Matrix acidizing is one of the well stimulation techniques that consists of pumping an acid solution at a pressure lower than the fracture pressure of the rock. In carbonate formations, as a result of the acid-calcite reaction, part of the rock is dissolved and high conductivity channels, called wormholes, are created. One of the major challenges associated with simulating this type of process is to incorporate the heterogeneities inherent in carbonate rocks into the numerical meshes. The main objective of this work is to simulate acidification in carbonate rock plugs musing the initial porosity field obtained from a microCT image. Two-scale modeling was used, with the balance of the amount of movement carried out using the Navier-Stokes-Brinkman approach. The simulations were carried out in a code developed in openFOAM, varying the speed of the acid on the face and obtaining the PVbt (Pore Volume to Breakthrough) for each condition. Mesh convergence analyses and the impact of varying the inlet interstitial velocity were carried out. Simulation results were compared with initial porosity fields generated using the uniform, normal and lognormal distributions. The initial porosity and permeability distributions obtained were consistent with the microCT image. Variations in the number of cells had no significant impact on the PVbt. By varying the injection speed on the face, it was possible to obtain the uniform, conical, branched, dominant wormhole, dissolution on the face and compact dissolution patterns, obtaining the PVbt curve to determine the optimum point (lowest PVbt). For the model developed from the image, the lowest PVbt obtained was 0.262 with an input speed of 2,12 . 10^-4 m/s. For the models with uniform, normal and lognormal porosity distributions, the lowest PVbt values obtained were 0.276, 0.261 and 0.309 at an input speed of 8,3 . 10^-5 m/s. The results presented showed that the methodology used to obtain porosity fields from microCT images can be used to obtain results that are more representative in terms of accounting for rock heterogeneities.

The present dissertation aims to understand the DOS, UV-Vis and Circular Dichroism spectroscopy of algal toxin molecules Anatoxin-a, Anatoxin-a(s), Cylindrospermopsin, Homoanatoxin-a and saxitoxin. The Gaussian 09W software is used for theoretical energy minimization calculations corresponding to the MM+ molecular mechanics method with the functional level B3lyp/6-311++G(d,p), used both in geometry optimization and in calculations of UV-Vis spectrometry, State Density and Circular Dichroism of molecules in water solvents. The research results show relevant UV-Vis spectra, State Density and Circular Dichroism, Raman and IR (infrared) and in the preparation of Tables that identify the modes of molecular vibrations of the aforementioned toxins, which led to identifying the types of vibrations in each region contained within specific wavelength ranges. They found that each algal toxin has a specific Gap, which makes it possible to identify the one that presents greater reactivity in relation to the other (smaller Gap) or greater stability (higher Gap). For the MEP (electrostatic potential map), it makes it possible to identify the region with the highest concentration of negative charges, which can be useful for identifying regions of reactivation between the toxin and a protein. The research is concluded considering the experimental comparison between the cylindrospermopsin toxin with graphical analyzes of the UV-Vis spectra, which led to a percentage of 0.5% as a margin of error, which was very significant, showing that the B3lyp base /6-311++G (d, p) chosen was very significant for comparing theoretical and experimental data.

Cassava is found in abundance in nature, especially in the State of Pará, from nthem it is possible to extract starch, rich in amylose and amylopectin, components that help in the production of bioplastics. Furthermore, Pará is the largest producer of açaí, a raw material that is also natural and has antioxidant, phenolic and healing compounds. The oil extracted from açaí has the same characteristics found in the pulp, which makes it an excellent agent for incorporation into
products added on polymers. The present study reports the characterization of cassava starch and evaluation of the biological characteristics of açaí oil, for the production of an active bioplastic, with the aim of incorporating the benefits found in the oil. To this end, some tests were carried out using plasticizers such as glycerol, ethylene glycol and sorbitol in the composition, to structure the
bioplastic, where glycerol proved to be the most viable option. Cassava starch was dried at three temperatures: 45, 60 and 75°C, for the drying curve, and it was observed that starch dried at 45°C had better performance, without significant losses in its structure. The analyzes carried out were relevant to detect the potential of açaí oil on incorporating bioplastic. It is known that the characterization of the oil is essential to ensure its quality. Açaí oil was evaluated for 1H NMR, which was essential for quantifying iodine (67.05 I2/g) and saponification (109.06 mg KOH/g) levels. Furthermore, the oil also presented satisfactory results, with emphasis on the following activities: antioxidant (532.56 μM of Trolox/g), anticancer (with reduced metabolic activity and cell viability for
the AGP01, SK19 and VERO lines, with IC50 75 .30; 80.15; 73.05 μg/ml, respectively), in addition to the promising result in anti-inflammatory activity that tested target gene TNF-α (tumor necrosis factor alpha) and detected that the samples analyzed with the oil presented anti-inflammatory effect even after 24 hours of exposure, which confirms its bioactivity. This highlights the gigantic potential of using açaí oil for improvement and application in new products, as it has proven to be a strong ally against infectious and cancerous diseases, with cell recovery capacity. Therefore, the oil was incorporated into a polymeric matrix based on cassava starch, which resulted in bioplastic with a thickness (0.157 mm), PVA (19.39 g.mm.KPa-1.d-1.m- 2), transparency (2.60), and one of the highlights was the colorimetric analysis that was able to detect shades of green in the sample, represented by values of -5.75 (a*) and 10.90 (b*), identifying the presence of chlorophyll from açaí oil. In this way, it was possible to note the relevance of using this oil for inclusion in products that bring benefits to the end consumer, in order to take advantage of the chemical and biological properties that this oil has in its composition, as is the case of bioplastic, which contributes to the pharmaceutical sector for presenting bioactivity, in addition to its possible use in the packaging sector and helping to reduce the use of plastics from petroleum, as it is a 100% biodegradable plastic.

The adaptation of industrialization in the form of a sustainable economy, technological advances and computational benefits have motivated the use of process simulators to evaluate the potential of oleaginous species native to the Amazon region through fast and automated simulations. Therefore, the objective of this work was to apply the AspenHYSYS simulator to describe the tucumã-do-Pará oil extraction process using supercritical carbon dioxide as solvent. The feasibility of simulations of the tucumã oil extraction process using the mathematical models of Menezes et al. (2023) and Tan and Liou (1989) were comparatively evaluated with experimental data previously selected from the literature. Simulations of the supercritical extraction of tucumã-do- Pará oil found that the model by Menezes et al. (2023) was adequate to describe the experimental kinetic data for all evaluated systems, which presented an RSD with a lower value of 0.57. The energy and material cost were calculated, and the value obtained (2.82 R$/g of oil) together with the high concentration of bioactives in the product demonstrate that the studied process presents a positive cost-benefit ratio. An increase in scale was carried out for beds 1, 5, 10 and 50L. For beds of up to 10L, an adequate projection of the process was obtained, considering that the deviations obtained were less than 1, however, for 50L, the adjustment presented a deviation of 58, which may infer that the model used has a scalability limit. Simulations of the, supercritical extraction of tucumã-do Pará oil, using AspenHYSYS, led to values consistent with the experimental data, thus confirming that the studied plant proved to be an effective tool for the study of the process.

The chemical contamination of water by dyes resulting from the disposal of industrial effluents triggered the need to develop technologies in order to remove such pollutants. Occurring naturally in the Amazon region, cassava differs from other varieties of cassava because of its high humidity and low starch yield. as part of a project on cassava technologies, this study analyzed the best conditions for the production of activated carbon from cassava solid residues for the adsorption of methylene blue dye. The Box-Behnken experimental design was used to determine the optimal production conditions. First, a physical-chemical analysis of the precursors was carried out, then 30 coal samples were produced according to the plan. The maximum amount adsorbed and removal percentage were determined under finite bath conditions, at a concentration of 120 mg/L and with 0.01 g of charcoal sample. The best conditions of temperature, acid concentration and time of contact with heat were observed at 600 oC, 25% and 3h for peel and 600 oC, 10.2% and 3h for pulp. These samples were submitted to physical-chemical analysis and morphological characterization by scanning electron microscopy and by infrared with Fourier transform. For the adsorption kinetics tests, the models that best fit the experimental data were intraparticle diffusion for shell and pulp coals, and for the adsorption equilibrium tests, the Freundlich and Langmuir models fitted best for shell and pulp, respectively. The analysis of the adsorbents reveals a lower concentration of functional groups, but in the pulp adsorbent the loss of functional groups related to oxygen-containing groups can be observed, which may help to explain the lower adsorption capacity observed for the pulp adsorbents. The activated carbons produced from solid residues of cassava roots (pulp and peel) showed that, under the conditions used in this work, they can be applied as effective bioadsorbents in the removal of methylene blue in aqueous solution.

CO2 capture, utilization, and storage techniques, known by the acronym CCUS (Carbon capture, utilization, and storage), have been studied as primary tools for achieving the decarbonization targets, stipulated to slow down the rise in temperature earth average. In this context, geological storage consists of injecting CO2 into the rock formation, so that it is trapped in saline aquifers, coal deposits or oil reservoirs. CO2 injection is already carried out, for example, in the Brazilian pre-salt fields, where the oil produced has a high concentration of CO2 in its composition. It is expected that other geological structures can be used for geological carbon storage. However, the geological sites must be carefully selected, one of the key points being the geochemical stability due to the contact of CO2 with the rock formation. Thus, this project aimed to study the process of interaction of CO2 with formations of carbonate rocks, to increase the fundamental knowledge regarding the processes of rock-fluid interaction in the geological storage of CO2. The methodology included the analysis of the petrophysical properties of commercial carbonate rocks (Indiana Limestone and Silurian Dolomite) and of the dolomitic carbonate sample from the Itaituba Formation, before and after exposure to CO2 in the form of carbonated water and in the supercritical form. We also used X-ray microtomography to study the porous structure of samples at different scales. The results showed that the Indiana rock samples present distributed porosity, being essentially formed by structures predominantly composed of pallets, skeletal grains, ooids and shell fragments. The samples of Silurian Dolomite presented a structure formed by less pores, however larger and more concentrated. The rock samples from the Itaituba formation showed very low porosity and permeability. Rock-fluid interaction studies will show changes in rock matrices resulting from the dissolution process. The microtomography technique of x-ray was used in the imaging of the samples to visualize the change in the morphology of the rocks, the technique allowed the comparison of before and after CO2 attack. The DRX and FRX analyzes showed positive results regarding the mineral composition of the samples used. The results of this work will contribute to the reduction of uncertainties related to the processes and mechanisms of the geological storage of CO2.

