61 |
Obten??o de suportes a partir da casca de arroz : imobiliza??o de l?quidos i?nicos e avalia??o em captura de CO2Duczinski, Rafael Borges 05 March 2018 (has links)
Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-10-10T14:17:08Z
No. of bitstreams: 1
Dissertac?a?o mestrado_rafa p?s banca - final.pdf: 6925259 bytes, checksum: 04c8ab3a00fa276e3a89008c46ce0d72 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-10-16T16:50:44Z (GMT) No. of bitstreams: 1
Dissertac?a?o mestrado_rafa p?s banca - final.pdf: 6925259 bytes, checksum: 04c8ab3a00fa276e3a89008c46ce0d72 (MD5) / Made available in DSpace on 2018-10-16T16:55:39Z (GMT). No. of bitstreams: 1
Dissertac?a?o mestrado_rafa p?s banca - final.pdf: 6925259 bytes, checksum: 04c8ab3a00fa276e3a89008c46ce0d72 (MD5)
Previous issue date: 2018-03-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Ionic liquids (ILs) grafting in inorganic solids sorbents is a promising alternative to replace the usual separation process of carbon dioxide from natural gas currently performed using amines. ILs presents unique properties such as, low environmental impact, non-corrosion and process efficiency. The ILs 1,3-bis(3-trimethoxysilylpropyl)imidazolium chloride and 1-methyl-3-(3-trimethoxysilylpropyl)imidazolium chloride were immobilized in MCM-41 and MCMRH silica. The MCMRH was synthesized from rice husk. ILs chemical immobilization was carried out by grafting method, where covalent bonds are formed between silane and hydroxyl groups present in the support. Syntheses were carried out in toluene under nitrogen atmosphere to prevent the hydrolysis and condensation of methoxy groups in the silane structure. CO2 sorption capacity and selectivity for CO2/CH4 were evaluated after synthesis. ILs in concentrations of 10 and 20% were tested. The samples characterization by XPS, NMR, FTIR and TGA confirmed the formation of the proposed IL structures. Sorption and selectivity results showed that the immobilization reduces the CO2sorption capacity, however the selectivity of the materials was higher in relation to the pristine silica. Supports immobilized with ILs 1-methyl-3- (3-trimethoxysilylpropyl) imidazole chloride presented better performance. The observed selectivity increase was 25% when 10% of IL was supported on MCMRH silica. / A imobiliza??o de l?quidos i?nicos ? LIs em suportes inorg?nicos ? uma alternativa ao uso de aminas no processo de separa??o e captura do di?xido de carbono contido no g?s natural, pois possui vantagens ligadas ao aumento de vida ?til de equipamentos, efici?ncia de processo e impacto ambiental. Os LIs cloreto de 1,3-bis(3-trimetoxisililpropil)imidazol e cloreto de 1-metil-3-(3-trimetoxisililpropil)imidazol foram imobilizados na s?lica comercial MCM-41 e na s?lica sintetizada a partir da casca de arroz nomeada neste trabalho como MCMRH. A imobiliza??o qu?mica dos LIs foi realizada atrav?s da forma??o de liga??es covalentes entre grupos silanos na estrutura do l?quido i?nico e grupos hidroxila presentes nos suportes. As s?nteses foram realizadas em tolueno sob condi??es inertes para controle da hidr?lise e condensa??o de grupos metoxi na estrutura dos silanos. Ap?s a sua s?ntese, os suportes imobilizados com LIs tiveram sua capacidade de sor??o de CO2 e seletividade em rela??o a CO2/CH4 avaliadas. LIs em concentra??es de 20 e 10% foram testadas. A caracteriza??o das amostras por XPS, RMN, FTIR e TGA confirmaram a forma??o das estruturas dos LIs propostos e os resultados de sor??o e seletividade mostraram que a imobiliza??o reduz a capacidade de sor??o em rela??o ao CO2, entretanto a seletividade dos materiais foram maiores em rela??o aos suportes antes da imobiliza??o. Os suportes imobilizados com o LIs cloreto de 1-metil-3-(3-trimetoxisililpropil)imidazol tiveram melhor desempenho em rela??o aos demais, o aumento de seletividade observado foi de 25% no melhor caso, onde 10% de LI foi suportado na s?lica MCMRH.
|
62 |
Estudo de adsorvente obtido de terras diatom?ceas para remo??o de metais pesados em ?guas produzidas: processamento, caracteriza??o e din?mica em leito fixoFontes, Vilsin?ia dos Anjos 02 August 2010 (has links)
Made available in DSpace on 2014-12-17T14:08:40Z (GMT). No. of bitstreams: 1
VilsineiaAF_DISSERT.pdf: 2438653 bytes, checksum: 9241425e98a35008922b9e1dd051a3af (MD5)
Previous issue date: 2010-08-02 / The acceleration of industrial growth in recent decades on all continents aroused the interest of the companies to counter the impacts produced on the environment, spurred primarily by major disasters in the petroleum industry. In this context, the water produced is responsible for the largest volume of effluent from the production and extraction of oil and natural gas. This effluent has in its composition some critical components such as inorganic salts, heavy metals (Fe, Cu, Zn, Pb, Cd, ), presence of oil and chemicals added in the various production processes. In response to impact, have been triggered by research alternative adsorbent materials for water treatment and water produced, in order to removing oils and acids and heavy metals. Many surveys of diatomaceous earth (diatomite) in Brazil involve studies on the physico-chemical, mineral deposits, extraction, processing and applications. The official estimated Jazi are around 2.5 million tonnes, the main located in the states of Bahia (44%) and Rio Grande do Norte (37,4%). Moreover, these two states appear as large offshore producers, earning a prominent role in research of adsorbents such as diatomite for treatment of water produced. Its main applications are as an agent of filtration, adsorption of oils and greases, industrial load and thermal insulator. The objective of this work was the processing and characterization of diatomite diatomaceous earth obtained from the municipality of Maca?ba-RN (known locally as tabatinga) as a low cost regenerative adsorbent for removal of heavy metals in the application of water produced treatment. In this work we adopted a methodology for batch processing, practiced by small businesses located in producing regions of Brazil. The characterization was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). Research conducted showed that the improvement process used was effective for small volume production of diatomite concentrated. The diatomite obtained was treated by calcination at temperature