Les smectites sont présentent dans de nombreux environnements de surface et sub-surface au sein desquels elles jouent un rôle prépondérant dans la mobilité des cations majeurs et traces de part leurs capacités d’adsorption. En contexte de réhabilitation de sites miniers exploités par lixiviation acide, ces smectites jouent un rôle dans la remontée du pH des eaux ainsi que dans l’immobilisation des éléments solubilisés. La nature des argiles présentent dans les sables non consolidés d’un aquifère exploité a donc été étudié. La présence de smectites du type beidellite (charge tétraédrique) a été mise en évidence. Cependant, il existe peu d’études sur les propriétés de la beidellite, la majorité portant sur la montmorillonite (charge octaédrique). Un modèle d’échange pour 5 cations majeurs des eaux naturelles (Na, K, Ca, Mg, H) et un élément trace (226Ra) a donc été réalisé sur une beidellite de référence. Les vitesses de dissolution et les mécanismes à l’interface solide/solution en milieu acide ont ensuite été étudiés, validant l’application du modèle d’échange à bas pH. Des effets dus à l’organisation des particules en suspension (texture/agrégation) ont aussi été mis en évidence sur les propriétés d’échange et de dissolution. Lors de ces travaux, l’accent a été mis sur l’impact de la cristallochimie sur la réactivité des smectites par comparaison entre les propriétés de la beidellite et de la montmorillonite. Les résultats indiquent que la cristallochimie des smectites a un impact significatif sur leur comportement, ce paramètre pourrait ainsi être utilisé afin d’alimenter les modèles de transport réactif prenant en compte les propriétés des smectites. / Swelling clay minerals, in particular smectites, are present in many surface and subsurface environments in which they have a major impact on the mobility of major cations and trace elements due to their adsorption capacity. In context of remediation of mining environments operated by acid leaching, these smectites can act as pH buffer and play a role in the immobilization of soluble elements. The type of clay minerals present in the poorly consolidated sands of an aquifer leached by acid solutions was studied. The presence of beidellite type smectites (di-octahedral, tetrahedral charge) was evidenced. However, few studies exist on the ion exchange properties or the dissolution of beidellite, as most of them deal with montmorillonite properties (di-octahedral, octahedral charge). Then, an ion-exchange model involving 5 major cations of natural waters (Na, K, Ca, Mg, H) and one trace element (226Ra) was proposed for a reference beidellite. Dissolution rates and interfacial mechanisms in acidic solutions were investigated in order to check for the validity the ion-exchange model at low pH. Moreover, effects due to the texture/aggregation of particles in suspension were evidenced on the ion-exchange and dissolution properties. This study was focused on the impact of the crystal chemistry on reactive property of the smectites, by comparison of the properties of beidellite with those of montmorillonitic minerals. Results indicate that smectites crystal chemistry has a significant impact on their properties, and such parameter could be considered in reactive transport models when they take into account cation exchange and dissolution properties of smectites.

Os atuais serviços de saúde tornaram-se ambientes complexos e vulneráveis, fazendo-nos repensar acerca da necessidade de simplificar os processos de trabalho de modo a torná-los mais éticos e seguros. Os objetivos do estudo foram analisar o sistema de medicação e os processos de preparo e de administração de medicamentos de uma UTI, à luz da abordagem restaurativa em saúde. Tratou-se de pesquisa multimétodos, com delineamento embutido, a qual aplicou técnicas de coleta de dados embasadas na perspectiva sócio-ecológica: grupos focais, narração fotográfica e foto elicitation. A pesquisa foi realizada em uma UTI de um hospital geral do interior paulista e envolveu a participação de 23 profissionais da enfermagem e um médico intensivista. A investigação ocorreu em quatro fases. Na primeira, grupos focais foram formados com o objetivo de fazer emergir as opiniões dos participantes em relação aos aspectos de segurança, bem como identificar situações no ambiente e nos processos de trabalho que poderiam comprometer a segurança do paciente no preparo e na administração de medicamentos. Na segunda, a pesquisadora, junto à gerente de enfermagem, realizou narrativas visuais com os propósitos de refletir sobre o ambiente assistencial onde os medicamentos são preparados e administrados, de observar condições passadas e de identificar possibilidades de melhorias futuras, no que diz respeito aos aspectos de segurança. Na terceira fase, as