Estudo da capacidade catalítica de nanopartículas de prata, estabilizadas por ramnolipídeos, na redução do corante azul de metileno
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Data
2019-11-13
Autores
Silveira, Giulia de Paula
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Universidade Estadual Paulista (Unesp)
Resumo
Corantes são substâncias amplamente utilizadas na indústria têxtil para fornecer cor a um substrato. Os efluentes gerados nesta indústria apresentam-se com colorações fortes e baixa biodegradabilidade gerando dificuldade de tratamento por métodos convencionais e implicando em impactos negativos a corpos d’água, como: diminuição da passagem de luz solar. O presente projeto de pesquisa teve como objetivo geral o estudo da capacidade catalítica das nanopartículas de prata na redução do corante têxtil azul de metileno em água, utilizando borohidreto de sódio como agente redutor. Foi adotado um delineamento experimental do tipo Composto Central, para realização dos testes de redução do corante, no qual se utilizou como variáveis o pH da síntese das nanopartículas, volume de solução de nanopartículas de prata e concentração do agente redutor. Para realizar os testes foram produzidos ramnolipídeos que estabilizaram as nanopartículas de prata durante a síntese destas. O produto final obtido continha baixa concentração do corante e foi possível demonstrar que as melhores condições para uma eficiência máxima de redução são de síntese de nanopartículas em pH 8, 0,4 mL de nanopartículas de prata em 10 mL de solução e 0,45 M de borohidreto de sódio. As nanopartículas de prata mostraram-se eficientes catalisadores na redução do corante azul de metileno. Foram realizados testes de toxicidade com Daphnia similis que demonstraram como tóxicas as concentrações de azul de metileno, nanopartículas de prata e ramnolipídeos utilizadas no estudo
Dyes are substances widely used in the textile industry to provide color to a substrate. The wastewater generated in this industry is strong in color and poorly biodegradable causing difficulty in treatment with conventional methods and implying damage to water bodies, such as decrease in sunlight passage. The present research Project had as general objective the study of catalytic capacity of silver nanoparticles in the reduction of the textile dye, methylene blue, in water, using sodium borohydride as reducing agent. An experimental design of Central Compound type was adopted to perform dye reduction and removal tests, the variables used were the pH of the silver nanoparticles synthesis, silver nanoparticles solution volume and reducing agent concentration. To perform the tests were used rhamnolipids that stabilized silver nanoparticles during they synthesis. The final product presented low dye concentration and made it possible demonstrated the best conditions for maximum reduction of the dye: pH 8 to synthesis the silver nanoparticles, 0,4 mL of silver solution nanoparticles in 10 mL of solution and 0,45M sodium borohydride. Silver nanoparticles have beem demonstrated as an efficient catalysts in reducing methylene blue dye. Toxicity tests with Daphnia similis were performed that evidenced as toxic the methylene blue, silver nanoparticles and rhamnolipids concentrations used in this study
Dyes are substances widely used in the textile industry to provide color to a substrate. The wastewater generated in this industry is strong in color and poorly biodegradable causing difficulty in treatment with conventional methods and implying damage to water bodies, such as decrease in sunlight passage. The present research Project had as general objective the study of catalytic capacity of silver nanoparticles in the reduction of the textile dye, methylene blue, in water, using sodium borohydride as reducing agent. An experimental design of Central Compound type was adopted to perform dye reduction and removal tests, the variables used were the pH of the silver nanoparticles synthesis, silver nanoparticles solution volume and reducing agent concentration. To perform the tests were used rhamnolipids that stabilized silver nanoparticles during they synthesis. The final product presented low dye concentration and made it possible demonstrated the best conditions for maximum reduction of the dye: pH 8 to synthesis the silver nanoparticles, 0,4 mL of silver solution nanoparticles in 10 mL of solution and 0,45M sodium borohydride. Silver nanoparticles have beem demonstrated as an efficient catalysts in reducing methylene blue dye. Toxicity tests with Daphnia similis were performed that evidenced as toxic the methylene blue, silver nanoparticles and rhamnolipids concentrations used in this study
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Palavras-chave
Nanopartículas, Nanotecnologia, Corantes, Planejamento composto central, Biossurfactante, AgNP, Nanotechnology, Central composite design, Biosurfactant