Engenharia de Materiais (UACSA)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/2913
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APP - Artigo Publicado em Periódico
TAE - Trabalho Apresentado em Evento
TCC - Trabalho de Conclusão de Curso
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Resultados da Pesquisa
Item Produção de nanopartículas magnéticas aplicada ao processo de tratamento de efluentes oriundos das indústrias têxteis(2018-08-27) Damasceno, Bárbara Souza; Araújo, Ana Cláudia Vaz de; http://lattes.cnpq.br/6861890992609511; http://lattes.cnpq.br/6533105269743189Iron oxide magnetic nanoparticles (NPs) were synthetized by chemical coprecipitation method under ultrasound. Synthetized NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, porosimetry and magnetometry. The crystalline phase of the obtained NPs was identified as maghemite and the crystallite average size was estimated by Scherrer equation around 31.5 nm. The FTIR spectra presented distinct absorptions bands at corresponding to intrinsic stretching vibrations of Fe–O bond at the iron oxides. Langmuir and BET surface areas of as-formed samples is 220,15 ± 19,81 m2 g-1 and 127,19 ± 4,94 m2 g-1 respectively. NPs samples present ferromagnetic behavior and saturation magnetization (SM) value of 46 emu g-1. Adsorption performances on synthetized and commercial nanoparticles were investigated and compared. The influences of parameters including pH, dye concentration, and agitation time have been investigated in order to find the optimum adsorption conditions. Parameters as pH 4.0, with 150 min of contact time and dye concentration of 20 mg L-1 were chosen. Adsorption results indicate that the isotherm and kinetics for dye adsorption on NPs obey Freundlich isotherm and pseudo-second-order kinetic, respectively. The maximum dye (20 mg·L-1) removal efficiency to maghemite NPs was found to be 43% and to commercial magnetite NPs was 33%. For the same experimental conditions, maghemite also had better application of the available area for adsorption than the magnetite NPs, presenting values of 8.80 mg g-1 and 6.12 mg g-1, respectively.Item Síntese e caracterização de um nanocompósito de grafite magnético para adsorção dos corantes Reactive Black 5 (RB5) e Azul de Metileno (AM)(2019-12-13) Damasceno, Bárbara Souza; Araújo, Ana Cláudia Vaz de; http://lattes.cnpq.br/6861890992609511; http://lattes.cnpq.br/6533105269743189Magnetic graphite nanocomposite (NGM) based on magnetic nanoparticles (NPs) and graphite nanoplatelets has been synthesized by a novel hydrothermal synthesis route. NGM and its precursors were characterized by X-ray diffraction (XRD) and infrared spectroscopy (FTIR). The nanomaterial discoloration efficiency (%Ads) using reactive black 5 (RB5) and methylene blue (AM) textile dyes in aqueous solution as target pollutant were evaluated. The influence of adsorptive parameters on effluent discoloration efficiency responses was evaluated from a 23 factorial design and the response surface analysis of central rotational composite design. Adsorption parameters evaluated include: adsorbent mass, adsorbate concentration and agitation speed. It was observed that the parameters agitation speed (rpm) and concentration of adsorbate (mg L-1) are the factors more significant than any other combination and it is highly indicated that they should be parameterized in combination. NGM statistical results showed %Ads ~98% in the RB5 removal, extremely high adsorption velocity, since it reached the adsorption equilibrium within 10 minutes of contact with the adsorbate and it presented 99% adjustment for pseudo first and second order kinetics, besides it presented a maximum adsorptive capacity of ~93 mg g-1 for the adjustment of Langmuir model, predominant in this system. The %Ads of AM onto NPs and graphite was ~59% and 100%, respectively. The study shows that NGM can be magnetically separated from the aqueous solution without introduce any byproduct during adsorption and presented favorable adsorptive properties, which makes evident its applicability of use as environmental remediator. The application of this synthetic rout becomes of technological interest when, besides being unprecedented and low cost, NGM adsorptive properties are attractive to effectively discolor wastewater.