imagens foram expostas ao segundo grupo focal com a finalidade de identificar potenciais mudanças a serem implantadas no sistema de medicação, bem como nos processos, nas práticas, nas políticas e no ambiente de trabalho da UTI. Na quarta, novos registros fotográficos foram feitos com o propósito de captar as mudanças ocorridas no sistema de medicação e no ambiente assistencial da UTI, por meio da comparação destes com as fotografias obtidas durante a segunda fase da pesquisa. A coleta e a análise dos dados ocorreram de maneira interativa em todas as fases da investigação, segundo a orientação teórica da abordagem restaurativa em saúde. Os achados auxiliaram na compreensão das barreiras e das medidas facilitadoras voltadas para a segurança no preparo e na administração de medicamentos, a partir da obtenção de seis temas: Identificando o ambiente assistencial como contribuinte para a segurança no preparo e na administração de medicamentos; Identificando riscos no ambiente assistencial; Percebendo o ambiente assistencial como fator de risco para os acidentes ocupacionais; Tendo que conviver com o sentimento de \"impotência\" diante da cultura organizacional vigente; Convivendo com os improvisos no dia-a-dia do trabalho e Vislumbrando possibilidades de mudanças no ambiente assistencial. A partir da construção conjunta do conhecimento entre pesquisadora e pesquisados, os resultados forneceram subsídios para pesquisas futuras e revelaram que os problemas existentes no sistema interferem na segurança, tanto do paciente como do profissional, devendo a instituição rever a forma de gerenciar os riscos existentes no ambiente assistencial. / The current health services have become vulnerable and complex environments. This has made us rethink about the need of simplifying the work processes so that they are more ethical and safer. The goals of the study were the analysis of the medication system and the processes of preparing and administering the medications at an ICU, in the light of the restorative approach in healthcare. It was a multi-method research, with an embedded delineation, which applied collecting techniques of data having a social ecological perspective: focus groups, photo narration and photo elicitation. The research was performed at an ICU of a general hospital in a city in the São Paulo state and it involved the participation of 23 nursing professionals and an intensivist physician. The investigation occurred in four phases. First, focus groups were formed with the goal of getting the participants\' opinions related to the safety aspects to emerge, as well as identifying situations in the work environment and in the processes that could compromise the patient\'s safety in the preparation and in the administration of medications. Next, the researcher, along with the nursing manager, performed several visual narratives with the purpose of reflecting about the healthcare environment where the medications are prepared and administrated, observing past conditions and identifying possibilities of future improvements, when it comes to the safety aspects. After that, the images were exposed to the second focus group with the aim to identify potential changes to be implemented in the medication system, as well as in the processes, in the practices, in the politics and in the workplace environment at the ICU. At the last phase, new photographic registrations were done with the aim to get the changes occurred in the medication system and in the care environment at the ICU, by comparing these ones with the pictures obtained during the second phase of the research. Collecting and analyzing data was performed in an interactive way at all the phases of the investigation, according to the theoretical orientations of the restorative approach in healthcare. The findings helped in understanding the barriers and the facilitating measures directed to the safety in the preparation and administration of medications, after obtaining six themes: Identifying the healthcare environment as a contributor for the safety in the preparation and administration of medications; Identifying risks in the healthcare environment; Realizing the healthcare environment as a risk factor for the occupational accidents; Having to live with an \"impotence\" feeling before the current organizational culture; Living with the everyday workarounds; and Envisioning possible changes in the healthcare environment. From the joint construction of the knowledge among the researcher and the investigated ones, the results provided subsidies for future investigations and revealed that the problems in the system interfere in the safety, both the patient and the professional, having the institution a necessity to revise the way it manages the risks in the healthcare environment.

