Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão
Ano de defesa: | 2008 |
---|---|
Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | |
Tipo de documento: | Tese |
Tipo de acesso: | Acesso aberto |
Idioma: | por |
Instituição de defesa: |
Universidade Federal do Rio Grande do Norte
|
Programa de Pós-Graduação: |
Programa de Pós-Graduação em Química
|
Departamento: |
Físico-Química; Química
|
País: |
BR
|
Palavras-chave em Português: | |
Palavras-chave em Inglês: | |
Área do conhecimento CNPq: | |
Link de acesso: | https://repositorio.ufrn.br/jspui/handle/123456789/17692 |
Resumo: | Leather tanneries generate effluents with high content of heavy metals, especially chromium, which is used in the mineral tanning process. Microemulsions have been studied in the extraction of heavy metals from aqueous solutions. Considering the problems related with the sediment resulting from the tanning process, due to its high content in chromium, in this work this sediment was characterized and microemulsion systems were applied for chromium removal. The extraction process consists in the removal of heavy metal ions present in an aqueous feeding solution (acid digestion solution) by a microemulsion system. First three different solid sludge digestion methods were evaluated, being chosen the method with higher digestion capacity. For this digestion method, seeking its optimization, was evaluated the influence of granule size, temperature and digestion time. Experimental results showed that the method proposed by USEPA (Method A) was the most efficient one, being obtained 95.77% of sample digestion. Regarding to the evaluated parameters, the best results were achieved at 95°C, 14 Mesh granule size, and 60 minutes digestion time. For chromium removal, three microemulsion extraction methods were evaluated: Method 1, in a Winsor II region, using as aqueous phase the acid digestion solution; Method 2, in a Winsor IV region, being obtained by the addition of the acid digestion solution to a microemulsion phase, whose aqueous phase is distilled water, until the formation of Winsor II system; and Method 3, in a Winsor III region, consisting in the formation of a Winsor III region using as aqueous phase the acid digestion solution, diluted in NaOH 0.01N. Seeking to optimize the extraction process only Method 1 (Systems I, II, and VIII) and Method 2 (System IX) were evaluated, being chosen points inside the interest regions (studied domains) to study the influence of contact time and pH in the extraction percentiles. The studied systems present the following compositions: System I: Surfactant Saponified coconut oil, Cosurfactant 1-Butanol, Oil phase Kerosene, Aqueous phase 2% NaCl solution; System II: Aqueous phase Acid digestion solution with pH adjusted using KOH (pH 3.5); System VIII: Aqueous phase - Acid digestion solution (pH 0.06); and System IX Aqueous phase Distilled water (pH 10.24), the other phases of Systems II, VIII and IX are similar to System I. Method 2 showed to be the more efficient one regarding chromium extraction percentile (up to 96.59% - pH 3.5). Considering that with Method 2 the microemulsion region only appears in the Winsor II region, it was studied Method 3 (System X) for the evaluation and characterization of a triphasic system, seeking to compare with a biphases system. System X is composed by: Surfactant Saponified coconut oil, Cosurfactant 1-Butanol, Oil phase Kerosene, Aqueous phase Acid digestion solution diluted with water and with its pH adjusted using 0.01N NaOH solution. The biphasic and triphasic microemulsion systems were analyzed regarding its viscosity, extraction efficiency and drop effective diameter. The experimental results showed that for viscosity studies the obtained values were low for all studied systems, the diameter of the drop is smaller in the Winsor II region, with 15.5 nm, reaching 46.0 nm in Winsor III region, being this difference attributed to variations in system compositions and micelle geometry. In chromium extraction, these points showed similar results, being achieved 99.76% for Winsor II system and 99.62% for Winsor III system. Winsor III system showed to be more efficient due to the obtaining of a icroemulsion with smaller volume, with the possibility to recover the oil phase in excess, and the use of a smaller proportion of surfactant and cosurfactant (C/S) |
