Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T23:01:39Z No. of bitstreams: 1 GislanePinhoDeOliveira_DISSERT.pdf: 2585969 bytes, checksum: 5a2ec44dfa4024c61a2f9bad2b0cc474 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-04T22:09:35Z (GMT) No. of bitstreams: 1 GislanePinhoDeOliveira_DISSERT.pdf: 2585969 bytes, checksum: 5a2ec44dfa4024c61a2f9bad2b0cc474 (MD5) / Made available in DSpace on 2016-04-04T22:09:35Z (GMT). No. of bitstreams: 1 GislanePinhoDeOliveira_DISSERT.pdf: 2585969 bytes, checksum: 5a2ec44dfa4024c61a2f9bad2b0cc474 (MD5) Previous issue date: 2015-06-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O progresso industrial moderno vem incorporando compostos fen?licos entre as impurezas encontradas na ?gua. Por se tratar de uma subst?ncia t?xica e cancer?gena, ? imprescind?vel que a mesma seja reduzida ? concentra??es toler?veis, determinadas pelo CONAMA. Neste contexto, este trabalho tem como objetivo o tratamento e caracteriza??o de catalisadores oriundos do biocarv?o, subproduto da pir?lise de biomassa (avel?s e p? de madeira), assim como sua avalia??o na degrada??o fotocatal?tica do fenol. Os ensaios foram realizados em um reator leito de lama, com medi??es instant?neas da temperatura, pH e oxig?nio dissolvido. Os experimentos foram realizados nas seguintes condi??es operacionais: temperatura igual a 50 ?C, vaz?o de oxig?nio igual a 410 mL min-1 , volume de solu??o reagente igual a 3,2 L, l?mpada UV de 400 W, press?o de 1 atm e tempo de rea??o de 2 horas. Os par?metros avaliados foram o pH do meio reacional (3,0; 6,9 e 10,7), concentra??o inicial de fenol comercial (250, 500 e 1000 ppm), concentra??o de catalisador (0, 1, 2 e 3 g L-1 ) e natureza do catalisador (carv?o do aveloz ativado e lavado com diclorometano, CAADCM, e carv?o da madeira ativado e lavado com diclorometano, CMADCM). Os resultados de FRX, DRX e BET comprovaram a presen?a de ferro e pot?ssio em quantidades satisfat?rias para o catalisador CAADCM e em quantidades reduzidas no catalisador CMADCM, e o aumento da ?rea superficial dos materiais ap?s a ativa??o qu?mica e f?sica. As curvas de degrada??o do fenol indicam que o pH tem uma influ?ncia significativa na convers?o do fenol, apresentando melhores resultados para os valores de pH mais reduzidos. A concentra??o ?tima de catalisador observada foi de 1 g L-1 e o aumento da concentra??o inicial de fenol exerce uma influ?ncia negativa na condu??o da rea??o. Tamb?m foi observado o efeito positivo da presen?a de ferro e pot?ssio na estrutura do catalisador: obteve-se convers?es melhores para os ensaios realizados com o catalisador CAADCM, quando comparado com o catalisador CMADCM nas mesmas condi??es. A maior convers?o foi obtida para o ensaio realizado em pH ?cido (3,0), com uma concentra??o inicial de fenol igual a 250 ppm na presen?a do catalisador CAADCM a 1 g L-1 . As amostras l?quidas retiradas a cada 15 minutos foram analisadas por cromatografia l?quida identificando e quantificando a hidroquinona, p-benzoquinona, catecol e ?cido maleico. Finalmente um mecanismo do processo reacional foi proposto, considerando que o fenol ? transformado em fase homog?nea e os demais reagem na superf?cie do catalisador. Aplicandose o modelo de Langmuir-Hinshelwood juntamente com um balan?o de massa, obteve-se um sistema de equa??es diferenciais que foi resolvido utilizando o m?todo de Runge-Kutta de 4? ordem associado a uma rotina de otimiza??o SWARM (enxame de part?culas), visando minimizar a fun??o objetivo de m?nimos quadrados para estima??o dos par?metros cin?ticos e de adsor??o. Obteve-se constantes cin?ticas da ordem de grandeza de 10-3 para a degrada??o do fenol, 10-4 ? 10-2 para a forma??o de ?cidos, 10-6 ? 10-9 para a mineraliza??o dos quin?nicos (hidroquinona, p-benzoquinona e catecol), 10-3 ? 