58 resultados para Descontaminação
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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A espécie Eichhornia crassipes (Pontederiaceae) é uma macrófita aquática conhecida popularmente como aguapé. É utilizada na descontaminação de ambientes aquáticos poluídos, pois possui alta capacidade de absorver e tolerar elevadas quantidades de íons metálicos. Segundo estudos, o cádmio é um dos metais mais absorvidos por essa espécie, que apresenta maior acúmulo em raízes em relação às partes aéreas. O objetivo desse trabalho foi verificar se a produção de antocianinas do aguapé é alterada pela presença de íons Cd(II) nos tecidos. Foram realizados experimentos in vivo submetendo os espécimes à solução nutritiva contendo ou não íons cádmio. Os extratos metanólicos acidificados com HCl das raízes foram analisados por CLAE-UV e fracionados por CC (C18 e Sephadex), seguidos por CLAE semipreparativa. Após as análises por CLAE-DAD-EM foi possível propor a estrutura de duas antocianidinas: delfinidina e delfinidina substituída por um grupo metoxílico (C16H13O8, 333,0609)
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After the discovery of ionizing radiation, its applications in various fields of science began to take significant proportions. In the case of medicine, there are the application areas in radiotherapy, diagnostic radiology and nuclear medicine. It was then necessary to create the field of radiological protection to establish the conditions necessary for the safe use of such ionizing radiation. Apply knowledge obtained during the graduation stage and in the practice of radiological protection in the areas of nuclear medicine and diagnostic radiology. In the area of nuclear medicine, tests were made in the Geiger-Muller counters (GM) and the dose calibrator (curiometer), the monitoring tests of radiation, waste management, clean of the Therapeutic room and testing the quality control of gamma-chambers. In the area of radiology, were performed tests of quality control equipment for conventional X-ray equipment and x-ray fluoroscopy, all following the rules of the National Health Surveillance Agency (ANVISA), and reporting of tests. The routine developed in the fields of nuclear medicine in hospitals has proved very useful, since the quality control of GM counters contribute to the values of possible contamination are more reliable. The control of dose calibrator enables the patient not to receive different doses of the recommended amounts, which prevents the repetition of tests and unnecessary exposure to radiation. The management of waste following the rules and laws established and required for its management. Tests for quality control of gamma chambers help to evaluate its medical performance through image. In part of diagnostic radiology, tests for quality control are performed in order to verify that the equipment is acceptable for usage or if repairs are needed. The knowledge acquired at the internship consolidated the learning of graduation course
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Pós-graduação em Química - IQ
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Pós-graduação em Química - IQ
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The contamination of the physical environment occurs as a result of the lack of planning and inadequate management of hazardous products. Due to the difficulty of the characterization and study of soil and groundwater, the contamination has been long neglected. The characterization of these areas by research techniques through direct methods such as physical and chemical analysis, are widely used in the diagnosis and monitoring. However, despite presenting quantitative results, this method is not representative in spatial terms. The purpose of this work is to bring geophysical complementation with the diagnosis, bringing the spatial element for the detection of the contamination plume. In the study area, there was a railway accident in 1999 in which three wagons fell and spilled 240,000 L of diesel onto the soil. The main objective is to assess the presence of contaminants in the residual phase and dissolved in the subsurface, using the technique of Electrical Tomography (ETR), understand the effects of natural attenuation process in the degradation of hydrocarbons and changes in electrical properties in soil and groundwater. The results allowed the definition of three distinct patterns of resistivity region with presence of dissolved phase, set in a historical chemical analyzes: low values (> 60Ω.m) associated with the presence of hydrocarbons in an advanced stage of degradation, intermediate values (260Ω.me 511Ω .m) indicative of coexistence of residual hydrocarbons and dissolved phase, and high values (> 1000Ω.m), which reveal the prevalence of residual phase with incipient degradation, possibly in high toxicity concentrations for effective action of biodegradation processes. The diagnostic of areas with potential accumulation of residual phase can subsidize the planning of remediation techniques and promote the complete decontamination of the area