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Melo, Keila Rejane de Oliveirahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783139Z0&dataRevisao=nullMoura, Maria Carlenise Paiva de Alencarhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4702157Y9Barros Neto, Eduardo Lins dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4798645D3Santanna, Vanessa Cristinahttp://lattes.cnpq.br/9445575768909084Peres, Antônio Eduardo Clarkhttp://lattes.cnpq.br/8666548473150908Dantas, Tereza Neuma de Castro2014-12-17T15:42:04Z2009-03-102014-12-17T15:42:04Z2008-11-10MELO, Keila Rejane de Oliveira. Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão. 2008. 194 f. Tese (Doutorado em Físico-Química; Química) - Universidade Federal do Rio Grande do Norte, Natal, 2008.https://repositorio.ufrn.br/jspui/handle/123456789/17692Leather tanneries generate effluents with high content of heavy metals, especially chromium, which is used in the mineral tanning process. Microemulsions have been studied in the extraction of heavy metals from aqueous solutions. Considering the problems related with the sediment resulting from the tanning process, due to its high content in chromium, in this work this sediment was characterized and microemulsion systems were applied for chromium removal. The extraction process consists in the removal of heavy metal ions present in an aqueous feeding solution (acid digestion solution) by a microemulsion system. First three different solid sludge digestion methods were evaluated, being chosen the method with higher digestion capacity. For this digestion method, seeking its optimization, was evaluated the influence of granule size, temperature and digestion time. Experimental results showed that the method proposed by USEPA (Method A) was the most efficient one, being obtained 95.77% of sample digestion. Regarding to the evaluated parameters, the best results were achieved at 95°C, 14 Mesh granule size, and 60 minutes digestion time. For chromium removal, three microemulsion extraction methods were evaluated: Method 1, in a Winsor II region, using as aqueous phase the acid digestion solution; Method 2, in a Winsor IV region, being obtained by the addition of the acid digestion solution to a microemulsion phase, whose aqueous phase is distilled water, until the formation of Winsor II system; and Method 3, in a Winsor III region, consisting in the formation of a Winsor III region using as aqueous phase the acid digestion solution, diluted in NaOH 0.01N. Seeking to optimize the extraction process only Method 1 (Systems I, II, and VIII) and Method 2 (System IX) were evaluated, being chosen points inside the interest regions (studied domains) to study the influence of contact time and pH in the extraction percentiles. The studied systems present the following compositions: System I: Surfactant Saponified coconut oil, Cosurfactant 1-Butanol, Oil phase Kerosene, Aqueous phase 2% NaCl solution; System II: Aqueous phase Acid digestion solution with pH adjusted using KOH (pH 3.5); System VIII: Aqueous phase - Acid digestion solution (pH 0.06); and System IX Aqueous phase Distilled water (pH 10.24), the other phases of Systems II, VIII and IX are similar to System I. Method 2 showed to be the more efficient one regarding chromium extraction percentile (up to 96.59% - pH 3.5). Considering that with Method 2 the microemulsion region only appears in the Winsor II region, it was studied Method 3 (System X) for the evaluation and characterization of a triphasic system, seeking to compare with a biphases system. System X is composed by: Surfactant Saponified coconut oil, Cosurfactant 1-Butanol, Oil phase Kerosene, Aqueous phase Acid digestion solution diluted with water and with its pH adjusted using 0.01N NaOH solution. The biphasic and triphasic microemulsion systems were analyzed regarding its viscosity, extraction efficiency and drop effective diameter. The experimental results showed that for viscosity studies the obtained values were low for all studied systems, the diameter of the drop is smaller in the Winsor II region, with 15.5 nm, reaching 46.0 nm in Winsor III region, being this difference attributed to variations in system compositions and micelle geometry. In chromium extraction, these points showed similar results, being achieved 99.76% for Winsor II system and 99.62% for Winsor III system. Winsor III system showed to be more efficient due to the obtaining of a icroemulsion