Os atuais serviços de saúde tornaram-se ambientes complexos e vulneráveis, fazendo-nos repensar acerca da necessidade de simplificar os processos de trabalho de modo a torná-los mais éticos e seguros. Os objetivos do estudo foram analisar o sistema de medicação e os processos de preparo e de administração de medicamentos de uma UTI, à luz da abordagem restaurativa em saúde. Tratou-se de pesquisa multimétodos, com delineamento embutido, a qual aplicou técnicas de coleta de dados embasadas na perspectiva sócio-ecológica: grupos focais, narração fotográfica e foto elicitation. A pesquisa foi realizada em uma UTI de um hospital geral do interior paulista e envolveu a participação de 23 profissionais da enfermagem e um médico intensivista. A investigação ocorreu em quatro fases. Na primeira, grupos focais foram formados com o objetivo de fazer emergir as opiniões dos participantes em relação aos aspectos de segurança, bem como identificar situações no ambiente e nos processos de trabalho que poderiam comprometer a segurança do paciente no preparo e na administração de medicamentos. Na segunda, a pesquisadora, junto à gerente de enfermagem, realizou narrativas visuais com os propósitos de refletir sobre o ambiente assistencial onde os medicamentos são preparados e administrados, de observar condições passadas e de identificar possibilidades de melhorias futuras, no que diz respeito aos aspectos de segurança. Na terceira fase, as imagens foram expostas ao segundo grupo focal com a finalidade de identificar potenciais mudanças a serem implantadas no sistema de medicação, bem como nos processos, nas práticas, nas políticas e no ambiente de trabalho da UTI. Na quarta, novos registros fotográficos foram feitos com o propósito de captar as mudanças ocorridas no sistema de medicação e no ambiente assistencial da UTI, por meio da comparação destes com as fotografias obtidas durante a segunda fase da pesquisa. A coleta e a análise dos dados ocorreram de maneira interativa em todas as fases da investigação, segundo a orientação teórica da abordagem restaurativa em saúde. Os achados auxiliaram na compreensão das barreiras e das medidas facilitadoras voltadas para a segurança no preparo e na administração de medicamentos, a partir da obtenção de seis temas: Identificando o ambiente assistencial como contribuinte para a segurança no preparo e na administração de medicamentos; Identificando riscos no ambiente assistencial; Percebendo o ambiente assistencial como fator de risco para os acidentes ocupacionais; Tendo que conviver com o sentimento de \"impotência\" diante da cultura organizacional vigente; Convivendo com os improvisos no dia-a-dia do trabalho e Vislumbrando possibilidades de mudanças no ambiente assistencial. A partir da construção conjunta do conhecimento entre pesquisadora e pesquisados, os resultados forneceram subsídios para pesquisas futuras e revelaram que os problemas existentes no sistema interferem na segurança, tanto do paciente como do profissional, devendo a instituição rever a forma de gerenciar os riscos existentes no ambiente assistencial. / The current health services have become vulnerable and complex environments. This has made us rethink about the need of simplifying the work processes so that they are more ethical and safer. The goals of the study were the analysis of the medication system and the processes of preparing and administering the medications at an ICU, in the light of the restorative approach in healthcare. It was a multi-method research, with an embedded delineation, which applied collecting techniques of data having a social ecological perspective: focus groups, photo narration and photo elicitation. The research was performed at an ICU of a general hospital in a city in the São Paulo state and it involved the participation of 23 nursing professionals and an intensivist physician. The investigation occurred in four phases. First, focus groups were formed with the goal of getting the participants\' opinions related to the safety aspects to emerge, as well as identifying situations in the work environment and in the processes that could compromise the patient\'s safety in the preparation and in the administration of medications. Next, the researcher, along with the nursing manager, performed several visual narratives with the purpose of reflecting about the healthcare environment where the medications are prepared and administrated, observing past conditions and identifying possibilities of future improvements, when it comes to the safety aspects. After that, the images were exposed to the second focus group with the aim to identify potential changes to be implemented in the medication system, as well as in the processes, in the practices, in the politics and in the workplace environment at the ICU. At the last