Centro de Tecnologia
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Article Adsorção de Cu2+ e Cr3+ em efluentes líquidos utilizando a cinza do bagaço da cana-de-açúcar(Associação Brasileira de Cerâmica - ABCeram, 2015) Melo, Marcus Antônio de Freitas; Ferreira, P. P. L.; Braga, Renata Martins; Teodoro, N. M. A.; Melo, Vítor Rodrigo de Melo e; Melo, Dulce Maria de AraújoThe liquid effluents of some industries have traces of harmful metals having bioaccumulative property, which contributes to the increase in their toxicity. Given the industrial growth, and the consequent increase in contaminant emissions in wastewater, the adsorption is among the operations applied to decrease the concentrations of metals in order to meet current environmental regulations. The residual biomass has been gaining attention in the treatment of these effluents by a renewable material and cost as compared with conventional adsorbents. The present work aims to evaluate the ashes of the efficiency of sugarcane bagasse (CBC) on the adsorption of metal ions Cu2+ and Cr3+, through isotherm adsorption tests. The CBC was characterized regarding its microstructure, chemical composition, specific surface area and morphology, and the adsorbate was analyzed by flame atomic absorption. The CBC has performed effectively as a bioadsorbent for both synthetic solutions containing Cu2+ and Cr3+ ions present in liquid effluents. The isotherms adsorption showed a growing profile, indicating the average removal efficiency of 97.3% to 96.4% Cr3+, and Cu2+ to, this material can be applied as an adsorbent in industrial effluentsArticle Caracterização e uso de xisto para adsorção de chumbo (II) em solução(Cerâmica - Associação Brasileira de Cerâmica, 2006-09) Melo, Marcus Antônio de Freitas; Pimentel, Patrícia Mendonça; Silva Júnior, C. N.; Melo, Dulce Maria de Araújo; Maldonado, G.; Henrique, Daniele de MacedoThere has been a growing interest in the use of cost-effective materials to remove heavy metals from wastewater. New processing techniques and adsorbents including natural clays, synthetic resins, peat and chitosan have been studied aiming at replacing activated coal. In the present investigation, retorted shale, a solid residue of the thermal transformation of oil shale, was characterized with the objective of preparing heavy metals adsorbents. In addition to the direct environmental benefits from the technology to wastewater, Brazil has the second world reserve of oil shale. The fine residue was fully characterized by different techniques including particle size determination, thermogravimetric analyses, BET, FTIR, X-ray diffraction, and SEM/EDS. The characteristics of the powder were appropriate for adsorption. Batch adsorption studies in Pb2+ synthetic solution were performed. The removal of Pb 2+ ion was found to be above 85%Article Adsorption of crude oil on anhydrous and hydrophobized vermiculite(Elsevier, 2003-04-15) Melo, Marcus Antônio de Freitas; Farias, Robson Fernandes de; Silva Júnior, Umberto Gomes da; Silva, Adaı́lton F. daArticle Caracterização e usos de argilas bentonitas e vermiculitas para adsorção de cobre (II) em solução(Cerâmica - Associação Brasileira de Cerâmica, 2002-12) Melo, Marcus Antônio de Freitas; Santos, C. P. F. dos; Melo, Dulce Maria de Araújo; Vitor Sobrinho, EledirMineral clays have been extensively used for metal removal. The process involves precipitation, ion exchange and adsorption. The present investigation assessed the adsorption of Cu (II) solution by natural vermiculite and both natural and synthetic bentonite. Tests were carried out at ambient temperature for the main parameters of the process, i.e., pH, contact time, and adsorbent content. Atomic absorption was also carried out both for the floater and solid residue. All raw materials used herein, i.e., sodic bentonite from Campina Grande-PB, sodic bentonite from Wyoming-USA, synthetic sodic bentonite and vermiculite from Piaui, were characterized both before and after adsorption of Cu (II) solution by chemical analysis, TG, DTA, BET surface area, infrared spectroscopy, X-ray diffraction, and pH determination. The results showed that clay minerals adsorb heavy metals by ionic exchange. Vermiculite was the most efficient material studied adsorbing 40.9% of Cu solutionArticle Oil recovery by ionic surfactant and sweep efficiency study in sandstones(Associação Brasileira de Pesquisa e Desenvolvimento em Petróleo e Gás, 2008) Curbelo, Fabíola Dias da Silva; Garnica, A. I. C.; Dantas, Tereza Neuma de Castro; Barros Neto, Eduardo Lins deIn this work, we have investigated the oil recovery performance, adsorption, sweep and displacement efficiency by ionic surfactants. In the adsorption and recovery assays, a surfactant aqueous solution at a concentration 30% above the corresponding critical micelle concentration (c.m.c.) was used to ensure micelle formation. The