Carbonate acidizing is a well stimulation technique used to improve oil production. This technique aims to inject acid into the formation below the fracture pressure, creating conductive paths resulting from the dissolution of the rock by the acid. In the laboratory, most experiments are performed on rock samples saturated with water, due to the assumption that there is only water in the formation, after preflush and previous drilling and completion operations. However, different saturation conditions can occur in the formation. One of the scenarios is if you have some oil saturation in the porous medium. This work proposes to carry out experiments and evaluate the influence of oil saturation on the acidification of carbonates. Reactive flow experiments were carried out, with HCl 0.5M and HCl 15%, in rocks saturated with water. For oil saturation, a high flow rate of 20 mL/min was used for the two acid systems at room temperature; and with HCl 15% the study was deepened with a temperature of 45°C at a flow rate of 1 and 20 mL/min. X-ray microtomography was used to image the sample to visualize the wormhole morphology, the influence of oil on the structure of the wormhole and the value of PVBt will be compared, highlighting the impact of oil for each acid concentration. The HCl 0.5M PVBt curves have values above HCl 15% in water-saturated samples. This effect is due to the lower concentration promoting a lower dissolution power of carbonates. The analysis of the wormhole area and porosity distribution after acidification shows that the oil influenced the efficient propagation of the wormhole and lower consumption of acid. The PVBt values are lower when the sample is saturated with oil and at a temperature of 45°C the value decreases by about 54% when using HCl 15% at 20 mL/min.

The most important worry involving the generation of industrial waste is associated with the effects those materials can have on the environment and human health, considering that the dangerous waste produced by the industry requires particular care and attention, because if managed improperly, it can become a serious environmental threat. Therefore, this paper demonstrates the studies conducted to recycle the residue from the Bayer process, as a raw material in the production of synthetic aggregate, intended for civil construction. Furthermore, this paper has analyzed the influence of calcium oxide in the solid-state reactions during sintering in the production of ceramic aggregates based on residue from bauxite processing because this oxide, besides being a melting material, also influences the formation of glass with lower viscosity, and may positively influence the mechanical strength of the material. For the conformation of the aggregates a composition based on bauxite residue and silica was adopted with and without the addition of calcium oxide. The pellets were produced in a rotating cylinder and sintered at temperatures of 1180, 1200 and 1250 °C with a burn time of 3 hours. For the characterization of the raw materials the techniques of X-ray Fluorescence (XRF), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TG) were employed. For the characterization of the aggregate, scanning electron microscopy (SEM), XRD and DSC tests were performed on the formulations composed of bauxite residue and clay with and without the addition of calcium oxide. The physical and technological properties determined were: Water absorption, apparent porosity and apparent specific mass. The results of this paper indicate that bauxite residue can be used as a source of alternative raw material for the production of synthetic ceramic aggregate. The results obtained also prove that the use of calcium oxide directly influenced the solid state reactions, especially in the mullite formation reaction. Therefore, the production of synthetic aggregate with the addition of calcium oxide proved to be a promising destination for the Bayer process residue.

Coronavirus is caused by the SARS-CoV-2 virus, named 2019-nCoV, has demonstrated rapid proliferation and scarcity of treatments with proven efficacy. Thus, research with nanomaterials has been widely suggested, can provide a viable alternative for virus inactivation, carbon nanospheres, act directly on biological structures because they present matrix-like structure with active components that can be adsorbed on the surface. Thus, different parts of the SARS-CoV-2 virus (M-Pro, S-Gly and E-Pro) can be inactivated or detected with nanotechnology. The computational procedures performed in this work were developed with the SwissDock server and the GROMACS software, allowing to extract relevant data on affinity energy, distance between molecules, free Gibbs energy and mean quadratic deviation of atomic positions, surface area accessible to solvents. DOC shows that all ligands have affinity for the active sites of the receptor. Nanospheres interact favorably with all proteins, presenting promising results, especially C60, which presented the best affinity energy and RMSD values for virtually all protein macromolecules investigated. Therefore, C60 presented the best stability during the DOC process and in the Molecular Dynamics process, while the analyses of the other structures showed promising results that can be used for other proteases.

Este trabalho tem como objetivo investigar a influência da temperatura e da impregnação química, na composição textural e morfológica de bioadsorventes produzidos via craquemento térmico das sementes de caroço de açaí. Os experimentos foram realizados a 400°C e 450°C, utilizando um reator em escala piloto. A eficiência do processo foi analisado em termos dos produtos líquidos e sólidos, foi verificado que com o aumento da temperatura do processo e com impregnação química com NaOH na matéria prima ocorreu uma maior conversão de produto líquido orgânico. As análises elementares de produtos sólidos, mostraram com ocorre uma carbonização com o aumento da temperatura do processo e ocorre a presença de sódio devido a impregnação. A caracterização textural e morfológica ocorreu com a análise de FT-IR, MEV/EDS, FRX e B.E.T. O produto em fase sólida obtido via creaqueamento do caroço de açaí in natura e impregnado com solução de NaOH (2M), nas temperaturas de 400°C e 450°C. A cinética de adsorção de ácido acético investigada em 5, 10, 15, 20, 60, 120 e 180 segundos. As isotermas de adsorção mostraram que o biocarvão produzido a 450°C e com impregnação química de NaOH foram capazes de remover em maior quantidade ácido acético.

The objective of this work was to study the kinetics of bio-oil production through the pyrolysis of raw acai kernel on a pilot scale, focusing on the yield of products obtained at temperatures of 350°C, 400°C and 450°C at 1 atm. In addition to studying the results obtained via gas chromatography coupled to mass spectrometry (GC-MS) of the bio-oils produced. For the experimental procedure, the raw material used was the açaí pits, a residue obtained after the process of pulping the fruit. This material went through stages of drying, comminution and sieving to remove unwanted residues for the process. This material was characterized by ndetermining the moisture content, volatile content, ash content, fixed carbon content and higher calorific value. After the characterization process, the lumps were submitted to the pyrolysis process and, after the due separation processes, the bio-oil obtained was submitted to tests to determine its acidity index, absolute density, refractive index, and dynamic viscosity. After this step the bio-oil was subjected to analysis in a gas chromatograph coupled to a mass spectrometer. The moisture content found in the açaí seeds was approximately 40% and the yield of the pre-treatment step was 46.84%. In the physical characterization of the seeds the results found were within the existing literature showing interesting properties for use in the pyrolysis process. With the increase in temperature there was a favorable production of bio-oil and biogas, while for the biochar there was a decrease in its mass produced. The physical-chemical analyses applied to the Bio-Oil produced were within the values that are available in the literature for this same type of material, however, it is still outside the standards that the National Petroleum Agency establishes for green diesel. The increase in temperature reduced the acidity of the bio-oil and increased its viscosity and density. With this, there was a reduction 92.87 (Exp.1) to 70.26 (mg of NaOH/g of sample) (Exp.3) and the lowest kinematic viscosity obtained of 77.62 mm2/s for the pyrolysis process with the temperature set up to 350°C. The chromatographic analysis showed that the compound with the highest percentage of peak area was phenol, where the average retention time was 8,466 min-1 independent of the programmed temperature. Exp.2 had the highest yield in terms of aromatic hydrocarbons and the lowest yield for phenols, showing that there is no linear behavior with temperature change.

Due to the study of new drugs to combat the SAR-CoV-2 virus, which is causing the Covid-19 pandemic. In this work, we address the use of three drugs (rodathin, scedapine C and sequinadoline A) as possible inhibitors of SARS-CoV-2, as they have several interactive properties, showing potential to be used in the treatment of COVID-19 disease. Molecular docking provided information about the affinity energy that was -8,186, -9,617, -7,866, -7,601, -7,527 kcal/mol, for the best conformations with sequinadoline A. Molecular couplings and affinity energy showed that active site residues of macrostructures, and we analyzed the electrostatic potential map to predict some promising candidates for virus antagonists, which if confirmed through experimental approaches, could contribute to the resolution of the global crisis of the COVID-19.

The mineral extraction and cutting industry discards materials that can be reused and, in search of a better destination and reduction of environmental impacts, they have to use these rejects in the manufacture of compact materials. In this way, polymeric matrix composites with marble and granite residue filler in the granulometry of 100, 200, 325 and 400 mesh of the Tyler series and hybrid composites with residue in the ranges of 100 and 200 mesh and sisal and plant fibers were manufactured. curauá in lengths of 15 mm in order to verify the particle size influence of the particles on the properties of the composites. The production methodology was based on the hand lay-up method, manual lamination in composites, associated with pressing in a rectangular metal mold. The polymer matrix consisted of an isophthalic polyester resin adjunct with catalytic materials and the dispersed phase was defined as a mass fraction, in which the composites with residue presented proportions of 5, 10, 15, 20 and 25% and the hybrid composites presented the addition fixed proportion of 3% fiber. Morphological characterizations were performed on the residue and fibers, in addition to mineralogical characterization on the residue. In the composites, physical tests, horizontal flammability and mechanical test of tensile strength were carried out. The characterization in the residue indicated components such as quartz, dolomite and calcite, as well as angular morphology and the fibers showed rough surface and irregularities. The physical characterization of them composites showed varying values, showing the sensitivity of the residue in terms of proportion and particle size. The flame resistance of the composites were effective with a gradual reduction of approximately 48% for the particle size of 100 mesh and flame extinction in the compositions MG-10 (325 mesh) and MG-10/F3 (100 mesh + FC) and the analysis of tensile strength obtained results superior to the full matrix with an increase of 58% for the composite in the range of 100 mesh of residue. The research showed the feasibility of using dispersed phase materials and the possibility of using them in various applications such as dividing walls, ceilings, residential gutters, internal coatings in the automobile, marine and air industries, respecting their characteristics.

Photochemical reactors have shown promise in the treatment of liquid effluents, thus, two usual prototypes have been developed in these applications, a solar photoreactor with a compound parabolic collector (CPC) and an annular photoreactor with an ultraviolet lamp. In the pilot- scale CPC solar photoreactor, the hydrodynamic study at different flow rates (100, 150, 200, 300 and 400 Lh-1 ) was evaluated, and the residence time distribution (RTD) was measured, with the application of a pulse type disturbance using methylene blue dye as tracer. In the RTD curves, the piston-flow with axial dispersion profile, in addition to “tail” effects were observed. The Approximate Bayesian Computation (ABC) technique, was used to correlate experimental measurements of RTD with hydrodynamic models, to select the best model and estimate its parameters. The models were separated into two groups. The models in group 1 did not represent all the physical conditions of the flow, with an average tolerance of 2.21 in the last populations. The models in group 2, on the other hand, described the RTD results satisfactorily, with an average tolerance of 0.58 in the last populations. In the annular photoreactor with ultraviolet light, the photocatalytic degradation of the dye Rhodamine 6G (R6G) was investigated. The layered double hydroxides (LDHs) of ZnAl and ZnNiAl and their respective mixed oxides were synthesized, characterized and used as catalysts. For the characterization of the catalysts, the techniques of x-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis, scanning electron microscopy and dispersive energy spectroscopy (SEM/EDS), and specific BET area were used. The solids presented usual LDHs and mixed oxides derived from LDHs characteristics, with surface morphology (surface areas and porosity), reflections in the XRD and IR bands recurrent for clay materials. To evaluate the performance of the photoreactor in the removal of the R6G dye in an aqueous medium, the influence of photolysis, catalysts, the pH of the reaction medium and the catalyst mass were studied. The most promising results were observed in the use of mixed oxides from LDHs, under the operating conditions of natural pH (5.70) of R6G dye, and proportion of 0.5 g catalyst.L-1, whose removal was 85.48% for ZnAl mixed oxide and 69.53% for ZnNiAl mixed oxide.

