barra Grande river at Vila Dois Rios, Ilha Grande, RJ.Oswaldo Luiz de Carvalho Maciel Junior 28 August 2014 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Os estuários são ambientes costeiros semifechados, que atuam como um sítio de troca de água e de matéria. De acordo com suas características, estuários podem exportar ou importar matéria orgânica (MO). A MO é um complexo bioquímico formado por diversos compostos orgânicos, e sua quantificação é normalmente traduzida pela quantidade de carbono orgânico total (COT), seu elemento mais abundante, tanto na forma de carbono orgânico dissolvido (COD), quanto carbono orgânico particulado (COP). Determinar a origem do carbono orgânico pode auxiliar na compreensão da dinâmica da MO, podendo ser feita com auxílio de isótopos estáveis de carbono (13C) e de nitrogênio (15N). Vila Dois Rios, é um vilarejo localizado ao sul da Ilha Grande, onde se localiza o rio Barra Grande, que possui pouca intervenção antrópica. Esse é um rio de porte pequeno, com uma mata ciliar bem preservada, representada por espécies de Mata Atlântica, com presença de manguezal, ao lado está localizado o Centro de Estudos Ambientais e Desenvolvimento Sustentável (CEADS). Foram realizadas amostragens sazonais, todas em maré de sizígia, ao longo do ano de 2012, totalizando quatro coletas trimestrais. Todas as campanhas ocorreram em uma estação fixa, na foz do rio Barra Grande. A amostragem de água foi realizada em duas profundidades, superfície e fundo, coletadas em intervalos de 30 minutos, ao longo de 25 horas, para as seguintes determinações: carbono orgânico particulado (COP), carbono orgânico dissolvido (COD) e isótopos estáveis de carbono (13C) e de nitrogênio (15N). Concomitantemente, foram medidos in situ: pH, salinidade, temperatura, oxigênio dissolvido (OD), profundidade do Disco de Secchi e medidas de fluxo. Ao fim da amostragem na Ilha Grande, o material coletado foi transportado para o Laboratório de Geoquímica Orgânica Marinha (LaGOM), na UERJ, onde foi analisado posteriormente. Durante todas as campanhas, foi observada uma maré mista, predominantemente semidiurna com desigualdade. Os resultados de temperatura e salinidade evidenciaram uma estratificação vertical em todas as campanhas. Os valores medianos de MPS foram sempre maiores no fundo em relação às amostras coletadas na superfície. O carbono orgânico apresentou maiores concentrações sob a forma dissolvida do que na particulada, variando entre as profundidades e as campanhas, sendo observadas maiores concentrações medianas, tanto de COD quanto de COP, em superfície e no fundo, na campanha de verão. As concentrações medianas de Nt observadas ao longo das três campanhas foram baixas, estando relacionadas às baixas concentrações de COP. A razão molar C/N e as isotópicas indicaram que o manguezal demonstrou ser a fonte mais abundante de COP nesse estuário. Os cálculos de fluxo indicaram que o estuário tanto importou, quanto exportou material, e apenas o COD foi importado em todas as campanhas. / Estuaries are semi-enclosed coastal environments, which act as a site of exchange of water and matter. According to its characteristics, estuaries can export or import organic matter (OM). The OM is a biochemical complex formed by various organic compounds and their quantification is usually translated by the amount of total organic carbon (TOC), its most abundant element, both in dissolved organic carbon (DOC) and particulate organic carbon (POC) form. Determine the source of organic carbon may assist to understand the dynamics of OM and can be done with stable carbon isotopes (13C) and nitrogen (15N). Vila Dois Rios, is a village located at south of the Ilha Grande, where is the Barra Grande river, which has little human intervention. This is a small river, with a well-preserved riparian forest, represented by Atlantic Forest species with presence of mangroves. The Centro de Estudos Ambientais e Desenvolvimento Sustentável (CEADS) is located next to the river. Seasonal samples, all in spring tide, during the year 2012, were made, a total of four quarterly. All campaigns have occurred at a fixed station at the mouth of Barra Grande river. The water sampling was performed at two depths, bottom and surfasse, collected at 30 minute intervals over 25 hours to the following determinations: Particulate organic carbon (POC), dissolved organic carbon (DOC), stable carbon isotope (13C) and stable nitrogen isotope (15N). Concomitantly, were measured in situ: pH, salinity, temperature, dissolved oxygen (DO), Secchi disk depth and flow measurements. After sampling at Ilha Grande, the material was transported to the Laboratório de Geoquímica Orgânica Marinha (LaGOM), UERJ, which was subsequently analyzed. During all campaigns, a mixed, predominantly semidiurnal tide with inequality was observed. The results of temperature and salinity showed a vertical stratification in all campaigns. Median values of MPS were always higher in the bottom. The organic carbon showed higher concentrations in the dissolved form than in particulate, ranging between depths and campaigns. Higher median concentrations of both DOC as POC in surface and bottom were observed in the summer campaign. The median concentrations of total nitrogen observed over the three campaigns were low, being related to low concentrations of POC. The molar ratio C/N and isotope indicated that the mangrove proved to be the most abundant source of POC in the estuary. The flow calculations indicated that the estuary both imported and exported material, where only DOC was imported in all campaigns.
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