FERNANDO MENDES DE OLIVEIRA
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Resumo IPEN-doc 24838 Immobilization of graphene oxide in a poly(divinylbenzene) matrix for the treatment of liquid radioactive waste containing 137Cs2017 - OLIVEIRA, FERNANDO M.; POTIENS JUNIOR, ADEMAR J.; FEJFAR, JOSE L.; RODRIGUES, DEBORA F.; DI VITTA, PATRICIA B.; SAKATA, SOLANGE K.Cesium is one of the fission products of major radiological concern, it is often found in nuclear radioactive waste generated at nuclear power plants. Several methods are used to treat radioactive aqueous waste, especially adsorption, which is a technique that combines cost and efficiency and is widely used in preconcentration of radionuclides. Graphene Oxide (GO) has attracted great attention due to its functionalized surface, which includes hydroxyl, epoxy, carbonyl and carboxyl groups, with great capacity of complexation of metal ions and it can be used as adsorbent to remove cesium from radioactive liquid wastes.This work, GO was immobilized in poly(divinylbenzene) to increase the specific mass and grain size of the adsorbent, that can be easily remove from solution by vaccum filtration or being used in a fixed bed column. The incorporation of the GO on the polymer surface was confirmed by electron scanning electron microscopy (SEM) Figure 1.Artigo IPEN-doc 24092 Studies of equilibrium and kinetics of adsorption of cesium ions by graphene oxide2017 - OLIVEIRA, FERNANDO M.; BUENO, VANESSA N.; OSHIRO, MAURICIO T.; POTIENS JUNIOR, ADEMAR J.; HIROMOTO, GORO; RODRIGUES, DEBORA F.; SAKATA, SOLANGE K.Cesium is one of the fission products of major radiological concern, it is often found in nuclear radioactive waste generated at nuclear power plants. Graphene Oxide (GO) has attracted great attention due to its functionalized surface, which includes hydroxyl, epoxy, carbonyl and carboxyl groups, with great capacity of complexation with metal ions and can be used as adsorbent to remove cations from aqueous solutions. In this work, a treatment of radioactive waste containing 137Cs was studied. For the batch experiments of Cs+ removal, 133Cs concentrations remained after the adsorption were determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and the results obtained were analyzed according to the Langmuir and Freundlich isotherms models. The kinetics of adsorption and Gibbs free energy were also determined. The Langmuir model was the best fit and defined a favorable adsorption. The cesium adsorption process is the pseudo-second model and the Gibbs free energy calculation indicated that the adsorption process is spontaneous.Artigo IPEN-doc 20978 Assessment of major and trace elements in soil and sediments from Osamu Utsumi uranium mine by WDXRF2015 - GUILHEN, SABINE N.; OLIVEIRA, FERNANDO M. de; FILHO, WALTER S.; COTRIM, MARYCEL E.B.; SAKATA, SOLANGE K.; SCAPIN, MARCOS A.