Adsorption of organic compounds in activated carbon is a technique widely used in the process of treatment of solutions from different sources. Thus, the understanding of the mechanisms of interaction between species is important for the planning of effective removal processes. Molecular dynamics is a viable method for understanding adsorption mechanisms, since it allows the provision of information at molecular levels. This work aimed to analyze the molecular interactions between phenolic compounds on the surface of activated carbon. Calculations of structure optimization and electronic and geometric properties of pollutants (phenol, ortho-cresol, meta-cresol and para-cresol) involved in the process were performed, as well as molecular dynamics calculations from adsorption systems with activated carbon structures, pollutant molecules and a solvation box. The results of the calculations of the electronic and geometric properties of phenolic compounds showed that they have similar behaviors about predominantly positive electronic distribution. Regarding the results of molecular dynamics simulations, the microcrystalline graphitic structure of coal was verified as the main point of interaction between the species, where phenolic compounds are positioned in a planar position. This result, combined with the results of the radial distribution regarding the position of phenolic compound structures in relation to the adsorbent and information from the literature indicates the tendency of formation of π-π. The molecular dynamics method proved, therefore, a viable method for this type of study, based on an approach of an active charcoal structure determined by experimental studies.

Pollutionofwater sources byindustrialwastewaters have beenmotiveof concern worldwide. Dyes are a class of organic pollutants which gives color to residualwaters causing impact on ecosystem and on human healthy due to its toxicity and mutagenicity. In this work was researched the removal of the synthetic basicdye auramine-o (AO)on singular and multi-compoundsystem by hydroxyapatite (HAP) produced from Pirarucu (Arapaima gigas) scalesin aqueous batch system. Basic dyes rhodamine 6G (R6G) and brilliant green (BG) were selected to compose binary systems (HAP-AO+R6G; HAP-AO+BG and HAP-R6G+BG) and ternary system (HAP-AO+R6G+VB). Synthetized HAP was charactered by XRD, FTIR, SEM/EDS and BET;the FTIR and SEManalysis were made beforeand after adsorption. XRD analysis confirmed presence of HAP on the synthetized material. FTIR and SEM analysis on HAP after adsorption confirmed the removal of dyes by surface groups on HAP, as -OH and PO4-. Adsorption kinetics of singular AO was studiedon concentrations of 50, 100 and 150 mg.L-1and therefore analyzed by Pseudo First Order (PFO), Pseudo Second Order (PSO), Intraparticle Diffusion and Boyd’s equation models.PSO model had the best fit for all concentrations studied;AOwas removed within60 minutes (equilibrium time) and the process was controlled by film diffusion. Adsorption equilibrium of singular AO was studied on concentrations of 10 to 400 mg.L-1and on the temperaturesof28, 38 and 48 °C.Isothermswere analysed by Langmuir, Freundlich and Sips modelsand were best represented bySips (28 and 38 °C) and Langmuir (48 °C)models. Adsorption on binary multi-compoundsystem showed, by means of the separation factor parameter, the preference adsorption orderofBG > R6G > AO. There was a synergistic interaction between AO and R6G dyes but an antagonistic interaction between AO and BG dyes. BG competitive interaction for the same adsorption sites reduced the maximum adsorption capacity of AO in 57% (binary mixture) and 54% (ternary mixture) compared with single compoundadsorption ofAO. A Central Composite Design(CCD) was realized to investigate adsorption in multi-compound system (ternary). Desirability analysiscalculated from CCD results returned the critical value for simultaneous optimum removal of dyes by HAP,within the experimental domain studied:bioadsorbent amount of 0,8 g.L-1, AO concentration of 53 mg.L-1, R6G concentration of 125 mg.L-1and BG concentration of 25 mg.L-1, for a removal of 93,33% of AO, 42,75% of R6G and 99,52% of BG. The bioadsorbent (HAP)investigated efficiently removed AO and BG dyes and partially removed R6G dye from singular and multi-compound systems.

The anthocyaninin the acai fruit is one of the most attractive industrial compounds.It is used as a natural dye due to its violetpigment and its antioxidant power. An alternative technique for the extraction of biomolecules isextraction usingLiquid-Liquid Equilibrium(LLE)systems, composed of Deep Eutectic Solvents (DESs) characterized by being economical, efficient and of low toxicity to the environment and human body. Therefore, this study aimed to determineliquid-liquid equilibrium data of DES-based systems: ChCl:GLI (choline chloride:glucose) + isopropanol + water and  ChCl:SAC (choline chloride:saccharose) + isopropanol + water at temperatures of 25oC and 35oC,and to assessits application in the partition of the acai anthocyanins. First, the physical-chemical characterization of the lyophilized acai was carried out. Second, Box-Behnken factorial design was applied to analyze and optimize the extraction process to evaluate the influence of experimental conditions on the extraction of anthocyanin and total polyphenols from the lyophilized acai. Once the optimization conditions were found, the DESs that would be used in the LLE system were prepared. Furthermore, the thermal and structural properties for each DESswere determined with DSC and FTIR respectively. Third, aiming to research DESs behavior with water and isopropanol mixtures in equilibrium phases, the LLE data at 25oC and 35oC were determined. The binodal curves were obtained by cloud point titration, and the tie lines were determinate for gravimetrical and analytical (HPLC and Karl-fischer) methods. The systems studied were characterized as quaternary systems and the experimental LLE data were correlated by NRTL obtaining a mean quadratic deviation (RMSD) of 0.438%. The anthocyanin partition in ELL was carried out using the anthocyanin extract obtained in optimal conditions. Finally, it was proven that the individual components of DESs have a high affinity with the anthocyanins, showing the total migration of the biomolecules in the bottom phase. The partition coefficients of total polyphenols (KPT) were higher than 1, showing the preference of biomolecules in the bottom phase and the extraction efficient (%EE) of 70% with ChCl + Glucose + isopropanol + water system. This result confirmed the potential of using these systems to extract natural pigments aiming at a probableuse of the separation of nonpolar biomolecules (acai lipids) in the alcohol-rich phase.

Composite materials have differentiated properties, such as good mechanical performance, low cost and biodegradability. For these reasons, the demand for these materials has increased over the years, highlighting the search for the development of polymeric composites reinforced with natural fibers, such as guaruman (Ischinosiphon arouma) an abundant species in floodplain regions of the state of Pará. Thus, this work aims to produce composites reinforced with guarumanfibers. Physical, chemical and thermal characterizations were performed on guarumã fibers. The compositeswere produced with incorporation of 10, 20 and 30% by volume of fiber. The physical characterizations of guarumã fibers indicated values of 1.27 g / cm³ of specific mass and moisture content 13.97%. The chemical composition of the fibers revealed cellulose content (39.7%) compared to the hemicellulose content (40, 3%) and thermal analysis revealed stability of guarumã fiber between temperatures of 30 ° C and 220 ° C. The mechanical properties of the composites were evaluated by tensile and flexiontests, carried out according to the standards ASTM D 638 and ASTM D 790. The results obtained show that the incorporation of fibers in an epoxy matrix, significantly increases the value of tensile strength in relation to pure resin, the value obtained for 30% involume of fiber was 57.15 MPa. In relation to flexural strength, the addition of guarumanfibers in an epoxy matrix caused a slight decrease in the strength module in relation to pure resin, however, statistically there was no variation. The analysis of the fracture region of the composites tested in traction and flexion, indicated that in general the fracture occurred in a fragile way, and there was no good adhesion between fiber and matrix.

The species Acmella Oleracea (L), popularly known as “jambu”, is grown mainly in the North of the country, more precisely, in Pará, where it is widely used in the food, cosmetics and pharmaceutical industry. Due to the properties found in the extract of its leaves as antioxidant, antifungal, antibacterial, anti-inflammatory and larvicidal activity. These properties are obtained immediately after harvest, due to the high moisture content of this plant, which would imply losses of raw material and, consequently, of its properties. The drying process presents itself as an alternative to increase the conservation time and useful life of the product, in addition to contributing to the facilitation of transportation, handling and storage. The present work aimed to study the convective drying of the “jambu” leaves, from obtaining the drying curves at three temperatures, 50, 55 and 60 ° C, which have been adjusted to mathematical models that provided parameters for determining the model predictive of the process. The analysis of the influence of drying on the responses of antioxidant activity and leaf color, evaluated from their averages, through Tukey's analysis. The results showed that the Midilli model is the one that best fits the experimental data. The temperature and the physical condition of the leaves favored big changes in the color difference (ΔE). In which, it demonstrated that the drying of the whole dried leaves, only at 55 ° C presented antioxidant activity above 50%. Since the leaves dried at differenttemperatures and cut in 4 parts were the ones that showed the best antioxidant activities, above 50%. In that, the drying temperature at 55 ° C, proved to be the most suitable for drying the species, as it showed greater antioxidant activity.

Environmental contamination is a recurring issue mainly when it takes population growth into
account and as finished water sources, being one of the biggest direct targets of pollution. Part
of the maintenance of this water is due to the treatment and sewage plants that are ineffective
in relation to certain pollutants: the emerging contaminants. A class of drugs presents a high
risk, when in high concentration, in the endocrine system of aquatic beings and in the
treatment of aqueous matrices used by these factors that are necessary. Adsorption shows a
very efficient process in the removal of drugs, especially when used as activated carbon as an
adsorbent. In this work, activated charcoal is produced from the tucumã endocarp (CATC),
using zinc chloride (ZnCl2) with active agent, using the removal of acid diclofenac (DCF), in
aqueous solution, in a batch and column system fixed bed, in addition to characterizing the
material adsorbent. CATC showed a predominance of isolated groups on its surface and
pHPZC equal to 5.54, in addition to a specific surface area of 608.24 m².g-1. The Elovich
kinetic model was the best to adjust the experimental data, as well as the Sips and LangmuirFreundlich models for adsorption equilibrium isotherms. For the batch system, or the CATC proved to be very efficient, it removed 97.81% of the sodium diclofenac in solution and natural pH. 

