Programa de Pós-Graduação em Engenharia Química - PPGEQ/ITEC

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2308

O Programa de Pós-Graduação em Engenharia Química (PPGEQ) do Insituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA). Sendo aprovado pela CAPES / MEC em 1991, foi oficialmente iniciado em março de 1992.

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Acesso aberto (Open Access)
Adsorção de corantes básicos empregados na indústria têxtil por argila: cinética e perfil de equílibrio
(Universidade Federal do Pará, 2015-10-14) AZEVEDO, Luiz Eduardo Chaves de; VIEIRA, Melissa Gurgel Adeodato; http://lattes.cnpq.br/6611289393148830; CARVALHO, Samira Maria Leão de; http://lattes.cnpq.br/6192858937057152
In this work, the adsorption of textile basic dyes by clay was studied in aqueous solutions and batch system. Clay was obtained from Icoaraci, metropolitan region of Belém, Pará (Brazil) and was used without treatment (A-BRU) and treated by sedimentation (A-TRA). The basic dyes studies were: Basic Yellow 28, Basic Blue 26 (Blue Victory), Basic Yellow 02 (Auramine), Basic Red 01 (Rhodamine 6G) and Basic Orange 02. The clays were characterized by chemical (CTC and charge density), physical (particle size analysis, SBET and He picnometry), thermal (ATG and DTA), mineralogical and morphological analyses (XRD, SEM/EDS and FTIR). Adsorption experiments were carried out to investigate affinity between dyes and clays (qualitative test), initial concentration and pH effects of the dye solutions. The adsorption kinetics data were analyzed by theoretical models. The adsorption equilibrium data were fitted by Langmuir and Freundlich models. The thermodynamic parameters were calculated from adsorption equilibrium data at different temperatures. The concentration of clay particles in the A-TRA increased 100% after sedimentation. In the clay composition minerals as quartzo, kaolinite and illite /muscovite were identified. The SBET increased from the 22.38 m².g-1 (A-BRU) to 33.02 m².g-1 (A-TRA). Significant differences between the values of density and total pore volume of the clays were not observed. Comparatively, the CTC value of the A-TRA increased 300%. The clay surfaces are predominantly negatives, according to the charge density results (Q). There were no significant differences between the thermal analysis results of the samples. From the adsorption affinity tests the more reactive dyes were the Basic Yellow 2 (BY2) and Basic Blue 26 (BB26) and the adsorbent with improved performance was A-TRA. The adsorption kinetics data were well fitted by pseudo-second order (BY2/A-TRA) and intraparticle diffusion models (A-TRA/BB26). The adsorption equilibrium data were well fitted by Langmuir (BY2/A-TRA) and Freundlich (A-TRA/BB26) models. The parameters of the mathematic models indicated that the adsorption is favorable. The thermodynamic parameters showed that the adsorption processes investigated are spontaneous and endothermic.
Acesso aberto (Open Access)
Adsorção de cromo hexavalente por carvão ativado granulado comercial na presença de surfactante aniônico (LAS)
(Universidade Federal do Pará, 2011-09-22) SILVA, Maria Vitória Roma da; CARVALHO, Samira Maria Leão de; http://lattes.cnpq.br/6192858937057152
The hexavalent chromium removal from solutions of anionic surfactant (LAS) by granular activated carbon (GAC) commercial was studied. At CAG characterization was used ASTM standard method (Sauter mean diameter, dDMS e pH) and method BET (S, specific surface area). Adsorbent surface group and PCZ were determined by the method of Boehm and potentiometric titration, respectively. The adsorbent characterization results: dDMS=2.4 mm, pH=9.0,S=677.4 m²/g; basic groups (70%) compared with the acidic groups and PCZ in the range (4.8 – 8.6). Tests of adsorption of the surfactant LAS were carried out in shaker (140 rpm/24 h./27ºC), 2.0 g CAG/50 mL, the LAS concentration were determined by methylene blue standard method. The removal results versus initial concentration and removal versus time of all LAS concentrations were more than 99%. The adsorption of Cr(VI) (5 – 20 mg/L) were carried out in thermostatic bath (140 rpm/27ºC); 2,0 g CAG/50 mL; 1 and 24 hours of processing; without and with addition of surfactant (70, 140, 210, 280, 350, 533 and 700 mg/L). The initial e residual concentrations of metal were determined by 1,5-diphenylcarbazide colorimetric method. The metal removal without the addition of LAS was not satisfactory values were obtained, around 15%. The metal removal with surfactant reached values, around 70% to the lowest metal concentration (5 mg/L) and between (58-65%) for the other concentrations.