102 para a mineraliza??o dos ?cidos. / The modern industrial progress has been contaminating water with phenolic compounds. These are toxic and carcinogenic substances and it is essential to reduce its concentration in water to a tolerable one, determined by CONAMA, in order to protect the living organisms. In this context, this work focuses on the treatment and characterization of catalysts derived from the bio-coal, by-product of biomass pyrolysis (avel?s and wood dust) as well as its evaluation in the phenol photocatalytic degradation reaction. Assays were carried out in a slurry bed reactor, which enables instantaneous measurements of temperature, pH and dissolved oxygen. The experiments were performed in the following operating conditions: temperature of 50 ?C, oxygen flow equals to 410 mL min-1 , volume of reagent solution equals to 3.2 L, 400 W UV lamp, at 1 atm pressure, with a 2 hours run. The parameters evaluated were the pH (3.0, 6.9 and 10.7), initial concentration of commercial phenol (250, 500 and 1000 ppm), catalyst concentration (0, 1, 2, and 3 g L-1 ), nature of the catalyst (activated avel?s carbon washed with dichloromethane, CAADCM, and CMADCM, activated dust wood carbon washed with dichloromethane). The results of XRF, XRD and BET confirmed the presence of iron and potassium in satisfactory amounts to the CAADCM catalyst and on a reduced amount to CMADCM catalyst, and also the surface area increase of the materials after a chemical and physical activation. The phenol degradation curves indicate that pH has a significant effect on the phenol conversion, showing better results for lowers pH. The optimum concentration of catalyst is observed equals to 1 g L-1 , and the increase of the initial phenol concentration exerts a negative influence in the reaction execution. It was also observed positive effect of the presence of iron and potassium in the catalyst structure: betters conversions were observed for tests conducted with the catalyst CAADCM compared to CMADCM catalyst under the same conditions. The higher conversion was achieved for the test carried out at acid pH (3.0) with an initial concentration of phenol at 250 ppm catalyst in the presence of CAADCM at 1 g L-1 . The liquid samples taken every 15 minutes were analyzed by liquid chromatography identifying and quantifying hydroquinone, p-benzoquinone, catechol and maleic acid. Finally, a reaction mechanism is proposed, cogitating the phenol is transformed into the homogeneous phase and the others react on the catalyst surface. Applying the model of Langmuir-Hinshelwood along with a mass balance it was obtained a system of differential equations that were solved using the Runge-Kutta 4th order method associated with a optimization routine called SWARM (particle swarm) aiming to minimize the least square objective function for obtaining the kinetic and adsorption parameters. Related to the kinetic rate constant, it was obtained a magnitude of 10-3 for the phenol degradation, 10-4 to 10-2 for forming the acids, 10-6 to 10-9 for the mineralization of quinones (hydroquinone, p-benzoquinone and catechol), 10-3 to 10-2 for the mineralization of acids.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T17:52:57Z No. of bitstreams: 1 LuanaMarciaBezerraBatista_DISSERT.pdf: 3442467 bytes, checksum: f724d9f875274efa5697bfe755c4ceb3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T19:39:10Z (GMT) No. of bitstreams: 1 LuanaMarciaBezerraBatista_DISSERT.pdf: 3442467 bytes, checksum: f724d9f875274efa5697bfe755c4ceb3 (MD5) / Made available in DSpace on 2016-01-28T19:39:10Z (GMT). No. of bitstreams: 1 LuanaMarciaBezerraBatista_DISSERT.pdf: 3442467 bytes, checksum: f724d9f875274efa5697bfe755c4ceb3 (MD5) Previous issue date: 2014-10-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A prepara??o de novos comp?sitos usando argilas naturais como suporte, vem sendo estudada na literatura, em virtude das mesmas serem encontradas na natureza e como consequ?ncia, apresentarem um baixo pre?o. As argilas podem ser empregadas como suportes para ?xidos met?licos aumentando a quantidade de s?tios ativos presentes na sua superf?cie, e assim, podem ser aplicadas para os mais variados fins como adsor??o, cat?lise e fotocat?lise. Uns dos materiais que estam em destaque s?o os compostos de ni?bio, em especial os ?xidos, por apresentarem ?timas propriedades oxidativas e fotocatal?ticas. Neste