A mathematical model was proposed in the present work in order to describe the extraction by
supercritical fluid. He started from the material differential balances of the fluid and the particle;
the method of lines (MOL) was used to solve this model. The system of ordinary differential
equations (ODE) resulting from the application of the numerical method was solved with the
aid of a computational tool developed by the author in FORTRAN 90/95 using the IVPAG
routine of the IMSL library. The effects of temperature and pressure were evaluated for the
extraction of priprioca oil, the flow effect was studied in the extraction of sesame seed oil, the
effect of the particle size was analyzed in the extraction of betacoratene from the carrot and an
analysis of the concentration profiles for each case was done. Data available in the literature
were used for the purpose of comparison with the results obtained in order to verify and validate
the model exposed in the present work.

In this work we applied the Generalized Integral Transform combined with theKirchhoff Transform Techniques to solve one-dimensional transient heat transfer problems considering the thermal conductivity dependence with the temperature. In this context, two cases of heat transfer based on the different boundary conditions of the original nonlinear problem were analyzed. For the first case analyzed, first and second species boundary conditions were used, where a simple filter was used to apply the hybrid methodology. While in the second case the boundary conditions were of second and third species, in this case the convergence acceleration strategy based on the local instantaneous filter was developed. The results obtained in the hybrid approach were compared with numerical results by the method of lines.

Faced with the intense disposal of plastic materials in the environment, researchers have given more importance to the use of biopolymers from renewable resources. Starch-based materials, for example, can yield good results because they are abundant, cheap and biodegradable. The objective of this work was to develop and characterize corn starch biocomposites reinforced with sisal micro and nanofibers. Microfibers were obtained by mechanical treatment followed by chemical treatment (Alkaline treatment and bleaching) and sisal nanofibers were obtained through acid hydrolysis. The films were produced by casting using commercial cornstarch and glycerol as plasticizer, reinforced with chemically treated and untreated sisal microfibers, as well as using sisal nanofibers. Twenty-one specimens were produced and subjected to tensile testing in accordance with ASTM D882-02. The fibers were characterized chemically (cellulose, lignin and hemicellulose) and morphologically (SEM and XRD) as well as nanofibers (TEM and XRD). Starch and films (matrices) were also morphologically characterized (SEM and XRD). The mechanical pre-treatment proved to be satisfactory, as it enabled the individualization of microfibrils by increasing their surface area, favoring chemical treatments to obtain nanofibers. Even using a lower H2SO4 concentration during acid hydrolysis than what the literature proposes, the results of XRD and TEM revealed that it was possible to obtain cellulose nanofibers with a highly crystalline elongated shape (needles) according to results in the literature. The results (SEM and XRD) obtained for starch also proved to be in agreement with those indicated by the literature. Composites reinforced with cellulose microfibers showed the best stress results. Composites reinforced with vegetable nanofibers showed lower stress results than matrices.

Geopolymers are inorganic polymers that have cementitious properties, resulting from the
activation reaction of amorphous aluminosilicates in an alkaline medium. Thus, this work
aimed to verify the applicability of copper ore residue in the production of a new geopolymer,
using kaolin and kaolinitic clay as aluminosilicate sources. The X-ray fluorescence analyzes
showed that the three raw materials present as major components silicon and aluminum oxides.
To obtain metakaolin, the kaolinitic clay was heat treated in the temperature range of 500 °C,
and in the kaolin at 700 °C, both for 2 hours. Then, kaolinite dehydroxylation in metakaolin
was observed from X-ray diffraction analyzes. Two geopolymer matrices were produced, the
first with residue and calcined kaolinitic clay with SiO2/Al2O3 ratios of 3.57 - 5.75 and solid /
liquid ratios of 2.1; the second with the residue and calcined kaolin with SiO2/Al2O3 ratios of
2.53 - 4.58 and solid / liquid ratios of 1.62; 2; 3 and 3,3. After the curing process, at controlled
temperature (90 º) and room temperature (25 ºC), it was found that the first matrix did not show
total cure in 28 days. On the other hand, the second matrix was submitted to the compressive
strength test with values ranging from 0.9 to 4.5 MPa. It was concluded that the geopolymer,
using residue and calcined kaolin, presented a mechanical behavior very similar to that of laying
mortar and wall and ceiling coverings.

This work investigates the adsorptive removal of Cr(VI) from an aqueous solution using activated LV with acids (H₂SO₄, HCl, H₃PO₄ and HNO₃). The physical and surface characteristics of the adsorbents were investigated by the XRD, SEM, TGA-DTA and pHpcz analyzes. Previous tests indicated that LV-HCl and LV-HNO₃ presented promising results for Cr(VI) adsorption. The response surface methodology was employed and the experiments were conducted according to the Box-Behnken statistical design with three input parameters, namely alkalinity of the solution (2 - 6), adsorbent mass (2 - 6 g/L) and initial concentration of Cr(VI) (10 - 30 mg / L). The contact time (60 min) was considered as a fixed input parameter. The optimum conditions for removal of Cr(VI) were pH = 5.06, m = 3,334 g/L and Co = 10 mg / L for LV-HCl and pH = 5.86, m = 4,9334 g/L and Co = 12 mg / L for LV-HNO₃. The applicability of the kinetic model of pseudo-second order, for both adsorbents, specifies the process of chemisorption. The adsorption data show better fit of the Redlich-Peterson isotherm model and Cr(VI) adsorption with the activated LV matches the adsorption in monolayer. The Cr(VI) removal and recovery were also evaluated in the fixed bed column system using the two adsorbents that obtained the best performance in the experimental design. The effect of flow rate (1, 3.5 and 5 mL / min), initial Cr(VI) concentration (10, 20 and 30 mg/L) and bed height (0.5, 1 and 1.5 cm) were examined and the experimental data were adjusted for the Thomas, Adams-Bohart, Yoon-Nelson and Wolborska models. The results indicate that at a flow rate of 1 mL / min, a concentration of 10 mg/L and a bed height of 1 cm, a maximum adsorption capacity is obtained for both adsorbents. The models of Thomas and Yoon-Nelson obtained values of X², RMS and R² very close and are able to describe the curves of rupture of the two adsorbents. Finally, it was found that a solution of HNO₃ is able to desorb the Cr(VI) ions of the fixed bed columns, supporting up to three adsorption-desorption cycles, reducing their adsorption capacities significantly in relation to the initial capacity.

The development of hybrid materials has been growing in recent years, whose objective is to meet the growing demand for new materials that have as main characteristics, various applications in the area of science, especially the medicinal area. In this sense, the pharmacological activity of the drug mefenamic acid (anti-inflammatory and analgesic) was evaluated by the nanocarrier of Lamellar Double Hydroxide (LDH) of magnesium (Mg2+) and aluminum (Al3+) ions in the in vivo tests (analgesia and gastric lesion) in mice. For the synthesis of the material, the constant pH coprecipitation method was used in which the experimental conditions were determined such as molar ratio between Mg2+ and Al3+ metal ions and drug/Al3+ molar ratio obtaining the control of other synthesis parameters as the aging temperature of the sample, the rate of addition, the agitation and the pH of the reaction medium. The synthesis of LDH-NO3 without the drug (LDH) and LDH-Mef intercalated LDH (LDH-Mef) at the molar ratio Mg2+/Al3+ equal to 2.0 was performed. In the intercalation step the drug/Al3+ molar ratio was used. Characterizations were performed using X-ray diffraction techniques ultraviolet-visible absorption spectroscopy and scanning electron microscopy (SEM). The hybrid material LDH-Mef had 36.539% (m/m) of drug. In vivo assays of analgesia and gastric damage were performed on male Swiss mice. In the analgesia test, the nociception model was used (acetic acid induced contortion test). The LDH-Mef system decreased the number of writings to 02, 24, 48 and reached 72 hours. In the gastric injury test in vivo pharmacological studies have showed that drug intercalation in LDH reduces the ulcerative damage of the drug. In face of the in vivo results, the drug mefenamic acid through LDH (LDH-Mef) extends its analgesic effects and also decreases the ulcers associated with its usage.

In this work, active materials were synthesized in the catalytic reaction of hydrogen peroxide (H2O2) decomposition for application in a heterogeneous Fenton system aiming at the degradation of toluene. The catalysts were synthesized from the controlled reduction of residue from the Bayer process (red mud), with the process of synthesis of the catalysts following the physical mixing stages of the red mud (LV) with charcoal (CV) in the proportions of 30% and 70% CV for subsequent calcination. At this stage, the mixture was calcined for 4 hours at temperatures of 600, 800 and 1000 °C. The catalysts were characterized by X-ray diffraction techniques, thermogravimetric analysis, Raman spectroscopy and scanning electron microscopy, with the catalysts being applied in the decomposition of H2O2 and the Fenton reaction for degradation of toluene. The efficiency of these catalysts was evaluated in the two reactions as well as the influence of the experimental variables, such as: catalyst concentration (Ccat), initial concentration of H2O2 (C0H2O2), concentration of toluene (Ctol) and pH. Based on the kinetic measurements of catalytic decomposition of H2O2, it was observed that the catalyst synthesized at 600 ° C for 4 hours and 70% by mass of charcoal (LV2) showed the best efficiency for the decomposition of hydrogen peroxide. The maximum conversion obtained was 39,55 % and Kobs of 0.016 mM.min-1 , with the experimental data being adjusted to zero order kinetics. This same behavior was repeated in the heterogeneous Fenton system for degradation of toluene when analyzing the variation of the absorbance during the kinetics of the reaction. Applying LV2, we observed the increase in the absorbance generated by the formation of phenolic intermediates in the first 20 minutes of reaction and the decrease of the signal until no longer detected in the time of 60 minutes. The characterization analyzes demonstrated that LV2 showed an efficient reduction of the hematite phase and the synthesis conditions made possible the formation of magnetite, a phase that is known to be more active in the decomposition of H2O2 and consequently more efficient in Fenton type systems. The best experimental conditions obtained for the decomposition of H2O2 occurred when Ccat: 2 g / L, C0H2O2: 25 mM and pH: 11 and for degradation of toluene similar behavior was observed, fact that makes it possible to suggest the same conditions considered more efficient in the decomposition of H2O2 in Fenton reactions for the degradation of organic compounds

Senegalia polyphylla (DC.). Britton & Rose belonging to the Fabaceae family, is a plant that
presents biological effects proven in the scientific literature as an effect of antifungal action
and insecticidal effect. However, allelopathic activity is also a
several species belonging to the same Senegalia polyphylla family. The chemical composition
of its seeds has already been studied in the scientific literature and it is a diversity of substances
with antioxidant activity, such as phenolic compounds. The objective of this work was
to identify qualitatively the chemical composition and the allelopathic effect of extracts of the species
Senegalia polyphylla obtained by supercritical extraction, using CO2 + cosolvent (ethanol),
compared to conventional extraction (maceration). Extraction with supercritical fluid is a
technology used for the extraction of these compounds, because it is presented as a method of
alternative extraction and considered a green technology. The raw material consisted of sheet
and stem of Senegalia polyphylla, the supercritical extraction tests were carried out on the basis of
in a factorial design 23, for three independent variables: pressure (300 and 400 bar),
temperature (40 and 60 ° C) and cosolvent percentage (10 and 15%). The results
that the highest overall yield for supercritical extraction (3.61%) was obtained in the condition
operating temperature of 400 bar, 60 ° C and 15% of cosolvent where an extract with a high
content of total phenolic compounds (124.38 mg EAG / g extract). The ethanolic extract obtained by
maceration showed extraction yield equal to 1.97% while the hexane extract
obtained by maceration showed extraction yield equal to 1.58%. In the analysis of
By thin layer chromatography the developers reacted positively to terpene,
flavonoids and antioxidant activity. The phytotoxic effect test was performed using the
extracts obtained by conventional separation and the supercritical extract obtained by 40 ° C, 400bar and
15% cosolvent, in which the results show a positive effect of inhibition of germination
of the seeds of Malícia (Mimosa pudica) and negative effect to inhibit the germination of
Mata-Pasto seeds (Senna obtusifolia)