with smaller volume, with the possibility to recover the oil phase in excess, and the use of a smaller proportion of surfactant and cosurfactant (C/S)Os curtumes geram efluentes carregados em metais pesados, especialmente o cromo, utilizado no processo de curtimento. Microemulsões têm sido estudadas na remoção de metais pesados. Considerando o problema encontrado no sedimento gerado no processo de curtimento, pelo elevado teor de cromo, no presente trabalho nos propomos a caracterizá-lo e aplicar sistemas microemulsionados para remoção do cromo. O processo de extração consiste em remover o metal de uma alimentação aquosa (solução ácida digerida) para uma fase microemulsão. Iniciou-se a pesquisa avaliando três diferentes métodos de digestão de sedimentos, escolhendo-se o método que apresentasse maior percentual de digestão, sendo este método otimizado através de mudanças no diâmetro das partículas do sedimento, tempo e temperatura de digestão. Nesse estudo, escolheu-se o método proposto pelo EPA (Método A), que se mostrou mais eficiente, obtendo-se um percentual de 95,77% de digestão da amostra. Com relação aos parâmetros avaliados, os melhores resultados foram obtidos com a temperatura a 95°C, granulometria de 14 Mesh e tempo de operação de 60 minutos. Para os estudos da extração foram utilizados três métodos: o Método 1, que consiste na formação de uma região de Winsor II, utilizando a solução ácida digerida como fase aquosa; o Método 2, que consiste em utilizar uma microemulsão cuja fase aquosa é água destilada e adicionar a solução ácida digerida até a obtenção de um sistema de Winsor II; e o Método 3, que consiste na formação de uma região de Winsor III, utilizando a solução ácida digerida, diluída em NaOH 0,01N, como fase aquosa. Para o estudo da otimização da extração foram avaliados apenas os Métodos 1 (Sistemas I, II e VIII) e 2 (Sistema IX), escolhendo-se pontos dentro das regiões de interesse (domínio estudado) para estudar a influência do tempo e do pH no percentual de extração. Os sistemas estudados apresentam as seguintes composições: Sistema I: Tensoativo Óleo de coco saponificado, Cotensoativo 1-Butanol, Fase oleosa Querosene, Fase aquosa NaCl 2,0%; Sistema II: Fase aquosa Solução ácida digerida ajustada c/ KOH (pH 3,5); Sistema VIII: Fase aquosa Solução ácida digerida (pH 0,06) e Sistema IX: Fase aquosa Água destilada (pH 10,24), as demais fases dos Sistemas II, VIII e IX são semelhantes ao Sistema I. Através desse estudo, observou-se que o Método 2 foi mais eficiente, com percentuais de 96,59% de extração, em pH 3,5. Tendo em vista que com a aplicação do Método 2 só se obtém os sistemas de Winsor II, estudou-se um sistema capaz de fornecer a região de Winsor III (três fases) para efeito de comparação da eficiência na extração do cromo, com um sistema de duas fases (Winsor II) e, assim, constituiu-se o Método 3, utilizando o Sistema X. O sistema X apresenta a seguinte composição: Tensoativo Óleo de coco saponificado, Cotensoativo 1-Butanol, Fase oleosa Querosene, Fase aquosa Solução ácida digerida diluída em água e ajustado com NaOH 0,01N. As microemulsões nas regiões bifásicas e trifásicas foram analisadas com relação à viscosidade, extração e diâmetro efetivo da gota. Os resultados obtidos nas regiões de W II e WIII foram os seguintes: a viscosidade é baixa em todos os pontos estudados e o comportamento dos fluidos é do tipo Newtoniano; o diâmetro da gota é menor na região de Winsor II, com diâmetro de 15,5 nm, atingindo 46 nm em Winsor III, sendo essa variação atribuída às composições estudadas e à geometria da micela; os resultados obtidos na extração com os dois sistemas foram semelhantes, com 99,76% de extração em WII e 99,62 % em WIII. O sistema utilizando WIII mostrou-se mais eficiente na extração do cromo devido a obtenção de uma microemulsão com menor volume, a possibilidade de recuperar o óleo em excesso e a utilização de uma menor proporção de cotensoativo e tensoativo (C/T)Coordenação de Aperfeiçoamento de Pessoal de Nível Superiorapplication/pdfporUniversidade Federal do Rio Grande do NortePrograma de Pós-Graduação em QuímicaUFRNBRFísico-Química; QuímicaCromoSedimentoExtração por microemulsãoDigestão ácidaGranulometriaChromiumSolid wasteMicroemulsion extractionAcid digestionGranule sizeCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICAEstudo da digestão de sedimento de curtume visando a extração do cromo por microemulsãoinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALKeilaROM.pdfapplication/pdf1106532https://repositorio.ufrn.br/bitstream/123456789/17692/1/KeilaROM.pdf919e086ca601ac57108653607838c88eMD51TEXTKeilaROM.pdf.txtKeilaROM.pdf.txtExtracted texttext/plain310218https://repositorio.ufrn.br/bitstream/123456789/17692/6/KeilaROM.pdf.txt2c7ca7409f66f4bb9e8cec533a79caa7MD56THUMBNAILKeilaROM.pdf.jpgKeilaROM.pdf.jpgIM Thumbnailimage/jpeg5220https://repositorio.ufrn.br/bitstream/123456789/17692/7/KeilaROM.pdf.jpg61f615a7b15e9224d32faa236bd4536bMD57123456789/176922017-11-04 15:10:18.231oai:https://repositorio.ufrn.br:123456789/17692Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2017-11-04T18:10:18Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false |
dc.title.por.fl_str_mv |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão |
title |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão |
spellingShingle |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão Melo, Keila Rejane de Oliveira Cromo Sedimento Extração por microemulsão Digestão ácida Granulometria Chromium Solid waste Microemulsion extraction Acid digestion Granule size CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão |
title_full |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão |
title_fullStr |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão |
title_full_unstemmed |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão |
title_sort |
Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão |
author |
Melo, Keila Rejane de Oliveira |
author_facet |
Melo, Keila Rejane de Oliveira |
author_role |
author |
dc.contributor.authorID.por.fl_str_mv |
|
dc.contributor.advisorID.por.fl_str_mv |
|
dc.contributor.advisorLattes.por.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783139Z0&dataRevisao=null |
dc.contributor.referees1.pt_BR.fl_str_mv |
Moura, Maria Carlenise Paiva de Alencar |
dc.contributor.referees1ID.por.fl_str_mv |
|
dc.contributor.referees1Lattes.por.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4702157Y9 |
dc.contributor.referees2.pt_BR.fl_str_mv |
Barros Neto, Eduardo Lins de |
dc.contributor.referees2ID.por.fl_str_mv |
|
dc.contributor.referees2Lattes.por.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4798645D3 |
dc.contributor.referees3.pt_BR.fl_str_mv |
Santanna, Vanessa Cristina |
dc.contributor.referees3ID.por.fl_str_mv |
|
dc.contributor.referees3Lattes.por.fl_str_mv |
http://lattes.cnpq.br/9445575768909084 |
dc.contributor.referees4.pt_BR.fl_str_mv |
Peres, Antônio Eduardo Clark |
dc.contributor.referees4ID.por.fl_str_mv |
|
dc.contributor.referees4Lattes.por.fl_str_mv |
http://lattes.cnpq.br/8666548473150908 |
dc.contributor.author.fl_str_mv |
Melo, Keila Rejane de Oliveira |
dc.contributor.advisor1.fl_str_mv |
Dantas, Tereza Neuma de Castro |
contributor_str_mv |
Dantas, Tereza Neuma de Castro |
dc.subject.por.fl_str_mv |
Cromo Sedimento Extração por microemulsão Digestão ácida Granulometria |
topic |
Cromo Sedimento Extração por microemulsão Digestão ácida Granulometria Chromium Solid waste Microemulsion extraction Acid digestion Granule size CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.eng.fl_str_mv |
Chromium Solid waste Microemulsion extraction Acid digestion Granule size |
dc.subject.cnpq.fl_str_mv |
CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
Leather tanneries generate effluents with high content of heavy metals, especially chromium, which is used in the mineral tanning process. Microemulsions have been studied in the extraction of heavy metals from aqueous solutions. Considering the problems related with the sediment resulting from the tanning process, due to its high content in chromium, in this work this sediment was characterized and microemulsion systems were applied for chromium removal. The extraction process consists in the removal of heavy metal ions present in an aqueous feeding solution (acid digestion solution) by a microemulsion system. First three different solid sludge digestion methods were evaluated, being chosen the method with higher digestion capacity. For this digestion method, seeking its optimization, was evaluated the influence of granule size, temperature and digestion time. Experimental results showed that the method proposed by USEPA (Method A) was the most efficient one, being obtained 95.77% of sample digestion. Regarding to the evaluated parameters, the