Remoção de corante Rodamina B em efluente sintético por fotocatálise heterogênea com ZnO e Nd/ZnO

• Ano de defesa: 2024
• Autor(a) principal: Barbosa, João Hampshire Olsson
• Outros Autores: [e-mail]
• Orientador(a): Zotin, Fátima Maria Zanon , Araújo, Lucia Regina Raddi de
• Banca de defesa: Gonçalves, Márcia Monteiro Machado , Henriques, Cristiane Assumpção , Merçon, Fábio , Gaspar, Alexandre Barros
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Engenharia Química
• Departamento: Centro de Tecnologia e Ciências::Instituto de Química
• País: Brasil
• Palavras-chave em Português: Fotocatálise heterogênea; Corantes e tingimentos; Rodamina b; Nd/ZnO; Efluente têxtil; Textile wastewater
• Palavras-chave em Inglês: Heterogenous photocatalysis; Rhodamine b
• Área do conhecimento CNPq: ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/22784

In this work, experimental tests were carried out to study the possibility of removing, by heterogeneous photocatalysis, the dye Rhodamine B (RhB) in aqueous solution and in synthetic effluent produced in the laboratory. Studies of textile dye degradation by heterogeneous photocatalysis show a significant increase in the photocatalytic activity of ZnO when doped with rare earths, with neodymium (Nd) being one of these promising options. Based on these studies, two Nd/ZnO catalysts were synthesized by wet impregnation with Nd(OH)3 solution, obtaining 0.1 and 0.5% by mass of Nd in ZnO. For the photocatalytic treatment with pure ZnO and Nd/ZnO, a UV-Vis lamp was used over the aqueous solution containing RhB in a reactor, under controlled stirring and temperature for 150 min. The same photocatalytic test with the three catalysts was carried out for the synthetic effluent prepared in the laboratory. The efficiency of color removal from the solution was evaluated using the UV-Vis spectrophotometry technique. Since the dye is organic, the reduction of organic load after treatment was also monitored by the analysis of chemical oxygen demand (COD). For the characterization of the catalysts, X-ray diffraction (XRD), N2 physisorption (BET, BJH), thermogravimetric analysis, chemical analysis by inductively coupled plasma optical emission spectroscopy (ICP-OES), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance absorption spectroscopy (DRS), scanning electron microscopy (SEM) and zeta potential were performed. By the characterizations of the synthesized Nd/ZnO catalysts, it was observed that the wurtzite structure and almost spherical morphology, presented in pure ZnO, were maintained. The textural analysis indicated materials with low specific area, and Type II isotherm, according to the IUPAC classification. By DRS analysis, the band gap energy EG of ZnO also remained unchanged after synthesis with the two concentrations of Nd, showing that the Nd/ZnO catalysts preferentially absorbed UV radiation. In the RhB aqueous solution, the Nd(0.1%)/ZnO catalyst obtained 100% decolorization, equal to pure ZnO, demonstrating great potential for the removal of dyes. In the synthetic textile effluent, despite the removal of RhB being lower (7%), the Nd(0.1%)/ZnO catalyst showed a significant reduction of the organic load (50%), higher than ZnO (30%). The promising results for COD reduction indicate that Nd/ZnO catalysts can be effective in the degradation of other organic compounds present in textile effluents. Optimizations in the synthesis and operating conditions can further improve the performance of the catalysts for the removal of RhB and other dyes. The research demonstrates the potential of Nd/ZnO catalysts for the treatment of textile effluents, with encouraging results in the reduction of organic load. Further studies are needed to optimize the application of these catalysts in the complete decolorization of textile effluents.