of 900 oC for 2 hours, with and without fluxing Na2CO3 (4%), according to optimal results in the literature. Column adsorption experiments were conducted to percolation of the in nature, calcined and calcined fluxing diatomites. Effluent was used as a saline solution containing ions of Cu, Zn, Na, Ca and Mg simulating the composition of produced waters in the state of Rio Grande do Norte, Brazil. The breakthrough curves for simultaneous removal of copper ions and zinc as a result, 84.3% for calcined diatomite and diatomite with 97.3 % for fluxing. The calcined fluxing diatomite was more efficient permeability through the bed and removal of copper and zinc ions. The fresh diatomite had trouble with the permeability through the bed under the conditions tested, compared with the other obtained diatomite. The results are presented as promising for application in the petroleum industry / A acelera??o do crescimento industrial nas ?ltimas d?cadas despertou em todos os continentes o interesse das empresas em se contrapor aos impactos produzidos sobre o meio ambiente, incentivadas principalmente pelas grandes cat?strofes ocorridas na ind?stria do petr?leo. Nesse contexto, a ?gua produzida ? respons?vel pelo maior volume de efluentes provenientes de processos de produ??o e extra??o de petr?leo e g?s natural. Este efluente tem em sua composi??o alguns componentes cr?ticos como sais inorg?nicos, metais pesados (Fe, Cu, Zn, Pb, Cd,...), presen?a de ?leo e de produtos qu?micos adicionados nos diversos processos de produ??o. Como resposta a estes problemas foram desencadeadas pesquisas com materiais adsorventes alternativos para o tratamento de ?guas produzidas e ?guas residuais, com a finalidade de remo??o de ?leos e graxos e de metais pesados. Muitas pesquisas feitas com terras de diatom?ceas (diatomita) no Brasil envolvem estudos sobre as caracter?sticas f?sico-qu?micas, jazidas, extra??o, beneficiamento e aplica??es. As jaziadas oficiais estimadas s?o da ordem de 2,5 milh?es de toneladas, sendo as principais localizadas nos estados da Bahia (44%) e Rio Grande do Norte (37,4%). Por outro lado, esses dois estados apresentam-se como grandes produtores de petr?leo em terra, merecendo um destaque importante nas pesquisas de adsorventes como a diatomita para tratamento de ?gua produzida. Suas principais aplica??es s?o como agente de filtra??o, adsor??o de ?leos e graxas, carga industrial e isolante t?rmico. Esse trabalho tem como objetivo o beneficiamento e a caracteriza??o da diatomita do munic?pio de Maca?ba-RN (conhecida na regi?o como tabatinga) como um adsorvente regenerativo de baixo custo para fins de remo??o de metais pesados na aplica??o do tratamento de ?guas produzidas. No presente trabalho adotou-se uma metodologia de beneficiamento por batelada, praticada por pequenas empresas estabelecidas nas regi?es produtoras do Brasil. A caracteriza??o foi feita por difra??o de raios-X (DRX), microscopia eletr?nica de varredura (MEV) e ?rea superficial espec?fica (BET). A investiga??o conduzida mostrou que o processo de beneficiamento utilizado foi eficaz para produ??o em pequena escala de diatomita concentrada. A diatomita obtida foi tratada por calcina??o na temperatura de 900 oC por 2 horas, sem e com fluxante carbonato de s?dio (Na2CO3, 4 %), de acordo com resultados otimizados na literatura. Ensaios de adsor??o em coluna de percola??o foram realizados para as diatomitas in natura, calcinada, e calcinada com fluxante. Como efluente foi utilizado uma solu??o sint?tica contendo ?ons de Cu, Zn, Na, Ca e Mg, simulando a composi??o de ?guas produzidas no estado do Rio Grande do Norte-Brasil. As curvas de ruptura para remo??o simult?nea dos ?ons de cobre e zinco apresentaram como resultados, 84,3 % para diatomita calcinada e 97,3 % para diatomita com fluxante. A diatomita calcinada com fluxante apresentou maior efici?ncia na permeabilidade atrav?s do leito e na remo??o dos ions de cobre e zinco. A diatomita in natura teve dificuldade com a permeabilidade atrav?s do leito nas condi??es testadas, comparada com as outras diatomitas. Os resultados obtidos apresentam-se como promissores para aplica??o na ind?stria do petr?leo
|
63 |
Formas e biodisponibilidade de f?sforo no solo em resposta ? adi??o de ?cido c?trico. / Forms and bioavailability of phosphorus in the soil in response to the addition of citric acid.Santos, Sheila Renata January 2012 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T13:30:37Z
No. of bitstreams: 5
66.pdf: 633982 bytes, checksum: fdad2ae3be9096fae7ea678fc3d85800 (MD5)
license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5)
license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T19:48:45Z (GMT) No. of bitstreams: 5
66.pdf: 633982 bytes, checksum: fdad2ae3be9096fae7ea678fc3d85800 (MD5)
license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5)
license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-27T19:48:45Z (GMT). No. of bitstreams: 5
66.pdf: 633982 bytes, checksum: fdad2ae3be9096fae7ea678fc3d85800 (MD5)
license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5)
license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5)
Previous issue date: 2012 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Melhorar a efici?ncia da absor??o de P no solo pelas culturas, por meio de manejos diferenciados da aduba??o fosfatada, diz respeito a um melhor aproveitamento do nutriente adicionado via fertiliza??o, que significa ganhos em produtividade. Em solos onde predominam argilas de baixa atividade e ?xidos em sua fra??o mineral, a fixa??o de P por meio dos processos de adsor??o e precipita??o torna a nutri??o fosfatada um fator limitante para produ??o da maioria das esp?cies cultiv?veis. O ?nion citrato, derivado da dissocia??o do ?cido c?trico no solo, possui elevado poder complexante de metais. Al?m disso, sua carga negativa garante afinidade com as cargas positivas dos ?xidos no solo, competindo com o fosfato pelos mesmos s?tios de liga??o. Com objetivo de verificar o potencial do ?cido c?trico em aumentar a biodisponibilidade ao milho e modificar as formas de P inorg?nico no solo, testou-se a combina??o das doses 0; 45; 90 e 180 mg dm-3 de P num Neossolo Quartzar?nico e 0; 100; 200 e 400 mg dm-3 de P num Latossolo Vermelho Amarelo, com doses equivalentes a 0; 1; 2 e 4 kg ha-1 de ?cido c?trico, em experimentos em vasos, em condi??es de casa de vegeta??o. No Neossolo Quartzar?nico, 119 mg dm-3 de P e equivalente a 0,8 kg ha-1 de ?cido c?trico proporcionaram m?ximo crescimento das plantas de milho. J? no Latossolo Vermelho Amarelo, a estimativa das doses foi de 96 mg dm-3 de P e equivalente a 2,0 kg ha-1 de ?cido c?trico. A resposta das plantas ? aplica??o do ?cido c?trico deveu-se ? solubiliza??o de formas menos l?beis aumentando as formas mais l?beis de P inorg?nico no solo. Os teores de P na planta e aqueles extra?dos por Mehlich-1e Resina de Troca Ani?nica n?o se correlacionaram quanto ? adi??o de ?cido c?trico no Latossolo Vermelho Amarelo. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT To improve the efficiency of absorption, by crops, of P in soil, through differentiated maneuvers of phosphorus fertilization, relates to a better utilization of nutrients added through fertilization, which means productivity gains. In soils with a predominance of low activity clays and oxides in their mineral fraction, the P fixation through the processes of adsorption and precipitation makes phosphorus nutrition a limiting factor for production of most cultivable species. The anion citrate derived from citric acid dissociation of the soil has high metal complexing power. Furthermore, its negative charge ensures an affinity with the positive charges of the oxides in the soil, competing with phosphate for the same binding sites. In order to verify the potential of citric acid to increase the bioavailability for maize and to modify the forms of inorganic P in the soil, there had been tested the combination doses of 0, 45, 90 and 180 mg dm-3 of P in a Typic Quartzipsamment soil and 0; 100, 200 and 400 mg dm-3 of P in a Typic Hapludox soil, with doses of 0, 1, 2 and 4 kg ha-1 of citric acid in experiments conducted in pots under greenhouse conditions. In Typic Quartzipsamment soil, 119 mg dm-3 of P and an equivalent to 0.8 kg ha-1 of citric acid gave maximum growth of maize crops. In the Typic Hapludox soil, the estimated dose was 96 mg dm-3 of P and equivalent to 2.0 kg ha-1 of citric acid. The plant response to the application of citric acid was due to solubilization of less labile forms increasing the more labile forms of inorganic P in soil. The phosphorus content in the plant and those extracted by Mehlich-1 and Anion Exchange Resin were not correlated to the addition of citric acid in the Typic Hapludox soil.
|
64 |
Adsor??o de cobre e cromo utilizando fibra de sisal visando o tratamento da ?gua produzida pela ind?stria petrol?feraBorba, Loiva Liana Santos 19 July 2010 (has links)
Made available in DSpace on 2014-12-17T14:08:47Z (GMT). No. of bitstreams: 1
LoivaLSB_DISSERT.pdf: 3990836 bytes, checksum: 3537e4304659ead550f1c758b72dbbce (MD5)
Previous issue date: 2010-07-19 / Currently, the oil industry is the biggest cause of environmental pollution. The objective was
to reduce the concentration of copper and chromium in the water produced by the oil industry.
It was used as adsorbent natural sisal fiber Agave sp treated with nitric acid and sodium
hydroxide. All vegetable fibers have physical and morphological properties that enablies the
adsorption of pollutants. The basic composition of sisal is cellulose, hemicellulose and lignin.
The features are typically found in the characterization of vegetable fibers, except the surface
area that was practically zero. In the first stage of adsorption, it was evaluated the effect of
temperature and time skeeking to optimize the execution of the factorial design. The results
showed that the most feasible fiber was the one treated with acid in five hours (30?C). The
second phase was a factorial design, using acid and five hours, this time was it determined in
the first phase. The tests were conducted following the experimental design and the results
were analyzed by statistical methods in order to optimize the main parameters that influence
the process: pH, concentration (mol / L) and fiber mass/ metal solution volume. The volume /
mass ratio factor showed significant interference in the adsorption process of chromium and
copper. The results obtained after optimization showed that the highest percentages of
extraction (98%) were obtained on the following operating conditions: pH: 5-6,
Concentration: 100 ppm and mass/ volume: 1 gram of fiber/50mL solution. The results
showed that the adsorption process was efficient to remove chromium and copper using sisal
fibers, however, requiring further studies to optimize the process. / A ind?stria de petr?leo ? atualmente uma das principais causadoras da polui??o
ambiental. O objetivo deste trabalho foi reduzir a concentra??o de cobre e cromo na ?gua
produzida pela ind?stria petrol?fera. Foi usado como adsorvente a fibra de sisal natural,
tratada com ?cido n?trico e hidr?xido de s?dio. Todas as fibras vegetais possuem
caracter?sticas f?sicas e morfol?gicas que possibilitam a adsor??o de poluentes. A composi??o
b?sica do sisal ? celulose, hemicelulose e lignina. As caracter?sticas encontradas na
caracteriza??o s?o t?picas de fibras vegetais, com exce??o da ?rea superficial que foi
praticamente zero. Na primeira fase da adsor??o foi realizado um estudo a temperatura (30?C,
45?C e 60?C) e tempo para otimizar a realiza??o do planejamento fatorial. Os resultados
mostraram que a fibra mais vi?vel para o estudo ? a fibra tratada com ?cido ? 30?C durante 5
horas. A segunda fase foi a do planejamento fatorial, usando a fibra ?cida e o tempo de cinco
horas determinado na primeira fase. Os ensaios foram efetuados seguindo o planejamento
Fatorial 2 3. Os resultados obtidos foram analisados, atrav?s de m?todos estat?sticos, visando a
otimiza??o dos principais par?metros que influenciam no processo: pH, concentra??o (mol/L)
e rela??o massa de fibra (g)/ volume de solu??o (mL). Os resultados do planejamento
descrevem, o fator concentra??o e o fator massa/volume apresentam interfer?ncia significativa
no processo de adsor??o do cromo e cobre. Os resultados, ap?s a otimiza??o, demonstraram
que os maiores percentuais de extra??o (98 %) foram obtidos nas seguintes condi??es
operacionais: pH: 5-6, Concentra??o: 100 ppm e a rela??o massa /volume: 1grama de
fibra/50mL de solu??o. Observou-se que o processo foi eficiente com rela??o ? adsor??o do
cromo e cobre, contudo s?o necess?rios mais estudos para a otimiza??o do processo.
