Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-04-03T19:41:30Z No. of bitstreams: 1 ArthurFelipeDeFariasMonteiro_DISSERT.pdf: 6373857 bytes, checksum: d6418f0c51f873b10d6e15be186817d7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-04-05T19:01:11Z (GMT) No. of bitstreams: 1 ArthurFelipeDeFariasMonteiro_DISSERT.pdf: 6373857 bytes, checksum: d6418f0c51f873b10d6e15be186817d7 (MD5) / Made available in DSpace on 2017-04-05T19:01:11Z (GMT). No. of bitstreams: 1 ArthurFelipeDeFariasMonteiro_DISSERT.pdf: 6373857 bytes, checksum: d6418f0c51f873b10d6e15be186817d7 (MD5) Previous issue date: 2016-04-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / As Redes Metalorg?nicas (Metal Organic Frameworks ? MOF?s) s?o materiais h?bridos, geralmente cristalinos, constitu?dos por ?tomos ou clusters met?licos, coordenados ? ligantes org?nicos polifuncionais, geralmente, observando-se a presen?a de poros/canais de dimens?es nanom?tricas. Suas estruturas s?o de baixa densidade em fun??o da porosidade, e apresentam alta ?rea superficial, bem como um grande volume de poro, o que ?s levam a lugar de destaque do ponto vista cient?fico-tecnol?gico, sendo aplic?veis na cat?lise, adsor??o, separa??o, estocagem de gases, entrega de f?rmacos, etc. Cu-MOF?s foram sintetizadas via m?todo eletroqu?mico a partir de dois ligantes distintos, 1,3-H2BDC e 1,4-H2BDC. Os par?metros sint?ticos empregados, tais como, meio reacional (raz?o H2O/DMF), diferen?a de potencial e corrente el?trica, foram avaliados e sua influ?ncia sobre a estrutura cristalina determinada. Os materiais foram obtidos em uma hora, sugerindo que esta ? uma rota cineticamente vantajosa para a obten??o de redes metalorg?nicas de cobre. O produto da s?ntese da rede Cu(1,4-BDC) ? composto de duas estruturas cristalinas lamelares (em camadas) e microporosas. A cristaliza??o destas diferentes estruturas est? diretamente relacionada ao valor de corrente el?trica empregada. As duas estruturas se diferenciam basicamente pelo deslocamento entre camadas consecutivas, 60? e 120?, respectivamente. O deslocamento das camadas resultou em estruturas com diferentes volumes de canais, sendo a estrutura com deslocamento de 60? a que apresenta canais com maior volume, mais indicado para a adsor??o. Essa estrutura, denominada Cu(1,4-BDC) 2, foi aplicada na adsor??o de azul de metileno, sendo avaliadas as influ?ncias de pH, temperatura e concentra??o. Observou-se que valores de pH entre 5,0 e 6,0 promovem uma melhor adsor??o. Diferentes condi??es foram testadas, tais como concentra??es entre 25 e 250 mg/L e temperaturas entre 293,15 e 313,15 K. Adicionalmente, tamb?m foram avaliados fatores cin?ticos, termodin?micos e de equil?brio para a adsor??o. Constatou-se que o modelo cin?tico de pseudo-segunda ordem ? o mais compat?vel com o processo. Para os fatores termodin?micos, verificou-se que o processo ? exot?rmico, espont?neo e com maior efici?ncia ? uma temperatura de 293,15 K. Foram testados dois modelos de isotermas, o de Langmuir e o de Freundlich, sendo o modelo de Langmuir o que apresentou maior compatibilidade, prognosticando uma capacidade adsortiva m?xima te?rica de 76,63 ?mol/g, sendo que para as condi??es otimizadas (14 horas), a capacidade experimentalmente obtida foi de 75,91 ?mol/g, (99,06% do valor te?rico). Foram realizados ensaios de reuso do material, onde foi constatada uma efici?ncia superior ? 60% para at? quatro ciclos de adsor??o/dessor??o. / The metal organic frameworks (MOF's) are hybrid materials, generally crystalline, consisting of metallic atoms or metallic clusters, coordinated to polyfunctional organic ligands, generally observing the presence of pores/channels in nanometer dimensions. Their structures shows low density due to the porosity, have high surface area and a high pore volume, which lead to the prominent place of scientific-technological area, applicable in various fields as catalysis, adsorption, separation, gases storage, drug delivery, etc. Cu-MOFs were synthesized by the electrochemical method, using the 1,3-H2BDC and 1,4-H2BDC linkers in different H2O/DMF solvent proportions. The influence of electrochemical variables of process, such as voltage and electric current, and their influence on the final structure of the material was examined. The materials were obtained within one hour, showing that this method is kinetically advantageous for the preparation of the copper network. The product of the synthesis of Cu (1,4-BDC) network is composed of two lamellar (layered) and microporous crystalline structures. The formation of different structures are directly relate to the electrical current condition imposed on the synthesis. The two structures differ mainly by the displacement between subsequent layers, 60? and 120?, respectively. The displacement of the layers resulted in structures with different channels volumes, where the structure with 60? of displacement presents channels with greater volume, what may be applicable in adsorption. This structure, called Cu(1,4-BDC)2, was applied for the blue methylene adsorption, where the study of the influence of pH, temperature and concentration was performed. It revealed that for pH values between 5.0 and 6.0 there is an increased amount of the adsorbed dye. Different conditions were tested, such as concentrations between 25 and 250 mg/L and temperatures between 293.15 and 313.15 K. Varying concentrations of the dye solution, the kinetic factors, thermodynamic and equilibrium for adsorption, were evaluated. It was find that the kinetic model of pseudo-second order is the most compatible with the process. For the thermodynamic factors, it was find that the process is exothermic, spontaneous and has the highest efficiency at 293.15 K. Two models were tested for adsorption isotherm, the Langmuir and Freundlich, and the most compatible with the data was the Langmuir model, theoretically predicting a maximum adsorption capacity of 76.63 ?mol/g, and for the optimized conditions (14 hours), the capacity obtained experimentally was 75.91 ?mol/g, (99.06% theoretical). Reuse tests of the material were carried out and it was found that the material can reach the reuse efficiencies higher than 60% for up to four adsorption/desorption recycles.