Licenciatura em Química (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/26
Siglas das Coleções:
APP - Artigo Publicado em Periódico
TAE - Trabalho Apresentado em Evento
TCC - Trabalho de Conclusão de Curso
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Resultados da Pesquisa
Item Aplicação da técnica de espectrometria de fluorescência de raios-x por dispersão de energia (EDXRF) para a quantificação de metais pesados em sedimentos de fundo(2025-02-26) Silva, Ingrid Coimbra da; Gomes, Maria José de Filgueiras; França, Elvis Joacir de; http://lattes.cnpq.br/1716496767364751; http://lattes.cnpq.br/0060810526769648; http://lattes.cnpq.br/9997365922939570Estudos recentes do monitoramento dos ecossistemas aquáticos retratam a relevância de tornarem os sedimentos de fundo como objeto de estudo dos impactos de contaminação ambiental por serem acumuladores, processadores e transportadores de metais pesados e espécies contaminantes. Nesse sentido, este presente estudo teve o objetivo de avaliar a aplicabilidade da técnica de Espectrometria de Fluorescência de Raios X por Dispersão de Energia (EDXRF) na quantificação dos elementos químicos Mn, Fe, Ni, Zn, Sr, Ti, Al, Si, K, Ca, V e La e avaliação da qualidade do sedimento a partir dos valores orientadores TEL e PEL de concentração estabelecidos pelo CCME (Canadian Council of Ministers of the Environment) e adotados pela CETESB para os elementos Ni e Zn como possíveis contaminantes em 52 amostras coletadas de 4 perfis de sedimentos originadas da Costa Brasileira, cedidos pela Pesquisa Desenvolvimento Inovação e Ensino (PDIE) ao Centro Regional de Ciências Nucleares do Nordeste (CRCN/NE). A natureza da pesquisa foi do tipo aplicada baseada em uma abordagem quantitativa através das médias aritméticas das concentrações dos metais pesados pelo EDX-720 e materiais de referências certificados (IAEA-SL-1) comparados com valores obtidos e certificados. O tratamento dos dados foi realizado mediante a metodologia de Fernández (2017) e o cálculo de incertezas analíticas com intervalo de 95% de confiança pela metodologia de Costa (2023). De maneira geral, o elemento Ni apresentou valores acima de TEL para a maioria dos pontos analisados, resultando na classificação de qualidade regular dos sedimentos analisados. O metal Zn esteve entre TEL e PEL para a maioria dos pontos coletados, sendo classificada a qualidade do sedimento como ótimo para esse elemento. As concentrações dos demais elementos não apresentam valores guias para comparação. Dessa forma, os objetivos deste trabalho foram atingidos e apresentaram relevância para a justificativa da aplicabilidade da técnica de EDXRF para o estudo de sedimentos de fundo e a importância da avaliação ambiental pela contaminação de metais pesados e seus impactos para os ecossistemas aquáticos causados pela ação antrópica ao longo dos anos.Item A experimentação no ensino de Química: análise de uma proposta de sequência didática para o ensino do conteúdo de metais pesados(2024-09-27) Lima, Isabela Januario de; Silva, Suely Alves da; http://lattes.cnpq.br/3497194749381919Chemistry and the knowledge it provides are extremely important for humanity since its beginning. Learning it provides the students comprehension about the most variable chemical transformations that happen around us. Teaching Chemistry can be challenging for various teachers that have troubles in getting attention from its students for this science, since it has very abstract characteristics and of tough comprehension. In this regard, practical pedagogics are needed to help catch the students’ attention on this science, and one way of achieve that goal is by practical experiments. The general goal of this research was to analyze a didactical sequence utilizing the experimentation as a methodology strategy for the teaching about the Heavy Metals. The utilization of practical activities in the teaching of Chemistry shows as a good strategy to simplify and enthrall the students in the process of learning so that they can articulate the theoretical concepts with practical experiments. This research shows the analysis of a didactical sequence about of using practical experiments when teaching about Heavy Metals. It shows the benefits that practical activities brought while learning the subject, as well the development of scientific abilities. The acquired data were analyzed in an articulated way along with the authors of the theoretical foundation under a qualitative perspective. The tools utilized were two questionnaires, one applied before the experimental activity, and a problem situation to conclude activities carried out afterwards. The research brought many positive outcomes, as a bigger participation of the students and a better comprehension of the same about the Heavy Metals and their characteristics. The engagement and curiosity about this specific subject and about clothes questions that involves chemistry in the experimental part of this science. In conclusion the experiment is one strategy that provides an improvement in the process of teaching and contributes to a bigger engagement of the students in the class, stimulating the curiosity of this science.Item Adsorção dos íons metálicos Cu2+ e Mn2+ em sistema bicomponente utilizando carvão ativado preparado a partir de sabugo de milho como adsorvente(2022-05-20) Campos, Natália Ferreira; Moraes, Alex Souza; Duarte, Marta