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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Fitorremediação de solo de terras baixas contendo imidazolinonas / Phytoremediation of soil land containing low imidazolinone

Souto, Kelen Müller 25 February 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Herbicides that present residual effect in the soil, preventing or reducing the emergence of weeds, are inputs of great importance to ensure the expected productivity of comercial crops. However, this residual can prejudice the next crops that do not have the tolerance to the active ingredient of these products and the longer they remain in the soil, the probability of leaching is higher, contaminating the environment. In view of the above, this doctorate thesis had as a goal evaluate the possibility of descontamination of rice cultivating soils with residual of the herbicides imazethapyr, imazapic and imazapyr, by the use of potential phytoremediator plants. The present study was divided in four chapters: 1) Phytoremediation in pots containing soil of irrigated rice with residual imidazolinone; 2) Imidazolinone degradation in rhizosphere of plants phytoremediator; 3 Efficiency of Vicia sativa in the remediation of soil contaminated with imazapyr + imazapic depending on soil type and 4) Use of plants in reducing the residual formulated mixtures of imazethapyr + imazapic and imazapyr + imazapic in codição field. Soybean, vetch, jack bean and consortium of white clover and birdsfoot trefoil, are plants that have the ability to remediate soil contaminated with herbicides belonging to the chemical group of the imidazolinone. The degradation of the herbicide imazethapyr, imazapyr and imazapic, is higher in vegetated soil than in bare soil, demonstrating phytoestimulator effect of these plant species under the existing microbiota in the rhizosphere of the same. Vetch is phytoremediation of soil contaminated with formulated mixture of imazapyr + imazapic even in different soil types. The herbicide imazapyr + imazapic causes greater residual effect that imazethapyr + imazapic, under field condition. . / Herbicidas que apresentam atividade residual no solo, impedindo ou reduzindo a emergência de plantas daninhas, são insumos de grande importância para garantir a produtividade esperada das culturas comerciais. Todavia, esse residual pode comprometer as culturas subsequentes que não possuem tolerância ao princípio ativo desses produtos e quanto mais tempo permanecerem no solo, maior será a probabilidade de sofrerem lixiviação, contaminado o ambiente. Em vista do exposto, essa tese teve por objetivo avaliar a possibilidade de descontaminação de solo de cultivo de arroz irrigado com residual dos herbicidas imazetapir, imazapique e imazapir, através da utilização de plantas potencialmente fitorremediadoras. O presente estudo foi dividido em quatro capítulos: 1) Fitorremediação em vasos contendo solo de cultivo de arroz irrigado com residual de imidazolinonas; 2) Degradação de imidazolinonas em solo rizosférico de plantas fitorremediadoras; 3) Eficiência de Vicia sativa na remediação de solo contaminado com imazapir + imazapique em função do tipo de solo e 4) Uso de plantas na redução do residual das misturas formuladas de imazetapir + imazapique e imazapir + imazapique em codição de campo. Soja, ervilhaca, feijão-de-porco e, consórcio de trevo branco e cornichão, são plantas que possuem capacidade de remediar solo contaminado com os herbicidas pertencentes ao grupo químico das imidazolinonas. A degradação dos herbicidas imazetapir, imazapique e imazapir é maior em solo vegetado do que em solo sem vegetação, demonstrando efeito fitoestimulador dessas espécies vegetais sob a microbiota existente na rizosfera das mesmas. A ervilhaca é fitorremediadora de solo contaminado com a mistura formulada de imazapir + imazapique, mesmo em diferentes tipos de solo. O herbicida imazapir + imazapique causa maior efeito residual que imazetapir + imazapique em condições de campo.
2

Mercúrio na área de disposição final dos resíduos sólidos do munícipio de São Pedro da Aldeia – RJ