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-02T19:56:10Z No. of bitstreams: 1 AnaLauraOliveiraDeSaLeitao_DISSERT.pdf: 2567835 bytes, checksum: 8d09f5d4c4935ef58bb6215cd5a73b5f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-06T00:09:33Z (GMT) No. of bitstreams: 1 AnaLauraOliveiraDeSaLeitao_DISSERT.pdf: 2567835 bytes, checksum: 8d09f5d4c4935ef58bb6215cd5a73b5f (MD5) / Made available in DSpace on 2017-06-06T00:09:33Z (GMT). No. of bitstreams: 1 AnaLauraOliveiraDeSaLeitao_DISSERT.pdf: 2567835 bytes, checksum: 8d09f5d4c4935ef58bb6215cd5a73b5f (MD5) Previous issue date: 2017-02-08 / Com o desenvolvimento da ind?stria biotecnol?gica, ? crescente o interesse por ant?genos recombinantes purificados para obten??o de vacinas. Por?m, para essa aplica??o esses ant?genos precisam apresentar um elevado grau de pureza, e por isso ? de grande relev?ncia o desenvolvimento de t?cnicas que permitam a redu??o do n?mero de opera??es unit?rias necess?rias ao processo de purifica??o, permitindo ainda uma elevada recupera??o e proporcionando uma maior economia na obten??o dos bioprodutos. A Adsor??o em Leito Expandido (ALE) vem se destacando como uma alternativa prop?cia para o downstream processing, pois ? uma t?cnica cromatogr?fica de modo simples e de baixo custo, que integra as etapas de clarifica??o, concentra??o, purifica??o em uma ?nica opera??o. Neste contexto, o presente trabalho tem como objetivo avaliar os m?todos de rompimento celular e os diferentes metais imobilizados em resina Streamline chelating para purifica??o do ant?geno 503 de Leishmania i. chagasi por ALE bem como remover os lipopolissacar?deos (LPS) liberados durante a etapa de rompimento celular. Primeiramente, foi avaliado qual o melhor m?todo de rompimento celular para obten??o da prote?na intracelular. As estrat?gias estudadas utilizando lisozima, p?rolas de vidro, ureia e EDTA foram avaliadas atrav?s de quatro planejamentos experimentais. Em seguida, foram realizados testes de adsor??o em batelada, utilizando-se cinco ?ons met?licos (Cu2+, Ni2+, Zn2+, Co2+ e Fe3+) nas concentra??es de 0,1, 0,5 e 0,8 mol/L acoplados na resina Streamline chelating, escolhendo-se o metal que apresentou melhor adsor??o do ant?geno para os ensaios usando ALE. Posteriormente, foi estimada a quantidade m?nima de tensoativo Triton X-114 necess?ria na etapa de lavagem da ALE para remo??o do LPS, a fim de obter-se o ant?geno 503 livre desse contaminante. E por fim, foram realizados ensaios de ALE visando recuperar e purificar a prote?na de interesse. Para os ensaios usando ALE utilizou-se uma coluna de 2,6 cm de di?metro por 30 cm de altura, acoplada a uma bomba perist?ltica. Com os planejamentos experimentais realizados para avalia??o do rompimento celular, observou-se que maiores quantidades de prote?nas totais e do ant?geno 503 liberadas foram obtidas para o m?todo da ureia e que o ?nico fator significativo para esse planejamento foi a concentra??o, correspondente a 8,0 M. Como resultado para a triagem do ?on met?lico, o cobre (Cu2+) foi o metal que apresentou maior capacidade de adsor??o do ant?geno 503, apresentando valores de capacidade de adsor??o de 0,102, 0,128 e 0,111 mg/mL de adsorvente para as concentra??es de 0,1, 0,5 e 0,8 mol/L, respectivamente. Tem-se ainda que para as tr?s condi??es analisadas (0,01, 0,05 e 0,1 % de Triton X-114) na etapa de lavagem da ALE o percentual de remo??o de LPS foi elevado e que a concentra??o m?nima utilizada (0,01 %) j? foi suficiente para a remo??o de 99,70 % deste contaminante. Para o teste de ALE utilizando elui??o isocr?tica (0,6 M de imidazol) os resultados obtidos mostraram baixa recupera??o (3,0 %) do ant?geno 503. Avaliou-se ent?o a elui??o em degrau, inicialmente em dois passos, aplicando-se 0,6 mol/L e, em seguida, 1,0 mol/L de imidazol. Por?m, esta estrat?gia ainda n?o foi eficiente para recuperar a prote?na de interesse. Um novo ensaio foi realizado, com um total de tr?s passos de elui??o, utilizando 0,3 e 0,6 mol/L. Esse ?ltimo teste mostrou uma recupera??o de 15,0 % da prote?na de interesse e um fator de purifica??o de, aproximadamente, 3,0. Portanto, a t?cnica cromatogr?fica de afinidade por ?ons met?licos imobilizados (IMAC) mostrou ser uma alternativa eficiente na recupera??o e purifica??o do ant?geno 503 a partir do homogeneizado de E. coli n?o clarificado. / Due to the development of biotechnology industry, there is a growing interest in purified recombinant antigens to obtain vaccines. However, for this application these antigens require a high degree of purity, thus, it is of great relevance the development of techniques that allow the reduction in the number of unitary operations required for the purification process, this would also allow a high recovery and a greater saving in obtaining bioproducts. The Expanded Bed Adsorption (EBA) has shown as a suitable alternative for downstream processing, once it is a simple