Maria Menezes Bezerra; http://lattes.cnpq.br/2069994676017059; http://lattes.cnpq.br/0440163845324480; http://lattes.cnpq.br/7441229690485153Heavy metals are used in several areas, especially in the pulp and paper industry, since their effluents contain high levels of copper and manganese, which can cause harmful effects on living systems due to their toxic nature, non-biodegradable and accumulate in organisms. This problem has led several research groups to seek treatment alternatives. Adsorption using activated carbon prepared from agro-industrial residues has been presented as an alternative for the treatment of effluents containing heavy metals. In view of the above, this work proposes the use of activated carbon prepared from corn cob as an adsorbent for the removal of Cu2+ and Mn2+ metallic ions in mono and bicomponent systems. Corn cob activated carbon was chemically activated with H3PO4. The characterization of corn cob and activated carbon was carried out by Fourier transform infrared spectroscopy, Boehm titration and determination of the pH of the zero charge point. The influence of the initial pH of the solution on the adsorptive process was studied in order to determine the pH used in further studies. Based on the results obtained, kinetic and adsorption equilibrium studies were carried out for the mono and bicomponent systems. The characterization indicated that the activation promoted an increase of carboxylic groups on the surface of the adsorbent, reduction of the pHZCP value from 4.7 in the corn cob to 3.0 in the activated carbon, increasing the pH range of the solution in which the surface of the coal becomes negatively charged, which favored the adsorption of Cu2+ and Mn2+ ions. In the study of the effect of the initial pH of the solution in a single-component system, pH 4 and 6 showed better results for Cu2+ and Mn2+ ions, respectively, whereas in the bicomponent system it was pH 4. The model that best represented the experimental data of the kinetic evolution was the pseudo-second order for monocomponent systems and for Cu2+ in the bicomponent system, while for Mn2+ it was the pseudo-first order model. In the adsorption equilibrium, it was found that the model that best fitted the experimental data was Sips for Cu2+ and Langmuir for Mn2+ in a monocomponent system. The experimental adsorptive capacity was 0.39 mmol•g-1 for Cu2+ and 0.22 mmol•g-1 for Mn2+. Regarding the bicomponent system, the antagonistic effect of the presence of Cu2+ for the adsorption of Mn2+ was verified, and the model that best described the process was the extended Langmuir process, as it indicated the highest affinity of Cu2+ with activated carbon. The results of this work demonstrate the technical potential of activated carbon prepared from corn cob for the adsorption of Cu2+ and Mn2+ ions in mono and bicomponent systems.Item Aplicação da geoquímica inorgânica na investigação da contaminação ambiental de sedimentos do Rio Ipojuca, Caruaru/PE, Brasil(2021-07-15) Bezerra, Emanuelle da Silva; Santos, Jandyson Machado; http://lattes.cnpq.br/4137257750865101; http://lattes.cnpq.br/7596013067584452In the study about contamination of aquatic environments, the chemical characterization of sediments in the context of inorganic geochemistry with metal determination can provide important information, as the historic contamination of the aquatic ecosystem, leading to the knowledge of quantity, quality, period and effects caused by that contamination, most often from anthropic activities. The current study aims to achieve the quantification of metals by Inductively coupled plasma optical emission spectroscopy (ICP-OES) of sediments from the Rio Ipojuca, in the stretch of the municipality of Caruaru, state of Pernambuco, in order to identify the level of contamination through these elements, based on the values of the quality guide described on the resolution of CONAMA nº 454/2012. The values of Cr, Cu, Pb and Zn revealed that the sediments are with values higher than the limit value of the Level 1 quality's reference (VRQ1) for the most samples, which indicates that they are above the determined level from which there is less probability of adverse effects on the biota. Furthermore, for the concentration of Cr and Zn, two of the samples were found with concentrations higher than the limit value for the Level 2 quality's reference (VRQ2), leading to regions with values above the determined which there is a greater probability of adverse effects on the biota. In order to follow the resolution of CONAMA nº 454/2012, nine of the ten sediments studied fit the condition in which there is a need to carry out additional experiments, as ecotoxicity tests, due to the values above VRQ1 and VRQ2 indicate a potential contamination. Through the multivariate statistics analysis (PCA e HCA/heatmap) we have found a visualization that show a trend from less contaminated to more contaminated sediment, in which the most contaminated are located close to the urban centers of Caruaru City, pointing out that human activities are responsible for this environmental contamination. Thus, it is possible to conclude that there is a broader need for environmental monitoring of the Rio Ipojuca regarding heavy metal concentrations in the aquatic system, in a way that there is a continuous assessment of its quality and the harmful effects that the contamination may represent.