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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo da modifica??o de bentonita para a remo??o de fenol em ?guas produzidas na ind?stria de petr?leo

Oliveira, Maryelzy Felipe David de 03 September 2009 (has links)
Made available in DSpace on 2014-12-17T15:41:46Z (GMT). No. of bitstreams: 1 MaryelzyFDOpdf.pdf: 2807390 bytes, checksum: 8f6874eb0deb6349d074ce9c9fbbe71e (MD5) Previous issue date: 2009-09-03 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study evaluates the inclusion of quaternary ammonium salt, bromide hexadecyl trimethyl ammonium (HDTMA-Br) on sodium bentonite to evaluate their performance on the adsorption of phenol present in produced water. It was observed an increase in d001 samples modified with HDTMA-Br by diffraction of X-rays, showing the intercalation of quaternary ammonium cations in the interlamellar layers of clay. Through the adsorption isotherms could be abserver adsorption behavior of sodium bentonite and organophilic bentonite produced in three different concentrations of HDTMA-Br for adsorption of phenol, which is the main phenolic compound found in the product water. Different concentrations of synthetic solutions of phenol were placed in contact with these adsorbents under the same conditions of agitation and temperature. The adsorbent showed adsorptive favorable, especially the clay modified with the highest concentration of HDTMA-Br, 150% CEC of clay, BEN30-14, with higher amounts of phenol adsorbed per gram of adsorbent (mg.g-1) / Este trabalho objetiva avaliar a inser??o do sal de am?nio quatern?rio, brometo de hexadecil trimetil am?nio (HDTMA-Br) em bentonita s?dica para avaliar seu desempenho na adsor??o de fenol presente em ?gua produzida. P?de-se observar o aumento na d001 das amostras modificadas com HDTMABr por meio de difra??o de raios-X, o que evidencia a intercala??o dos c?tions quatern?rios de am?nio nas camadas interlamelares da argila. Atrav?s das isotermas de adsor??o p?de-se abservar os comportamentos adsortivos da bentonita s?dica e da bentonita organof?lica produzida em tr?s concentra??es de HDTMA-Br para adsor??o do fenol, o qual ? o principal composto fen?lico encontrado na ?gua produzida. Diferentes concentra??es de solu??es sint?ticas de fenol foram colocadas em contato com estes adsorventes sob mesmas condi??es de agita??o e de temperatura. Os adsorventes apresentaram comportamento adsortivo favor?vel, destacando-se a argila modificada com a maior concentra??o de HDTMA-Br, 150% da CTC da argila, BEN30-14, com maiores quantidades de fenol adsorvida por grama de adsorvente (mg.g-1)
2

Remo??o de corantes t?xteis em solu??o aquosa utilizando bentonita natural e organof?lica

Oliveira, Maryelzy Felipe David de 30 January 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-03T22:43:01Z No. of bitstreams: 1 MaryelzyFelipeDavidDeOliveira_TESE.pdf: 3483277 bytes, checksum: c54fb20860788733c7a849a58b127e1b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-05T00:13:38Z (GMT) No. of bitstreams: 1 MaryelzyFelipeDavidDeOliveira_TESE.pdf: 3483277 bytes, checksum: c54fb20860788733c7a849a58b127e1b (MD5) / Made available in DSpace on 2016-05-05T00:13:38Z (GMT). No. of bitstreams: 1 MaryelzyFelipeDavidDeOliveira_TESE.pdf: 3483277 bytes, checksum: c54fb20860788733c7a849a58b127e1b (MD5) Previous issue date: 2015-01-30 / Pesquisas utilizando argilas organof?licas t?m sido objeto de grande interesse devido a sua ampla aplica??o na ind?stria e na remo??o de poluentes ambientais. As argilas organof?licas foram obtidas usando bentonita (BEN) e os surfactantes cati?nicos: brometo de hexadeciltrimetil am?nio (HDTMA-Br) e brometo de trimetiloctadecil am?nio (TMOA-Br) nas raz?es de 50 e 100 % de sua capacidade de troca i?nica. Os materiais foram caracterizados pelas t?cnicas de difra??o raios-X (DRX), espectroscopia na regi?o do infravermelho (IR) e fluoresc?ncia de raios-X (FRX). A bentonita e as argilas organof?licas foram usadas na adsor??o dos corantes Remazol Azul RR (AZ) e Remazol Vermelho RR (VM) em solu??o aquosa. Os modelos de adsor??o de Fre?ndlich e Langmuir foram usados pra descri??o matem?tica dos dados de sor??o no equil?brio e obter as constantes das isotermas. O modelo de Fre?ndlich se ajustou aos dados de equil?brio dos ensaios de adsor??o da bentonita, por outro lado ambos o modelo de Langmuir se ajustou aos ensaios adsortivos das argilas organof?licas. Os processos de adsor??o utilizando ambos corantes com os adsorventes intercalados com HDTMA-Br apresentam natureza endot?rmica e exot?rmica, respectivamente. / Searches using organoclays have been the subject of great interest due to its wide application in industry and removal of environmental pollutants. The organoclays were obtained using bentonite (BEN) and cationic surfactants: hexadecyltrimethyl ammonium bromide (HDTMA-Br) and trimethyloctadecyl ammonium bromide (TMOA-Br) in ratios of 50 and 100 % of its ion exchange capacity. The materials were characterized by the techniques of X-ray diffraction (DRX), infrared spectroscopy (IR), X-ray fluorescence (FRX), thermal analysis (TA) and scanning electron microscopy (SEM). The bentonite and organobentonite were used on the adsorption of dyes, Remazol Blue RR (AZ) and Remazol Red RR (VM) in aqueous solution. The adsorption models of Langmuir and Freundlich were used for mathematical description of sorption equilibrium data and obtain the constants of the isotherms. The Freundlich model fit to the data for adsorption equilibrium of bentonite, on the other hand both the model fit to the Langmuir adsorption test of organoclays. The adsorption processes using adsorbents with both dyes interspersed with HDTMA-Br show endothermic and exothermic nature, respectively.
3