|
65 |
Recupera??o e purifica??o do ant?geno 503 de Leishmania i. chagasi expresso em E. coli e remo??o de endotoxina utilizando adsor??o em leito expandidoSousa J?nior, Francisco Canind? de 27 February 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-22T19:38:42Z
No. of bitstreams: 1
FranciscoCanindeDeSousaJunior_TESE.pdf: 1665223 bytes, checksum: a3c9c1fa573d5e42243d0808e537d798 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-28T19:44:15Z (GMT) No. of bitstreams: 1
FranciscoCanindeDeSousaJunior_TESE.pdf: 1665223 bytes, checksum: a3c9c1fa573d5e42243d0808e537d798 (MD5) / Made available in DSpace on 2016-03-28T19:44:15Z (GMT). No. of bitstreams: 1
FranciscoCanindeDeSousaJunior_TESE.pdf: 1665223 bytes, checksum: a3c9c1fa573d5e42243d0808e537d798 (MD5)
Previous issue date: 2015-02-27 / O crescente interesse e aplica??es dos produtos biotecnol?gicos v?m aumentando o
desenvolvimento de novos processos de recupera??o e purifica??o de prote?nas. A
adsor??o em leito expandido (ALE) tem se destacado como uma t?cnica promissora
para essa finalidade, pois combina em uma ?nica opera??o as etapas de
clarifica??o, concentra??o e purifica??o da prote?na alvo, reduzindo assim tempo e
custos de opera??o. Neste contexto, o objetivo desta tese foi avaliar a recupera??o e
purifica??o do ant?geno 503 de Leishmania i. chagasi expresso em E. coli M15 e a
remo??o de endotoxina por ALE. Na primeira etapa do trabalho foram realizados
ensaios em taques agitados sob a forma de dois planejamentos experimentais, para
definir as condi??es ?timas de adsor??o e elui??o do ant?geno na resina Streamline
chelating. Nos ensaios de adsor??o usando o leito na forma expandida empregou-se
uma coluna de 2,6 cm de di?metro por 30,0 cm de altura, acoplada a uma bomba
perist?ltica. Na segunda etapa do trabalho, avaliou-se a remo??o de endotoxina
durante o processo de recupera??o do ant?geno, empregando o tensoativo n?oi?nico
triton X-114 na etapa de lavagem da ALE. Na terceira etapa, buscou-se
elaborar um modelo matem?tico capaz de prever as curvas de ruptura do ant?geno
503 em coluna na forma expandida. Os resultados do planejamento experimental
para adsor??o do ant?geno 503 mostraram o pH 8,0 e a concentra??o de NaCl de
2,4 M como melhores condi??es de adsor??o. No segundo planejamento, o ?nico
fator significativo para elui??o foi a concentra??o de imidazol, definida em 600 mM. A
isoterma de adsor??o do ant?geno 503 mostrou bom ajuste ao modelo de Langmuir
(R=0,98) e os valores de qmax (capacidade m?xima de adsor??o) e Kd (constante de
equil?brio) estimados foram de 1,95 mg/g e 0,34 mg/mL, respectivamente. Atrav?s
dos testes de purifica??o diretamente do homogeneizado n?o clarificado obteve-se
uma recupera??o de 59,2% da prote?na de interesse e um fator de purifica??o de
6,0. A adi??o do tensoativo n?o-i?nico Triton X-114 ? etapa de lavagem da ALE
proporcionou altos valores (>99%) de remo??o do LPS inicialmente presente nas
amostras para todas as condi??es estudadas. O modelo matem?tico obtido para
descrever a curva de ruptura do ant?geno 503 na resina Streamline Chelanting em
leito expandido apresentou bom ajuste aos dados experimentais, tanto para etapa
de estimativa de par?metros quanto para de valida??o. O modelo validado foi
utilizado na otimiza??o das efici?ncias, obtendo-se os valores m?ximos de efici?ncia
do processo e efici?ncia da coluna de 89,2% e 75,9%, respectivamente. Portanto,
ALE mostrou ser uma alternativa eficiente na recupera??o da prote?na-alvo e
remo??o de endotoxina a partir de um extrato de E. coli n?o clarificado em apenas
uma etapa. / The growing interest and applications of biotechnology products have increased the
development of new processes for recovery and purification of proteins. The
expanded bed adsorption (EBA) has emerged as a promising technique for this
purpose. It combines into one operation the steps of clarification, concentration and
purification of the target molecule. Hence, the method reduces the time and the cost
of operation. In this context, this thesis aim was to evaluate the recovery and
purification of 503 antigen of Leishmania i. chagasi expressed in E. coli M15 and
endotoxin removal by EBA. In the first step of this study, batch experiments were
carried out using two experimental designs to define the optimal adsorption and
elution conditions of 503 antigen onto Streamline chelating resin. For adsorption
assays, using expanded bed, it was used a column of 2.6 cm in diameter by 30.0 cm
in height coupled to a peristaltic pump. In the second step of study, the removal of
endotoxin during antigen recovery process was evaluated employing the non-ionic
surfactant Triton X-114 in the washing step ALE. In the third step, we sought
developing a mathematical model able to predict the 503 antigen breakthrough
curves in expanded mode. The experimental design results to adsorption showed the
pH 8.0 and the NaCl concentration of 2.4 M as the optimum adsorption condition. In
the second design, the only significant factor for elution was the concentration of
imidazole, which was taken at 600 mM. The adsorption isotherm of the 503 antigen
showed a good fit to the Langmuir model (R = 0.98) and values for qmax (maximum
adsorption capacity) and Kd (equilibrium constant) estimated were 1.95 mg/g and
0.34 mg/mL, respectively. Purification tests directly from unclarified feedstock
showed a recovery of 59.2% of the target protein and a purification factor of 6.0. The
addition of the non-ionic surfactant Triton X-114 to the washing step of EBA led to
high levels (> 99%) of LPS removal initially present in the samples for all conditions
tested. The mathematical model obtained to describe the 503 antigen breakthrough
curves in Streamline Chelanting resin in expanded mode showed a good fit for both
parameter estimation and validation steps. The validated model was used to optimize
the efficiencies, achieving maximum values of the process and of the column
efficiencies of 89.2% and 75.9%, respectively. Therefore, EBA is an efficient
alternative for the recovery of the target protein and removal of endotoxin from an E.