Spinola, Eduardo Costa 24 October 2017 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-10-24T14:24:59Z No. of bitstreams: 1 Mercúrio na área de disposição final dos resíduos sólidos do Município de São Pedro da Aldeia - R.pdf: 1346116 bytes, checksum: bcb9b68a2545bcaaa2fb66437b33505e (MD5) / Made available in DSpace on 2017-10-24T14:24:59Z (GMT). No. of bitstreams: 1 Mercúrio na área de disposição final dos resíduos sólidos do Município de São Pedro da Aldeia - R.pdf: 1346116 bytes, checksum: bcb9b68a2545bcaaa2fb66437b33505e (MD5) / Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / A água é fator de produção e elemento fundamental para o desenvolvimento dos povos. Com a intensificação do seu uso, a água é encarada como um recurso finito. Isto é causado pelo crescimento da população. Como conseqüência da crescente oferta do lixo gerado por bens de consumo descartáveis e resíduos sólidos industriais diversos. São improvisadas áreas de destino aos resíduos sólidos sem uma infra-estrutura adequada. Essas áreas, freqüentemente acabam se tornando definitivas e gerando uma série de transtornos. Essas áreas, os “lixões”, são fontes do elemento mercúrio (Hg) que é considerado um poluente global com boa mobilidade, encontrado principalmente na água e alimentos aquáticos, capaz de causar disfunções no sistema nervoso deixando a população mundial em constante alerta. Esta poluição restringe o uso da água, devido a problemas ambientais e danos à saúde da população. No município de São Pedro da Aldeia, foram realizadas análises químicas, em água e sedimento em área de “lixão”, medindo a concentração de Hg e alguns outros metais (Fe, Mn e Zn), matéria orgânica, pH, condutividade e sulfeto, com o propósito de quantificar a concentração dos metais e estudar seu comportamento na região. / The water is a factor of production and fundamental element for the development of the peoples. With the intensification of its use, the water becomes faced as a finite resource. This is caused by the population growth. As a consequence of the increasing offer of disposable consumption products garbage and industrial solid residues are generated. Destination areas are improvised to the solid residues often without an appropriate infrastructure. Those areas frequently end if turning definitive and generating a series of upsets. Those areas, the landfills, are sources of the element mercury (Hg) that is considered a global pollutant with good mobility, found mainly in the water and aquatics foods, capable to cause dysfunctions in the nervous system leaving the world population in alert constant. This pollution restricts the use of the water, due to environmental problems and damages to the health of the population. In the municipal district of São Pedro da Aldeia, we realized chemical analyses, in water and sediment in a landfill area, measuring the concentration of Hg and some other metals (Fe, Mn and Zn), organic matter, pH, conductivity and sulfide, with the purpose of quantify the concentration of the metals and to study its behavior in the region.
3

Detecção de resíduos de soluções sanitizantes empregadas em pedilúvio para bovinos no leite e solo / Residues detection of sanization solution used in foot bath for bovines in milk and soil