The interest in processes that have more efficient and cheaper steps to obtain biofuels engages the demand for constant research in this area. Hydroesterification is a recent process within this context and has been established as a way to overcome problems related to conventional methods of producing biofuels from oil and fats. In this work, the reaction mechanism of the fatty acid hydrolysis reaction was investigated, evaluating three different kinetic models found in the literature: i) classical through homogeneous catalysis ii) autocatalytic and iii) mixed (classical and autocatalytic), in which model selection and parameter estimation were performed using Bayesian Inference. The MCMC technique was implemented through the Metropolis-Hastings algorithm and used as a tool to solve the inverse problem of parameter estimation. The individual monitoring given by the variation in the values of metrics as the deviation attributed to the measurements (σ_m) and the parameters (σ_p) made it possible to evaluate the convergence of the Markov chains. The sensitivity analysis was performed with the values obtained from the most satisfactory estimates, indicating the most sensitive parameters. The corrected Akaike Information criterion (AICc) was used in the selection of models and the result pointed to the classic model as the most adequate for the adjustment of the experimental data.

he objective of this work is to evaluate the hydrodynamic behavior of reactors
from the Bayesian inference application. To achieve this, the strategy was
resort to the principles of residence time distribution and to develop experiments
the stimulus-response type, which make it possible to obtain data on the concentration of
tracer. These data are treated as the state variables during the analysis of the
Bayesian inference techniques, which make it possible to estimate
parameters using the Markov Chain Monte Carlo Method (MCMC) and
the estimation of parameters together with the selection of models when using Calculus
Approximate Bayesian (ABC). In order to do so, an investigation of the
the applicability of ABC for the hydrodynamic characterization of a
reactor, the continuous stirred tank type reactor, using the proposed algorithm
by Toni et al. (2009), however, with the proposal of a stopping criterion based on the
principle of discrepancy. The results obtained in this first analysis
shown to be quite promising, since both parameter estimation and
the hydrodynamic model, presented physical bias. Then, the
ABC, however, for the model selection and parameter estimation of an anaerobic reactor
from the simulated measure generation under different scenarios, the results
obtained were in agreement with those available in the literature. In front of such
positive results, it was obtained safety to perform the hydrodynamic characterization of
a fixed bed aerobic reactor operated under two flow regimes and from the application
of three tracers, the eosin Y, the bromocresol green and the bromophenol blue. For this,
it was made the analysis of four mathematical models quite widespread in the literature
(Small dispersion, large dispersion, N-CSTR in seriousness and PDE (Piston with
exchange of matter)) and the parallel N-CSTR model was proposed. The estimate of
parameters was performed via MCMC, and again, it was shown that by merging the concepts
of Bayesian inference with those of time distribution of residence, one obtains
parameters that lead to a reliable diagnosis of
the flow inside the reactor.

Kaolin is an important clay as an abundant and inexpensive raw material. However, kaolin
processing generate considerable volume of waste, making it an interesting issue to use this
material. Due to its chemical and mineralogical composition, mainly constituted by kaolinite,
this material represents a highly viable clay mineral for synthesis of zeolitic materials. Zeolites
are alumino silicates of porous crystalline structure and present several industrial applications,
such as adsorption of molecules. Sodalite-type zeolites, due to their kinetic aperture diameter,
represent a potential group in separation of small molecules, such as water, present in almost
all industrial processes. The present work aims synthesis and characterization of sodalite-type
zeolite obtained from kaolin waste and investigation of its capacity of water adsorption, through
experiments and molecular simulation. The starting material was submitted to thermal
treatment through calcination process at 700 °C for 2 h, in order to obtain metakaolin. Synthesis
processes were carried out with the reaction of metakaolin with NaOH and additional source of
silica, using autoclave, in hydrothermal conditions, analyzing the influence of SiO2/Al2O3
molar ratio, crystallization time and temperature. The materials were characterized by XRF,
XRD, SEM, TG/DSC, FTIR, surface area and pore diameter distribution. The molecular model
for synthesized sodalite zeolite was obtained from crystallographic data present in literature
and the adsorption capacity estimated by Monte Carlo simulation. Infrared and Raman
spectroscopy calculations were also performed. The product obtained at 90 oC for 48 h using
SiO2/Al2O3 ratio of 3 showed great result, forming sodalite as the only crystalline phase.
Experimental adsorption tests showed low adsorptive capacity for water vapor at temperatures
and pressure range studied. GCMC simulations represented the experimental tests in a limited
way, in the conditions of low pressures analyzed. However, in high pressures regions, the
simulations were in agreement with data observed in the literature. The simulated infrared and
Raman calculations were in agreement with experimental data.

The food industry produces many wastes that are often disposed of uncontrollably in
industrial and urban effluents which causes damage to the environment.. One of these
residues is the frying residual oil which by means of the transesterification can be
transformed into an organic liquid product and incorporated into the diluted asphalt,
providing an alternative to this residue. The diluted asphalt is used in the asphalt primer
that is made from the penetration of the asphalt cement (AC) in the soil, so that the AC
must have its reduced viscosity either by dissolution in solvents, petroleum derivatives
or water (by means of suspended particles, herein referred to as asphalt primers for
priming). The organic liquid product derived from frying oil (OLPDORF) was used
together with kerosene, standard solvent, for the production of medium curing type
asphalt (CM-30). In order to evaluate the performance of the CM-30 in relation to the
addition of OLPDORF, the percentage of the CM-30 was varied in a complementary
way to the kerosene, maintaining the percentage of AC in the standard of 60%,
characterizing them according to standard 393/97 of the DNER (currently DNIT) for the
CM-30 and applying them to the asphalt primer service in lateritic soils according to
standard M-199/89 of DER-SP. The results of the CM-30 produced with OLPDORF
were satisfactory in relation to the viscosities: kinematic and Saybolt-Furol and flash
point and for the penetration of the primer the results of curing time and penetration
were satisfactory in reduced percentages of OLPDORF, varying from 1 to 5%, proving
that the incorporation of OLPDORF into the standard ADP-CM-30 production can be
performed without prejudice the performance, provided that such parameters are
observed. 

In this work the liquid-liquid equilibrium of biphasic aqueous systems formed by
polyethylene glycol (PEG) of different molecular masses (1500 and 6000), ammonium
sulphate (NH4) 2SO4 and water at 25ºC and 35ºC was carried out. To obtain the equilibrium
data the binodal curve of the system was constructed using the cloud point method. The
equilibrium data were determined by preparing mixtures of known compositions within the
two-phase region. The quantification of the components in each phase was performed
indirectly with the use of binodal curve data, calibration curve and material balance. The
quality of the experimental data of the tie lines was determined by the empirical correlations
of Othmer-Tobias and Hand. It was observed that the increase in temperature and the increase
of the molar mass of the polymer caused the increase in the region of two phases and changes
in the length and slope of the tie lines. The values of the partition coefficient showed that the
PEG partitions preferentially in the upper phase and the selectivity values, above the unit,
indicate that the systems have characteristics suitable for the application in extraction
processes. The liquid-liquid equilibrium thermodynamic modeling was performed with the
NRTL, UNIQUAC, UNIFAC and ASOG models, and the overall mean deviations in the
composition were close to 1%

Generalized Integral Transform Technique, packed bed tubular reactor,
adsorption, local equilibrium, linear driving force

In this work it was proposed the use of lateritic filler in the production of polymer based composites in order to improve thermal and mechanical properties. The mineral sample was submitted to a gravitational sedimentation for particle size fractionation and subsequent physical, chemical and mineralogical characterization. The composite production was doneby manual method (hand lay-up) and compression molding. It was produced the isotopic polyester composites using the laterite (LT) and the products of the gravitational sedimentation: laterite first layer (LPC), laterite second layer (LSC) and laterite third layer (LTC) in proportions of mass fraction of 10, 20, and 30% for each of the samples. The composites were characterized in tests of tensile strength and flammability, in addition to the determination of their physical properties, such as specific mass, water absorption and porosity. The addition of the laterite significantly increased the value of the apparent specific mass of the composite in all the fractions, a fact that was not repeated with the values of apparent porosity and water absorption, causing increase in some samples and decrease in others. The results showed that the composites that obtained the best tensile performance were those loaded with 20% of LTC (28.97 MPa). Fracture surface analyzes indicated that the improvement in the properties of the composites is influenced by an efficient dispersion of the particles in the matrix. The composites containing 30% of LSC presented better fire performance.

In the present work were produced: full polymer matrix, composites of polymeric matrix with
reinforcement of bamboo fibers in sizes 15 mm and 30 mm, using chemically treated bamboo
fibers with 5% v / v sodium hydroxide not chemically treated, matrix polymer with copper
residue loading insert and hybrid polymer composites reinforced with bamboo fibers and
insertion of copper residue. The copper residue was characterized by X-ray Diffraction -
XRD, the bamboo fibers were treated with 5% v / v sodium hydroxide solution. The
composites were manufactured by hand-lay-up, compression molding and room temperature
(T = 25 °). The physical properties of the composites were evaluated, the mechanical
properties of the composites were analyzed by means of traction tests. The fracture surfaces
generated from the composites were verified by scanning electron microscopy (SEM), in
order to correlate aspects of fracture with the mechanical properties of the composites. The
physical properties of apparent porosity, water absorption and apparent specific mass
increased with the addition of the constituents (residues and fibers). The composites with 40%
mass fraction of copper residue had a value of 40.24 MPa of tensile strength, while the
reinforced composites of 15 mm bamboo fibers with chemical treatment reached a value of
33.05 MPa, composites with reinforcements of 30 mm bamboo fibers without chemical
treatment reached the value of 33.11 MPa. Hybrid composites with insertion of copper residue
and 15 mm bamboo fibers without chemical treatment showed the best tensile strength
reaching 37.94 MPa. The fracture surfaces presented the predominant failure mechanisms for
each series of fabricated composites. For composites with fiber reinforcements, residue
incorporation and hybrids with higher mechanical strengths, the predominant mechanisms of
failure were fiber disruption and good distribution of the residue on the matrix surface; for
composites with fiber reinforcement, incorporation of residues and hybrids of lower
mechanical resistance, the mechanisms of predominant failure were the pull out and the
detachment of the fiber from the matrix and concentration of the residue at the ends of the
matrix. 