coli unclarified feedstock in just one step.
|
66 |
Estudo da adsor??o do c?lcio e estr?ncio da ?gua produzida utilizando carv?o baba?u / A study on adsorption of calcium and strontium from produced water by using babassu charcoalMedeiros, Hena Lissa de Sousa 30 June 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T22:49:41Z
No. of bitstreams: 1
HenaLissaDeSousaMedeiros_DISSERT.pdf: 2450139 bytes, checksum: 33f229e4eaf5df1a317d891b6b53240c (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-17T22:45:27Z (GMT) No. of bitstreams: 1
HenaLissaDeSousaMedeiros_DISSERT.pdf: 2450139 bytes, checksum: 33f229e4eaf5df1a317d891b6b53240c (MD5) / Made available in DSpace on 2016-05-17T22:45:27Z (GMT). No. of bitstreams: 1
HenaLissaDeSousaMedeiros_DISSERT.pdf: 2450139 bytes, checksum: 33f229e4eaf5df1a317d891b6b53240c (MD5)
Previous issue date: 2015-06-30 / Ag?ncia Nacional do Petr?leo - ANP / A ?gua produzida ? um dos principais res?duos gerados durante a explora??o e produ??o de petr?leo, devido ao grande volume e a sua composi??o qu?mica complexa surge ? preocupa??o para que as concentra??es dos contaminantes atendam as legisla??es vigentes, com a finalidade de reduzir os efeitos nocivos ao meio ambiente provocado pelo seu descarte sem tratamento pr?vio. Assim, o objetivo deste trabalho ? caracterizar a ?gua produzida no Campo de Periquito, do Estado do RN e avaliar o potencial adsortivo do carv?o vegetal de coco baba?u para remo??o dos metais Ca e Sr da ?gua produzida, visando a sua adequa??o para descarte. Atrav?s da caracteriza??o f?sico-qu?mica da ?gua produzida, p?de-se observar que as concentra??es dos metais c?lcio e estr?ncio foram: 322 mg/L e 69 mg/L, respectivamente. O material a ser utilizado como adsorvente foi caracterizado por diferentes t?cnicas f?sico-qu?micas, tais como: granulometria, densidade aparente, an?lise elementar, an?lise t?rmica, FRX, MEV, DRX e pHPZC. De posse das an?lises das caracteriza??es foram realizados ensaios de adsor??o, pelo m?todo de banho finito em solu??es sint?ticas dos metais Ca e Sr. Os resultados demonstraram que o carv?o baba?u possui remo??o m?xima em baixas concentra??es. Paralelamente ao estudo de adsor??o em solu??es sint?ticas, foi realizado ensaios de adsor??o com a ?gua produzida e o resultado mostrou que o carv?o baba?u possui bom potencial de adsor??o, removendo acima de 50 % do c?lcio e acima 45 % do estr?ncio, e apresentando valores para a capacidade de adsor??o de 17,31 mg/g para o c?lcio e 3,15 mg/g para o estr?ncio. Para otimizar os ensaios de adsor??o foi aplicado o planejamento fatorial completo de dois n?veis com o intuito de verificar a influ?ncia da concentra??o dos metais Ca e Sr e a massa do adsorvente em solu??o sint?tica sobre a % remo??o e a capacidade de adsor??o dos metais. Atrav?s dos resultados das an?lises das superf?cies de respostas p?de-se observar que as regi?es ?timas para a remo??o dos metais foram no n?vel superior da concentra??o dos metais e no n?vel superior da massa de adsorvente (+1,+1) obtendo uma remo??o m?xima de 58 % do c?lcio e 63 % do estr?ncio. / Produced water is a major waste generated during oil exploration and production. Due to its large volume and complex chemical composition an effort arises so that the contaminant concentrations meet the current legislation, in order to reduce harmful effects on the environment caused by its disposal without prior treatment. The objective of this paper is to characterize produced water from the Periquito field, RN, Brazil, and assess the adsorptive potential of babassu nut charcoal for removal of calcium and strontium from produced water, focusing on its suitability for disposal. Through the physicochemical characterization of the produced water, it was possible to observe that the concentrations of calcium and strontium were: 322 mg/L and 69 mg/L, respectively. The material to be used as an adsorbent was characterized through different physicochemical techniques, such as laser particle size, density, elemental analysis, thermal analysis, XRF, SEM, XRD and pHPZC. Provided the characterization analysis, adsorption experiments were carried out using the method of finite bath in synthetic solutions of both calcium and strontium. The results showed that babassu nut charcoal has maximum adsorption removal at low concentrations. In parallel with the study on adsorption in synthetic solutions, adsorption experiments were performed with produced water, whose results showed that babassu nut charcoal has good adsorption potential, removing over 50% of calcium and above 45% strontium, and having values of 17.31 mg/g for the adsorption capacity for calcium and 3.15 mg/g for strontium. In order to optimize the experiments, the full factorial design of two levels was applied in order to verify the influence of the concentration of calcium, strontium and the mass of the adsorbent in synthetic solution on the percentage of removal (%) and the adsorption capacity of adsorption of these metals. From the analysis results, it was possible to observe that the optimal regions for the removal of these metals was in the upper level of the metal concentration and in the upper level of the adsorbent mass (+1, +1) obtaining a maximum removal of 58 % for calcium and 63 % for strontium.
