Uso de Eichhornia Crassipes (Mart.) Solms in natura e carbonizada como biossorvente para a remoção de corante catiônico em meio aquoso
Data
2022-06-13
Autores
Lima, Herbert de Paula 
Orientadores
Asencios, Yvan Jesus Olortiga
Tipo
Dissertação de mestrado
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ISSN da Revista
Título de Volume
Resumo
Eichhornia crassipes (Mart.) Solms é uma erva aquática, considerada uma praga em muitos países, que pode ocasionar prejuízos como obstrução de fluxos de água em sistemas hídricos e comprometimento de atividades pesqueiras. Entretanto, a habilidade da planta em adsorver poluentes recalcitrantes, como o corante azul de metileno, tem sido objeto de estudo de várias pesquisas cientificas nas últimas décadas. O corante catiônico azul de metileno é amplamente utilizado como molécula modelo de contaminantes em estudos de adsorção para avaliar as propriedades adsorventes de materiais de interesse tecnológico. Atualmente, as tecnologias utilizadas em tratamentos de águas residuais contaminadas por corantes apresentam desvantagens como custo elevado e geração de resíduos tóxicos. Este trabalho propôs investigar a capacidade de adsorção de raízes, folhas e caules in natura e na forma carbonizada de Eichhornia crassipes, e desenvolver um biossorvente renovável e de baixo custo para competir com as tecnologias atuais no tratamento de águas contaminadas por corantes, utilizando o azul de metileno como molécula modelo. Nos testes de adsorção com o corante azul de metileno foram analisados os seguintes parâmetros: influência do pH, dosagem do biossorvente, e tempo de contato entre biossorvente/adsorvato. Com o intuito de entender os mecanismos envolvidos neste processo, os resultados de adsorção foram ajustados aos modelos cinéticos e de equilíbrio sólido-líquido de Langmuir e de Freundlich. A caracterização dos biossorventes foi realizada por espectroscopia no infravermelho com transformada de Fourier (FTIR), área superficial específica por adsorção/dessorção de N2 (BET), microscopia óptica, microscopia eletrônica de varredura (MEV), espectroscopia de dispersão de raios-X (EDX), e difratometria de raios-X (DRX). Espera-se que os resultados desse projeto contribuam para um melhor entendimento desta tecnologia, para futuras projeções à escala piloto e aplicações em sistemas reais.
Eichhornia crassipes (Mart.) Solms is an aquatic weed, considered a plague in many countries, which can cause damage such as obstruction of water flows in water systems and compromising fishing activities. However, the plant's ability to adsorb recalcitrant pollutants, such as methylene blue dye, has been the subject of several scientific research studies in recent decades. The cationic dye methylene blue is widely used as a model molecule for contaminants in adsorption studies to evaluate the adsorbent properties of materials of technological interest. Currently, the technologies used in treatment of wastewater contaminated by dyes have disadvantages such as high cost and generation of toxic residues. This work proposed to investigate the adsorption capacity of roots, leaves and stems in natura and in the carbonized form of Eichhornia crassipes, and to develop a renewable and low-cost biosorbent to compete with current technologies in the treatment of water contaminated by dyes, using methylene blue as model molecule. In the adsorption tests with methylene blue dye, the following parameters were analyzed: influence of pH, biosorbent dosage, and contact time between biosorbent/adsorbate. In order to understand the mechanisms involved in this process, the adsorption results were fitted to the kinetic and solid-liquid equilibrium of Langmuir and Freundlich models.The characterization of the biosorbents was performed by Fourier transform infrared spectroscopy (FTIR), specific surface area by N2 adsorption/desorption (BET), optical microscopy, scanning electron microscopy (SEM), X-ray dispersion spectroscopy (EDX), and X-ray diffractometry (XRD). It is expected that the results of this project will contribute to a better understanding of this technology, for future pilot-scale projections and applications in real systems.
Eichhornia crassipes (Mart.) Solms is an aquatic weed, considered a plague in many countries, which can cause damage such as obstruction of water flows in water systems and compromising fishing activities. However, the plant's ability to adsorb recalcitrant pollutants, such as methylene blue dye, has been the subject of several scientific research studies in recent decades. The cationic dye methylene blue is widely used as a model molecule for contaminants in adsorption studies to evaluate the adsorbent properties of materials of technological interest. Currently, the technologies used in treatment of wastewater contaminated by dyes have disadvantages such as high cost and generation of toxic residues. This work proposed to investigate the adsorption capacity of roots, leaves and stems in natura and in the carbonized form of Eichhornia crassipes, and to develop a renewable and low-cost biosorbent to compete with current technologies in the treatment of water contaminated by dyes, using methylene blue as model molecule. In the adsorption tests with methylene blue dye, the following parameters were analyzed: influence of pH, biosorbent dosage, and contact time between biosorbent/adsorbate. In order to understand the mechanisms involved in this process, the adsorption results were fitted to the kinetic and solid-liquid equilibrium of Langmuir and Freundlich models.The characterization of the biosorbents was performed by Fourier transform infrared spectroscopy (FTIR), specific surface area by N2 adsorption/desorption (BET), optical microscopy, scanning electron microscopy (SEM), X-ray dispersion spectroscopy (EDX), and X-ray diffractometry (XRD). It is expected that the results of this project will contribute to a better understanding of this technology, for future pilot-scale projections and applications in real systems.
Descrição
Citação
LIMA, Herbert de Paula. Uso de Eichhornia Crassipes (Mart.) Solms in natura e carbonizada como biossorvente para a remoção de corante catiônico em meio aquoso. 2022. 103 f. Dissertação (Mestrado Interdisciplinar em Ciência e Tecnologia do Mar) - Instituto do Mar, Universidade Federal de São Paulo, Santos, 2022.