Experimental data of liquid-liquid equilibrium (LL) of three ternary systems containing 2-hydroxyethylammonium butyrate (2-HEAB) + ethanol + ester (butyl acetate or pentyl acetate or hexyl acetate) were determined at the temperature T = 25 ° C ± 0.05ºC and atmospheric pressure to evaluate the influence of the diluent chain (ester) on the solubility of the system and for the possible application of 2-HEAB in a process of ethanol extraction and dehydration. The LI 2-HEAB was synthesized in the laboratory and the efficiency of the synthesis with the formation of the liquid salts was verified by the analysis of structures by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR). The liquid - liquid equilibrium data were obtained by the cloud point technique and by the gravimetric method. To verify the quality of the experimental data the correlations of Hand and Othmer and Tobias were used, and the average of the coefficients of determination presented were, respectively, 0.99 and 0.96. The solvent partition (ethanol) in the solvent (2-HEAB) was evaluated by the distribution coefficient for each system in the different diluents studied (esters) proving the selectivity of 2-HEAB by ethanol. The liquid-liquid balance (ELL) experimental data were correlated using the Nonrandom Two-Liquid (NRTL) and UNIversal QUAsiChemical (UNIQUAC) models for the activity coefficients. And the results indicated that the models were able to describe the equilibrium data, producing global mean deviations in composition lower than 0.97% for both models.

In the present study, the thermal characteristics of the electro-osmotic flow of newtonian fluids in microchannels of rectangular geometry are investigated in the presence of a pressure gradient. The equations representative of the electric potential profile, velocity profile and temperature profile for the fully developed flow under H1 thermal boundary conditions are studied using the Generalized Integral Transformation Technique. The influence of the main parameters on the thermal characteristics of the flow, such as the temperature distribution is discussed by a complete parametric study, in which the analyzed parameters are aspect ratio, joule heating factor, dissipation factor viscous, velocity rate and Debye-Hückel parameter. The results show that the aspect ratio of the channel, as well as other parameters, directly affect the temperature distribution and velocity profile. It is observed that the decrease of the parameter of the aspect ratio of the channel causes that the generated energy, due to the viscous heating, becomes more significant. The velocity profile is also analyzed by checking the difference in flow behavior when the pressure gradient is conducive to flow and when it is contrary to the electro-osmotic flow. In order to confirm the efficiency of the technique used in this work, a convergence analysis of mean temperature, mean velocity and Nusselt number is also performed.

Activated carbon is an adsorbent material used in the treatment of liquid and gaseous effluents, purification, discoloration, among others. These adsorbents can be produced from different carbonaceous materials, such as agricultural and forest residues. In this study we investigated the influence of the textural and chemical properties of the adsorbents and the molecular descriptors of the dye structures obtained by molecular modeling. It was studied the removal of four basic textile dyes by six activated charcoal samples. The textile dyes used were basic blue 26 (blue victory), basic yellow 2 (auramine), basic red 1 (rhodamine 6G) and basic green 1 (bright green). Activated carbons (ACs) were produced from açaí pits (Euterpe oleracea) and Brazil nuts (Bertholletia excelsa H.B.K.), named as RCA and RCCB. The ACs were produced by three processes: carbonization and thermal activation, carbonization at 400 ° C / 3 h and activation at 800 ° C / 1 h, samples (CAT_RCA and CAT_RCCB); oxidation with 6M HNO₃, samples (CAHNO₃_RCA and CAHNO₃_RCCB) and chemical activation using H₃PO₄ at 450 ° C / 2h, samples (CAH₃PO₄_RCA and CAH₃PO₄_RCCB). The physico-chemical and textural properties of CAs were determined according to standardized methodologies such as moisture and ash content, XRD, ATG and ATD, FTIR, surface functional groups (acid and basic) by titration of Bohem, pHPCZ, MEV, SBET, gas pycnometry and porosimetry by mercury intrusion. The reactivities of the molecular structures of the basic dyes were investigated using HOMO, LUMO, gap energy, electronic chemical potential, global chemical hardness and overall electrophilicity index calculated by the DFT method, functional B3LYP and the base 6-31G *.The samples had low levels of ash and humidity and non - crystalline structures. The ATG and ATD curves showed endothermic peaks corresponding to water elimination and elimination of volatile substances. From the FTIR spectrograms, Boehm and pHPCZ titration results, the acid and basic groups (carboxylic, phenolic, lactone and pironas) present on the surface of the CAs were identified and quantified.According to the SEM the CAs presented rough texture and a large number of pores of different sizes and shapes. The samples CAH₃PO₄_RCA and CAH₃PO₄_RCCB presented the highest values of specific area being 990,811 m² / g and 1651,311 m² / g, respectively, and micropore volume 71, 69% and 91.31%, respectively. Considering the results of the studies of molecular quantum descriptors of the synthetic dyes investigated, the molecules of VDB1 and AZB26 are strong electrófilos of low hardness, being more reactive than the dyes AMB2 and VMB1. Results of the adsorption experiments showed that the produced CAs presented two types of adsorption, electrostatic interaction and π-π binding. The CAs produced by chemical activation were the most efficient for the removal of all the dyes tested, the removal percentages reached a maximum value of 99%. CA shell precursor of Brazil nuts showed textural characteristics, specific surface area and pore structure than the values obtained from the precursor acai lumps

This work consisted of the synthesis of protic ionic liquids (Ethyl 2-hydroxyethylammonium propionate [E2HEAP][PR], Diethylammonium propionate, [DEA][PR] and Butylammonium propionate, [BA][PR] and determination of density and viscosity of protic ionic liquids [DEA] [PR] and [BA] [PR] pure and the binary systems formed by these ionic liquids + water at different temperatures and atmospheric pressure. The density data were determined using a digital densimeter and viscosity by the viscometer, both of Anton Paar, the experimental results were used to obtain excess molar volume ( ), apparent molar volume ( ), viscosity deviation (∆η) and excess Gibbs free energy (∆G^E), being the results correlated with the Redlich-Kister or Redlich-Meyer equation. The results were compared and discussed based on the molecular interactions between the studied componentes. It was also made the study of liquid-liquid equilibrium data (LLE) for systems, involving 1-butanol + water + protic ionic liquids: [E2HEA][PR] or [DEA][PR] or [BA][PR] K and atmospheric pressure, being the systems quantified by the gravimetric method. The quality of the equilibrium data was verified by the semi-empirical methods of Othmer-Tobias and Hand. From the obtained equilibrium data, the values of the distribution coefficient found indicated the hydrophilic behavior of the LIs studied. Data liquid–liquid equilibrium was correlated by the NRTL and UNIQUAC thermodynamic models, which was observed that the NRTL model correlated in a more satisfactory way the results presenting global deviation of 1,56% for NRTL and 1,78% for UNIQUAC.

The utilization of the fuels fossils like main source of energy has carried to the generation of countless environmental and economic problems, creating the need of diversification of the energetic matrix. In Brazil, country with vast territorial extension and agroindustry very established stands out the production of biofuels, such as: ethanol and biodiesel. Particularly, the production of biodiesel with the increasing governmental incentives exponentially has its production increased to each year placing Brazil in prominence in the worldwide scene of biofuels. In the process of transesterification of vegetal oils with a primary alcohol, beyond biodiesel, the rude glycerin in a ratio of 10% is generated 11% in volume. The bio refining of the deriving glycerin of the manufacture of biodiesel, becomes the production of biodiesel economically more viable, leading to the formation of products with raised aggregate values. For this reason, the present work has as main objective the valuation of the chain of production of biodiesel for the transformation of glycerol to the products of bigger value added through reaction catalytic decomposition of glycerol using perovskitas of the CeNi_1-xCu_xO₃ type (x=0 and 0,25) as you will catalyze. The gotten results had shown that the use of high temperature (500 °C) favors the gas production of synthesis with approach relation H2/CO of 1, this occur for the strong craqueamento of the molecule of glycerol, At 410 ° C and inert reaction atmosphere, hydroxyacetone (acetol) was the major product exhibiting selectivity in the range of 22-28% depending on the catalyst used. The effect of the addition of hydrogen on the reaction load was investigated and its insertion promoted the hydrogenation of the hydroxyacetone, leading to an increase in selectivity for 1,2-propanediol whose selectivity varied in the range of 4-9% depending on the catalyst.

Croton matourensis Aubl. is a species of the genus Croton in which a diterpene called maravúico was extracted and isolated, and preliminary studies indicate the need to carry out chemical studies and microbiological tests to better elucidate the substances contained in this plant. Therefore, this work focused on the characterization of the botanical material, the study of the extraction process and microbiological tests to ratify possible medicinal uses made by the population. In the characterization of the material was carried out a test to determine the final moisture of the material and granulometry of the same. Scientific literature has reported that in the stem bark of Croton Matourensis Aubl. contains the wonder-rich component for which it associates possible therapeutic actions. To ratify this information, a preliminary extraction with the leaves, stem bark and leaves of C. matourensis and, later, 1H NMR spectra were carried out. After confirming the part of the plant that would be used in this study, the extraction process was performed using three methodologies that were maceration, extraction with reactor jacketed through a Rotational Central Compound Planning (PCCR) and supercritical extraction. For the PCCR runs, four input variables were defined: temperature, time, extractive solution concentration and botanical material versus extractive solution. In super-critical extraction, a solvent system was used that was ethanol and carbon dioxide (CO2). In the evaluation of the efficiency of the extraction the yield and the amount of fumaric acid were analyzed. It was verified that only the yield variable presented statistical significance, where the time (t) and temperature (T) variables acted synergistically to obtain the answer; And the variable concentration of fumaric acid did not present statistical significance. According to the results of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC), it was observed that the extract obtained from the bark of the stem shows positive microbiological activity against Escherichia coli andSalmonella ssp., But this action is bacteriostatic. The yield results of the extractions through supercritical methodology, PCCR and maceration showed that, in the experimental area stipulated in this study, the last presented better yield results in comparison to the other methodologies used.

The X-ray diffraction analysis of the first synthesis characterized the material as a mixture of zeolite, sodalite and faujasite phases. Zeolite A and sodalite were also obtained for the 8th synthesis (external heating) and zeolite A for the best synthesis without external heating (12th). Through the adsorption results applying the products with and without external heating, the same potentiality was observed regarding the adsorption of the ammonium ion. Scanning electron microscopy (SEM) of hard kaolin did not show a hexagonal profile, typical of kaolin with structural disorder. The SEM of the best zeolitic products with and without heating, presented in a little evident way the cubic morphology of the zeolite A and a crystallization of crystals. The use of the zeolite product of the 1st synthesis (sodalite and faujasite) in both powder and pellet form showed the same adsorption capacity of water vapor, with and without moisture control, according to the statistical tests. The results obtained in the adsorption applying the products of the 8th and 12th synthesis, in the form of powder and in pellet, demonstrated capacity of adsorption of ammonium ion. As already expected, the material in powder form showed a more significant efficiency in relation to the pelletized product.