cen?rio, o trabalho teve como objetivo sintetizar o comp?sito oxihidr?xido de ni?bio (NbO2OH)/vermiculita, bem como avaliar sua efic?cia com rela??o ? vermiculita s?dica (V0) e ao NbO2OH. O comp?sito foi preparado atrav?s do m?todo de precipita??o-deposi??o. Em seguida, foi caracterizado por difratometria de raios-X (DRX), espectroscopia de absor??o do infravermelho (IV), espectroscopia de energia dispersiva de raios-X (EDS), an?lise termogravim?trica (TG/DTG), microscopia eletr?nica de varredura (MEV), adsor??o e dessor??o de N2 pelo m?todo B.E.T e investiga??o da distribui??o de carga. A aplica??o do material NbO2OH/V0 foi dividida em duas etapas: (I) atrav?s dos m?todos de adsor??o e oxida??o e (II) por meio da oxida??o fotocatal?tica usando a irradia??o solar. Os estudos de adsor??o, oxida??o e oxida??o fotocatal?tica foram monitorados com rela??o a porcentagem de remo??o da cor do corante azul de metileno (AM) atrav?s da espectroscopia de UV-Vis. Os resultados de DRX evidenciaram diminui??o e alargamento na reflex?o d(001) da argila ap?s modifica??o, o IV indicou a presen?a tanto da argila quanto do oxihidr?xido de ni?bio ao apresentar bandas em 1003 e 800 cm-1 referentes, respectivamente, ao estiramento Si-O e Nb-O. A presen?a do ni?bio foi confirmada tamb?m por EDS que indicou quantidade 17 % em massa do metal. A an?lise t?rmica constatou a estabilidade do comp?sito em 217 ?C e as micrografias mostraram que houve diminui??o no tamanho das part?culas da argila. A investiga??o da distribui??o de carga do NbO2OH/V0 constatou que o material apresentou uma superf?cie heterog?nea com cargas negativas baixa, m?dia e elevada. O teste de adsor??o mostrou que o comp?sito NbO2OH/V0 apresentou maior capacidade adsortiva conseguindo remover 56 % da cor do AM, enquanto o material V0 removeu apenas 13 %. O NbO2OH n?o apresentou capacidade adsortiva em virtude da forma??o de agregados-H. A porcentagem de remo??o da cor do corante para os testes de oxida??o apresentou pouca diferen?a com rela??o a adsor??o, sendo 18 e 66 % de remo??o da cor do corante para V0 e NbO2OH/V0, respectivamente. O material NbO2OH/V0 apresentou excelente atividade fotocatal?tica conseguindo remover em apenas 180 minutos 95,5 % da cor do AM comparado a 41,4 % da V0 e 82,2 % do NbO2OH, comprovando a forma??o de um novo comp?sito com propriedades distintas dos seus precursores. / The preparation of nanostructured materials using natural clays as support, has been studied in literature under the same are found in nature and consequently, have a low price. Generally, clays serve as supports for metal oxides by increasing the number of active sites present on the surface and can be applied for various purposes such as adsorption, catalysis and photocatalysis. Some of the materials that are currently highlighted are niobium compounds, in particular, its oxides, by its characteristics such as high acidity, rigidity, water insolubility, oxidative and photocatalytic properties. In this scenario, the study aimed preparing a composite material oxyhydroxide niobium (NbO2OH) / sodium vermiculite clay and evaluate its effectiveness with respect to the natural clay (V0) and NbO2OH. The composite was prepared by precipitation-deposition method and then characterized by X-ray diffraction, infrared spectroscopy (XRD), energy dispersive X-ray (EDS), thermal analysis (TG/DTG), scanning electron microscopy (SEM), N2 adsorption-desorption and investigation of distribution of load. The application of the material NbO2OH/V0 was divided in two steps: first through oxidation and adsorption methods, and second through photocatalytic activity using solar irradiation. Studies of adsorption, oxidation and photocatalytic oxidation monitored the percentage of color removal from the dye methylene blue (MB) by UV-Vis spectroscopy. The XRD showed a decrease in reflection d (001) clay after modification; the FTIR indicated the presence of both the clay when the oxyhydroxide niobium to present bands in 1003 cm-1 related to Si-O stretching bands and 800 cm-1 to the Nb-O stretching. The presence