GOULART, Daniel Silva 04 July 2011 (has links)
Made available in DSpace on 2014-07-29T14:46:48Z (GMT). No. of bitstreams: 1 Dissertacao Daniel Silva Goulart.pdf: 1005845 bytes, checksum: 66a59436f38bdb12852e5089e10e7187 (MD5) Previous issue date: 2011-07-04 / Copper sulfate and sodium hypochlorite are used in the preparation of cattle footbath solutions, aimed at treating and preventing digital diseases, but little is known about the residues that these substances leave in animal products. The purpose of this study was to evaluate, on soil and milk, residues left by chemicals used in cattle foot bath. The study was developed in two stages. In the first stage, the residual of chlorine and copper in the milk of healthy cows after successive passages in footbath solutions containing these substances was analyzed and the costs of the solutions were estimated. The presence of copper residues was evaluated using atomic absorption spectrophotometry and chlorine residues were evaluated by dosing total chloride in milk using a commercial kit. In the experiment, 14 healthy cows were divided into two groups (GI and GII) of seven animals each. In GI a solution of sodium hypochlorite 1% was used and in GII copper sulphate 5% was used. The milk samples were collected before the passage through the footbath (M0) after 24 (M1), 48 (M2) and 72 hours (M3) and 15 days (M15), following the last passage. Statistical analysis comparing the moments of each sample and the substances evaluated was performed using Friedman test followed by Dunn's test (p <0.05). It was concluded that the values of total chloride and copper in the milk of healthy cattle, after daily passage in footbath for a period of seven days, showed some variations considered insufficient to cause harm to human health and the solutions did not show exorbitant costs. In the second stage, copper residues were evaluated in soil treated with a mixture of cattle feces and urine, simulating cattle liquid manure, containing or not copper sulfate solution. Initially samples were collected from soil in pastures of EVZ / UFG, which were placed in PVC columns divided into four layers. The columns were divided into three treatments (CI, CII and CIII). The CI treatment received only cattle liquid manure and the CII and CIII treatments received the same material added of different amounts of copper sulfate solution. During 120 days, rain was simulated on the PVC columns. In the statistical analysis, analysis of variance followed by the Scott-Knott test at 5% probability were used. It was observed that copper levels were significantly higher in CIII treatment than in CI and CII. The same is true regarding the treatments CII for CI. In treatments CII and CIII copper levels were significantly higher in the superficial layer of soil throughout the experimental period. It was concluded that copper residues available to plants in soil treated with a mixture containing bovine feces and urine associated with copper sulfate solution and water are higher in the upper layers of the soil showing no significant changes in the deeper layers after consecutive rains. / Apesar do hipoclorito de sódio e o sulfato de cobre serem compostos químicos utilizados na preparação de soluções empregadas em pedilúvio para bovinos, visando o tratamento e prevenção de enfermidades digitais, são escassas as informações técnicas com relação à produção de resíduos por estas substâncias nos produtos de origem animal. O objetivo desta pesquisa foi detectar, no leite e solo, os resíduos de produtos químicos empregados em pedilúvio para bovinos, desenvolvendo o trabalho em duas etapas. Na primeira estudou-se o resíduo de cloro e cobre no leite de vacas saudáveis após passagens sucessivas em pedilúvio contendo soluções formuladas com estas substâncias e estimou-se os custos das soluções. A presença de resíduos de cobre foi avaliada empregando espectrofotometria de absorção atômica e a de cloro por meio de dosagem de cloretos totais no leite empregando kit comercial. No experimento, utilizou-se 14 vacas saudáveis distribuídas em dois grupos (GI e GII) de sete animais cada. Em GI empregou-se solução de hipoclorito de sódio a 1% e em GII sulfato de cobre a 5%. As amostras de leite foram colhidas antes da passagem pelo pedilúvio (M0), após 24 (M1), 48 (M2) e 72 (M3) horas e 15 dias (M15), subsequentes a última passagem. Na análise estatística a comparação entre momentos de cada amostra das substâncias avaliadas foi realizada empregando o teste de Friedman, seguido pelo teste de Dunn s (p<0,05). Concluiu-se que os valores de cloretos totais e de cobre no leite de bovinos saudáveis, após passagens diárias dos animais em pedilúvio por um período de sete dias, apresentaram algumas variações consideradas insuficientes para provocarem danos à saúde humana e as soluções medicamentosas não apresentaram custos exorbitantes. Na segunda etapa avaliou-se os resíduos de cobre em solo tratado com uma mistura de fezes e urina bovinas, simulando efluentes de esterqueira usada na bovinocultura, contendo ou não solução de sulfato de cobre. Inicialmente foram colhidas amostras de solo nas pastagens da EVZ/UFG, que foram acondicionadas em colunas de PVC subdivididas em quatro camadas. As colunas foram divididas em três tratamentos (CI, CII e CIII). O tratamento CI recebeu somente dejetos líquidos de bovinos e os tratamentos CII e CIII receberam este mesmo material adicionado de diferentes quantidades de solução de sulfato de cobre. Durante 120 dias foram simuladas chuvas sobre as colunas de PVC. Na análise estatística empregou-se a análise de variância seguida pelo teste de Scott-Knott a 5% de probabilidade. Observou-se que no tratamento CIII os níveis de cobre foram significativamente maior que em CI e CII. O mesmo ocorre em relação ao tratamento CII ao CI. Nos tratamentos CII e CIII observou-se que os níveis de cobre foram significativamente maiores na camada mais superficial do solo durante todo o período experimental. Conclui-se que os resíduos de cobre disponíveis para as plantas, em solo tratado com uma mistura contendo fezes e urina bovina associadas à solução de sulfato de cobre e água são maiores nas camadas mais superficiais do solo, não apresentaram alterações expressivas nas camadas mais profundas após chuvas consecutivas.
4