The use of Acai seed (Euterpe oleracea Mart), for energy purposes has been little studied, therefore we sought in this work to study the production of second generation ethanol from enzymatic hydrolysis of core açai in natura and treated with solvent two temperature conditions (60 to 70 °C). The enzyme β-glucosidase used in this study as technical specifications (Table 5). The Açai core samples, passed through washing, drying at ambient temperature, in an oven with air circulation at 105 ± 5 °C until constant weight, grinding and solvent treatment. The moisture content and the yield on a wet basis of acai core "in natura" was 39.59 and 60.41%. Morphological analysis by scanning electron microscopy (SEM), allowed to analyze the structure and the presence of chemical elements (C, O, Si and Al) in the core and fiber. The -ethanoic acid extract of acai seed showed satisfactory capacity (82%) to scavenge free radicals (antioxidant activity), against free radical DPPH. As a result of the enzymatic hydrolysis process, the core acai without treatment (CANT60) proved to be a promising lignocellulosic biomass to obtain second generation ethanol, it contains a high cellulose content (40.29%), besides presenting good income in the release of glucose (13.687 g L^-1) after enzymatic hydrolysis. The average ash content for CANT and CAT were 0.15 and 0.13%. Treatment with acai core of the solvent in the conversion of cellulose into glucose, the yield was below 25%, in both temperature conditions (60 to 70 °C), it was not able to disrupt the plant wall biomass in particular cellulose, hemicellulose and lignin, making fermentable sugars available on the enzymatic hydrolysis process, because of possible inhibitors generated during the treatment. By analyzing the experimental data, we can say that the best condition of enzymatic hydrolysis of acai core was CANT60 and glucose obtained by enzymatic hydrolysis of acai seed was well assimilated by the yeast Saccharomyces cerevisiae for ethanol production.

This study aimed to investigate the fractionation and deacidification of organic liquid product (PLO) as the distilled fractions in Bench Scale and Pilot Unit; moreover, in the bench scale we studied the effect distillation with or without reflux, and vary the size of the Vigreux type column, which was ten (10), thity (30) and fifty (50) centimeters. First, for the production of PLO was performed cracking catalyst term in Pilot Unit, for it, was used as raw material oil palm (Elais guineensis Jacq) and Na2CO3 catalyst, of which percentage varied at 5, 10 and 15%. Then, the PLO was fractionated into bench and pilot scale, in the cutting bands established by Thomas et al. Distilled fractions and the PLO’s were submitted to physical and chemical analysis, FT-IR, NMR and GC-MS. In a general way, those from experiments the catalytic cracking term with 15% Na2CO3 showed the best results in both operating parameters and the qualities of physical-chemical analysis and composition, whose incomes range 62.6% to 80,9mm.) and 71.7% to 89.4% (wt.) for distillations bench with and without reflux, respectively. It can be said that the reflux in the fractional distillation bench was essential to a better refining fractions, given that most of the physico-chemical analysis is within the limits of the ANP specifications, as the density and viscosity. The variation of the size of the Vigreux column in bench scale with / without reflux, macro point of view, does not change or improves the refining of distilled fractions, that is, its variation does not represent significant changes in effective production / quality of distilled fractions. For the distillation experiments in pilot scale, acidity values of green gasoline, kerosene green, green diesel obtained the best results which were 0.33, 0.42, and 0.34 mg KOH / g, respectively. Moreover, distillation in the Pilot Unit obtained excellent results, as the analysis of FT-IR and GC-MS showed the presence of paraffinic, naphthenic and olefinic hydrocarbons; with hydrocarbon percentages of 83.95%, 93.63% and 100% to green gasoline, green kerosene and green diesel, respectively, which confirms that the refining through distillation operation satisfactorily contributes to the separation and purity of the organic liquid product.

O processamento térmico de biomassa é uma operação importante para agregar valor aos resíduos gerados pelas indústrias de dendê. O objetivo deste trabalho foi acompanhar a influência da temperatura (400, 500, 600 e 700°C) e do tamanho das partículas no processamento térmico de cachos sem frutos (CSF) de palma. Utilizou-se um equipamento para processamento térmico contendo um reator de 4,4x10^-4 m³, com possibilidade de recuperação de produtos sólidos e líquidos. As matérias primas utilizadas eram constituídas de frações do CSF com granulometrias variadas (amostra inteira (sem peneiramento), fração grossa (retida em peneira de 28 mesh), fração média (retida em peneira de 60 mesh) e fração fina (retida no fundo da peneira)), que foram devidamente caracterizadas através de análise imediata, composição lignocelulosica, termogravimetrica e poder calorifico superior. Nos produtos sólidos foi feita a análise imediata e poder calorifico superior e nos produtos líquidos foram realizadas as medidas de poder calorifico superior, densidade, viscosidade cinemática e pH. O rendimento máximo de sólido ocorreu a 400ºC, o de produto gasoso a 700^oC e o de líquido apresentou valores equivalentes nas temperaturas de 400, 500 e 600°C. As matérias-primas utilizadas apresentaram em sua composição lignocelulósica valores que variaram de 45 a 53% de celulose, 17 a 23% de hemicelulose e 30 a 40% de lignina. A análise termogravimétrica mostrou maiores porcentagens de degradação na temperatura de 300°C, indicando maior perda de massa relativa à celulose. Produto sólido apresentou maiores teores de carbono fixo e menores teores de voláteis a 600 e 700°C, apresentou também ganhos significativos quanto ao poder calorifico, de 40,57 a 55,04% para amostra inteira, de 56,74 a 70,12% para fração grossa, de 44,22 a 54,25% para fração média e de 32,77 a 45,52% para fração fina. Produto líquido também apresentou ganhos significativos quanto ao poder calorifico, de 56,48 a 68,59% para amostra inteira, de 71,69 a 85,00% para fração grossa, de 54,76 a 66,28% para fração média e de 46,42 a 63,31% para fração fina. Valores de densidade, viscosidade cinemática e pH diminuíram com a redução granulométrica de CSF.

A utilização de resíduos industriais a exemplo de cinza volante para reciclagem e reaproveitamento, tem sido intensificada nos últimos anos muito por suas características físico-químicas que podem resultar, após processamento, em um material com boa resistência mecânica podendo ser destinado a aplicação em diversas áreas como a construção civil. Este trabalho objetiva a obtenção de agregados sintéticos, após processo de sinterização em reator de leito fixo. Para a produção dos agregados confeccionaram-se pelotas em betoneira a partir de uma mistura de cinza volante, argila e carvão vegetal. Após o processo de sinterização foram medidas as propriedades cerâmicas do material tais quais: porosidade, densidade e absorção de água. Para a caracterização de fases e estruturas mineralógicas do material sinterizado, utilizou-se as técnicas de difração de raios-X e Microscopia eletrônica de varredura. Desta forma a contribuição desse trabalho está direcionada a redução de impactos ambientais, em razão da possibilidade que o material produzido tem em substituir agregados naturais.

Foram analisadas várias propriedades termodinâmicas através de sistemas de simulações computacionais, onde se utilizou um nanotubo de carbono uma molécula de gás (H₂), a temperatura inicial muito baixa, da ordem de 10^-3K. Esta molécula de H₂ foi escolhida devido à suas propriedades serem de grande aplicação, em diferentes ramos de estudo, das ciências físicas, químicas e biológicas. A molécula de H₂ foi relaxada individualmente fora e dentro do nanotubo durante as simulações. Cada sistema foi submetido à influência de um campo elétrico uniforme paralelo ao nanotubo de carbono e o efeito térmico sobre a temperatura inicial nas simulações gerando o efeito evanescente. Devido ao campo elétrico, a molécula em baixa temperatura gira em órbita sobre o nanotubo de carbono enquanto se uamenta o valor do campo elétrico permitiu a variação do raio da órbita dos átomos. As quantidades calculadas foram as seguintes: a energia cinética, a energia potencial, a energia total, a variação da temperatura in situ, a entropia molar e o raio médio da órbita de átomos. Os dados sugerem apenas a ação do campo elétrico é suficiente para gerar o potencial atrativo evanescente e este sistema pode ser usado como um sensor selecionador de átomos.

Morinda citrifolia Linn, conhecida popularmente como Noni, é uma planta da família Rubiaceae, usada por muitos séculos na medicina popular. A descoberta da planta se deu pelos ancestrais dos polinésios e tem sido largamente reportada por suas propriedades terapêuticas e nutricionais. Por esse motivo, resolveu-se realizar pesquisa com os frutos da espécie Morinda citrifolia L.,.Observar as propriedades do produto seco para o consumo na dieta alimentar, bem como, comprovar o potencial funcional pós-secagem. Neste trabalho foi realizado o estudo da secagem dos frutos de Noni, avaliação e quantificação dos compostos fenólicos e atividade antioxidante dos extratos obtidos. No processo de secagem, foi utilizado um secador com lâmpadas refletoras em escala laboratorial. Na análise do processo tomou-se por base o modelo estatístico, quantificando-se os efeitos das variáveis de entrada nas Respostas, por meio das análises de regressão através do planejamento composto central rotacional (PCCR) com duas variáveis de entrada, e cinco níveis. Empregando-se temperatura, e tamanho das polpas como variáveis de entrada e Teor de umidade final, capacidade antioxidante e teor de fenólicos totais como resposta.Observou-se que o aumento da temperatura de secagem, causou um decréscimo no teor de umidade final nos frutos de Morinda citrifolia L.A faixa de conteúdo de umidade final variou de 0,01 a 3,50 kg de água/kg de sólido seco e 1,32% a 38,8%, em base úmida. Os valores médios de compostos fenólicos totais variaram de 12,54 a 26,56 mgEAG/g,e capacidade Antioxidante foi de 23,12 a 77,86mg de Trolóx /g de amostra,dentro do domínio experimental. Somente variável de entrada isolada X₁ (temperatura) na forma linear e quadrática, foi estatisticamente influente sobre a variável de resposta X_bs.