|
67 |
Aplica??o de microemuls?es na solubiliza??o de fra??es pesadas de petr?leoGomes, Diego ?ngelo de Ara?jo 06 March 2009 (has links)
Made available in DSpace on 2014-12-17T15:01:18Z (GMT). No. of bitstreams: 1
DiegoAAG_partesautorizadas.pdf: 1805054 bytes, checksum: 0bbdfaaf4272f15a091664e96c012ed7 (MD5)
Previous issue date: 2009-03-06 / This work presents studies related to the use of microemulsions in the solubilization of heavy crude oil fractions responsible by the formation of deposits. The first stage of the work was addressed to the construction of phases diagrams, with the intention of determining the area within which the microemulsion is formed. The following systems were studied: UNITOL L 90 n-Butanol - Water - Kerosene (system 1); UNITOL L 90 - n-Butanol - Water - Xylene (system 2); UNITOL L 90 n-Butanol - Water - Kerosene/Xylene 10% (system 3); UNITOL L 90 - Sec-Butanol - Water - Xylene (system 4). In parallel experiments of physical adsorption were carried out by the static method, with the intention of simulating natural conditions of reservoirs. Crude oil of the Fazenda Bel?m field (Rio Grande do Norte), was used as solute, xylene as solvent and the Assu sandstone (Rio Grande do Norte, Brazil) and Botucatu sandstone (Paran?, Brazil) as rock reservoirs. The curves of adsorption presented the S format type, in agreement with the classification proposed by Giles, Smith and Huitson (1974). The solubilization process was accomplished in the batch method, by varying the time of agitation, the microemulsions and the solid/solution ratio. The experiments showed that the microemulsions presented high efficiency in the solubilization of the crude oil adsorbed on the sandstones. System 2 presented an efficiency of 99% for the Assu sandstone and 97% for the Botucatu sandstone / No presente trabalho foi avaliado o desempenho das microemuls?es na solubiliza??o de fra??es pesadas do petr?leo, respons?veis pela forma??o de dep?sitos. A primeira fase do trabalho foi direcionada ? constru??o dos diagramas de fases, com o intuito de determinar a regi?o na qual a microemuls?o ? formada. Os seguintes sistemas foram estudados: UNITOL L 90 n-Butanol ?gua Querosene (sistema 1); Unitol L 90 n-Butanol ?gua Xileno (sistema 2); Unitol L 90 n-Butanol ?gua Querosene/Xileno 10% (sistema 3); Unitol L 90 Sec-Butanol ?gua Xileno (sistema 4). Em paralelo foram conduzidos experimentos de adsor??o f?sica pelo m?todo est?tico, com o intuito de simular condi??es naturais de reservat?rio. Utilizou-se ?leo bruto do campo de Fazenda Bel?m, (Petrobras - Rio Grande do Norte), xileno como solvente, arenito Assu (Rio Grande do Norte, Brasil) e arenito Botucatu (Paran?, Brasil) como rochas reservat?rio. As curvas de adsor??o foram enquadradas no formato S , de acordo com a classifica??o proposta por Giles, Smith & Huitson (1974). O processo de solubiliza??o foi realizado em regime de batelada, variando o tempo de agita??o, as microemuls?es e a raz?o arenito/microemuls?o. Ensaios mostraram que os sistemas apresentaram alta efici?ncia na solubiliza??o do ?leo bruto adsorvido sobre os arenitos. O sistema 2 apresentou uma efici?ncia de 99% para o arenito Assu e 97% para o arenito Botucatu
|
68 |
Adsor??o do corante amarelo reativo BF-4G 200% por argila esmectita / Adsorption of the dye reactive yellow BF-4G 200% by smectite clayRodrigues Filho, Geraldo Martins 28 September 2012 (has links)
Made available in DSpace on 2014-12-17T15:01:30Z (GMT). No. of bitstreams: 1
GeraldoMRF_TESE.pdf: 3870711 bytes, checksum: 6a5339896637d234e88f58bd692fe8cf (MD5)
Previous issue date: 2012-09-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This study aimed to evaluate the potential use of smectite clays for color removal of
textile effluents. The experiments were performed by testing exploratory/planning method
factorial and fractional factorial where the factors and levels are predetermined. The smectite
clays were used originating from gypsum hub of the region Araripe-PE, and the dye used was
Reactive Yellow BF-4G 200%. The smectite clay was collected and transported to the
Laboratory of Soil Physics of UFRPE, where it held its preparation through air drying, lump
breaking and classification in sieve to then submit it to the adsorption process. Upon
completion of 22 complete factorial design it was concluded that the values of (96, 96,5 and
95,8%) corresponding to the percentage of of removal for "in-kind", chemically and thermally
activated, respectively and adsorbed amounts of (4,80, 4,61 and 4,74 mg/g) for three clays.