Acesso aberto (Open Access)
Adsorção monocomponente e binária de antiinflamatórios não esteroidais (Ibuprofeno e Diclofenaco) do meio aquoso por carvão ativado de resíduos da castanha-do-Brasil (Bertholletia excelsa H.B.K.)
(Universidade Federal do Pará, 2024-09-12) SILVA, João Paulo Sousa da; VIEIRA, Melissa Gurgel Adeodato; http://lattes.cnpq.br/6611289393148830; CARVALHO, Samira Maria Leão de; http://lattes.cnpq.br/6192858937057152
Emerging contaminants (ECs) present in low concentrations have caused damage to water bodies. This study investigated the single-component and binary adsorption of sodium ibuprofen (IBU) and diclofenac (DIC) using activated carbon (AC) produced from Brazil nut shells. The single-component adsorption process of IBU and DIC by AC was denoted as (AC_IBU and AC_DIC), and the binary adsorption process was denoted as (AC_IBU+DIC). The AC was synthesized by chemical activation using phosphoric acid (H3PO4) as the activating agent. The AC was characterized through physical, chemical, and textural analyses, including moisture content, ash content, yield, Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDS), surface pH, point of zero charge (pHPZC), Boehm titration, and nitrogen (N2) adsorption/desorption at 77 K. The AC presented moisture and ash contents of 8.62% and 4.2%, respectively. The XRD analysis confirmed the amorphous nature of the AC, while FT-IR, surface pH, and pHPZC analyses indicated its acidic nature. The specific surface area (SBET) of the AC was 1,383.624 m².g-1 , with a predominance of micropores (VMIC=77.88%). From the analysis of the Central Composite Rotational Design (CCRD), the experimental conditions for the kinetic and equilibrium adsorption tests were defined for single-component adsorption: (i) IBU (pH = 6.1; initial adsorbate concentration, C0 = 50 mg.L-1 ; adsorbent dosage, DA = 0.5 g.L-1 ) and (ii) DIC (pH = 5.5; C0 = 50 mg.L-1 ; DA = 0.5 g.L-1 ). In the single-component adsorption kinetics study, the pseudofirst-order (PFO) and pseudo-second-order (PSO) models resulted in the best fits to the experimental data for the AC_IBU and AC_DIC adsorption processes, respectively, and external mass transfer was the rate-controlling step of the processes. In the singlecomponent adsorption equilibrium study, the Langmuir, Freundlich, Sips, DubininRadushkevich, and Redlich-Peterson isotherms were investigated. The Sips and Freundlich models showed the best correlations for AC_IBU and AC_DIC, respectively. The thermodynamic parameters calculated from the adsorption isotherms showed that the AC_IBU and AC_DIC processes are spontaneous, favorable, and exothermic. The CCRD, the experimental conditions for the binary adsorption kinetics and equilibrium tests were defined: (i) AC_IBU+DIC (C0IBU = 50 mg.L -1 ; C0DIC = 50 mg.L-1 ; DA= 0.5 g.L-1 ). Binary adsorption indicated, through the calculation of the separation factor parameter, that the adsorption preference order by the adsorbent is IBU > DIC, and the interaction between the adsorbates was antagonistic. In the binary adsorption process, the PSO model was well fitted to the experimental kinetics data of IBU and DIC; the intraparticle diffusion (IPD) kinetic models and the Boyd equation were correlated with the experimental data, and external mass transfer was the rate-controlling step of the adsorption processes. The isotherms of binary adsorption (AC_IBU+DIC) at different temperatures (26 ºC, 45 ºC, and 55 ºC) showed inflection points, and after these inflection points, there was an increase in the adsorption capacity values of AC (qe). The qe values of binary adsorption (AC_IBU+DIC) were lower than the qe values of the singlecomponent adsorption processes of the adsorbates IBU and DIC. The reduction percentages of the qe values were approximately 35% to 48% for IBU and about 52% to 53% for DIC.