of niobium was also confirmed by EDS indicated that 17 % by mass amount of the metal. Thermal analysis showed thermal stability of the composite at 217 ?C and micrographs showed that there was a decrease in particle size. The investigation of the surface charge of NbO2OH/V0 found that the material exhibits a heterogeneous surface with average low and high negative charges. Adsorption tests showed that the composite NbO2OH/V0 higher adsorption capacity to remove 56 % of AM, while the material removed from V0 only 13 % showed no NbO2OH and adsorptive capacity due to the formation of H-aggregates. The percent removal of dye color for the oxidation tests showed little difference from the adsorption, being 18 and 66 % removal of dye color for V0 and NbO2OH/V0 respectively. The NbO2OH/V0 material shows excellent photocatalytic activity managing to remove just 95,5 % in 180 minutes of the color of MB compared to 41,4 % and 82,2 % of V0 the NbO2OH, proving the formation of a new composite with distinct properties of its precursors.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-08T21:11:24Z No. of bitstreams: 1 EmersonAlencarDeMedeiros_DISSERT.pdf: 2911970 bytes, checksum: f1aed4ff1b910b2a9a0ab98f785583a7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-12T21:29:33Z (GMT) No. of bitstreams: 1 EmersonAlencarDeMedeiros_DISSERT.pdf: 2911970 bytes, checksum: f1aed4ff1b910b2a9a0ab98f785583a7 (MD5) / Made available in DSpace on 2016-07-12T21:29:33Z (GMT). No. of bitstreams: 1 EmersonAlencarDeMedeiros_DISSERT.pdf: 2911970 bytes, checksum: f1aed4ff1b910b2a9a0ab98f785583a7 (MD5) Previous issue date: 2015-10-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / ? preocupante o descontrole por parte das ind?strias que produzem insumos relacionados aos compostos fen?licos, promovendo a emiss?o ou descarte desse poluente no meio ambiente, trazendo danos irrevers?veis ? natureza bem como ao ser humano. Diante disso, ? imprescind?vel a realiza??o de um tratamento desses efluentes antes de serem descartados no meio ambiente, reduzindo a concentra??o do contaminante ? valores determinados pela legisla??o. Procura-se, portanto, o tratamento desses efluentes utilizando novos materiais catal?ticos que viabilizem o processo como um todo. Nesse contexto, o presente trabalho tem como objetivo o tratamento, caracteriza??o e avalia??o de novos catalisadores na rea??o de degrada??o fotocatal?tica do fenol. Os ensaios foram realizados em um reator fotocatal?tico, em condi??es constantes de temperatura (50 ?C), pot?ncia da l?mpada (400 W), volume da fase l?quida (3,4 L), concentra??o do catalisador (1 g L-1), concentra??o inicial do fenol (500 ppm) e tempo de rea??o 3 horas. Preliminarmente ? rea??o foi realizado um estudo com a vaz?o de oxig?nio (410, 515, 650 e 750 mL min-1) a fim de identificar o valor ?timo (650 ml min-1) a ser utilizado no processo de degrada??o do fenol. Os demais par?metros foram variados: pH do meio reacional (3, 5,5 e 10) e a natureza do catalisador (paligorsquita acidificada calcinada, paligorsquita impregnada com 3,8% de ferro e carv?o originado da pir?lise do lodo de esgoto dom?stico). Os materiais catal?ticos foram caracterizados por DRX, FRX, BET e distribui??o granulom?trica. No processo de degrada??o fotocatal?tica do fenol, os resultados mostraram que o pH tem influ?ncia significativa na convers?o do fenol, apresentando melhores resultados para o pH igual a 5,5. Os valores da convers?o do fenol variaram entre 58% (para a paligorsquita acidificada calcinada) e 52% para o carv?o do lodo de esgoto. As amostras l?quidas analisadas por cromatografia l?quida identificaram e quantificaram os seguintes produtos da degrada??o: hidroquinona, catecol e o ?cido mal?ico. Por fim, foi proposto um mecanismo do processo reacional, considerando que o fenol ? transformado em fase homog?nea e os demais reagem na superf?cie do catalisador. Para este ?ltimo, foi aplicado o modelo Langmuir-Hinshelwood, cujos balan?os de massas conduziram a um sistema de equa??es diferenciais que foram resolvidas utilizando o m?todo num?rico associado a uma