Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/21364 |
Resumo: | One of the major concerns with the environment and aquatic life is related to the discharge of effluents containing synthetic dyes. Among the most used synthetic dyes is tartrazine, a lemon yellow azo dye, used in the food coloring, cosmetics and textile industries. These wastewater can contain high coloration, moderate organic content, large amounts of toxic, not biodegradable and highly resistant in the environment, being difficult to degrade by conventional methods, making it impossible to reach the standards of release in river systems. As an alternative to the treatment of these liquid wastes, the advanced oxidative processes, notably the photo-Fenton process, which is the combination of a powerful oxidizing agent (such as H2O2), an iron-based photocatalyst (example ferrite) and UV-Vis radiation. However, studies report that a problem presented by semiconductor oxides, when employed pure as photocatalysts, is related to the high recombination rates that occur between the electron/hole pairs formed after activation. Thus, the use of supported photocatalysts is a technique applied to improve the photocatalytic performance of a semiconductor and to overcome this problem. In the present study, SnFe2O4 was synthesized and then an unprecedented composite was formed, supporting different masses of SnFe2O4 in polypyrrole (conductive polymer). Preliminary tests indicated a greater color reduction of tartrazine dye solution using the composite containing 10% of SnFe2O4 when compared to pure SnFe2O4 and in percentages of 5 and 15%. The characterization of the samples demonstrated that the SnFe2O4 can be inside the pores of the polypyrrole, suggesting the formation of the composite. The main operational parameters of the reaction such as pH and H2O2 concentration were evaluated using a laboratory-scale photoreactor exposed in artificial UV-Vis irradiation. Color reduction was chosen as the response variable. pH 3 and 34 μL H2O2 concentration demonstrated higher efficiency, removing 98% of the color in 60 minutes. This may be linked to the formation of Fenton reagents under acid conditions (generation of •OH radicals) and to the fact that very high or very low concentrations of H2O2 do not favor the process. The recycle of the material showed that it is stable, presenting high efficiencies after eight reuses. The photo-Fenton process with artificial light was compared with the solar, demonstrating color removal efficiency in both processes. A capture of the main radicals was performed, evidencing that the radicals • O2 - and •OH act in the photo-Fenton process. After the chromatography analysis it was possible to verify the degradation of the molecule in fragments of lower mass. Finally, a mechanism was suggested based on the results obtained. Based on all characterizations and tests of catalytic activity, this composite has promising activity against the degradation of aqueous pollutants. |
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Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fentonSynthesis and characterization of the SnFe2O4/polypyrrole composite for use in the tartrazine dye degradation by fotofenton processCorante tartrazinaProcesso foto-fentonRecombinaçãoCompósitosTartrazine dyePhoto-Fenton processRecombinationCompositesCNPQ::ENGENHARIAS::ENGENHARIA QUIMICAOne of the major concerns with the environment and aquatic life is related to the discharge of effluents containing synthetic dyes. Among the most used synthetic dyes is tartrazine, a lemon yellow azo dye, used in the food coloring, cosmetics and textile industries. These wastewater can contain high coloration, moderate organic content, large amounts of toxic, not biodegradable and highly resistant in the environment, being difficult to degrade by conventional methods, making it impossible to reach the standards of release in river systems. As an alternative to the treatment of these liquid wastes, the advanced oxidative processes, notably the photo-Fenton process, which is the combination of a powerful oxidizing agent (such as H2O2), an iron-based photocatalyst (example ferrite) and UV-Vis radiation. However, studies report that a problem presented by semiconductor oxides, when employed pure as photocatalysts, is related to the high recombination rates that occur between the electron/hole pairs formed after activation. Thus, the use of supported photocatalysts is a technique applied to improve the photocatalytic performance of a semiconductor and to overcome this problem. In the present study, SnFe2O4 was synthesized and then an unprecedented composite was formed, supporting different masses of SnFe2O4 in polypyrrole (conductive polymer). Preliminary tests indicated a greater color reduction of tartrazine dye solution using the composite containing 10% of SnFe2O4 when compared to pure SnFe2O4 and in percentages of 5 and 15%. The characterization of the samples demonstrated that the SnFe2O4 can be inside the pores of the polypyrrole, suggesting the formation of the composite. The main operational