phase, new photographic registrations were done with the aim to get the changes occurred in the medication system and in the care environment at the ICU, by comparing these ones with the pictures obtained during the second phase of the research. Collecting and analyzing data was performed in an interactive way at all the phases of the investigation, according to the theoretical orientations of the restorative approach in healthcare. The findings helped in understanding the barriers and the facilitating measures directed to the safety in the preparation and administration of medications, after obtaining six themes: Identifying the healthcare environment as a contributor for the safety in the preparation and administration of medications; Identifying risks in the healthcare environment; Realizing the healthcare environment as a risk factor for the occupational accidents; Having to live with an \"impotence\" feeling before the current organizational culture; Living with the everyday workarounds; and Envisioning possible changes in the healthcare environment. From the joint construction of the knowledge among the researcher and the investigated ones, the results provided subsidies for future investigations and revealed that the problems in the system interfere in the safety, both the patient and the professional, having the institution a necessity to revise the way it manages the risks in the healthcare environment.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Water hyacinth (Eichhornia crassipes) is an invasive aquatic weed whose main characteristic is its high growth rate. The methods applied to control this plant have high cost and waste generation. Using the water hyacinth as an adsorbent for remediation of metals is a viable and eco-friendly application. In this work, a magnetic hybrid adsorbent matrix (AGMG) was synthesized utilizing water hyacinth (Eichhornia crassipes) biomass to compose an organic phase, and its adsorption efficiency was compared to the adsorption efficiency of in natura (AGIN) water hyacinth and its biochar (BIO) in the remediation of metals in water. The adsorbents were characterized by infrared spectroscopy, confirming the presence of hydroxyl groups and carboxylates, with bands that are typical of cellulose, hemicellulose and lignin, structures found in AGIN and BIO. The AGMG spectrum presented the bands previously described and new bands in the region of 513 cm-1, characteristic of the Fe-O bond of CoFeO4, confirming the formation of a magnetic hybrid. The essays on the influence of pH on the remediation of copper, zinc, nickel and cobalt presented higher percentages of removal in the range of pH 4-5 for all adsorbents, and the following crescent order of removal efficiency AGIN<AGMG<BIO for all metals. The kinetic studies showed fast kinetics for the three adsorbents and the metals under study with a removal rate of more than 50% in the first 5 minutes. The kinetic data were adjusted to the pseudo-second order model, with correlation coefficients higher than 0,99 for the three materials. The AGMG was prominent among the other adsorbents because its adsorption capacity is high and its separation from the aqueous medium is more feasible. The isotherm data for the AGMG were adjusted to the Langmuir model, showing a good linear correlation in the concentration range studied (5-250 mg g-1), with correlation coefficient r2 between 0,9973-0,9999. The values of the calculated maximum capacity of AGMG (qmax) were 18,3 mg g-1 Cu (II), 10,1 mg g-1 Zn (II) and 7,33 mg-1 Ni (II). The percentage of removal in the different mixed solutions by the adsorbent AGMG followed this order of selectivity, Cu>Zn>Ni, copper as a highlight, > 84% removal in all evaluated mixed solutions. The AGMG was reused in four cycles of adsorption in mixed solution, without using a desorption process, and the efficiency varied according to the metal. The adsorption of copper remained high in all cycles, with 77% removal in the first cycle and 72% in the fourth cycle. For zinc and nickel, the removal decreased with each cycle, and in the third cycle there was no more nickel removal. The saturated with metals AGMG residues (AGMG-sat) showed high catalytic activities in the reduction of 4- nitrophenol to 4-aminophenol. The residues were reused in ten reduction cycles and the conversion rate in the cycles ranged from 88,9 to 100%, with short periods of time (21-26 s). / Aguapé (Eichhornia crassipes) é uma planta daninha aquática invasora cuja principal característica é sua alta taxa de crescimento. Os métodos aplicados para o controle dessas plantas possuem alto custo e geração de resíduos. Uma aplicação viável e eco-amigável é utilizá-la como adsorvente para a remediação de metais. Neste trabalho foi efetuada a síntese de uma matriz adsorvente híbrida