and low cost chromatographic technique that integrates clarification, concentration and purification in a single operation. This study aims at evaluating the methods of cell disruption and the different metals immobilized in Streamline Chelating resin for purification of Leishmania i. chagasi 503 antigen by EBA as well as removing the lipopolysaccharides (endotoxin) released during the stage of cell disruption. Firstly, the best method of cell disruption to obtain intracellular protein was evaluated. The strategies studied using lysozyme, glass beads, urea and EDTA were evaluated through four experimental designs. Then, batch adsorption tests were carried out using five metal ions (Cu2+, Ni2+, Zn2+, Co2+ and Fe3+) at concentrations of 0.1, 0.5 and 0.8 M coupled in the Streamline chelating resin, selecting the metal that showed the best adsorption of the antigen for the assays using EBA. Then, the minimum amount of Triton X-114 tensioactive required in the EBA wash stage for LPS removal was estimated in order to obtain the 503 antigen free of this contaminant. Finally, EBA assays were performed in order to recover and purify the protein of interest. EBA experiments were carried out using a column of 2.6 cm in diameter (30 cm height), coupled to a peristaltic pump. The experimental plannings carried out to evaluate cell disruption, showed that higher amounts of total proteins and 503 antigen released were obtained for the urea method and that the only significant factor for this planning was the concentration corresponding to 8.0 M. As a result of the metal ion screening, copper (Cu2+) was the metal with the highest adsorption capacity of 503 antigen, presenting adsorption capacity values of 0.102, 0.128 and 0.111 mg / mL of adsorbent at concentrations of 0.1, 0.5 and 0.8 M, respectively. For the three analyzed conditions (0.01, 0.05 and 0.1% Triton X-114) in the EBA washing stage, the percentage of LPS removal was high and the minimum concentration used (0.01%) was enough to remove 99.70% of this contaminant. For the EBA test using isocratic elution (0.6 M imidazole) the results obtained showed a low recovery (3.0 %) of the 503 antigen. The step elution was then evaluated, initially in two steps, applying 0.6 M and then 1.0 M imidazole. However, this strategy has not yet been effective in recovering the protein of interest. A new assay was performed, with a total of three elution steps, using 0.3 and 0.6 M. This test showed that a recovery of 15.0% of the protein of interest and a purification factor of 3.0. Therefore, the immobilized metal ion affinity chromatography (IMAC) technique has been shown to be an efficient alternative in the recovery and purification of the 503 antigen from the homogenized E. coli unclarified.

Made available in DSpace on 2014-12-17T15:41:49Z (GMT). No. of bitstreams: 1 DanyelleMA_DISSERT.pdf: 886887 bytes, checksum: bdfc465050e9656b4d629363ccd362a0 (MD5) Previous issue date: 2010-07-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Corrosion inhibitors in solution are utilized to minimize processes from corrosion in steel. Of the present dissertation was evaluated the efficiency by inhibition from the surfactant saponified coconut oil (OCS) in the carbon steel 1020 through in linear polarization electrochemistry technique, well as, studied the process from adsorption through from the isotherms from Langmuir, Frumkin and Temkin. The corrosion current was determined through in Tafel extrapolation from the curves in the polarization, and then, was calculated the efficiency in the inhibitor to each concentration and temperature. Were studied four concentrations (12,5 ppm, 25 ppm, 50 ppm, and 75 ppm) in the inhibitor OCS and one in the NaCl salt (10.000 ppm) in six temperatures (301 K, 308 K, 313 K, 318 K, 323 K, and 328 K) in triplicate. By the results obtained observed that the technique applied can evaluated with rapidity and efficiency corrosion inhibitors. In relation to the isotherms, the than best appropriated was the in Langmuir and in the concentrations studied, the that obtained the best efficiency was the concentration of 75 ppm / Inibidores de corros?o em solu??o s?o utilizados para minimizar processos de corros?o em a?o. Na presente disserta??o foi avaliada a efici?ncia de inibi??o do tensoativo ?leo de coco saponificado (OCS) no a?o carbono 1020, atrav?s da t?cnica eletroqu?mica polariza??o linear, bem como, estudado o processo de adsor??o atrav?s das isotermas de Langmuir, Frumkin e Temkin. A corrente de corros?o foi determinada atrav?s da extrapola??o de Tafel nas curvas de polariza??o e, ent?o, foi calculada a efici?ncia do inibidor para cada concentra??o e temperatura. Foram estudadas quatro concentra??es (12,5, 25,0, 50,0 e 75,0 ppm) do inibidor OCS e uma do sal NaCl (10.000 ppm) em seis temperaturas (301, 308, 313, 318, 323 e 328 K) em triplicata. Pelos resultados obtidos, observou-se que a t?cnica utilizada pode avaliar com rapidez e efici?ncia inibidores de corros?o. Em rela??o ?s isotermas, a que melhor se adequou foi a de Langmuir e dentre as concentra??es estudadas a que obteve a melhor efici?ncia foi ? concentra??o de 75 ppm