parameters of the reaction such as pH and H2O2 concentration were evaluated using a laboratory-scale photoreactor exposed in artificial UV-Vis irradiation. Color reduction was chosen as the response variable. pH 3 and 34 μL H2O2 concentration demonstrated higher efficiency, removing 98% of the color in 60 minutes. This may be linked to the formation of Fenton reagents under acid conditions (generation of •OH radicals) and to the fact that very high or very low concentrations of H2O2 do not favor the process. The recycle of the material showed that it is stable, presenting high efficiencies after eight reuses. The photo-Fenton process with artificial light was compared with the solar, demonstrating color removal efficiency in both processes. A capture of the main radicals was performed, evidencing that the radicals • O2 - and •OH act in the photo-Fenton process. After the chromatography analysis it was possible to verify the degradation of the molecule in fragments of lower mass. Finally, a mechanism was suggested based on the results obtained. Based on all characterizations and tests of catalytic activity, this composite has promising activity against the degradation of aqueous pollutants.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESUma das grandes preocupações com o meio ambiente e com a vida aquática está relacionada a descarga de efluentes contendo corantes sintéticos. Dentre os corantes sintéticos mais utilizados pode-se destacar a tartrazina, um corante azo, amarelo limão, utilizado nas indústrias de corantes alimentícios, cosméticos e têxteis. Essas águas residuais podem conter elevada coloração, moderado teor orgânico, grandes quantidades de substâncias tóxicas, não biodegradáveis e altamente resistentes no meio ambiente, sendo difíceis de degradar pelos métodos convencionais, impossibilitando atingir os padrões de lançamento em corpos hídricos. Como alternativa de tratamento desses resíduos líquidos, surgem os processos de oxidação avançada, destacando-se o processo foto-Fenton, que é a combinação de um poderoso agente oxidante (como o H2O2), um fotocatalisador a base de ferro (por exemplo as ferritas) e radiação UVVis. Entretanto, estudos relatam que um problema apresentado pelos óxidos semicondutores, quando empregados puros como fotocatalisadores, está relacionado às altas taxas de recombinação que ocorrem entre os pares elétrons/lacuna, formados após a ativação. Assim, a utilização de fotocatalisadores suportados é uma técnica aplicada para melhorar o desempenho fotocatalítico de um semicondutor e contornar esse problema. No presente estudo, a SnFe2O4 foi sintetizada e em seguida um compósito inédito foi formado, suportando diferentes massas de SnFe2O4 no polipirrol (um polímero condutor). Testes preliminares indicaram uma maior redução da cor da solução de corante tartrazina utilizando o compósito contendo 10% de SnFe2O4, quando comparado a SnFe2O4 pura e em porcentagens de 5 e 15%. As caracterizações das amostras demonstraram que a SnFe2O4 pode estar no interior dos poros do polipirrol, sugerindo a formação do compósito. Os principais parâmetros operacionais da reação tais como pH da solução e dosagem de H2O2 foram avaliados utilizando um fotorreator de escala laboratorial exposto em irradiação UV-Vis artificial. A redução da cor foi escolhida como variável resposta. pH 3 e dosagem de 34 μL de H2O2 demonstraram maior eficiência, removendo 98% da cor em 60 minutos. Isto pode estar atrelado à formação de reagentes de Fenton em condição ácida (geração de radicais •OH) e ao fato de que concentrações muitos elevadas ou muito baixas de H2O2 não favorecem o processo. O reciclo do material demostrou que ele é estável, apresentando elevadas eficiências após oito reutilizações. O processo foto-Fenton com luz artificial foi comparado com o solar, demostrando eficiência de remoção de cor em ambos os processos. Uma captura dos principais radicais foi realizada, evidenciando que os radicais •O2 − e •OH atuam no processo foto-Fenton. Após a análise de cromatografia foi possível verificar a degradação da molécula em fragmentos de menor massa. Por fim, foi sugerido um mecanismo com base nos resultados obtidos. De acordo com todas as caracterizações e testes de atividade catalítica, esse compósito tem atividade promissora frente a degradação de poluentes aquosos.Universidade Federal de Santa MariaBrasilEngenharia QuímicaUFSMPrograma de Pós-Graduação em Engenharia QuímicaCentro de TecnologiaFoletto, Edson Luizhttp://lattes.cnpq.br/6550340290019699Silvestri, SiaraOliveira, Jivago Schumacher deRhoden, Cristiano Rodrigo BohnLeichtweis, Jandira2021-07-09T10:56:37Z2021-07-09T10:56:37Z2019-07-22info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://repositorio.ufsm.br/handle/1/21364porAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2021-07-10T06:01:40Zoai:repositorio.ufsm.br:1/21364Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2021-07-10T06:01:40Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton Synthesis and characterization of the SnFe2O4/polypyrrole composite for use in the tartrazine dye degradation by fotofenton process |
