Buscar

 

RI UFLA (Universidade Federal de Lavras) >
DQI - Departamento de Química >
DQI - Programa de Pós-graduação >
DQI - Multicêntrico em Química de Minas Gerais - Mestrado (Dissertações) >

Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/11207

Title: Obtenção de fotocatalisadores magnéticos a partir de resíduos industriais e TiO2 para a degradação de contaminantes orgânicos
Other Titles: Photocatalysts magnetic obtained from industrial waste and tio2 for the degradation of organic contaminants
???metadata.dc.creator???: Pereira, Leydiane de Oliveira
???metadata.dc.creator.Lattes???: http://lattes.cnpq.br/4605068188764005
???metadata.dc.contributor.advisor1???: Magalhães, Fabiano
???metadata.dc.contributor.referee1???: Urzedo, Ana Paula Fonseca Maia de
???metadata.dc.contributor.referee2???: Carvalho, Iara Rosário Guimarães
???metadata.dc.contributor.referee3???: Magalhães, Fabiano
Keywords: Fotocatálise
Preto reativo 5
Dióxido de titânio
Lama vermelha
Alcatrão
Photocatalysis
Remazol Black
Titanium dioxide
Red mud
Tar
???metadata.dc.date.submitted???: 20-Apr-2016
Issue Date: 31-May-2016
???metadata.dc.description.sponsorship???: Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)
Citation: PEREIRA, L. de O. Obtenção de fotocatalisadores magnéticos a partir de resíduos industriais e TiO2 para a degradação de contaminantes orgânicos. 2016. 96 p. Dissertação (Mestrado Multicêntrico em Química de Minas Gerais) - Universidade Federal de Lavras, Lavras, 2016.
???metadata.dc.description.resumo???: Neste trabalho, foram sintetizados fotocatalisadores magnéticos, contendo diferentes teores de TiO2 (40, 60 e 80%) suportado no suporte C/LV, formando os fotocatalisadores 40, 60 e 80Ti/C/LV, utilizando alcatrão como fonte de carbono (C) e lama vermelha (LV) como fonte de ferro. Os materiais preparados e o TiO2 foram utilizados para degradar o corante têxtil preto reativo 5 (PR5) e a matéria orgânica presente em um efluente têxtil. A caracterização dos fotocatalisadores realizadas por Raman, Difração de raios-x, Microscopia Eletrônica de Transmissão e Varredura, Espectroscopia de Energia Dispersiva, Termogravimetria e Análise Elementar confirmam a presença de carvão e magnetita no suporte C/LV e a presença do TiO2 nos fotocatalisadores. As reações fotocatalíticas realizadas com o TiO2 P25 foram estudadas variando condições experimentais, tais como: massa do TiO2 (30 - 240 mg), pH da solução (2 – 10), intensidade luminosa (0,871 e 1,20 mWcm-2), tipo de radiação (UV e solar – 1,420 mWcm-2), área de incidência da radiação (44,2 e 143,1 cm2) e oxigênio dissolvido (OD, 1,9 e 7,6 mgL-1). Os resultados mostraram que as reações realizadas nas seguintes condições: 240 mg de TiO2, pH 10, radiação solar, 7,6 mgL-1 de OD e com uma área de incidência da radiação de 143,1 cm2, apresentaram melhores resultados para a degradação do corante. As reações realizadas com os fotocatalisadores magnéticos para a degradação do PR5 mostraram que a eficiência aumenta com o teor de TiO2 no suporte C/LV, sendo que acima de 60% não houve aumento significativo na velocidade da reação. Além disso, a radiação solar foi mais vantajosa para a fotocatálise. Para verificar a presença de uma fração não magnética no fotocatalisador 60Ti/C/LV, foi realizada a separação magnética. As caracterizações da fração magnética (FM) e não magnética (FNM) confirmou que aproximadamente 25% do TiO2 não se fixou no fotocatalisador. Os resultados das reações fotocatalíticas realizadas com a FM e FNM mostraram que ambas as fases possuem atividade fotocatalítica para a degradação do PR5. As reações realizadas para a degradação da matéria orgânica presente na amostra real de efluente têxtil mostraram que o TiO2 P25 e o fotocatalisador magnético, 60Ti/C/LV, apresentaram melhores resultados para remoção de cor (85 e 35%), sólidos solúveis (11 e 3%), DQO (90 e 86%) e turbidez (94 e 11%) do que o tratamento realizado pela indústria têxtil. Os testes de cinética de sedimentação realizados na presença de um imã mostraram que os fotocatalisadores são separados mais rapidamente do meio aquoso do que o TiO2 P25 puro. Os resultados obtidos mostraram que os fotocatalisadores magnéticos possuem ótima atividade fotocatalítica e podem ser separados do meio reacional de forma simples e rápida quando um campo magnético é aplicado.