Development of a sensitive electrochemical sensor based on carbon dots and graphitic carbon nitride for the detection of 2-chlorophenol and arsenic (III) in water

Moundzounga, Theo Herman Gael 02 1900 (has links)
M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / The presence of organic and inorganic pollutants in aqueous environments is one of the major challenges confronting man. It is therefore important to develop sensitive, versatile and cheap techniques for their detection. Arsenic (III), 2-chlorophenol (2-CP) and sulfamethoxazole (SMX) are priority pollutants that pose health threats to humans and animals. This study was thus aimed at exploring two promising carbon nanomaterials as electrode modifiers for the electrochemical sensing of arsenic (III), 2-CP and SMX in water. Glassy carbon electrode (GCE) was modified with a nanocomposite of carbon dots (CDs) and graphitic carbon nitride (g-C3N4) and used as a sensor for the analytes in aqueous media. The CDs was prepared by a facile one-pot hydrothermal method using pine cone as the carbon source; g-C3N4 and g-C3N4/CDs nanocomposite were prepared via the microwave irradiation heating method. CDs, g-C3N4 and g-C3N4/CDs were dropped-dried on the surface of bare GCE. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the prepared materials. GCE, g-C3N4/GCE, CDs/GCE and g-C3N4/CDs/GCE electrodes were electrochemically investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) using a ferrocyanide [Fe (CN) 6]3-/4- redox probe. The current and the reversibility of the redox probes were enhanced in the presence of modifiers. The electrochemical behavior of arsenic (III), 2-CP and SMX on different electrodes (GCE, CDs/GCE, g-C3N4/GCE and g-C3N4/CDs/GCE) were investigated by differential pulse voltammetry (DPV) under optimized conditions in a phosphate buffer solution (pH 7.6, 6 and 5 for 2-CP, As (III) and SMX respectively). The results demonstrated that the g-C3N4/CDs/GCE electrode significantly enhanced the oxidation peak current of all three analytes. The detection sensitivity of the analytes was greatly improved, suggesting that this new modified electrode has great potential in the determination of trace level of arsenic (III), 2-CP and SMX in water. The oxidation peak currents displayed a linear relationship to concentrations for 2-CP (0.5 - 2.5 μM, R2=0.958, n=5), arsenic (III) (2 - 10 μM R2=0.978, n=5) and SMX (0.3 - 1.3 μM R2=0.9906, n=5). The detection limits of 0.62 μM, 1.64 μM and 0.10 μM were obtained for 2-CP, arsenic and SMX, respectively. Phenol and 4-chloro-3-methyl-phenol were found to interfere with the detection of 2-CP, while, Cu2+, Zn2+, Pb2+ and Cd2+ were the only significant ions that interfered with the electrochemical detection of arsenic (III). EDTA was used as a ligand to mask the interference effects of copper, cadmium, lead and zinc on arsenic sensing. The modified electrode (g-C3N4/CDs/GCE) was used to determine arsenic, 2-CP and SMX in spiked tap and effluent water samples by the standard addition method and the results showed percentage recoveries varying from 93-118% for 2-CP, 98-100% for arsenic and 80-105% for SMX. The outcomes of this study established that the nanocomposite material represents an easy and sensitive sensing platform for the monitoring of arsenic (III), 2-CP and SMX in aqueous media.

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