Acesso aberto (Open Access)
Argila caulinita da região norte do Brasil: caracterização e aplicação como adsorvente de compostos orgânicos (btx) e oxiânions de cromo hexavalente
(Universidade Federal do Pará, 2014-06-26) MIRANDA, Edgar de Souza; VIEIRA, Melissa Gurgel Adeodato; http://lattes.cnpq.br/6611289393148830; CARVALHO, Samira Maria Leão de; http://lattes.cnpq.br/6192858937057152
Clays have a high technical-economic viability for diverse industrial applications. In certain regions of State of Pará, clays are abundant and their extraction occurs intensively, usually used in manufactures of ceramic artifacts. The use of modified clays as adsorbents in the remediation of contaminated water has been the subject of several studies. In this work, a kaolinite characterization and its application as adsorbent in the form "in natura" heat treated in the adsorption of BTX and after modification of its surface by catônico surfactant (HDTMA-Br) was studied, as adsorbent of hexavalent chromium oxyanions. In the study of adsorption of chromium (VI) a factorial design (DCCR) was used, applying variables such as pH and concentrations of surfactant. The clay from Icoaraci District (PA) was classified by sieving, as (NBR 7181). Fractions "in natura" (FR-NAT) and modified (FR-ORG) and (FR-TR), with particles smaller than 44 m and the modified materials were submitted to analysis: x- ray diffraction (XRD), x-ray fluorescence, ATG/DTA, electron microscopy (SEM), determination of surface area (SBET), mercury porosimetry, CTC and pH (pcz). The composition of the clay material were identified: quartz, kaolinite and illite/muscovite (I/M); SiO2 (59.6%) and Al2O3 (17.5%). The property values of: 21.8 SBET m2/g; pore size distribution in the mesopore and macropore region; CTC 17 (meq/100 g) and pHPCZ value equal to 4.3. The analyzes of ATG/DTA samples of organoclays showed that there was loading the clay surface by surfactant (HDTMA-Br). Samples thermally modified natural clay and showed no affinity for organic compounds (BTX). In the study of the adsorption of hexavalent chromium, a factorial design (CCRD) based on pH and concentration of surfactant was used. The adsorption of hexavalent chromium by natural clay was not satisfactory, but the chemically modified clay reached satisfactory values. From the statistical analysis of the adsorption data, only the concentration of cationic surfactant produced statistically significant effects in removing the adsorbate.
Acesso aberto (Open Access)
Modificação da superfície de carvão ativado comercial (CAG) para a aplicação na adsorção de benzeno e tolueno
(Universidade Federal do Pará, 2012-09-28) LOPES, Anna Sylmara da Costa; CARVALHO, Samira Maria Leão de; http://lattes.cnpq.br/6192858937057152; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219
In this work they were studied the characteristics of surface of CAG commercial in natura (CA-1) and treated for (HNO3) (CA-2) and their applications in the adsorption of benzene and tolueno. Characterization of the adsorventes: specific superficial area - SBET and distribution of pores (adsorption of N2/77 K), pH (norm ASTM D3838-05), functional groups of surface (FTIR and method of Boehm). Adsorption tests were performed in batch system and fixed bed column (25 ° C/140 rpm/25 minutes), where the samples were quantified by gas chromatography with headspace extraction by EPA method 0010. The SBET and the average volume of the pores of the adsorbent CA-2 decreased with relation to the values of CA1 as well as the pH. There was an increase of acidic functional groups determined by the method Boehm of the adsorbent CA-2 in relation to CA-1, which was confirmed by determining FTIR, in which the intensity of the absorption bands were more intense for CA-2. Test data were fitted satisfactorily by kinetic mathematical model of pseudo-second order, based on statistical tests applied, with statistically significant differences between the treated adsorbent (CA-2) and in natura (CA-1). Assays were performed equilibrium adsorption, and the results correlated by the Langmuir isotherm, with satisfactory response for that model. From the adsorption system in a fixed bed column and considering the highest volumetric flow (Q = 100 mL / min) used in this system yielded the most important results of adsorption of benzene and toluene using (CA-2) as adsorbent.