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Introduction: As a new alternative in the complementary treatment lasers teem different systems were employed in the decontamination of dental surfaces implants however, some systems have caused significant changes in its surface. Purpose: Analyze by Scanning Electron Microscopy (SEM) the effects of laser irradiation of Er,Cr: YSGG on different surfaces of titanium. Material and method: Study of 20 titanium discs, and 10 Machined Surface (MS) and 10 surfaces treated with acid (AC). The 10 discs with the same treatment were divided into two groups with five units each, the irradiation was performed in powers of 1 W and 2 W. Result: Showed that the irradiation with 1 W of power resulted in no significant morphological changes in the MS-irradiated compared to non-irradiated surfaces. In MS surfaces, minor changes were observed in the increase of 1000× when compared to non-irradiated surface. With 2 W of power, there were no significant morphological changes in the MS, compared to non-irradiated areas. In AC some changes were observed in the increase of X 1000, showing areas of wear suggestive of treatment and some areas with melting point. Conclusion: Considering the results and the parameters used in this study it was concluded that the Er, Cr: YSGG irradiation can be used for the machined surfaces of implants, but in acid-treated surfaces irradiation parameters should be more controlled.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Apesar da industrialização no setor farmacêutico, o emprego de drogas vegetais constitui desafio atual quando considerado alternativa terapêutica para as populações de baixa renda ou aquelas que apresentam tradição no uso dessas drogas. Além disso, tendências modernas valorizam a variedade de espécies com propriedades curativas, em particular as espécies brasileiras, desafiando os pesquisadores a intensificar investigações nessa área e induzindo à população um crescente consumo. Assim, questões relacionadas à qualidade dessas drogas apresentam fundamental importância. Devido à origem, a carga microbiana detectada nas mesmas é normalmente elevada, oferecendo riscos potenciais ao usuário. Desta forma, a avaliação de sua qualidade sanitária constitui etapa obrigatória no que se refere ao aspecto de segurança ao consumidor. Além disso, a eficácia terapêutica pode igualmente ser comprometida por decomposição de componentes, decorrente da ação de microrganismos. Com o objetivo de eliminar os efeitos decorrentes da biocarga presente nas drogas vegetais, agentes descontaminantes, de natureza física ou química, têm sido empregados. A utilização de tais procedimentos de descontaminação, prevista na legislação vigente, requer estudos relacionados à estabilidade dos princípios ativos após exposição ao agente selecionado. Dentre os agentes destaca-se a irradiação gama, amplamente utilizada em função de sua aplicabilidade na ausência de água e de temperatura elevada, além de apresentar alta penetrabilidade e reduzir, com eficácia, a carga microbiana viável. Os objetivos do presente trabalho foram avaliar os efeitos de diferentes doses de radiação ionizante sobre a carga microbiana de quatro espécies de drogas vegetais: alcachofra (Cynara scolymus L.), camomila (Matricaria recutita L.), ginkgo (Ginkgo biloba L.) e guaraná (Paullinia cupana H.B.K.), bem como detectar possíveis alterações provocadas pela radiação sobre os teores de seus princípios ativos. As análises microbiológicas e químicas foram realizadas antes e após irradiação com doses médias de 5,5 kGy, 11,4 kGy e 17,8 kGy. Os resultados obtidos anteriormente à irradiação revelaram elevados níveis de contaminação: média de 4,1 x106 para microrganismos aeróbicos totais e 3,3x105 para fungos. Após descontaminação, a dose média de 11,4 kGy, reduziu a carga de microrganismos aeróbicos totais a níveis menores ou iguais a 102 em todas as drogas, com exceção da camomila proveniente do fornecedor B (3,2x104). Para os fungos, a menor dose aplicada (5,5 kGy) foi suficiente para reduzir a contagem a níveis da ordem de 10. Com relação à determinação dos marcadores nas drogas vegetais, os resultados obtidos não revelaram alterações significativas nos teores de cafeína no guaraná e de glicosídeos flavonoídicos no ginkgo. Para a camomila, as amostras antes a após irradiação, apresentaram o mesmo teor de óleo volátil bem como ausência de diferenças significativas no teor de α-bisabolol. Em contraste, observou-se redução no teor de 7-glicosil apigenina após submissão à radiação ionizante, indicando degradação decorrente do processo. Com relação à alcachofra, permanece ainda desconhecida a influência da radiação devido à ausência de metodologias adequadas para extração e determinação da cinarina.