Made available in DSpace on 2014-12-17T15:41:57Z (GMT). No. of bitstreams: 1 RobertoRCL_DISSERT.pdf: 1216220 bytes, checksum: 291b5b64177a1fbc1bc254c50866a9c9 (MD5) Previous issue date: 2012-05-23 / The phenomenon of adsorption is of fundamental importance for the treatment of textile effluents and removal of dyes. Chitosan is characterized as an excellent adsorbent material, not only for its adsorption capacity but also the low cost production. Equilibrium and kinetic studies were developed in this study to describe the mechanism of adsorption of the anionic azo dye Orange G in chitosan, with the isotherms obtained from the variation of the concentration of dye in the continuous phase. The kinetics of the process was analyzed based on models involving the adsorption of molecules of the dye in nonpolar and polar sites. Adsorption experiments were carried out in water and in saline media with different NaCl concentrations, both for the determination of the equilibrium time as isotherms for making kinetic curves in which the amount of dye adsorbed measured indirectly varied with time. The experiments revealed the opening of the biopolymer structure with increasing concentration of Orange G, accompanied by high pH values and change on the type of interaction between the dye and the adsorbent surface, suggesting behavior advocated by the Langmuir equation in a certain range of concentration of the adsorbate and following the Henry's Law at higher concentrations, from the increased number of sites available for adsorption. The studies conducted showed that the saline medium reduces the chitosan s adsorption capacity according to a certain concentration, the occurrence of the cooperative adsorption process steps kinetic mechanism suggested as a new alternative for the interpretation of the phenomenon / O fen?meno da adsor??o ? de fundamental import?ncia no tratamento de efluentes t?xteis e remo??o de corantes. A quitosana caracteriza-se como excelente material adsorvente, n?o s? pela sua capacidade de adsor??o mas tamb?m pelo baixo custo de obten??o. Estudos cin?ticos e de equil?brio foram desenvolvidos neste trabalho para descrever o mecanismo de adsor??o do azo-corante ani?nico Alaranjado G em quitosana, com a obten??o de isotermas a partir da varia??o da concentra??o de corante na fase cont?nua. A cin?tica do processo foi analisada a partir de modelos envolvendo a adsor??o de mol?culas do corante em dois tipos de s?tios: polares e apolares. Experimentos de adsor??o foram desenvolvidos em ?gua e em meios salinos com diferentes concentra??es de NaCl, tanto para a determina??o do tempo de equil?brio como para a confec??o de isotermas e curvas cin?ticas nas quais a quantidade de corante adsorvido, medida de forma indireta, variou em fun??o do tempo. Os experimentos revelaram abertura da estrutura do biopol?mero com a eleva??o da concentra??o do Alaranjado G, acompanhada pela eleva??o do pH e modifica??o no tipo de intera??o entre o corante e a superf?cie do adsorvente, sugerindo comportamento preconizado pela equa??o de Langmuir em certa faixa de concentra??o do adsorvato e obedecendo ? lei de Henry em concentra??es mais elevadas, a partir do aumento do n?mero de s?tios dispon?veis para a adsor??o. Os estudos desenvolvidos mostraram que o meio salino reduz a capacidade de adsor??o do Alaranjado G em quitosana e pode impedir, em certa concentra??o, a ocorr?ncia de processo cooperativo de adsor??o conforme mecanismo cin?tico em etapas sugerido como uma nova alternativa para a interpreta??o do fen?meno

Made available in DSpace on 2014-12-17T15:42:21Z (GMT). No. of bitstreams: 1 JoseCVM_TESE_capa_ate_pag128.pdf: 3265790 bytes, checksum: 756c257ab1c64e4914df34565709a45f (MD5) Previous issue date: 2013-07-31 / In this work were synthesized the materials called vanadyl phosphate, hydrogen vanadyl phosphate and vanadyl phosphate doped by transition metals with the aim in adsorption the following compounds: ammonia, hydrogen sulfide and nitrogen oxide. To characterize the starting compounds was used DRX, FTIR, FRX and TG analysis. After the characterization of substrates, proceeded de adsorption of NH3 and H2S gases in reactor, passing the gases with continuous flow for 30 min and room temperature. Gravimetric data indicate that the matrices of higher performance in adsorption of ammonia was those doped by aluminum and manganese, obtaining results of 216,77 mgNH3/g and 200,40 mgNH3/g of matrix, respectively. The matrice of higher performance in adsorption of hydrogen sulfide was that doped by manganese, obtaining results of 86,94 mgH2S/g of matrix. The synthesis of substrates VOPO4.2H2O and MnVOPO4.2H2O with nitrogen oxide was made in solution, aiming the final products VOPO4.G.nH2O and MnVOPO4.G.nH2O (G = NO and n = number of water molecules). The thermo analytical behavior and the infrared spectroscopy are indicative of formation of VOPO4.2,5NO.3H2O compound. Results of scanning electron microscopy (SEM) and Energy dispersive spectroscopy (EDS) of materials vanadyl phosphate and vanadyl phosphate modified after reaction in solid state or in solution with the gases show morphology changes in substrates, beyond the formation of orthorhombic sulfur crystals over their respective hosts when these adsorb hydrogen sulfide / Neste trabalho foram sintetizados os materiais denominados fosfato de vanadila, hidrogeno fosfato de vanadila e fosfatos de vanadila dopados por metais de transi??o com fins na adsor??o de am?nia, sulfeto de hidrog?nio e ?xido de nitrog?nio. Para a caracteriza??o dos compostos de partida, recorre-se ?s t?cnicas de DRX, FTIR, FRX e TG. Ap?s a caracteriza??o dos substratos, procedeu-se a adsor??o dos gases NH3 e H2S em reator, passando os gases a vaz?o cont?nua durante 30 min e temperatura ambiente. Dados gravim?tricos indicam que as matrizes de maior desempenho na adsor??o de am?nia foram ?quelas dopadas por alum?nio e mangan?s, obtendo resultado de 216,77 mgNH3/g e 200,40 mgNH3/g de