best results were achieved at 95°C, 14 Mesh granule size, and 60 minutes digestion time. For chromium removal, three microemulsion extraction methods were evaluated: Method 1, in a Winsor II region, using as aqueous phase the acid digestion solution; Method 2, in a Winsor IV region, being obtained by the addition of the acid digestion solution to a microemulsion phase, whose aqueous phase is distilled water, until the formation of Winsor II system; and Method 3, in a Winsor III region, consisting in the formation of a Winsor III region using as aqueous phase the acid digestion solution, diluted in NaOH 0.01N. Seeking to optimize the extraction process only Method 1 (Systems I, II, and VIII) and Method 2 (System IX) were evaluated, being chosen points inside the interest regions (studied domains) to study the influence of contact time and pH in the extraction percentiles. The studied systems present the following compositions: System I: Surfactant Saponified coconut oil, Cosurfactant 1-Butanol, Oil phase Kerosene, Aqueous phase 2% NaCl solution; System II: Aqueous phase Acid digestion solution with pH adjusted using KOH (pH 3.5); System VIII: Aqueous phase - Acid digestion solution (pH 0.06); and System IX Aqueous phase Distilled water (pH 10.24), the other phases of Systems II, VIII and IX are similar to System I. Method 2 showed to be the more efficient one regarding chromium extraction percentile (up to 96.59% - pH 3.5). Considering that with Method 2 the microemulsion region only appears in the Winsor II region, it was studied Method 3 (System X) for the evaluation and characterization of a triphasic system, seeking to compare with a biphases system. System X is composed by: Surfactant Saponified coconut oil, Cosurfactant 1-Butanol, Oil phase Kerosene, Aqueous phase Acid digestion solution diluted with water and with its pH adjusted using 0.01N NaOH solution. The biphasic and triphasic microemulsion systems were analyzed regarding its viscosity, extraction efficiency and drop effective diameter. The experimental results showed that for viscosity studies the obtained values were low for all studied systems, the diameter of the drop is smaller in the Winsor II region, with 15.5 nm, reaching 46.0 nm in Winsor III region, being this difference attributed to variations in system compositions and micelle geometry. In chromium extraction, these points showed similar results, being achieved 99.76% for Winsor II system and 99.62% for Winsor III system. Winsor III system showed to be more efficient due to the obtaining of a icroemulsion with smaller volume, with the possibility to recover the oil phase in excess, and the use of a smaller proportion of surfactant and cosurfactant (C/S) |
publishDate |
2008 |
dc.date.issued.fl_str_mv |
2008-11-10 |
dc.date.available.fl_str_mv |
2009-03-10 2014-12-17T15:42:04Z |
dc.date.accessioned.fl_str_mv |
2014-12-17T15:42:04Z |
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info:eu-repo/semantics/publishedVersion |
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info:eu-repo/semantics/doctoralThesis |
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doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
MELO, Keila Rejane de Oliveira. Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão. 2008. 194 f. Tese (Doutorado em Físico-Química; Química) - Universidade Federal do Rio Grande do Norte, Natal, 2008. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufrn.br/jspui/handle/123456789/17692 |
identifier_str_mv |
MELO, Keila Rejane de Oliveira. Estudo da digestão de sedimento de curtume visando a extração do cromo por microemulsão. 2008. 194 f. Tese (Doutorado em Físico-Química; Química) - Universidade Federal do Rio Grande do Norte, Natal, 2008. |
url |
https://repositorio.ufrn.br/jspui/handle/123456789/17692 |
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por |
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Universidade Federal do Rio Grande do Norte |
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Programa de Pós-Graduação em Química |
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UFRN |
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BR |
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Físico-Química; Química |
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Universidade Federal do Rio Grande do Norte |
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