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Environmental liabilities from accidents in the retail petroleum industry, especially in urban areas, have represented a serious problem whose impact reaches the underground, people's health and even economic losses with the remediation process. In U.S.A. are estimated hundreds of billions of dollars invested in soil remediation processes. The results of the reports and investigative reports of liabilities in fuel stations distributed in the urban area of Natal-RN were used to estimate the local scenario of contamination. This database has been possible to determine the main contaminants (BTEX, PAHs, TOC), affected neighborhoods and types of potentially more impacted soils. Experiments were carried out in order to reverse contamination of this scenario, where the soil type was a factor in the planning, because it influences directly on the effectiveness of remediation techniques studied: Oxidation by hydrogen peroxide and oxidation by sodium persulphate. These oxidants are activated forming free radicals (HO•-, SO4 •-, HO2 • , O2 •-, S2O8 -2, etc) responsible for to mineralize the hydrocarbons and other organic compounds (releasing O2 e CO2). In the activation process, the ferrous ions (II) and ferric (III) were studied as well as hydrogen peroxide activation technique with sodium persulfate, the latter being presented the best efficiency among all the study, when activated with Fe+3. In addition to defining the most efficient technique, the aim of this study was to evaluate the influence of different soils among oxidative techniques, characterizing the effect of the concentration of these oxidants and also the concentration of the catalysts. Exists in most scenarios evaluated the presence of intrinsic total iron soil matrix. The so-called latosols present microaggregates reddish indicating the presence of these reactive species like iron and clayey aspect. The kinetic study was conducted by experimental design and monitoring of the percentage of total carbon (SSM-5000A) in the solid and liquid phases, knowing that 82.4% of the diesel molecule is carbon. Yet organic carbon and pH of liquid samples were analyzed for technical, characterizing the influence of soil type and its operating condition. The Fenton-like technique H2O2 e Fe+2 presented satisfactory oxidation, including sandy soil, but well below the best result. The sodium persulphate only activated with temperature, even in the most favorable soil, did not provide good efficiency. The best technique in the study had the concentration profile with 2,2x10- 1mol.L-1 of Na2S2O8 activated with 6,53x10-1mol.L-1 of H2O2 and 2,5x10-2 Fe3+mol.L-1 which reduced in less than a day 96 contamination in red soil, initially with 66,667 mg of diesel per kg of clean soil
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This work was performing effluent degradation studies by electrochemical treatment. The electrochemical oxidation (EO) hydroquinone (H2Q) was carried out in acid medium, using PbO2 electrode by galvanostatic electrolysis, applying current densities of 10 and 30 mA/cm2 . The concentration of H2Q was monitored by differential pulse voltammetry (DPV). The experimental results showed that the galvanostatic electrolysis process performance significantly depends on the applied current density, achieving removal efficiencies of 100% and 80 % and 10 applying 30 mA/cm2 , respectively. Furthermore, the electroanalytical technique was effective in H2Q be used as a detection method. In order to test the efficiency of PbO2 electrode, the electrochemical treatment was conducted in an actual effluent, leachate from a landfill. The liquid waste leachate (600ml effluent) was treated in a batch electrochemical cell, with or without addition of NaCl by applying 7 mA/cm2 . The efficiency of EO was assessed against the removal of thermo-tolerant coliforms, total organic carbon (TOC), total phosphorus and metals (copper, cobalt, chromium, iron and nickel). These results showed that efficient removal of coliforms was obtained (100%), and was further decrease the concentration of heavy metals by the cathode processes. However, results were not satisfactory TOC, achieving low total removal of dissolved organic load. Because it is considered an effluent complex were developed other tests with this effluent to monitor a larger number of decontamination parameters (Turbidity, Total Solids, Color, Conductivity, Total Organic Carbon (TOC) and metals (barium, chromium, lithium, manganese and Zinc), comparing the efficiency of this type of electrochemical treatment (EO or electrocoagulation) using a flow cell. In this assay was compared to electro streaming. In the case of the OE, Ti/IrO2-TaO5 was used as the anode, however, the electrocoagulation process, aluminum electrodes were used; applying current densities of 10, 20 and 30 mA/cm2 in the presence and absence of NaCl as an electrolyte. The results showed that EO using Ti/IrO2–TaO5 was anode as efficient when Cl- was present in the effluent. In contrast, the electrocoagulation flow reduces the dissolved organic matter in the effluent, under certain experimental conditions.
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Electrochemical technologies have been proposed as a promising alternative for the treatment of effluents and contaminated soils. Therefore, the objective of this work was to study the treatment of contaminated soils and wastewaters using electrochemical technologies. Thus, the study regarding the scale-up of the electrochemical system with continuous flow treatment of wastewater of the petrochemical industry was investigated using platinum electrodes supported on titanium (Ti / Pt), and boron-doped diamond (BDD). The results clearly showed that under the operating conditions studied and electrocatalytic materials employed, the better removal efficiency was achieved with BDD electrode reducing the chemical oxygen demand (COD) from 2746 mg L-1 to 200 mg L-1 in 5 h consuming 56.2 kWh m-3 . The decontamination of soils and effluents by petrochemical products was evaluated by studying the effects of electrokinetic remediation for removal of total petroleum hydrocarbons (HTP) from contaminated soil with diesel. The efficiency of this process was dependent on the electrolyte used Na2SO4 (96.46%), citric acid (81.36%) and NaOH (68.03%) for 15 days. Furthermore, the effluent after treatment of the soil was treated by electrochemical oxidation, achieving a good elimination of the organic polluting load dissolved. Depending on the physical behavior of wastewater contaminated with oil (emulsified state); atrazine emulsified effluents were investigated. The main characteristics of the effluent produced during the washing of contaminated soil were studied, being dependent on the surfactant dosage used; which determined its electrolytic treatment with BDD. The electrochemical oxidation of emulsified effluent of atrazine was efficient, but the key to the treatment is reducing the size of micelles.