magnética (AGMG) utilizando a biomassa aguapé (Eichhornia crassipes), para compor a fase orgânica, e comparou sua eficiência adsortiva com a aguapé in natura (AGIN) e seu biocarvão (BIO), na remediação de metais em água. Os adsorventes foram caracterizados por espectroscopia de infravermelho, que confirmou a presença de grupos hidroxilas e carboxilatos, com bandas típicas da celulose, hemicelulose e lignina, estruturas essas encontradas no AGIN e BIO. O espectro do AGMG apresentou as bandas descritas anteriormente e novas bandas na região de 513 cm-1, característica da ligação Fe-O da CoFeO4, confirmando a formação do híbrido magnético. Os ensaios da influência do pH na remediação do cobre, zinco, níquel e cobalto mostraram maiores porcentagens de remoção na faixa de pH 4-5, para todos os adsorventes, podendo estabelecer a seguinte ordem crescente de eficiência de remoção AGIN<AGMG<BIO para todos os metais. O estudo cinético evidenciou uma cinética rápida para os três adsorventes e os metais em estudo com uma taxa de remoção superior a 50% nos primeiros 5 minutos. Os dados cinéticos ajustaram-se ao modelo de pseudo-segunda ordem, com coeficientes de correlação superiores a 0,99 para os três materiais. O AGMG destacou-se entre os demais adsorventes devido sua alta capacidade de adsorção e de ser mais viável sua separação do meio aquoso. Os dados das isotermas para o AGMG ajustaram-se ao modelo de Langmuir, apresentando boa correlação linear na faixa de concentração estudada (5-250 mg g-1), com coeficiente de correlação r2 entre 0,9973-0,9999. Os valores de capacidade máxima do AGMG calculada (qmax) foram de 18,3 mg g-1 Cu(II), 10,1 mg g-1 Zn(II) e 7,33 mg -1 Ni(II). A porcentagem de remoção nas diferentes soluções mistas pelo adsorvente AGMG seguiu a ordem de seletividade, Cu>Zn>Ni, com destaque para o cobre >84% de remoção em todas as soluções mistas avaliadas. O AGMG foi reutilizado em quatro ciclos de adsorção em solução mista, sem utilização de processo de dessorção, e a eficiência variou de acordo com o metal. A adsorção para o cobre permaneceu elevada em todos os ciclos, com 77% de remoção no primeiro ciclo e 72% no quarto ciclo. Para o zinco e níquel, a remoção diminuiu a cada ciclo, sendo que no terceiro ciclo não houve mais remoção de níquel. Os resíduos do AGMG saturados com metais (AGMG-sat) apresentaram altas atividades catalíticas na redução do 4-nitrofenol a 4-aminofenol. Os resíduos foram reutilizados em dez ciclos de redução e a taxa de conversão nos ciclos variou de 88,9-100%, com curtos tempos (21-26 s). / São Cristóvão, SE

Master of Science / Department of Chemistry / Kenneth J. Klabunde / Although Degussia-Huls P-25 TiO[subscript]2 semiconductor photocatalyst has high photodegradation rate for organic molecules, it works only under ultra-violet (UV) light. Mesoporous metal doped V-MCM-48 silica was synthesized under ambient conditions for use as a visible-light photocatalyst to convert toxic probe molecules to innocuous products: CO[subscript]2 + H[subscript]2O. The synthesis employed a modified Stober metal doped MCM-48 silica method. Powder X-ray diffraction (XRD), diffuse-reflectance-ultra-violet-visible (DR-UV-vis) spectroscopy, and N[subscript]2 adsorption-desorpton analysis characterization methods were completed on V-MCM-48 mesoporous material. These characterization methods indicate V-MCM-48 structure had formed with visible light absorption and mesoporous properties. Photocatalysis studies were completed with V-MCM-48 under dark, visible, and UV-light illumination conditions for the following probe molecules: acetaldehyde, carbon monoxide, ethanol, acetone, 2-propanol, and acetonitrile. Acetaldehyde over V-MCM-48 was converted to CO[subscript]2 under dark, visible, and UV-light conditions. Carbon monoxide photooxidation occurred over V-MCM-48 under visible and UV-light. Ethanol and acetonitrile had smaller photodegradation activity over V-MCM-48. Acetone and 2-propanol had no activity photocatalytically. Under dark and visible light illumination, V-MCM-48 consumed approximately one-half acetaldehyde and produced one-third CO[subscript]2 concentration as compared with the P-25 TiO[subscript]2 under UV-light. V-MCM-48 produced two-thirds of the amount of CO[subscript]2 in comparison to nanoparticle Au/ZnO catalyst under UV-light. The results infer V-MCM-48 might be useful in gas and liquid phase photocatalysis including water-splitting due to a high oxidation state (V[superscript]5+), visible light absorption, and high surface area. In conclusion, an extended literature review has been completed and literature employed extensively throughout the thesis with potential methods to further the research on V-MCM-48/Si-MCM-48 in catalysis, chromatography, adsorption/gas separation, and solar collection/water-splitting.