results obtained showed that the ionic surfactant recovered 89.0% of the original oil in place. High efficiency was provided both in the displacement assays, observed by oil recovery in core, and in the swept, due to the fact that the viscosity of the surfactant solution (3.0 cP) was close to that of the oil (2.9 cP)Article Study of new alternatives for removal of sulfur from diesel(Associação Brasileira de Pesquisa e Desenvolvimento em Petróleo e Gás, 2014) Dantas, Tereza Neuma de Castro; Dantas Neto, Afonso Avelino; Moura, Maria Carlenise Paiva de Alencar; Barros Neto, Eduardo Lins de; Duarte, Kahildete Rodrigues ForteThis work aims to develop new methods of removing sulfur from commercial diesel using surfactants and microemulsion systems. Its main purpose is to propose new technologies and add economic viability to the process. First, for the choice of the surfactant, a preliminary study was made using an extraction formulation based on a Winsor-I microemulsion system formed with either dodecyl ammonium chloride (DDAC) or ethoxylated nonylphenol (RNX95) as surfactant. It was verified that RNX95 was the best surfactant to be used in microemulsion systems to modify adsorbent surfaces, and as extracting agents in liquid-liquid extraction operations. Vermiculite treated with a microemulsion system was used as adsorbent. The microemulsion system used in the modification of the vermiculite surface was composed of RNX95 (surfactant), butan-1-ol (cosurfactant), n-hexane (oil phase), and distilled water (aqueous phase). Batch adsorption tests were carried out to assess the ability of vermiculite to adsorb sulfur from diesel. The experiments were performed according to a factorial design (23 ) evaluating the effects of temperature, concentration of CaCl2 in the aqueous phase, and vermiculite granule size. The best result was obtained at 60°C, 1500-ppm CaCl2 aqueous solution, and -48+65 mesh vermiculite particle size. Under such conditions, the vermiculite adsorbed 4.24 mg of sulfur/g of adsorbent, corresponding to 68.7% sulfur removal. Two and six-stage liquid-liquid extraction experiments were performed using the same surfactant-to-diesel ratio. The process yielded 46.8% sulfur removal in the two-stage experiment, and 73.15% in the six-stage one. An alternative study, for comparison purposes, was made using bentonite and diatomite as adsorbents. The batch experiments were done using microemulsion systems with the same aqueous phases used in the vermiculite study, with 20-ppm and 1500-ppm BaCl2 solutions. With bentonite, the best adsorption capacity was 7. 53 mg sulfur/g adsorbent with distilled water as aqueous phase of the microemulsion system, and with diatomite the best result was 17.04 mg sulfur/g adsorbent using a 20- ppm CaCl2 solutionArticle Biological and chemical analysis in the detection of methamidophos in soil: ecotoxicological test with liquid chromatography/mass spectrometry(International Journal of Current Research - IJCR, 2016-03-16) Chiquetti, Samanta Cristina; Dantas, Tereza Neuma de Castro; Silva, Djalma Ribeiro da; Barros Neto, Eduardo Lins de; Medeiros, Guilherme Fulgêncio de; Bertoletti, EduardoArticle Synergism study of mixtures of ionic and nonionic surfactants in enhanced oil recovery adsorption(ASSOCIAÇÃO BRASILEIRA DE PETRÓLEO E GÁS - ABPG, 2017-07-18) Curbelo, Fabiola Dias da Silva; Garnica, Alfredo Ismael Curbelo; Dantas, T. N. Castro; Barros Neto, Eduardo Lins deAdsorption of surfactants from aqueous solutions in porous media is fundamental in enhanced oil recovery (EOR) because surfactant loss reduces the effectiveness of the chemical solution injected, making the process economically unfeasible. This paper analyzes surfactants’ synergistic effects in adsorption and enhanced oil recovery. This study used nonionic (nonylphenol 20 ethylene oxide – R200) and anionic surfactants (saponified coconut oil – OCS and base soap - SB) with the two mixtures studied (R200/OCS and R200/SB). The mixture R200/SB, due to its higher viscosity because of the presence of SB, saturated the ionic surfactant (SB) faster, reaching a higher oil recovery (70.0%). The addition of SB surfactant in the R200 solution led to an increase in oil recovery (70.0%) when compared to R200 alone (64.5%)Article Copper removal using carnauba straw powder: Equilibrium, kinetics, and thermodynamic studies(Elsevier, 2018-10-19) Silva, Alfredo José Ferreira da; Moura, Maria Carlenise Paiva de Alencar; Santos, Erinéia da Silva; Pereira, Jéssyca Emanuella Saraiva; Barros Neto, Eduardo Lins deArticle Removal of organic contaminants from a synthetic oilfield produced water by adsorption process using vegetable and bone bovine activated carbons(ASSOCIAÇÃO BRASILEIRA DE PETRÓLEO E GÁS - ABPG, 2019-10-08) Carvalho, P. C. A. P.; Foletto, Edson Luiz; Dotto, Guilherme Luiz; Rackov, C. K. O. S.; Barros Neto, Eduardo Lins de; Chiavone Filho, Osvaldo