matriz, respectivamente. A matriz de maior desempenho para a adsor??o de sulfeto de hidrog?nio foi ?quela dopada por mangan?s, obtendo resultado de 86,94 mgH2S/g de matriz. As s?nteses dos substratos VOPO4.2H2O e MnVOPO4.2H2O com o g?s ?xido de nitrog?nio foram realizadas em solu??o, objetivando-se os produtos finais VOPO4.G.nH2O e MnVOPO4.G.nH2O (G = NO e n = n?mero de mol?culas de ?gua). O comportamento termoanal?tico e a espectroscopia na regi?o do infravermelho s?o indicativos da forma??o do composto VOPO4.2,5NO.3H2O. Resultados de microscopia eletr?nica de varredura (MEV) e espectroscopia de energia dispersiva (EDS) dos materiais fosfatos de vanadila e fosfatos de vanadila dopados ap?s rea??o no estado s?lido ou em solu??o com os gases indicam mudan?a na morfologia dos substratos, al?m da forma??o de cristais de enxofre ortorr?mbico sobre seus respectivos hospedeiros quando estes adsorvem sulfeto de hidrog?nio

Made available in DSpace on 2014-12-17T15:42:27Z (GMT). No. of bitstreams: 1 SamantaCC_TESE.pdf: 1799576 bytes, checksum: cb7da23d45f604db518addfb2da4a069 (MD5) Previous issue date: 2013-06-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Soil contamination by pesticides is an environmental problem that needs to be monitored and avoided. However, the lack of fast, accurate and low cost analytical methods for discovering residual pesticide in complex matrices, such as soil, is a problem still unresolved. This problem needs to be solved before we are able to assess the quality of environmental samples. The intensive use of pesticides has increased since the 60s, because the dependence of their use, causing biological imbalances and promoting resistance and recurrence of high populations of pests and pathogens (upwelling). This has contributed to the appearance of new pests that were previously under natural control. To develop analytical methods that are able to quantify residues pesticide in complex environment. It is still a challenge for many laboratories. The integration of two analytical methods one ecotoxicological and another chemical demonstrates the potential for environmental analysis of methamidophos. The aim of this study was to evaluate an ecotoxicological method as "screening" analytical methamidophos in the soil and perform analytical confirmation in the samples of the concentration of the analyte by chemical method LC-MS/MS In this work we tested two soils: a clayey and sandy, both in contact with the kinetic methamidophos model followed pseudo-second order. The clay soil showed higher absorption of methamidophos and followed the Freundlich model, while the sandy, the Langmuir model. The chemical method was validated LC-MS/MS satisfactory, showing all parameters of linearity, range, precision, accuracy, and sensitivity adequate. In chronic ecotoxicological tests with C. dubia, the NOEC was 4.93 and 3.24 for ng L-1 of methamidophos to elutriate assays of sandy and clay soils, respectively. The method for ecotoxicological levels was more sensitive than LC-MS/MS detection of methamidophos, loamy and sandy soils. However, decreasing the concentration of the standard for analytical methamidophos and adjusting for the validation conditions chemical acquires a limit of quantification (LOQ) in ng L-1, consistent with the provisions of ecotoxicological test. The methods described should be used as an analytical tool for methamidophos in soil, and the ecotoxicological analysis can be used as a "screening" and LC-MS/MS as confirmatory analysis of the analyte molecule, confirming the objectives of this work / A contamina??o de solos por agrot?xicos ? um problema ambiental que precisa ser monitorado e evitado. Por?m, a falta de m?todos de an?lise r?pidos, precisos e de baixo custo, para res?duos de agrot?xicos em matrizes complexas, como o solo, ? um problema ainda sem solu??o e precisa ser resolvido para que se possa avaliar a qualidade de amostras ambientais. O uso intensivo de agrot?xicos tem aumentado desde a d?cada de 60, causando a depend?ncia do seu uso, provocando desequil?brios biol?gicos e favorecendo a resist?ncia e a reincid?ncia de altas popula??es das pragas e pat?genos (ressurg?ncia), o que contribui com o aparecimento de novas pragas que anteriormente estavam sob o controle natural. O desenvolvimento de m?todos anal?ticos que atendam as legisla??es ambientais de quantificar res?duos de pesticidas em matrizes complexas ambientais continua sendo um desafio para v?rios laborat?rios. O objetivo deste trabalho foi avaliar um m?todo ecotoxicol?gico como screening anal?tico do metamidof?s em solos e realizar a confirma??o anal?tica das concentra??es do analito nas amostras pelo m?todo qu?mico LC-MS/MS.A integra??o de dois m?todos anal?ticos, um ecotoxicol?gico e outro qu?mico, demonstra potencial para a an?lise ambiental do metamidof?s. Neste trabalho foram testados dois solos: um argiloso e outro arenoso, ambos seguiram o modelo cin?tico de pseudo-segunda ordem para a adsor??o do metamidof?s. O solo argiloso apresentou maior adsor??o de metamidof?s e seguiu o modelo de Freundlich, enquanto o arenoso, o modelo de Langmuir. O m?todo qu?mico LC-MS/MS validado foi satisfat?rio, apresentando todos os par?metros de linearidade, intervalo, precis?o, exatid?o e sensibilidade adequados. Nos ensaios ecotoxicol?gicos cr?nicos com Ceriodapnhia dubia, as CENO foram 4,93 e 3,24 ng L-1 de metamidof?s para os elutriatos dos solos arenoso e argiloso, respectivamente. O m?todo ecotoxicol?gico apresentou-se mais sens?vel que o LC-MS/MS na detec??o do metamidof?s, nos solos argiloso e arenoso. No entanto, diminuindo-se a concentra??o do padr?o anal?tico do metamidof?s e ajustando-se as condi??es de valida??o qu?mica, adquire-se um limite de quantifica??o (LOQ) em ng L-1, compat?vel com o estabelecido no ensaio ecotoxicol?gico. Os m?todos utilizados apresentam-se como uma boa ferramenta anal?tica para o metamidof?s em solos, sendo que a an?lise ecotoxicol?gica poder? ser utilizada como um screening e o LC-MS/MS como an?lise confirmat?ria da mol?cula do analito, confirmando os objetivos desse trabalho

