Avalia??o da casca da semente da seringueira como adsorvente no tratamento de efluentes aquosos: estudo cin?tico e termodin?mico

• Ano de defesa: 2019
• Autor(a) principal: Megale, Eliana Zaroni
• Orientador(a): Mendes, Marisa Fernandes
• Banca de defesa: Cunha, Fab?ola Oliveira da, Pereira, Cristiane de Souza Siqueira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Engenharia Qu?mica
• Departamento: Instituto de Tecnologia
• País: Brasil
• Palavras-chave em Português: bioadsorvente; isoterma de equil?brio; cin?tica; MEV
• Palavras-chave em Inglês: bioadsorbent; isotherm; kinetics; SEM
• Área do conhecimento CNPq: Engenharia Qu?mica
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/5278

The removal of dye present in industrial effluents has been a subject of great interest in recent years, due to the irreversible environmental damage caused by its improper disposal in aqueous streams. Among the diversity of processes that can be applied to treat these streams, the adsorption technique has been studied because of the high efficiency and low cost. Moreover, the motivation is the possibility to use as adsorbents many biochars. Therefore, in this work, it was decided to study the adsorption potential of the rubber seed shell (Hevea brasiliensis), in four forms (in nature, calcinated, acid activated carbon and basic activated carbon) for the removal of the methyl orange dye. All the four adsorbents were evaluated, and it was observed that the in nature material did not have adsorption potential. On the other hand, the application of calcination, acid activation and basic activation provided higher adsorption capacities, but the acid activated carbon was more efficient due to the increase of the porosity employed by the pre-treatment, favoring the adsorption process. As a result, the activated carbon was used to evaluate the effects of the solution initial concentration (25-150 mg/L), temperature (25, 35 and 45 ?C), and the contact time (0-360 min), as well as to study the kinetics (pseudo-first order, pseudo-second order and intraparticle diffusion), the equilibrium isotherms (Freundlich, Langmuir, Temkin and Dubinin-Radushkevich) and the thermodynamic variables (?H, ?S e ?G) of the adsorption process. The increase of the initial concentration and temperature resulted in improvements in the adsorbed amount, indicating the endothermic nature of the process. The kinetic and isotherm models that best fitted to the experimental data were the pseudo-second order and Freundlich models, respectively. The thermodynamic study indicated that the adsorption process is endothermic, only spontaneous for the initial solution concentration of 25 mg/L, and indicated a good affinity between adsorbent and adsorbate.