Acesso aberto (Open Access)
Síntese e caracterização de materiais carbonáceos e hidróxido duplo lamelar (HDL) para aplicação na adsorção dos contaminantes emergentes ibuprofeno e paracetamol
(Universidade Federal do Pará, 2023-09-14) SOUZA, Lukas Oliveira; VIEIRA, Melissa Gurgel Adeodato; http://lattes.cnpq.br/6611289393148830; CARVALHO, Samira Maria Leão de; http://lattes.cnpq.br/6192858937057152
Emerging contaminants (ECs) are chemical compounds that are inserted into water bodies by society, which cause serious consequences to the aquatic ecosystem, in addition to the production of compounds harmful to human health when effective treatment methods are not implemented. Ibuprofen (IBU) and paracetamol (PAR) are drugs that are included in the group of ECs, classified as non-steroidal anti-inflammatory drug (NSAID) and analgesic, respectively. Activated carbons (ACs) from biomass have been sources of studies in the field of drug adsorption. Lamellar double hydroxides (LDHs) are anionic synthetic clays capable of adsorbing these pollutants from the aqueous medium. The synthesis of AC, composites of LDH and AC are studied as an environmental remedy. In this work, carbonaceous adsorbents and lamellar double hydroxide were used to remove IBU and PAR from the aqueous medium in a batch system. AC was produced from Brazil nut shells (Bertholletia excelsa H.B.K.) and chemically activated using H3PO4 (55% m/v, in mL). LDH and LDH-AC composite were synthesized by coprecipitation method; cationic ratio 3:1 (Mg/Al). The results of chemical and textural characterizations showed that AC has an acid character, point of zero charge (pHPCZ 3.2), hydrophobic (hydrophobicity index, HI of 0.93), high surface area value (SBET 1651.31 m2 .g-1 ) and pore volume (VTOTAL 1194 cm3 .g-1 ). The composite LDH-AC and LDH have a basic character and pHPCZ values (9.2 and 8.2, respectively), HI values (0.35 and 0.44 respectively); the LDH-AC and LDH materials showed SBET and VTOTAL values lower than the AC values: LDH-AC (SBET 79.9781 m2 .g-1 ; VTOTAL 0.067211 cm3 .g-1 ) and LDH (SBET 2.1179 m2 .g-1 ; VTOTAL 0.004648 cm3 .g-1 ). The optimal experimental conditions for adsorption defined in this study were: initial pH of the solution (pH of 3.0), mass of adsorbent (m of 0.015 g) and initial concentration of adsorbate (C0 of 20 mg.L-1 ). The pseudo-second order kinetic model (PSO) showed the best fit to the experimental data of the studied adsorptive processes. The Freundlich isotherm was well suited to the experimental data of the adsorptive processes (AC_IBU) and the Sips isotherm best described the experimental data of the adsorptive processes (LDHAC_IBU and LDH_IBU), at temperatures of 26, 45 and 55 °C. The thermodynamic configurations confirmed that the adsorption process for both systems (AC_IBU, LDHAC_IBU, LDH_IBU) is favorable at low temperatures, exothermic (LDH-AC_IBU and LDH_IBU) and endothermic (AC_IBU) and with greater accuracy of the CA adsorbent by IBU .The adsorbents in this study were classified as potential materials under development for adsorption of the emerging contaminants investigated.

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