Made available in DSpace on 2014-12-17T15:42:29Z (GMT). No. of bitstreams: 1 MarcelaNB_TESE.pdf: 4650032 bytes, checksum: 4b8ec547749f785718e5f099093fa925 (MD5) Previous issue date: 2013-09-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Intensive use of machinery and engines burning fuel dumps into the atmosphere huge amounts of carbon dioxide (CO2), causing the intensification of the greenhouse effect. Climate changes that are occurring in the world are directly related to emissions of greenhouse gases, mainly CO2, gases, mainly due to the excessive use of fossil fuels. The search for new technologies to minimize the environmental impacts of this phenomenon has been investigated. Sequestration of CO2 is one of the alternatives that can help minimize greenhouse gas emissions. The CO2 can be captured by the post-combustion technology, by adsorption using adsorbents selective for this purpose. With this objective, were synthesized by hydrothermal method at 100 ?C, the type mesoporous materials MCM - 41 and SBA-15. After the synthesis, the materials were submitted to a calcination step and subsequently functionalized with different amines (APTES, MEA, DEA and PEI) through reflux method. The samples functionalized with amines were tested for adsorption of CO2 in order to evaluate their adsorption capacities as well, were subjected to various analyzes of characterization in order to assess the efficiency of the method used for functionalization with amines. The physic-chemical techniques were used: X- ray diffraction (XRD), nitrogen adsorption and desorption (BET/BJH), scanning electron microscopy (SEM), transmission electron microscopy (TEM), CNH Analysis, Thermogravimetry (TG/DTG) and photoelectron spectroscopy X-ray (XPS). The CO2 adsorption experiments were carried out under the following conditions: 100 mg of adsorbent, at 25 ?C under a flow of 100 ml/min of CO2, atmospheric pressure and the adsorption variation in time 10-210 min. The X-ray diffraction with the transmission electron micrographs for the samples synthesized and functionalized, MCM-41 and SBA-15 showed characteristic peaks of hexagonal mesoporous structure formation, showing the structure thereof was obtained. The method used was efficient reflux according to XPS and elemental analysis, which showed the presence of amines in the starting materials. The functionalized SBA -15 samples were those that had potential as best adsorbent for CO2 capture when compared with samples of MCM-41, obtaining the maximum adsorption capacity for SBA-15-P sample / A intensa utiliza??o de m?quinas e motores queimando combust?veis despeja na atmosfera imensas quantidades de di?xido de carbono (CO2), causando a intensifica??o do Efeito Estufa. As mudan?as clim?ticas que v?m ocorrendo no mundo est?o diretamente relacionadas ?s emiss?es de gases de efeito estufa, principalmente CO2, devido, sobretudo, ao uso excessivo de combust?veis f?sseis. A busca por novas tecnologias para minimizar os impactos ambientais decorrentes deste fen?meno vem sendo investigadas. O sequestro de CO2 ? uma das alternativas que pode ajudar a minimizar as emiss?es desses gases. O CO2 pode ser capturado pela tecnologia p?s-combust?o, atrav?s do processo de adsor??o, utilizando adsorventes seletivos para este fim. Com este objetivo, foram sintetizados, pelo m?todo hidrot?rmico a 100?C, materiais mesoporosos do tipo MCM-41 e SBA-15. Ap?s as s?nteses os materiais foram submetidos ? etapa de calcina??o e, posteriormente, funcionalizados com diferentes tipos de aminas (APTES, MEA, DEA e PEI), atrav?s do m?todo de refluxo. As amostras funcionalizadas com as aminas foram testadas nos ensaios de adsor??o de CO2 afim de avaliar suas capacidades de adsor??o, bem como, foram submetidas a diversas an?lises de caracteriza??o no intuito de avaliar a efici?ncia do m?todo utilizado para a funcionaliza??o com as aminas. As t?cnicas f?sico-qu?micas utilizadas foram: Difra??o de Raios-X (DRX), Adsor??o e Dessor??o de nitrog?nio (BET/BJH), Microscopia eletr?nica de varredura (MEV), Microscopia eletr?nica de transmiss?o (MET), An?lise elementar CNH, Termogravimetria (TG/DTG) e Espectroscopia fotoeletr?nica de Raios-X (XPS). Os ensaios de adsor??o de CO2 foram realizados nas seguintes condi??es: 100 mg de adsorvente, temperatura de 25 ?C sob fluxo de 100 mL/min de CO2, press?o atmosf?rica e com varia??o no tempo de adsor??o de 10 a 210 min. Os difratogramas de Raios-X juntamente com as micrografias eletr?nicas de transmiss?o para as amostras sintetizadas e funcionalizadas, MCM-41 e SBA-15, apresentaram os picos caracter?sticos da forma??o de estrutura mesoporosa hexagonal, evidenciando que a estrutura do mesmo foi obtida. O m?todo de refluxo utilizado foi eficiente segundo as an?lises de elementar e XPS, na qual, mostrou a presen?a das aminas nos materiais de partida. As amostras funcionalizadas de SBA-15 foram as que tiveram melhor potencial como adsorvente para captura de CO2 quando comparadas com as amostras de MCM-41, obtendo a m?xima capacidade de adsor??o para a amostra SBA-15-P

