Detalhes bibliográficos
| Ano de defesa: |
2022 |
| Autor(a) principal: |
Pompêu, Lenise Deon |
| Orientador(a): |
Fernandes , Liana da Silva |
| Banca de defesa: |
Carvalho, Fabiano Barbosa,
Mallmann, Evandro Stoffels,
Zamberlan, Alexandre de Oliveira,
Rech , Virginia Cielo |
| Tipo de documento: |
Tese
|
| Tipo de acesso: |
Acesso embargado |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Franciscana
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação em Nanociências
|
| Departamento: |
Biociências e Nanomateriais
|
| País: |
Brasil
|
| Palavras-chave em Português: |
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| Palavras-chave em Inglês: |
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| Área do conhecimento CNPq: |
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| Link de acesso: |
http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/1165
|
Resumo: |
During the last few years, the growing environmental concern has been notorious, due to the significant increase in wastewater as well as waste from the fishing industry, with emphasis on wastewater from textile industries, contaminated by dyes and shrimp shells. In this sense, adsorption stands out as a promising alternative both for the removal of organic dyes, in relation to conventional methods, and for promoting the reuse of residues that would otherwise be discarded, shrimp shells. The adsorption process is highly efficient, simple to operate, environmentally and economically viable, as it allows alternative low-cost materials (waste) to be used as adsorbents (biosorbents). Thus, the present thesis aims to evaluate the potential for removal of the dye Rhodamine B (RhB) using nanochitosan (extracted from shrimp shell) and the production of a biochar, through carbonization followed by activation of nanochitosan for the same purpose ( RhB adsorption). The adsorption study was carried out using adsorption isotherms (equilibrium), adsorption kinetics and thermodynamics. For this, pseudo first-order (PFO), pseudo second-order (PSO) and intraparticle diffusion kinetic models were used to adjust the experimental data. About the equilibrium adsorption, the models of Langmuir, Freundlich, Sips and Redlich-Peterson were used. Nanochitosan and biochar were characterized by X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), scanning electron microscope and energy dispersive X-ray spectroscopy (SEM-EDS), N2 porosimetry (BET/ BJH), zeta potential (ZP), zero charge point (pHZCP) and cellular activity. In addition, in order to determine the ideal condition of the process, a central composite rotational design (CCRD 2²) was performed, evaluating the pH of the medium and concentration of both the biosorbent and the biochar. In addition, assays of antimicrobial activity against strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus were carried out, as well as the safety profile of the antibiofilm against Pseudomonas aeruginosa, Staphylococcus epidermidis, Enterococcus faecium, Acinetobacter baumannii and Escherichia coli. For NQ, the adsorption data were fitted to the Langmuir isotherm and the pseudo-second order kinetic model, indicating a chemisorption. Thermodynamic studies confirmed it to be an exothermic process, in which the removal of RhB was considered spontaneous and with an increase in the randomness of the system. And, for the biochar it was adjusted for the Freundlich isotherm, second order kinetic model and the thermodynamics confirmed that the adsorption of RhB in the biochar is endothermic and spontaneous. In terms of antimicrobial activity, it was found that biochar showed activity for all bacterial strains tested and NQ showed activity against E. coli, P. aeruginosa, K. pneumoniae, S. aureus tested at a concentration of 0.25 mg mL-1. The adsorption test was performed at pH 9, according to ideal conditions ([adsorbent] = 4.5 g L-1, [RhB] = 50 mg L-1) determined through experimental design CCRD 22 , resulting in 72.34 % of biochar and 86.84% of nanochitosan for RhB removal. Therefore, the nanochitosan biosorbent and the biochar showed a potential application in the treatment of wastewater with dyes by the adsorption process. |