Showed that the activation processes used did not increase the adsorption capacity of smectite
clay. The kinetic data were best fitted to the Freundlich isotherm, with an exponential
distribution of active sites and that shows above the Langmuir equation for adsorption of
cations and anions by clays. The kinetic model that best adapted to the results was the pseudosecond
order model. In the factorial design study 24-1, at concentrations up to 500 mg/L
obtains high percentage of color removal (92,37, 90,92 and 93,40%) and adsorbed amount
(230,94, 227,31 and 233,50 mg/g) for three clays. The kinetic data fitted well to Langmuir
and Freundlich isotherms. The kinetic model that best adapted to the results was the pseudosecond
order model / Este trabalho teve como objetivo avaliar o potencial de utiliza??o das argilas
esmectitas, para remo??o de cor de efluentes t?xteis. Os experimentos foram realizados
atrav?s de ensaios explorat?rios/m?todo de planejamento fatorial e fatorial fracion?rio, em
que os fatores e os n?veis s?o pr?-determinados. As argilas esmectitas usadas foram
origin?rias do p?lo gesseiro da regi?o do Araripe-PE, e o corante utilizado foi o Amarelo
Reativo BF-4G 200%. A argila esmectita foi coletada e transportada para o Laborat?rio de
F?sica de Solos da UFRPE, onde se realizou a sua prepara??o atrav?s de secagem ao ar,
destorroamento e classifica??o em peneiras para, em seguida, submet?-la ao processo de
adsor??o. A partir da realiza??o do planejamento fatorial 22 concluiu-se que os valores de 96,
96,5 e 95,8%, correspondentes aos percentuais de remo??o para as argilas esmectitas innatura ,
quimicamente e termicamente ativadas, respectivamente, e com quantidades
adsorvidas de 4,80, 4,61 e 4,74 mg/g, para as tr?s argilas, mostraram que os processos de
ativa??o utilizados n?o aumentaram o poder de adsor??o da argila esmectita. Os dados
cin?ticos ajustaram-se melhor ? isoterma de Freundlich, com uma distribui??o exponencial de
s?tios ativos e que se mostra superior ? equa??o de Langmuir para adsor??o de c?tions e
?nions pelas argilas. O modelo cin?tico que melhor se adequou aos resultados foi o modelo
pseudo-segunda ordem. No estudo do planejamento fatorial 24-1, em concentra??es de at? 500
mg/L se obt?m elevados percentuais de remo??o de cor (92,37, 90,92 e 93,40 %) e quantidade
adsorvida (230,94, 227,31 e 233,50 mg/g) para as tr?s argilas. Os dados cin?ticos ajustaram-se
bem ?s isotermas de Langmuir e Freundlich. O modelo cin?tico que melhor se adequou aos
resultados foi o modelo pseudo-segunda ordem
|
69 |
Avalia??o da capacidade de adsor??o do CO2 em ze?lita 12X com gases sint?ticos e originados da pir?lise do lodo de esgotoLessa, Mayara de Oliveira 27 December 2012 (has links)
Made available in DSpace on 2014-12-17T15:01:31Z (GMT). No. of bitstreams: 1
MayaraOL_DISSERT.pdf: 2406797 bytes, checksum: e542f1e52029a933cac4b8af8d311ef3 (MD5)
Previous issue date: 2012-12-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This work depicts a study of the adsorption of carbon dioxide on zeolite 13X. The
activities were divided into four stages: study batch adsorption capacity of the adsorbent
with synthetic CO2 (4%), fixed bed dynamic evaluation with the commercial mixture of
gases (4% CO2, 1.11% CO, 1 2% H2, 0.233% CH4, 0.1% C3, 0.0233% C4 argon as inert
closing balance), fixed bed dynamic modeling and evaluation of the breakthrough curve
of CO2 originated from the pyrolysis of sewage sludge. The sewage sludge and the
adsorbent were characterized by analysis TG / DTA, SEM, XRF and BET. Adsorption
studies were carried out under the following operating conditions: temperature 40 ?C
(for the pyrolysis of the sludge T = 600 ?C), pressures of 0.55 to 5.05 bar (batch
process), flow rate of the gaseous mixture between 50 - 72 ml/min and the adsorbent
masses of 10, 15 and 20 g (fixed bed process). The time for the adsorption batch was 7
h and on the fixed bed was around 180 min. The results of this study showed that in
batch adsorption process step with zeolite 13X is efficient and the mass of adsorbed
CO2 increases with the increases pressure, decreases with temperature increases and
rises due the increase of activation temperature adsorbent. In the batch process were
evaluated the breakthrough curves, which were compared with adsorption isotherms
represented by the models of Langmuir, Fre?ndlich and Toth. All models well adjusted
to the experimental points, but the Langmuir model was chosen in view of its use in the
dynamic model does not have implications for adsorption (indeterminacy and larger
number of parameters such as occurred with others) in solving the equation. In the fixed
bed dynamic study with the synthetic gas mixture, 20 g of mass adsorbent showed the
maximum adsorption percentage 46.7% at 40 ?C temperature and 50 mL/min of flow
rate. The model was satisfactorily fitted to the three breakthrough curves and the
parameters were: axial dispersion coefficient (0.0165 dm2/min), effective diffusivity
inside the particle (dm2/min 0.0884) and external transfer coefficient mass (0.45
dm/min). The breakthrough curve for CO2 in the process of pyrolysis of the sludge
showed a fast saturation with traces of aerosols presents in the gas phase into the fixed
bed under the reaction process / O presente trabalho retrata um estudo da adsor??o de di?xido de carbono
em ze?lita comercial do tipo 13X. As atividades desenvolvidas foram divididas em
quatro etapas: estudo em batelada da capacidade de adsor??o do adsorvente com o CO2
sint?tico (4%), avalia??o din?mica em leito fixo com a mistura sint?tica de gases (4%
CO2, 1,11% CO, 1,2% H2, 0,233% CH4, 0,1% C3, 0,0233% C4 e arg?nio como inerte
fechando o balan?o), modelagem din?mica em leito fixo e avalia??o em leito fixo da
curva de ruptura do CO2 com o g?s de pir?lise do lodo de esgoto. O lodo e o adsorvente
foram caraterizados por an?lises TG/DTA, MEV, FRX e BET. Os estudos de adsor??o
foram realizados nas seguintes condi??es operat?rias: temperatura de 40 ?C (para a
pir?lise do lodo T = 600 ?C), press?o de 0,55 5,05 bar (processo batelada), vaz?o da
mistura gasosa entre 50 72 mL/min e massa de adsorvente igual a 10, 15 e 20 g
(processo em leito fixo). O tempo do processo de adsor??o em batelada foi de 7h e em
leito fixo foi em torno de 180 min. Os resultados obtidos nesta etapa mostraram que no
estudo batelada o processo de adsor??o com a ze?lita 13X ? eficiente e que a massa
adsorvida do CO2 aumenta com o crescimento da press?o, diminui com o aumento da
temperatura e se eleva com a temperatura de ativa??o do adsorvente. No processo
din?mico foram avaliadas as curvas de rupturas, as quais foram comparadas ?s
isotermas de adsor??o representadas pelos modelos de Langmuir, Fre?ndlich e Toth.