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-01-20T13:13:06Z No. of bitstreams: 1 2013 - Mauro Meliga Wysard Junior.pdf: 3560905 bytes, checksum: 2826a580c7e2ec9ebe3a9e07daacb4f7 (MD5) / Made available in DSpace on 2017-01-20T13:13:06Z (GMT). No. of bitstreams: 1 2013 - Mauro Meliga Wysard Junior.pdf: 3560905 bytes, checksum: 2826a580c7e2ec9ebe3a9e07daacb4f7 (MD5) Previous issue date: 2013-10-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The need to reduce environmental impacts while maintaining economic efficiency of various processes has motivated research to develop cheaper and sustainable technologies, to replace those already employed in the industrial sectors. Thus, recycling and utilization of natural materials such as coconut fiber or marine animal shells, is envisioned as an alternative to reduce the environmental impact and at the same time the use of these components in industrial processes reduces operational costs. In this context the biosorbents are included, such as coconut fibers and chitosan, which have high applicability to processes for removing metal ions, and are widely available at low cost. In addition, the problem found in the recovery of these adsorbents and adsorbate after the adsorption process can be bypassed by setting biosorbents in polymeric matrixes, obtaining larger parts, which facilitates the separation steps. Thus, this work aims to develop porous composite adsorbent properties, from the physical mixture of maleic anhydride polyethylene (PE-g-MA), coconut fiber (FC), chitosan (Q), and sodium chloride (NaCl) used as porogen agent), and assess the capacity of these new porous composite in the removal of metallic chromium (III) Ion, since this is a residue present in large industrial activities such as electroplating. The porosity of this material was obtained by leaching of NaCl, present in the composition of composite material. For this assessment, we conducted a trial planning, where could be evaluate the influence of particle size of coconut fiber and the amount of chitosan on adsorption process efficiency, as well as the pH of an aqueous solution containing the chromium (III) adsorbate. With the results could be concluded that the model used in planning was valid for the evaluation of the significance of these variables, as well as the trend of better removal of chromium (III), which took place in the higher pH values (between 6 and 7) and in the presence of increased amounts of chitosan (7.5-8.6 g). The granulometric size range of coconut fiber that was more favorable was between 0.097-0.142 mm. Analyzing these porous composites by spectroscopy in the infrared (FTIR), X-ray diffraction (XRD), water absorption and scanning electron microscopy (SEM), you can see and confirm the strong interaction between the components of the mixture, possibly by interfering in the process efficiency of adsorption of chromium / A necessidade de reduzir impactos ambientais e ao mesmo tempo manter a efici?ncia econ?mica de diversos processos, vem motivando o meio acad?mico a realizar pesquisas voltadas para o desenvolvimento de novas tecnologias mais baratas e sustent?veis, que possam substituir as j? empregadas nos setores industriais. Desta forma, a reciclagem e a utiliza??o de mat?rias-primas naturais como a casca de coco e carapa?as de animais marinhos ? vislumbrada como uma alternativa para a redu??o do impacto ambiental, e ao mesmo tempo, pela utiliza??o desses componentes em processos industriais com a finalidade de reduzir custos operacionais. Neste contexto encontram-se os biossorventes naturais, como a fibra de coco e a quitosana, que apresentam alta aplicabilidade em processos de remo??o de ?ons met?licos, e uma grande disponibilidade a baixo custo. Al?m disso, o problema encontrado na recupera??o desses adsorventes e do adsorvato ap?s o processo de adsor??o pode ser contornado pela fixa??o dos biossorventes em matrizes polim?ricas, obtendo-se pe?as de maior volume, o que facilita as etapas de separa??o. Assim, este trabalho teve como objetivo desenvolver comp?sitos porosos com propriedades adsorventes, a partir da mistura f?sica de polietileno graftizado com anidrido maleico (PE-g-MA), fibra de coco (FC), quitosana (Q) e cloreto de s?dio (NaCl) utilizado como agente porog?nico), e avaliar a capacidade de adsor??o desses novos comp?sitos porosos na remo??o do ?on met?lico cromo (III), j? que este, ? um res?duo presente em grandes atividades industriais, como a galvanoplastia. Com esta finalidade, foi realizado um planejamento experimental, onde foi avaliada a influ?ncia do tamanho das part?culas de fibra de coco e da quantidade de quitosana na efici?ncia do processo de adsor??o, assim como o pH da solu??o aquosa contendo o adsorvato cromo (III). Com os resultados pode-se concluir que o modelo usado no planejamento experimental foi v?lido para a avalia??o da signific?ncia dessas vari?veis, como para as melhores condi??es de remo??o do cromo (III), as quais aconteceram nos valores mais elevados de pH (entre 6 e 7) e na presen?a de maiores quantidades de quitosana (7,5-8,6 g). A faixa granulom?trica da fibra de coco que se mostrou mais favor?vel foi de 0,097-0,142 mm. Analisando esses comp?sitos porosos por espectroscopia na regi?o do infravermelho (FTIR), difra??o de raios-X (DRX), absor??o de ?gua e microscopia eletr?nica de varredura (MEV), p?de-se constatar e confirmar a forte intera??o ocorrida entre os componentes da mistura, possivelmente, interferindo na efici?ncia do processo de adsor??o do cromo (III).

