Engenharia Química

URI Permanente desta comunidade

http://repositorio.ufes.br/handle/10/17472
Programa de Pós-Graduação em Engenharia Química

Centro: CCAE
Telefone: (28) 3552 8719
URL do programa: http://www.engenhariaquimica.alegre.ufes.br/pos-graduacao/PPEQ

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Navegando Engenharia Química por Autor "Altoé, Mário Alberto Simonato"

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    Catalisador ternário de PtRhSn0² disperso em carbono aplicado na reação de eletro-oxidação de glicerol
    (Universidade Federal do Espírito Santo, 2017-09-06) Junco, Gustavo Garcia; Profeti, Demetriu; Profeti, Luciene Paula Roberto; Pinheiro, Christiano Jorge Gomes; Altoé, Mário Alberto Simonato
    Currently, there is extensive discussion about energy issues, and due to the great apprehension related to the pollution generated by the use of fossil fuels and their probable scarcity, it is interesting to develop methods capable of supplying energy from renewable sources. Several research groups aim to develop fuel cells (FC’s) that operate with hydrogen or alcohols as fuel. However, a catalyst for direct alcohol fuel cell (DAFC) with high catalytic efficiency, tolerant to COads species poisoning and low cost was not found yet. In this work, PtRhSnO2/C electrocatalysts were developed and the results of electrochemical characterization using cyclic voltammetry (VC) showed that this catalyst has a profile similar to the polycrystalline platinum catalyst. These tests also allowed to identify the greater stability of PtRhSnO2/C in alkaline medium. The experiments performed by CV and chronoamperometry (CA) showed that the PtRhSnO2/C electrodes without thermal treatment (TT) and with TT had good catalytic activity for the electrooxidation of glycerol 0.5 mol L -1, since they demonstrated superior results to those obtained by the commercial platinum electrode (Pt/C 30% of E-TEK). It is important to note that the catalyst treated at 500 °C showed the best results in the tests performed by CV and CA. Also in this work, it was observed that the activation energy of the PtRhSnO2/C catalyst without TT decreases with the increase of temperature during the electrooxidation of glycerol. By means of the kinetic study, it was verified that PtRhSnO2/C without TT has less activation energy when compared to Pt/C 30% of E- TEK.
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    Estudo da adsorção do antibiótico sulfanilamida em esmectita modificada com Na
    (Universidade Federal do Espírito Santo, 2019-02-19) Massariol, Polyana Silvério; Profeti, Demetrius; Profeti, Luciene Paula Roberto; Neves, Mirna Aparecida; Altoé, Mário Alberto Simonato
    The indiscriminate disposal of pharmaceutical products, as sulfanilamide antibiotic, contaminates the environment and alter the water quality. Conventional methods of removal of contaminants are expensive and present reduced efficiency by the conventional treatment methods. The adsorption is more effective for the removal of pollutants, easy operation and minimizes the amount of toxic substances in the effluents. The use of adsorbent materials, accessible and low cost, is a promising method for the adsorption of organic compounds. The potential of smectite clay was investigated in sulfanilamide adsorption in aqueous solutions by batch analysis using physical and chemical modifications in the clay in order to increase the removal capacity. The clay in natura, the clay with thermal treatment, the clay rinsed with ultrapure water, the clay rinsed with HCl solution and with NaCl solution, were investigated as adsorbent for removal of sulphanilamide (SAA). The best conditions for SAA removal was in solution at pH 4 with the clay treated at 200 °C, which fitted to pseudo first order kinetics process, and in solution at pH 8 with the clay treated with NaCl, adjusting to a pseudo second order kinetics process. The latter was chosen the optimal process condition. The SAA adsorption was described by the Langmuir isotherm by using the nonlinear method. The maximum amount of SAA adsorbed by clay was near to the experimental value (Qe at 79,79 mg g-1 at 55 °C). The temperature showed a great influence on the removal of SAA by the clay and the adsorption process was characterized as spontaneous for all temperatures studied (25, 35, 45, and 55 °C). The adsorbent material was characterized, and the X-ray diffraction allowed to identify the crystalline phases characteristic of the smectite, with structural changes according to the applied treatments, including the variation of the distance between lamellas due to the intercalation of the sodium ion. Elemental analysis, performed by EDS, showed the presence of silicon, oxygen, potassium and aluminum as the main elements of the clay structure, which are characteristic of smectite. The adsorbent showed morphology with high porosity and sodium was only identified in Na modified clay. Sodium modified clay has the potential to be used as a low cost alternative adsorbent for the treatment of effluent and waters containing the emerging sulphanilamide contaminant.