Todos os modelos se ajustaram bem aos pontos experimentais, por?m o modelo de
Langmuir foi o escolhido tendo em vista sua utiliza??o no modelo din?mico de adsor??o
n?o apresentar implica??es (indetermina??o e maior n?mero de par?metros como
ocorreu com os demais) na resolu??o da equa??o. No estudo din?mico em leito fixo
com a mistura de gases sint?ticos e diferentes massas de adsorvente, a massa de 20 g
apresentou maior percentual de adsor??o 46,7% na temperatura de 40 oC e vaz?o da
mistura gasosa de 50 mL/min. O modelo se ajustou satisfatoriamente para as tr?s curvas
de ruptura e os par?metros avaliados foram: coeficiente de dispers?o axial (0,0165
dm2/min), difusividade efetiva no interior da part?cula (0,0884 dm2/min) e coeficiente
externo de transfer?ncia de massa (0,45 dm/min). A curva de ruptura para o CO2
constru?da no processo de pir?lise do lodo mostrou uma r?pida satura??o do leito
proveniente de tra?os de aeross?is, presentes na fase gasosa, decorrentes do processo
reacional
|
70 |
Microemuls?es aplicadas ao tratamento de ?leos isolantesSilva, Ana Cristina Morais da 18 December 2006 (has links)
Made available in DSpace on 2014-12-17T15:01:43Z (GMT). No. of bitstreams: 1
AnaCMS.pdf: 1022234 bytes, checksum: 6525fbcf6f201d09af59285b78bcba6b (MD5)
Previous issue date: 2006-12-18 / Naphthenic lubricating oils are used in transformers with the purpose of promoting electrical
insulation and dissipating heat. The working temperature range of these oils typically lies
between 60?C and 90?C and their useful life is 40 years in average. In that temperature range,
the oils are decomposed during operation, whereby a small fraction of polar compounds are
formed. The presence of these compounds may induce failure and loss of physical, chemical
and electrical properties of the oil, thus impairing the transformer operation. By removing
these contaminants, one allows the oxidized insulating oil to be reused without damaging the
equipment. In view of this, an investigation on the use of surfactants and microemulsions as
extracting agents, and modified diatomite as adsorbent, has been proprosed in this work
aiming to remove polar substances detected in oxidized transformer oils. The extraction was
carried out by a simple-contact technique at room temperature. The system under examination
was stirred for about 10 minutes, after which it was allowed to settle at 25?C until complete
phase separation. In another experimental approach, adsorption equilibrium data were
obtained by using a batch system operating at temperatures of 60, 80 and 100?C. Analytical
techniques involving determination of the Total Acidity Number (TAN) and infrared
spectrophotometry have been employed when monitoring the decomposition and recovery
processes of the oils. The acquired results indicated that the microemulsion extraction system
comprising Triton? X114 as surfactant proved to be more effective in removing polar
compounds, with a decrease in TAN index from 0.19 to 0.01 mg KOH/g, which is consistent
with the limits established for new transformer oils (maximal TAN = 0.03 mg KOH/g). In the
adsorption studies, the best adsorption capacity values were as high as 0.1606 meq.g/g during
conventional adsoprtion procedures using natural bauxite, and as high as 0.016 meq.g/g for
the system diatomite/Tensiofix? 8426. Comparatively in this case, a negative effect could be
observed on the adsorption phenomenon due to microemulsion impregnation on the surface of
the diatomite / ?leos lubrificantes naft?nicos s?o usados em transformadores tem com a finalidade de promover um isolamento el?trico e agir como fonte dissipadora de calor. A temperatura de
trabalho destes ?leos est? entre 60 a 90?C e sua vida ?til ? de em m?dia 40 anos. Nesta temperatura, durante o servi?o, ocorre a degrada??o do ?leo, onde uma pequena fra??o de
compostos polares ? formada. A presen?a desta fra??o pode provocar falhas e a perda das propriedades f?sicas, qu?micas e el?tricas do ?leo, impossibilitando o uso do transformador. A
remo??o destes compostos permite que o ?leo isolante oxidado possa ser novamente utilizado, sem causar preju?zo ao equipamento. Nestes contexto, este trabalho prop?e-se a investigar a utiliza??o de tensoativos e microemuls?es, como extratantes, e a diatomita modificada, como adsorvente, na remo??o dos compostos polares existentes nos ?leos oxidados de transformador. A extra??o foi realizada pelo m?todo de contato simples ? temperatura ambiente. O sistema em estudo foi agitado por cerca de 10 minutos, em seguida mantido em repouso ? 25?C at? completa separa??o das fases. Por outro lado, os dados de equil?brio de
adsor??o foram obtidos utilizando um sistema em batelada para as temperaturas de 60, 80 e 100oC. As t?cnicas anal?ticas de IAT (?ndice de Acidez Total) e espectrofotometria no infravermelho foram utilizadas no acompanhamento dos processos de degrada??o e
recupera??o dos ?leos degradados. Os resultados obtidos indicam que o sistema de extra??o por microemuls?o utilizando triton X114 mostrou-se ser o m?todo mais eficiente na remo??o dos compostos polares, com redu??o no ?ndice de acidez total (IAT) de 0,19 para 0,01 mg KOH/g. Este valor se encontra dentro dos limites especificados para um ?leo de
transformador novo (IAT m?ximo = 0,03 mg KOH/g). Nos estudos de adsor??o, os maiores valores de capacidade de adsor??o foram de 0,1606 meq.g/g na adsor??o convencional usando bauxita natural e de 0,016 meq.g/g para o sistema diatomita/tensiofix 8426. Comparativamente, neste caso, observou-se um forte efeito negativo apresentado sobre o
fen?meno adsortivo devido ao processo de impregna??o com microemuls?o
|
Page generated in 0.0333 seconds