Desenvolvimento de membranas porosas de fibroína e aplicação como potencial adsorvente para a remoção de poluentes orgânicos e inorgânicos
Data
2024-06-07
Autores
Ottaiano, Gabriel Yoshiaki 
Orientadores
Moraes, Mariana Agostini de
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A poluição ambiental preocupa todas as esferas da sociedade contemporânea, podendo atingir os solos, águas e ar, afetando a vida de todos os seres vivos em todos os ambientes. Os compostos poluentes podem ser divididos em duas categorias, os compostos orgânicos e os inorgânicos. A remoção destes poluentes reúne esforços de pesquisadores ao redor do mundo, com foco em processos de tratamento cada vez mais verdes e sustentáveis. A adsorção é uma técnica de tratamento onde os compostos poluentes ficam retidos na superfície do material adsorvente. Um dos materiais mais utilizados atualmente é o carvão ativado, porém a necessidade de tratamento para sua ativação o torna uma opção não tão atraente considerando as necessidades ambientais e ecológicas que estão sendo cada vez mais demandadas pela sociedade. Neste trabalho, objetivou-se o estudo da utilização de membranas de fibroína densas (MD) e porosas (MP) para adsorver compostos poluentes como corantes e metais tóxicos. Foram estudados os corantes azul de metileno e alaranjado de metila e diversos íons metálicos. A adsorção máxima para o azul de metileno foi de 64 mg.g-1 para MD (45 ºC) e 76 mg.g-1 para MP (45 ºC). A membrana porosa também foi capaz de suportar quatro ciclos de adsorção e dessorção mantendo a capacidade de remover até 80% do azul de metileno da solução. Em relação aos metais, as membranas de fibroína foram preferenciais para a adsorção de Cu (II), Pb (II) e Cr (III). A adsorção foi ajustada usando a isoterma de Sips e a capacidade máxima de adsorção para o Cu (II) foi de 25 mg.g-1 (25 ºC). Para a cinética, foram necessários mais de 300 minutos para atingir o equilíbrio de adsorção para a membrana densa e 90 minutos para a membrana porosa para o Cu (II) e Pb (II). As membranas porosas de fibroína tiveram a capacidade de remover os corantes e descolorir o efluente e além de adsorver tão bem como a membrana densa, tem menos etapas de produção e tem potencial para serem utilizadas em sistema contínuo para remoção de poluentes
Environmental pollution concerns altogether the various spheres of contemporary society, and can reach the soil, water, and air, affecting the life of all living beings in all environments. The polluting compounds can be divided into two categories, the organics and the inorganics. The removal of these pollutants brings together efforts of researchers all around the world, focusing on increasingly green and sustainable treatment processes. Adsorption is a treatment technique where the pollutant compounds are retained on the surface of the adsorbent material. One of the most widely used materials today is activated carbon, but the need for treatment to activate it makes it a less attractive option considering the environmental and ecological needs that are being increasingly demanded by society. The aim of this work was to study the use of dense (MD) and porous (MP) fibroin membranes to adsorb polluting compounds such as dyes and heavy metals. The dyes methylene blue and methyl orange and various metal ions were studied. The maximum adsorption for methylene blue was 64 mg.g-1 for MD (45 ºC) and 76 mg.g-1 for MP (45 ºC). The porous membrane was also able to endure four cycles of adsorption and desorption while maintaining the ability to remove up to 80% of the methylene blue from the solution. Regarding all metals tested, fibroin membranes were preferred for the adsorption of Cu (II), Pb (II) and Cr (III). Adsorption was adjusted using the Sips isotherm and the maximum adsorption capacity for the Cu (II) was 25 mg.g-1. For the kinetics, it took more than 300 minutes to reach adsorption equilibrium for the dense membrane and 90 for the porous membrane for Cu (II) and Pb (II). The porous fibroin membranes were able to remove the dyes and decolorize the effluent and, in addition to adsorbing as well as the dense membrane, they have fewer production steps and have the potential to be used in a continuous system to remove pollutants
Environmental pollution concerns altogether the various spheres of contemporary society, and can reach the soil, water, and air, affecting the life of all living beings in all environments. The polluting compounds can be divided into two categories, the organics and the inorganics. The removal of these pollutants brings together efforts of researchers all around the world, focusing on increasingly green and sustainable treatment processes. Adsorption is a treatment technique where the pollutant compounds are retained on the surface of the adsorbent material. One of the most widely used materials today is activated carbon, but the need for treatment to activate it makes it a less attractive option considering the environmental and ecological needs that are being increasingly demanded by society. The aim of this work was to study the use of dense (MD) and porous (MP) fibroin membranes to adsorb polluting compounds such as dyes and heavy metals. The dyes methylene blue and methyl orange and various metal ions were studied. The maximum adsorption for methylene blue was 64 mg.g-1 for MD (45 ºC) and 76 mg.g-1 for MP (45 ºC). The porous membrane was also able to endure four cycles of adsorption and desorption while maintaining the ability to remove up to 80% of the methylene blue from the solution. Regarding all metals tested, fibroin membranes were preferred for the adsorption of Cu (II), Pb (II) and Cr (III). Adsorption was adjusted using the Sips isotherm and the maximum adsorption capacity for the Cu (II) was 25 mg.g-1. For the kinetics, it took more than 300 minutes to reach adsorption equilibrium for the dense membrane and 90 for the porous membrane for Cu (II) and Pb (II). The porous fibroin membranes were able to remove the dyes and decolorize the effluent and, in addition to adsorbing as well as the dense membrane, they have fewer production steps and have the potential to be used in a continuous system to remove pollutants