Dissertações em Engenharia Química (Mestrado) - PPGEQ/ITEC

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2309

O Mestrado Acadêmico iniciou-se em 1992 e pertence ao Programa de Pós-Graduação em Engenharia Química (PPGEQ) do Instituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA).

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Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Inserção da temperatura no modelo de Langmuir aplicado na adsorção de íons cobre por zeólita 5A : experimental e estatística Bayesiana
(Universidade Federal do Pará, 2025-02-05) SOUSA, Ana Paula Souza de; RODRIGUES, Emerson Cardoso; http://lattes.cnpq.br/7459428211048580; HTTPS://ORCID.ORG/0000-0002-0303-4578; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The treatment of wastewater contaminated by heavy metals represents a significant environmental challenge, with adsorption being one of the main approaches for removing these contaminants, as it exhibits high efficiency in molecular separation. Understanding the interaction between adsorbent and adsorbate is essential for predicting dynamics under different operational conditions. Thus, the use of modeling techniques in isotherm prediction allows for estimating adsorption performance, reducing the need for intensive experimentation, while promoting process optimization. Considering these factors, this work aimed to develop a predictive model capable of estimating adsorption isotherms of copper ions by zeolite 5A at different temperatures. The methodology involved the production and characterization of kaolin waste, metakaolin, and the zeolitic product, utilizing characterization techniques such as X-ray Fluorescence Spectrometry (XRF), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and thermal analyses, including Thermogravimetry (TG), Differential Thermogravimetry (DTG), and Differential Scanning Calorimetry (DSC), to determine the chemical and mineralogical composition, morphology, and thermal stability of the material. Adsorption isotherms of copper ions were performed at temperatures of 25 ºC, 35 ºC, 45 ºC, 55 ºC, 65 ºC, 75 ºC, 85 ºC, and 95 ºC. To study the adsorption mechanisms and the adsorbent/adsorbate interaction, the Markov Chain Monte Carlo (MCMC) method with the Metropolis-Hastings algorithm was used to estimate model parameters and subsequently fit them to the experimental data. Based on these data, the Langmuir model was adapted to incorporate temperature, in the range of 25 ºC to 150 ºC, followed by the calibration, validation, and prediction of adsorption dynamics. The characterization results confirmed the potential use of kaolinitic waste for zeolite synthesis, as well as the successful formation of zeolite 5A through its chemical composition, mineralogy, and morphology. The isotherms revealed that copper removal capacity increased proportionally with temperature, obtaining a maximum adsorption capacity of 754.85 mg/g at 95 ºC. The parameter estimation validated the adaptation of the Langmuir model for different thermal conditions, which proved effective in predicting the isotherms, optimizing the adsorption process at different temperatures, and providing a good model estimate, thus enabling the reduction of extensive experimental activities.
Acesso aberto (Open Access)
Modelagem, simulação e estimação dos parâmetros por MCMC de um modelo que descreve a dinâmica de adsorção em uma coluna de leito fixo
(Universidade Federal do Pará, 2023-01-18) SOEIRO, Wilhamis Fonseca; VIEGAS, Bruno Marques; http://lattes.cnpq.br/1196600058247902; HTTPS://ORCID.ORG/0000-0002-2768-652X; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The treatment of industrial effluents is extremely important for both the environment and human health. The purification of water from polluting components, such as metals and organic compounds, for reuse in the industrial process can be considered one of the main applications in this field. Therefore, there is interest in modeling one of the most used treatment processes, adsorption. Aiming to describe the dynamics of the process in an adsorption column, in this work the method of lines and the pdepe function (matlab) are used to solve the model formed by the mass balance in the liquid phase, linear driving force equation (LDF) and the Langmuir isotherm for equilibrium. An evaluation of the model varying some experiment conditions was carried out, from which results congruent with those found in the literature were observed. In addition, a sensitivity analysis of the phenomenon was carried out in relation to the parameters: Langmuir constant, intraparticle mass transfer coefficient and axial dispersion coefficient. Subsequently, these parameters were estimated using the Monte Carlo technique via Markov chain (MCMC) using experimental data found in the literature. Finally, in general, the estimates were good enough to represent the adsorption dynamics of the evaluated experiments.
Acesso aberto (Open Access)
Produção de material zeolítico em escala semi piloto com o calor proveniente da dissolução de hidróxido de sódio
(Universidade Federal do Pará, 2025-02-05) LIMA, Haianny Beatriz Saraiva; COSTA, Deibson Silva da; http://lattes.cnpq.br/1521124351431087; HTTPS://ORCID.ORG/0000-0002-2165-2628; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The increasing demand for zeolitic materials, due to their high adsorption capacity, selectivity, and ion exchange, highlights the need for more efficient and sustainable production methods. Thus, the study aimed to produce zeolites on a semi pilot scale from kaolin waste, utilizing reactive heat for hydrothermal synthesis and applying these zeolites for copper ion adsorption. The methodology involved drying, disaggregation, and calcination of the kaolinitic waste, followed by the synthesis of the zeolitic material. Characterization of the materials was performed using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA), Differential Thermogravimetric Analysis (DTG), and Differential Scanning Calorimetry (DSC). Subsequently, equilibrium isotherms were conducted at temperatures of 25 ºC, 35 ºC, 45 ºC, 55 ºC, 65 ºC, 75 ºC, 85 ºC, and 95 ºC, along with parameter estimation to study the adsorption mechanisms and the adsorbate/adsorbent interface. Additionally, modeling of the adsorption process for hydrogen sulfide (H2S) and carbon dioxide (CO2) gases was carried out, using experimental data from the literature and employing analytical breakthrough curve models to describe the adsorption phenomenon in continuous flow. The results confirmed the predominant presence of kaolinite in the waste, the efficiency of the calcination process, and the formation of zeolitic material, evidenced by the mineralogical and chemical composition, as well as the cubic morphology characteristic of zeolite 4A and the spherical shapes of sodalite. Thermal analyses elucidated changes associated with water loss and phase transitions. Adsorption tests demonstrated that the produced material was effective in removing copper ions, with a maximum amount adsorbed of 782,76 mg/g at 95 ºC, indicating a good interaction between the adsorbent and the adsorbate. Furthermore, the use of Bayesian techniques for parameter estimation in isotherm and breakthrough curve models enabled a better understanding of the process dynamics. Finally, this study demonstrated the feasibility of producing zeolites from kaolin residue on a semi-pilot scale using reactional heat, offering an approach that is less harmful to the environment and reduces costs through the reuse of industrial waste and energy optimization of the process.

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