Abstract: In this work, magnetic photocatalysts were synthesized containing differents levels of TiO2 (40, 60 e 80%) supported at the supporter of C/LV, forming the photocatalysts 40, 60, 80Ti/C/LV, using tar pitch as carbon (C) source and red mud (LV) as iron source. The prepared magnetic photocatalysts and TiO2 were used to degrade the Remazol Black textile dye (PR5) and the organic material present in samples of a textile dye effluent. The characterization of photocatalysts by Raman, X-Ray Diffraction, Transmission Electron Micoscope and Scanning, Energy Dispersive X-ray Spectrometry, Termogravimetry and Elemental Analysis, confirms the presence of carbon and magnetite in support C/LV and the presence of TiO2 in prepared photocatalysts. The photocatalytic reactions with TiO2 were analyzed by different experimental conditions, such as: mass of TiO2 (30-240 mg), solution pH (2-10), light intensity (0.871 and 1.20 mWcm-2), type of radiation (UV and sunlight-1.420 mWcm-2), radiation incidence area (44.2 to 143.1 cm2) and dissolved oxygen (OD, 1.9 and 7.6 mg L- 1). Results showed that reactions with the following conditions: 220 mg of TiO2, pH 10, solar radiation, 7.6 mg L-1 of OD and an incidence area of radiation of 143.1 cm2 showed the best results for degradation of PR5 dye. Photocatalytic reactions with magnetic photocatalysts for degrading PR5 shows that efficiency increases with TiO2 content in the C/LV support, where, above 60% of TiO2, there was not significant increase in reaction velocity. In addition, solar radiation has proved to be advantageous for photocatalytic reactions. In order to verify the presence of a non-magnetic fraction in the photocatalyst 60Ti/C/LV0, magnetic separation was proceeded. The characterizations of the magnetic (FM) and nonmagnetic (NMF) fraction confirmed that about 25% of TiO2 did not fixed in 60Ti/C/LV photocatalyst. Results of photocatalytic reactions with FM and FNM showed that both phases have photocatalytic activity for degradation of PR5. The reactions executed for the degradation of organic matter present in the actual sample of textile effluent showed that TiO2 and magnetic photocatalyst 60Ti/C/ LV have better results for color removal (85 to 35%), soluble solids ( 11 and 3%), DQO (90 and 86%) and turbidity (94 and 11%) than the treatment done by the textile industry. Sedimentation kinetics tests in presence of a magnet showed that photocatalysts are separated faster from aqueous environment than pure TiO2. Obtained results showed that magnetic photocatalysts have excellent photocatalytic activity and can be separated from the reaction environment on a simple and quick way when a magnetic field is applied.
In this work, magnetic photocatalysts were synthesized containing differents levels of TiO2 (40, 60 e 80%) supported at the supporter of C/LV, forming the photocatalysts 40, 60, 80Ti/C/LV, using tar pitch as carbon (C) source and red mud (LV) as iron source. The prepared magnetic photocatalysts and TiO2 were used to degrade the Remazol Black textile dye (PR5) and the organic material present in samples of a textile dye effluent. The characterization of photocatalysts by Raman, X-Ray Diffraction, Transmission Electron Micoscope and Scanning, Energy Dispersive X-ray Spectrometry, Termogravimetry and Elemental Analysis, confirms the presence of carbon and magnetite in support C/LV and the presence of TiO2 in prepared photocatalysts. The photocatalytic reactions with TiO2 were analyzed by different experimental conditions, such as: mass of TiO2 (30-240 mg), solution pH (2-10), light intensity (0.871 and 1.20 mWcm-2), type of radiation (UV and sunlight-1.420 mWcm-2), radiation incidence area (44.2 to 143.1 cm2) and dissolved oxygen (OD, 1.9 and 7.6 mg L- 1). Results showed that reactions with the following conditions: 220 mg of TiO2, pH 10, solar radiation, 7.6 mg L-1 of OD and an incidence area of radiation of 143.1 cm2 showed the best results for degradation of PR5 dye. Photocatalytic reactions with magnetic photocatalysts for degrading PR5 shows that efficiency increases with TiO2 content in the C/LV support, where, above 60% of TiO2, there was not significant increase in reaction velocity. In addition, solar radiation has proved to be advantageous for photocatalytic reactions. In order to verify the presence of a non-magnetic fraction in the photocatalyst 60Ti/C/LV0, magnetic separation was proceeded. The characterizations of the magnetic (FM) and nonmagnetic (NMF) fraction confirmed that about 25% of TiO2 did not fixed in 60Ti/C/LV photocatalyst. Results of photocatalytic reactions with FM and FNM showed that both phases have photocatalytic activity for degradation of PR5. The reactions executed for the degradation of organic matter present in the actual sample of textile effluent showed that TiO2 and magnetic photocatalyst 60Ti/C/ LV have better results for color removal (85 to 35%), soluble solids ( 11 and 3%), DQO (90 and 86%) and turbidity (94 and 11%) than the treatment done by the textile industry. Sedimentation kinetics tests in presence of a magnet showed that photocatalysts are separated faster from aqueous environment than pure TiO2. Obtained results showed that magnetic photocatalysts have excellent photocatalytic activity and can be separated from the reaction environment on a simple and quick way when a magnetic field is applied.
Description: Arquivo retido a pedido da autora até maio de 2017.
URI: http://repositorio.ufla.br/jspui/handle/1/11207
Publisher: Universidade Federal de Lavras
???metadata.dc.language???: por
Appears in Collections:DQI - Multicêntrico em Química de Minas Gerais - Mestrado (Dissertações)

Files in This Item:

There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


View Statistics

 


DSpace Software Copyright © 2002-2010  Duraspace - Feedback