minimiza??o da fun??o objetivo para obten??o e otimiza??o dos par?metros cin?ticos e de adsor??o. O modelo se ajustou satisfatoriamente aos resultados experimentais. A partir do mecanismo proposto e com as condi??es operat?rias utilizadas no presente trabalho, a etapa mais favorecida, independente do catalisador, foi a do grupo ?cidos (originada dos compostos quin?nicos), sendo transformado em CO2 e ?gua, cuja constante de velocidade k4 apresentou valor 0,578 mol L-1 min-1 para a paligorsquita acidificada calcinada, 0,472 mol L-1 min-1 para o Fe2O3/paligorsquita e 1,276 mol L-1 min-1 para o carv?o do lodo, sendo este ?ltimo o melhor catalisador para mineraliza??o dos ?cidos em CO2 e ?gua. Os quin?nicos foram mais fortemente adsorvidos nos s?tios dos catalisadores paligorsquita acidificada calcinada e Fe2O3/paligorsquita, cujas constantes de adsor??o foram semelhantes (~4,45 L mol-1) e superior ao carv?o do lodo (3,77 L mol-1). / The uncontrolled disposal of wastewaters containing phenolic compounds by the industry has caused irreversible damage to the environment. Because of this, it is now mandatory to develop new methods to treat these effluents before they are disposed of. One of the most promising and low cost approaches is the degradation of phenolic compounds via photocatalysis. This work, in particular, has as the main goal, the customization of a bench scale photoreactor and the preparation of catalysts via utilization of char originated from the fast pyrolysis of sewage sludge. The experiments were carried out at constant temperature (50?C) under oxygen (410, 515, 650 and 750 ml min-1). The reaction took place in the liquid phase (3.4 liters), where the catalyst concentration was 1g L-1 and the initial concentration of phenol was 500 mg L-1 and the reaction time was set to 3 hours. A 400 W lamp was adapted to the reactor. The flow of oxygen was optimized to 650 ml min-1. The pH of the liquid and the nature of the catalyst (acidified and calcined palygorskite, palygorskite impregnated with 3.8% Fe and the pyrolysis char) were investigated. The catalytic materials were characterized by XRD, XRF, and BET. In the process of photocatalytic degradation of phenol, the results showed that the pH has a significant influence on the phenol conversion, with best results for pH equal to 5.5. The phenol conversion ranged from 51.78% for the char sewage sludge to 58.02% (for palygorskite acidified calcined). Liquid samples analyzed by liquid chromatography and the following compounds were identified: hydroquinone, catechol and maleic acid. A mechanism of the reaction was proposed, whereas the phenol is transformed into the homogeneous phase and the others react on the catalyst surface. For the latter, the Langmuir-Hinshelwood model was applied, whose mass balances led to a system of differential equations and these were solved using numerical methods in order to get estimates for the kinetic and adsorption parameters. The model was adjusted satisfactorily to the experimental results. From the proposed mechanism and the operating conditions used in this study, the most favored step, regardless of the catalyst, was the acid group (originated from quinone compounds), being transformed into CO2 and water, whose rate constant k4 presented value of 0.578 mol L-1 min-1 for acidified calcined palygorskite, 0.472 mol L-1 min-1 for Fe2O3/palygorskite and 1.276 mol L-1 min-1 for the sludge to char, the latter being the best catalyst for mineralization of acid to CO2 and water. The quinones were adsorbed to the acidic sites of the calcined palygorskite and Fe2O3/palygorskite whose adsorption constants were similar (~ 4.45 L mol-1) and higher than that of the sewage sludge char (3.77 L mol-1).