Estudo de tensoativos na organofiliza??o de argila benton?tica para uso em fluido de perfura??o ? base de ?leo

Silva, Rhaul Phillypi da 21 March 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-16T22:25:59Z No. of bitstreams: 1 RhaulPhillypiDaSilva_DISSERT.pdf: 3293809 bytes, checksum: bb1598adff094d59d1e342b8a9cae1eb (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-23T22:01:35Z (GMT) No. of bitstreams: 1 RhaulPhillypiDaSilva_DISSERT.pdf: 3293809 bytes, checksum: bb1598adff094d59d1e342b8a9cae1eb (MD5) / Made available in DSpace on 2016-08-23T22:01:35Z (GMT). No. of bitstreams: 1 RhaulPhillypiDaSilva_DISSERT.pdf: 3293809 bytes, checksum: bb1598adff094d59d1e342b8a9cae1eb (MD5) Previous issue date: 2016-03-21 / Devido aos grandes desafios encontrados na perfura??o de po?os, h? uma necessidade de se desenvolver fluidos com propriedades adequadas e capazes de atender todas as exig?ncias da perfura??o. As propriedades f?sico-qu?micas e reol?gicas devem ser cuidadosamente controladas para que um fluido possa exercer todas suas fun??es. Nas perfura??es onde as forma??es sens?veis a ?gua e ?offshore?, torna-se necess?ria a utiliza??o de fluidos de perfura??o base ?leo, por?m as argilas benton?ticas n?o podem ser usadas sem uma pr?via mudan?a superficial para que suas superf?cies se tornem hidrof?bicas. Ultimamente, as empresas de petr?leo no Brasil utilizam argilas organof?licas importadas na prepara??o de fluidos de perfura??o a base de ?leo. O trabalho teve por objetivo modificar uma argila c?lcica visando aumentar a afinidade da mesma pela fase org?nica de fluidos de perfura??o a base de ?leo, aplicando tr?s tensoativos (OCS, CTAB e UTM 150) em diferentes concentra??es. O resultados indicaram que os tensoativos UTM 150 e CTAB apresentaram resultados superiores quando comparados com OCS. Considerando o tipo de tensoativo e concentra??o como vari?veis utilizadas na an?lise estat?stica, os resultados indicaram que somente a tens?o superficial e concentra??o de ?xido de c?lcio como resposta no processo de organofiliza??o apresentaram os efeitos estatisticamente significativos. A argila organofilizada apresenta potencial para aplica??o em fluido de perfura??o ? base de ?leo. / Due to the great challenges encountered in drilling wells, there is a need to develop fluids with appropriated properties and able to meet all the requirements of drilling operations. The physicochemical and rheological properties must be carefully controlled so that a fluid can exercise all its functions. In perforations sensitive to contact with water and "offshore", it becomes necessary the use of oil based drilling fluids, but the bentonite clay cannot be used without a previous surface modification so that their surfaces become hydrophobic. Lately, the oil companies in Brazil use imported organoclays in the preparation of oil-based drilling fluids. The study aimed to modify a calcium clay to increase the affinity of the same organic phase of oil-based drilling fluids, applying three surfactants (OCS, CTAB and UTM 150) at different concentrations. The results indicated that the surfactants UTM 150 and CTAB showed better results compared to OCS. Considering the type of surfactant and concentration as variables used in the statistical analysis, the results indicated that only the surface tension and concentration of calcium oxide in response to organophilization process showed statistically significant effects. The organophilizated clay has potential for application in oil-based drilling fluids.

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