Engenharia Química
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Navegando Engenharia Química por Assunto "Adsorção"
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- ItemAdsorção de amina aromática em negro de fumo(Universidade Federal do Espírito Santo, 2021-08-27) Rodrigues, Layza; Profeti, Demetrius; https://orcid.org/0000000345653331; http://lattes.cnpq.br/5030262115789096; https://orcid.org/0000-0002-2999-5377; http://lattes.cnpq.br/8836000296144436; Costa, Ariany Binda Silva; https://orcid.org/0000-0001-7320-3317; http://lattes.cnpq.br/9518055204202962; Passos, Renato Ribeiro; https://orcid.org/000000017730748X; http://lattes.cnpq.br/3882320619443256Aromatic amines, such as ortho tolidine (o-tolidine), are used as raw material for dye synthesis and are also used as reagent for analyzing residual chlorine level within treated drinking water. Due to the high toxicity, these compounds require proper disposal and treatment of wastes to avoid the contamination of water resources. Adsorption is an efficient, low-cost, and simple design technique in the treatment of liquid waste, compared to other conventional methods used in the removal of contaminants. In this context, the study of adsorbent materials has been developed with an emphasis on low-cost and highly available materials. Carbon black is considered a versatile recycled material with great applicability, but despite the suitable characteristics, its use as adsorbent material is still scarce. Therefore, in this work, the removal of aromatic amine (otolidine) from aqueous solutions using carbon black (Vulcan XC 72R) as adsorbent material was studied. The Vulcan XC 72R was characterized by Raman spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS) and hydrogen ion potential corresponding to the zero point of charge (pHzpc). Batch adsorption experiments were performed for evaluating the effects of contact time, pH and concentration on adsorption. Moreover, the study of the adsorption equilibrium and kinetics were carried out. According to the Raman spectrum, Vulcan XC 72R showed two characteristic bands of amorphous and graphitic phase, D and G respectively. Furthermore, the intensity ratio of the two bands showed that the amorphous phase prevails. The SEM images showed a rough surface with small agglomerates uniformly distributed. TGA showed a rapid thermal decomposition, which is assigned the presence of carbon and oxygen. The elemental analysis performed by EDS confirms the TGA results. The pHPZC was found as 6.74. The Avrami kinetic model best fit the process. The Webber and Morris model indicated that the adsorption mechanism is controlled by the boundary layer effect in addition to intraparticle diffusion. The Temkim isotherm best fitted the equilibrium results and a maximum removal capacity around 64 mg g-1 at 25°C. Temperature and pH did not significantly influence the o-tolidine adsorption mechanism. According to the results, the carbon black Vulcan XC-72 R showed high potential to be used as an adsorbent material for decontamination of effluents containing the aromatic amine o-tolidine.
- ItemAdsorção de sulfato por compósito de hidróxido duplo lamelar do tipo Mg6Al2(CO3)(OH)16.4H2O e quitosana(Universidade Federal do Espírito Santo, 2022-08-18) Pessanha, Maria Luiza Gomes Soares; Guimarães, Damaris; https://orcid.org/0000000249323252; http://lattes.cnpq.br/6576377621734943; Altoe, Mario Alberto Simonato; http://lattes.cnpq.br/8481776828705621; Profeti, Demetrius; https://orcid.org/0000000345653331; http://lattes.cnpq.br/5030262115789096The sulfate is a common ion present in several wastewater industrial segments and domestic wastewater. The high concentration of sulfate ion could cause several types of damage, like laxative effect on humans and animals, and is related to incrustation and corrosion of industrial pipes. For the treatment of these effluents, the adsorption technique stands out for the variety of adsorbents. In this work, the SO4 2- adsorption process by the LDH-Mg-Al-CO3 and chitosan composite was carried out. The chitosan was synthesized from shrimp residues from the region, and the composite was synthesized by the co-precipitation method, common in the LDH synthesis. The DD% was determinated for chitosan, obtaining the value of 54,47% which confirms that the material obtained from the deacetylation of chitin can be considered chitosan. The characterization of adsorbents was carried out through the XDR, SEM-EDS and FTIR techniques, showing that the material has characteristic peaks and morphological aspects of LDH-Mg-Al-CO3 and chitosan before and after adsorption, indicating there was no change in the structure of the material. The kinetic test showed the SO4 2- loading by the LDH-Mg-Al-CO3 and chitosan composite was 234,15 mg g-1, and the equilibrium time was reached in 180 minutes. Applying kinetic models to the data, pseudo-first order (R² = 0,93) and pseudo-second order (R² = 0,91) resulted in similar values, and it was not possible to conclude which of them best fitted the kinetic data. With the isotherm study, it was observed the Redlich-Peterson model (R²= 0,96, β=0,84) was the best model adjusted to data, assuming behavior of the Langmuir isotherm with monolayer adsorption, because the β parameter is closer to 1. In view of the results obtained throughout the study, it was possible to observe that there was a synergy between LDH-Mg-Al-CO3 and chitosan in the composite, which resulted in better loading results of SO4 2- adsorption, in relation to the precursor adsorbents.
- ItemAvaliação da adsorção da etilenotioureia utilizando esmectita Cu(II) como adsorvente(Universidade Federal do Espírito Santo, 2019-02-22) Bazzarella, Andréia Zacchi; Profeti, Demetrius; Profeti, Luciene Paula Roberto; Neves, Mirna Aparecida; Altoe, Mario Alberto Simonato
- ItemEstimação de parâmetros e estados via filtros Bayesianos em um processo de adsorção de SO_4^(-2) em resinas de troca iônica.(Universidade Federal do Espírito Santo, 2018-02-23) Carvalho, Rhynara Niandra Silva de; Dutra, Julio Cesar Sampaio; Guimarães, Damaris; Silva, Wellington Betencurte da; Pinheiro, Christiano Jorge Gomes; Costa, José Mir Justino daIn the adsorption processes in fixed bed columns, which is very applied for the treatment of effluents, the measurements obtained at the end of the column allow to identify the efficiency of the process, but are accompanied by noise from measuring equipment. Since such systems are considered to be dynamic, therefore, the realtime monitoring of this process becomes a major challenge for the industry in order to providing a more accurate analysis of the process. Thus, the present work demonstrates the efficiency of the particle filter known as Sampling Importance Resampling (SIR) as a fast and robust tool for estimation and monitoring in a problem of sulfate ions (SO4 -2 ) removal in a fixed bed adsorption column. The fixed bed model and the mass transfer rate model were used to represent the whole process and experimental measures were used to validate the methodology used. Particle filter performance was evaluated through Root Mean Square Error (RMS) and Mean Absolute Deviation (MAD) analysis, as well as computational time verification. It was observed that the generated particles did not show degeneration by means of the verification of effective sample size (Neff) and the SIR filter presented better performance in the estimation when a higher value was used for the number of particles (Np) and for the deviation of the model of evolution (sm). In addition, flow estimation was of great importance for the filter to be able to make reliable estimates. In the analysis of the isotherms, the choice did not influence the estimation of the states. It was observed satisfactory results were observed and with remarkable applicability, once the use of the SIR filter has not yet been used to this type of process in the literature.