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-02T11:57:41Z No. of bitstreams: 1 MarcellaJordannaSilvaMontorilAraujo_DISSERT.pdf: 3443985 bytes, checksum: 367c6ae398c4c1ef8054fbb595d56752 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-06T20:29:13Z (GMT) No. of bitstreams: 1 MarcellaJordannaSilvaMontorilAraujo_DISSERT.pdf: 3443985 bytes, checksum: 367c6ae398c4c1ef8054fbb595d56752 (MD5) / Made available in DSpace on 2017-02-06T20:29:13Z (GMT). No. of bitstreams: 1 MarcellaJordannaSilvaMontorilAraujo_DISSERT.pdf: 3443985 bytes, checksum: 367c6ae398c4c1ef8054fbb595d56752 (MD5) Previous issue date: 2016-07-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A ind?stria t?xtil gera um grande volume de efluentes que, muitas vezes, s?o descartados no meio ambiente sem estarem devidamente tratados. Esses efluentes s?o formados de mol?culas org?nicas e caracterizam-se por apresentar cor, que alteram as propriedades da ?gua deixando-a impr?pria para o consumo. Para o tratamento desses efluentes, a utiliza??o de processos catal?ticos heterog?neos de custo baixo pode ser vantajoso. As argilas v?m sendo bastante estudadas como suportes catal?ticos em raz?o de sua abund?ncia na crosta terrestre e seu baixo custo. Portanto, neste trabalho as argilas vermiculita e bentonita foram usadas como suporte para o catalisador oxihidr?xido de ni?bio e pelo m?todo de deposi??o-precipita??o foram obtidos comp?sitos formados por esses materiais. Os comp?sitos Nb/argila foram caracterizados e as principais t?cnicas mostraram que ocorreu uma modifica??o em cada argila. Os resultados de difratrometria de raios X (DRX) indicaram que ocorreu uma diminui??o da intensidade da reflex?o e um deslocamento do pico principal de ambas as argilas quando o oxihidr?xido de ni?bio ? adicionado na estrutura. As an?lises de espectroscopia na regi?o do infravermelho mostram bandas de adsor??o de ambos os materiais nos comp?sitos Nb/argila, dando a indicativa de que o comp?sito foi realmente formado. As imagens de microscopia eletr?nica de varredura tamb?m confirmaram essa modifica??o de estrutura. Foram realizados testes de oxida??o e oxida??o fotocatal?tica com os comp?sitos obtidos e o teste de oxida??o fotocatal?tica foi o que apresentou melhores resultados, pois o comp?sito de vermiculita (Nb/V0) apresentou uma maior atividade fotocatal?tica removendo 98% da cor do corante alaranjado de metila em 90 minutos de rea??o enquanto que o material comp?sito de bentonita (Nb/B0) removeu apenas 63% durante o mesmo tempo de rea??o. Essa atividade ? devido o comp?sito Nb/V0 ter apresentado um menor valor de band gap (3,08eV) que o comp?sito Nb/B0 (3,33eV). / The textile industry produces a large volume of waste that often is discarded into the environment without being properly treated. These effluents are made of organic molecules and are characterized by their color that alter the properties of water which leave it unfit for consumption. For the treatment of these effluents, the use of heterogeneous catalytic processes of low cost can be advantageous. Clays have been widely studied as catalyst supports because of their abundance in the Earth's crust and its low cost. Therefore, in this study the clays vermiculite and bentonite were used as support for the catalyst oxyhydroxide niobium and by the method of deposition-precipitation it was obtained composites formed from these materials. The composite Nb/clay were characterized and the main techniques showed that was changes in each clay. The results X-ray diffractometer (XRD) showed that there was a decrease in reflection intensity and a shift of the main peak of both clays when oxyhydroxide niobium is added to the structure. The spectroscopic analyzes show infrared adsorption bands of in both materials composite Nb/clay which indicates that the composite was actually formed. The scanning electron microscopy images also confirmed that structure modification. Oxidation and photocatalytic oxidation tests were performed with the obtained composite and photocatalytic oxidation test showed the best results, because the vermiculite composite (Nb/V0) showed higher photocatalytic activity by removing 98% of the color orange dye methyl in 90 minutes of reaction while the composite material of bentonite (Nb/B0) removed only 63% over the same reaction time. This activity is due to the composite Nb/V0 have presented a smaller value of band gap (3,08eV) than the composite Nb/B0 (3,33eV).