Desempenho da sílica mesoporosa Al-MCM41 na adsorção de tetraciclina em colunas de leito fixo
Data
2022-11-23
Orientadores
Felisbino, Romilda Fernández 
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A tetraciclina é um antibiótico amplamente utilizado em humanos e animais devido a sua ampla faixa de ação contra diversos microrganismos. Esse composto é pouco absorvido e metabolizado, sendo a maior parte excretada nas fezes e urina. As estações de tratamento de esgotos e de água não possuem capacidade para remover a tetraciclina, contaminando toda a matriz ambiental e a cadeia alimentar. O maior agravante para essa classe de poluentes emergentes é o grande risco da formação de genes resistentes e da criação de superbactérias que ameaçam a saúde pública e o meio ambiente. Diversos métodos de remoção de antibióticos são atualmente estudados, com destaque para a adsorção em colunas. Dentre os promissores adsorventes desenvolvidos recentemente, o grupo das sílicas mesoporosas tem despertado interesse. Nesse estudo foi sintetizado a sílica mesoporosa Al-MCM-41 com razão Si/Al = 16.1 e caracterizada com os testes de DRX, IR e BET. Com os testes em batelada obteve-se as isotermas de equilíbrio e os dados de cinética. Os testes em coluna de leito fixo foram realizados para a obtenção das curvas de ruptura e a aplicação das equações não lineares de diversos modelos da literatura. As melhores isotermas foram obtidas com os modelos de Jovanovich e Freundlich. O modelo Elovich descreveu melhor a cinética dos dados experimentais. Já nos testes em coluna realizados com três diferentes concentrações iniciais, o modelo de Yoon e Nelson obteve o menor erro para capacidade da coluna e os modelos de Yan e Clark descreveram melhor os dados experimentais. A Al-MCM41 demonstrou possuir uma superfície heterogênea e ser um bom adsorvente para baixas concentrações de tetraciclina.
Tetracycline is an antibiotic widely used in humans and animals due to its wide range of action against various microorganisms. This compound is poorly absorbed and metabolized by human and animal organisms, most of which is excreted in feces and urine. Sewage and water treatment plants don’t have the capacity to remove this tetracycline, contaminating the entire environmental matrix and the food chain. The aggravating factor for this class of emerging pollutants is the great risk of the formation of resistant genes and the creation of superbugs that threaten public health and the environment. Thus, several methods of antibiotic removal have been currently studied, with emphasis on adsorption in columns. Among the promising adsorbents developed recently, the group of mesoporous silicas has aroused interest. In this study, Al-MCM-41 was synthesized with Si/Al ratio = 16.1 and characterized with XRD, IR and BET tests. Batch tests were performed to obtain equilibrium isotherms and kinetic data. The tests in a fixed bed column were carried out to obtain the rupture curves and the application of the nonlinear equations models in the literature. The isotherm obtained was better represented by the Jovanovich and Freundlich models. The Elovich model better described the kinetics of the experimental data. in column tests performed with three different initial concentrations, the Yoon and Nelson model had the lowest error for column capacity and the Yan and Clark models best described the experimental data. Al-MCM41 has been shown to have a heterogeneous surface and to be a good adsorbent for low concentrations of tetracycline.
Tetracycline is an antibiotic widely used in humans and animals due to its wide range of action against various microorganisms. This compound is poorly absorbed and metabolized by human and animal organisms, most of which is excreted in feces and urine. Sewage and water treatment plants don’t have the capacity to remove this tetracycline, contaminating the entire environmental matrix and the food chain. The aggravating factor for this class of emerging pollutants is the great risk of the formation of resistant genes and the creation of superbugs that threaten public health and the environment. Thus, several methods of antibiotic removal have been currently studied, with emphasis on adsorption in columns. Among the promising adsorbents developed recently, the group of mesoporous silicas has aroused interest. In this study, Al-MCM-41 was synthesized with Si/Al ratio = 16.1 and characterized with XRD, IR and BET tests. Batch tests were performed to obtain equilibrium isotherms and kinetic data. The tests in a fixed bed column were carried out to obtain the rupture curves and the application of the nonlinear equations models in the literature. The isotherm obtained was better represented by the Jovanovich and Freundlich models. The Elovich model better described the kinetics of the experimental data. in column tests performed with three different initial concentrations, the Yoon and Nelson model had the lowest error for column capacity and the Yan and Clark models best described the experimental data. Al-MCM41 has been shown to have a heterogeneous surface and to be a good adsorbent for low concentrations of tetracycline.