dc.contributorDotto, Guilherme Luiz
dc.contributorhttp://lattes.cnpq.br/5412544199323879
dc.contributorCollazzo, Gabriela Carvalho
dc.contributorhttp://lattes.cnpq.br/0650318761058659
dc.contributorGonçalves, Janaína Oliveira
dc.contributorhttp://lattes.cnpq.br/9378137815366494
dc.creatorSchio, Rejiane Da Rosa
dc.date.accessioned2021-01-04T10:55:03Z
dc.date.accessioned2022-10-07T23:03:25Z
dc.date.available2021-01-04T10:55:03Z
dc.date.available2022-10-07T23:03:25Z
dc.date.created2021-01-04T10:55:03Z
dc.date.issued2019-02-18
dc.identifierhttp://repositorio.ufsm.br/handle/1/20240
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/4039151
dc.description.abstractPolyurethane foams (PU) may be used as the immobilization matrix for chitosan, in order to overcome/minimize the disadvantages with respect to chitosan as an adsorbent. However, the polyurethane and chitosan foams synthesized to date use conventional reagents, most of which are highly costly and non-renewable. In this context, the present study aims at the synthesis of a foam composed of polyurethane/chitosan based on a polyol derived from castor oil and its application in the removal of Food red 17 dye in batch system and fixed bed. The adsorbent was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), mechanical tests (shear force and degree of swelling) and color analysis. Firstly, adsorption tests were performed to evaluate the effect of the amount of chitosan on PU synthesis, the effect of the amount of adsorbent (0.1 - 1 g) and the effect of pH (2 - 10). The batch adsorption study was performed through equilibrium isotherms, kinetic curves and thermodynamic parameters. In the fixed bed adsorption study, the rupture curves were constructed at different flow rates and bed heights and these parameters were optimized using the response surface methodology (RSM). The characterization indicated that the polyurethane/chitosan composite foam presented more adequate characteristics and adsorption potential than PU. In addition, the material presented a semi-crystalline structure, with adequate functional groups, high porosity and good mechanical properties. The Pseudo-second order model was suitable to represent the adsorption kinetics and the Sips model was appropriate to represent the equilibrium isotherms. The maximum adsorption capacity was 267.24 mg g-1, obtained at 328 K. The adsorption process was spontaneous, favorable and endothermic. Using identical adsorption conditions, the PU/chitosan composite foam was able to remove more than 98% of the dye from the solution, while the PU removed only 40%. The adsorption was favored at pH 2, using 1 g of adsorbent. Models for the forward curves, including Thomas, Yoon-Nelson and Bed Depth Service Time (BDST) were fitted to the experimental data. The optimum experimental condition for the adsorption of Food red 17 dye in fixed bed using PU/chitosan composite foam was 15 mL min-1 and bed height 6 cm. In this condition, the treated effluent volume was 2175 mL and the adsorption capacity of the column was 108.1 mg g-1. The results also showed that the Yoon-Nelson and BDST models accurately adjusted the experimental data under the optimal condition. The results showed that polyurethane foams are able to withstand chitosan, resulting in an adsorbent with better mechanical characteristics and high potential for removal of anionic dyes in aqueous media.
dc.publisherUniversidade Federal de Santa Maria
dc.publisherBrasil
dc.publisherEngenharia Química
dc.publisherUFSM
dc.publisherPrograma de Pós-Graduação em Engenharia Química
dc.publisherCentro de Tecnologia
dc.rightshttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 International
dc.subjectAdsorção
dc.subjectBatelada
dc.subjectLeito fixo
dc.subjectQuitosana
dc.subjectEspuma de poliuretano
dc.subjectÓleo de mamona
dc.subjectVermelho n° 40
dc.subjectAdsorption
dc.subjectBatch
dc.subjectFixed-bed
dc.subjectChitosan
dc.subjectPolyurethane foam
dc.subjectCastor oil
dc.subjectFood red 17
dc.titleSíntese de uma espuma composta de poliuretano/quitosana para adsorção do corante vermelho n° 40 em batelada e leito fixo
dc.typeDissertação


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