title |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton |
spellingShingle |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton Leichtweis, Jandira Corante tartrazina Processo foto-fenton Recombinação Compósitos Tartrazine dye Photo-Fenton process Recombination Composites CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA |
title_short |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton |
title_full |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton |
title_fullStr |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton |
title_full_unstemmed |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton |
title_sort |
Síntese e caracterização do compósito SnFe2O4/polipirrol para utilização na degradação do corante tartrazina via processo foto-fenton |
author |
Leichtweis, Jandira |
author_facet |
Leichtweis, Jandira |
author_role |
author |
dc.contributor.none.fl_str_mv |
Foletto, Edson Luiz http://lattes.cnpq.br/6550340290019699 Silvestri, Siara Oliveira, Jivago Schumacher de Rhoden, Cristiano Rodrigo Bohn |
dc.contributor.author.fl_str_mv |
Leichtweis, Jandira |
dc.subject.por.fl_str_mv |
Corante tartrazina Processo foto-fenton Recombinação Compósitos Tartrazine dye Photo-Fenton process Recombination Composites CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA |
topic |
Corante tartrazina Processo foto-fenton Recombinação Compósitos Tartrazine dye Photo-Fenton process Recombination Composites CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA |
description |
One of the major concerns with the environment and aquatic life is related to the discharge of effluents containing synthetic dyes. Among the most used synthetic dyes is tartrazine, a lemon yellow azo dye, used in the food coloring, cosmetics and textile industries. These wastewater can contain high coloration, moderate organic content, large amounts of toxic, not biodegradable and highly resistant in the environment, being difficult to degrade by conventional methods, making it impossible to reach the standards of release in river systems. As an alternative to the treatment of these liquid wastes, the advanced oxidative processes, notably the photo-Fenton process, which is the combination of a powerful oxidizing agent (such as H2O2), an iron-based photocatalyst (example ferrite) and UV-Vis radiation. However, studies report that a problem presented by semiconductor oxides, when employed pure as photocatalysts, is related to the high recombination rates that occur between the electron/hole pairs formed after activation. Thus, the use of supported photocatalysts is a technique applied to improve the photocatalytic performance of a semiconductor and to overcome this problem. In the present study, SnFe2O4 was synthesized and then an unprecedented composite was formed, supporting different masses of SnFe2O4 in polypyrrole (conductive polymer). Preliminary tests indicated a greater color reduction of tartrazine dye solution using the composite containing 10% of SnFe2O4 when compared to pure SnFe2O4 and in percentages of 5 and 15%. The characterization of the samples demonstrated that the SnFe2O4 can be inside the pores of the polypyrrole, suggesting the formation of the composite. The main operational parameters of the reaction such as pH and H2O2 concentration were evaluated using a laboratory-scale photoreactor exposed in artificial UV-Vis irradiation. Color reduction was chosen as the response variable. pH 3 and 34 μL H2O2 concentration demonstrated higher efficiency, removing 98% of the color in 60 minutes. This may be linked to the formation of Fenton reagents under acid conditions (generation of •OH radicals) and to the fact that very high or very low concentrations of H2O2 do not favor the process. The recycle of the material showed that it is stable, presenting high efficiencies after eight reuses. The photo-Fenton process with artificial light was compared with the solar, demonstrating color removal efficiency in both processes. A capture of the main radicals was performed, evidencing that the radicals • O2 - and •OH act in the photo-Fenton process. After the chromatography analysis it was possible to verify the degradation of the molecule in fragments of lower mass. Finally, a mechanism was suggested based on the results obtained. Based on all characterizations and tests of catalytic activity, this composite has promising activity against the degradation of aqueous pollutants. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-07-22 2021-07-09T10:56:37Z 2021-07-09T10:56:37Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufsm.br/handle/1/21364 |
url |
http://repositorio.ufsm.br/handle/1/21364 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Engenharia Química UFSM Programa de Pós-Graduação em Engenharia Química Centro de Tecnologia |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Engenharia Química UFSM Programa de Pós-Graduação em Engenharia Química Centro de Tecnologia |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
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1805922143440994304 |