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-09T20:05:40Z No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) / Made available in DSpace on 2017-05-09T20:05:40Z (GMT). No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) Previous issue date: 2016-12-12 / CAPES / Natural gas is extensively used in industries as well as in other sectors as an energy resource and, sometimes, it needs to undergo processes for the removal of impurities present in its composition. Among them are the sulfur compounds, which can cause damages to pipes and catalysts, making it necessary to develop and/or improve deep desulfurization methods. In this context, granular activated carbon was modified through two methods, oxidation using nitric acid, and impregnation using a ferric chloride solution. The resulting adsorbents were evaluated for their capacity of adsorbing seven sulfur compounds present in the synthetic natural gas sample, through their rupture curves. Afterwards, the adsorbents desorption was performed by using supercritical carbon dioxide under the conditions of 60?C at 100 bar, 150 bar and 200 bar. The results indicate that all the modification methods improved the sulfur compounds retention when compared to virgin activated carbon. The compound that had the greatest increase in the adsorption capacity after iron impregnation was the tert-butyl mercaptan (TBM), and with the activated carbon oxidized by HNO3 it was the dimethyl sulfide (DMS). Nevertheless, the supercritical conditions studied in the desorption stage were efficient only for the unmodified activated carbon. The adsorption capacities of both modified adsorbents after the regeneration were inferior to those capacities obtained in the first adsorption, then two hypotheses were investigated: (1) destruction of the newly created sites after regeneration; and (2) incomplete desorption in the studied supercritical conditions. Through other experiments it was proved that, after regeneration, there was no destruction of the newly created sites; therefore, further studies on the operating conditions are required in order to the modified adsorbents to achieve high regeneration capacities. / O g?s natural ? utilizado nas ind?strias e em outros setores como fonte de energia e necessita, por vezes, de processos de remo??o das impurezas presentes em sua composi??o. Dentre elas est?o os compostos de enxofre, que provocam danos em tubula??es e catalisadores, sendo necess?rio o desenvolvimento e/ou o aperfei?oamento de m?todos para a dessulfuriza??o profunda. Nesse contexto, um carv?o ativado granular foi modificado por meio de dois m?todos, oxida??o utilizando ?cido n?trico e por impregna??o usando uma solu??o de cloreto de ferro III, os adsorventes resultantes foram avaliados quanto ? sua capacidade para adsorver sete compostos de enxofre presentes em uma amostra de g?s natural sint?tica, atrav?s das curvas de rupturas. Posteriormente, foi realizada a dessor??o dos adsorventes utilizando di?xido de carbono supercr?tico nas condi??es de 60 ?C a 100 bar, 150 bar e 200 bar. Os resultados indicam que todos os m?todos de modifica??o melhoraram a reten??o dos compostos sulfurados individuais em compara??o com o carv?o ativado virgem. O composto que obteve maior aumento da capacidade de adsor??o ap?s a impregna??o com ferro foi o terc-butilmercaptana (TBM), e com o carv?o ativado oxidado pelo HNO3 foi o metiletilsulfeto (DMS). J? as condi??es supercr?ticas estudadas na etapa de dessor??o foram eficientes somente para o carv?o ativado n?o modificado. As capacidades de adsor??o dos dois adsorventes modificados ap?s a regenera??o foram inferiores aos obtidos na primeira adsor??o, ent?o duas hip?teses foram investigadas: (1) destrui??o dos novos s?tios criados ap?s a regenera??o; e (2) dessor??o incompleta nas condi??es supercr?ticas estudadas. Atrav?s de outros experimentos comprovou-se que n?o houve ? destrui??o dos novos s?tios criados ap?s a regenera??o, sendo necess?rio um estudo mais profundo em rela??o ?s condi??es operacionais, a fim de alcan?ar altas capacidades de regenera??o dos adsorventes modificados.

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.