A alumina é um dos óxidos mais importantes na indústria cerâmica, sendo utilizado principalmente na forma de alumina calcinada ou fundida sendo aplicada, dentre outras formas, como material adsorvente. Neste trabalho desenvolveu-se um método de produção de alumina de transição a partir da mistura de gibbsita, proveniente do processo Bayer, e hidróxido de alumínio gel, proveniente de reação de sulfato de alumínio e hidróxido de amônio visando a aplicação como material adsorvente para remoção de Cu ²⁺  em solução aquosa. Foram investigadas as condições de adsorção incluindo tempo de contato e pH. Os ensaios foram realizados a 30 ^oC e 50 ºC, nos quais 1 g de alumina produzida foi submetida a contato com 100 ml de uma solução aquosa contendo Cu²⁺. As concentrações das soluções aquosas empregadas foram de 100, 200, 400, 800, 1600 e 2000 ppm de solução de sulfato de cobre. A caracterização das soluções de sulfato de cobre foi realizada em espectrofotometria UV e a caracterização do material produzido foi realizada através de DRX, EDX e área superficial BET. Avaliou-se o tempo de contato para o alcance do equilíbrio de adsorção sendo este tempo otimizado em 15 min. O efeito do pH sobre a adsorção mostrou que aumentando a temperatura de adsorção há um aumento do valor de pH em relação ao pH da solução inicial de sulfato de cobre. As isotermas de Langmuir e Freundlich apresentaram resultados satisfatórios para adsorção, sendo a isoterma de Langmuir a que melhor se ajustou aos dados de adsorção. Através das isotermas de equilíbrio verificou-se que o material produzido tem boa capacidade de adsorção para o íon Cu²⁺.

O objetivo do presente trabalho é a modelagem matemática e a simulação computacional do processo de reforma de metano com dióxido de carbono em reator de leito fixo sobre catalisador de níquel. O modelo proposto consiste de um sistema de equações diferenciais parciais não-lineares e não-homogêneas decorrentes dos balanços materiais no reator e na partícula do catalisador. A solução do problema é obtida com a aplicação da Técnica das Equações Integrais Acopladas nas equações para a fase sólida resultando em um modelo simplificado unidimensional transiente para as duas fases (fluida e sólida). Ao modelo simplificado são empregados os procedimentos da Técnica da Transformada Integral Generalizada e do Método das Linhas com o objetivo de transformar o sistema de equações parciais em um sistema de equações diferenciais ordinárias. Para a solução do sistema de EDOs, foi desenvolvido um código em linguagem de programação Fortran 90/95 no qual foi utilizada a subrotina IVPAG, em dupla precisão, da biblioteca IMSL. Os resultados obtidos foram, então, comparados a fim de que o modelo proposto fosse verificado.

O Método das Linhas (MOL) foi utilizado na análise das equações que descrevem o processo de transferência de calor durante o processo de solidificação de ligas binárias. O modelo físico consistiu em simular a solidificação dessas ligas com base em resultados experimentais, existentes na literatura, obtidos em um dispositivo de solidificação direcional vertical ascendente. Um código computacional baseado em linguagem de programação FORTRAN 90/95, utilizando a sub-rotina DIVPAG da biblioteca IMSL, foi desenvolvido para resolver numericamente os sistemas de equações diferencias ordinárias. As variáveis térmicas tais como velocidade da isoterma liquidus (V_L), gradiente térmicos (G_L) e taxa de resfriamento (T_R) foram determinadas a partir das curvas de resfriamento para ligas de três diferentes sistemas utilizados nesse trabalho (Al-Sn, Al-Cu e Sn-Pb). Finalmente, foram realizadas comparações dos resultados numéricos obtidos nesse estudo com valores da literatura, demonstrando a potencialidade da técnica utilizada em tratar problemas dessa natureza.

O presente trabalho apresenta a gordura residual retirada de caixas retentoras de gordura como uma matéria-prima potencial e alternativa para produção de combustíveis renováveis. A gordura residual foi utilizada como carga em experimentos de craqueamento térmico catalítico em Unidades de Bancada, Semi-Piloto e Piloto. Diferentes teores de carbonato de sódio (5%, 10% e 15%) foram utilizados como catalisador nos experimentos de craqueamneto térmico catalítico. Os produtos líquidos orgânicos (PLO’s) obtidos nos experimentos de craqueamento foram destilados em unidades de destilação em escala de bancada e piloto. Os processos de destilação resultaram na obtenção de frações de hidrocarbonetos nas faixas do querosene, diesel leve e pesado. Os PLO’s juntamente com as frações de diesel verde leve e pesado foram caracterizados de acordo com as especificações estabelecidas pela norma da ANP Nº65 para óleo diesel S10. As frações de querosene verde foram caracterizadas de acordo com as especificações estabelecidas pela norma da ANP Nº37 para querosene derivado do petróleo. Os resultados mostraram que os PLO’sapresentaram baixos valores para o índice de acidez, além disso, foi confirmado que a utilização de diferentes percentuais do catalisador carbonato de sódio nas três escalas de produção contribuiu para a obtenção de resultados promissores quanto ao rendimento e as características físico-químicas e composicionais, indicando a eficiência deste catalisador básico. Os resultados também mostraram que as frações de querosene verde, diesel verde leve e pesado apresentaram baixos teores de ácidos graxos livres, rendimentos significativos e características físico-químicas consonantes com as suas respectivas normas. Os experimentos que utilizaram o percentual de 10% de carbonato de sódio como catalisador apresentaram os maiores rendimentos, os menores índices de acidez e os melhores resultados das caracterizações físico-químicas e composicionais entre todos os testes feitos neste estudo. O PLO produzido utilizando o teor de 10% de carbonato de sódio apresentou um total de 78,98% de hidrocarbonetos em sua composição, enquanto o querosene verde obtido após a destilação deste mesmo PLO apresentou um total de 92,64% de hidrocarbonetos em sua composição, estes resultados foram ratificados através de análises como: FT-IR, RMN e GC-MS.

O presente trabalho teve o intuito de avaliar a utilização da gordura residual retirada de caixas retentoras de gordura como uma matéria-prima alternativa no processo de produção de biocombustíveis. O processo de craqueamento térmico catalítico da gordura residual foi realizado nas escalas de bancada e piloto utilizando a Lama vermelha (LV) calcinada a 1000°C como catalisador em diferentes concentrações (5%, 10% e 15%). Os produtos líquidos orgânicos (PLO’s) obtidos nos experimentos de craqueamento foram destilados em uma Unidade de Bancada, onde ocorreu a produção de frações de hidrocarbonetos nas faixas do diesel verde leve e diesel verde pesado. Desta forma, os PLO´s e as frações foram caracterizados através da realização de análises físico-químicas e composicional, onde os resultados obtidos acabaram sendo comparados de acordo com as especificações estabelecidas pela norma da ANP N° 65 para óleo diesel S10. O PLO produzido na unidade de bancada e piloto de craqueamento utilizando o teor de 5% de catalisador (LV calcinada a 1000°C) quando comparado com os experimentos que utilizaram concentrações de 10% e 15% de LV, mostrou os melhores resultados para o índice de acidez, viscosidade cinemática e densidade, ratificando que esse experimento apresentou um dos melhores rendimentos do processo e resultados significativos no que tange as análises físico-químicas e de composição. Os processos de destilação dos PLO’s realizado na Unidade de Destilação em Escala de Bancada apresentaram bons rendimentos para as frações de hidrocarbonetos na faixa do diesel verde pesado. As frações de diesel verde pesado obtidas após a destilação do PLO produzido com o teor de 5% de catalisador apresentaram rendimento significativo e os melhores resultados físicoquímicos entre todas as frações obtidas neste estudo, principalmente no que tange ao índice de acidez. Foi comprovado através das análises de Infravermelho, Ressonância Magnética Nuclear e Cromatografia gasosa acoplado a um espectrômetro de massa a presença de hidrocarbonetos na composição dos produtos líquidos orgânicos. 

No presente trabalho, visou-se estudar o processo de craqueamento termocatalítico do óleo de palma para a produção de biocombustíveis. No desenvolvimento desse estudo foram realizados craqueamentos nas Escalas de Bancada e Semipiloto. Inicialmente, foram realizados testes de craqueamento com catalisadores básicos (Lama Vermelha; Lama Vermelha Calcinada a 550ºC; Lama Vermelha Calcinada a 800ºC; Lama Vermelha Calcinada a 1000ºC; Alumina Ativada (AA) com solução de NaOH a 20% e Alumina Ativada (AA) com solução de NaOH a 30%) e ácido (Alumina não ativada)  na Escala de Bancada utilizando como matéria-prima o óleo de palma. Antes dos catalisadores mencionados serem utilizados nos craqueamentos termocatalíticos, eles foram submetidos às seguintes análises: Infravermelho com Transformada de Fourier (FT-IR); Microscopia Eletrônica de Varredura (MEV); Difração de Raios-X (DRX) e B.E.T com o intuito de caracterizá-los. Os resultados obtidos na Escala de Bancada mostraram que os Produtos Craqueados Brutos (PCB’s) conseguidos nos craqueamentos termocatalíticos do óleo, utilizando como catalisadores 15% de Lama Vermelha Calcinada a 800 ºC e 15% de AA com solução de NaOH a 20%, tiveram uma redução significativa nos seus Índices de Acidez (IA’s) quando comparados com os IA’s dos craqueamentos térmico e termocatalíticos realizados com os outros catalisadores. Na Escala Semipiloto foram desenvolvidos os craqueamentos termocatalíticos com os melhores resultados obtidos, na Escala de Bancada, entre as Lamas Vermelhas Calcinadas ou não em diferentes concentrações (15% de Lama Vermelha Calcinada a 800 ºC) e entre as Aluminas Ativadas ou não em concentrações diversas (15% de AA com solução de NaOH a 20%) em relação aos IA’s, além do craqueamento térmico que também foi reproduzido nessa escala. Parte dos produtos obtidos na Escala Semipiloto foi submetida à destilação em Escala de Bancada visando obter frações correspondentes às faixas: da gasolina, do querosene, do diesel leve e do diesel pesado. A análise de RMN de ¹³C, realizada sobre os dieseis dos craqueamentos térmico e termocatalítico com 15% de Lama Vermelha Calcinada a 800 ºC comprovou que eles são formados basicamente por ácidos graxos de cadeias longas. Além disso, os GC-MS realizados na faixa de corte da gasolina (40ºC-175ºC) comprovaram que as três gasolinas analisadas apresentaram a formação de hidrocarbonetos parafínicos, olefínicos e naftênicos.

Neste trabalho foi estudado o processo de adsorção de ácidos graxos livres residuais (ácidos carboxílicos) presentes em frações destiladas provenientes do Produto Líquido Orgânico (PLO) obtido por craqueamentotermo-catalítico de óleo vegetal. O objetivo foi a desacidificação das frações destiladas obtidas a partir da destilação doPLO. Os experimentos foram realizados empregando diferentes frações destiladas empregando três diferentes adsorventes, g-Alumina, Lama Vermelha Ativada Termicamente (400ºC) e Lama Vermelha Ativada Quimicamente com soluções de HCl em diferentes concentrações (0.25, 1 e 2M).A capacidade do adsorvente em relação à adsorção de ácidos graxos livres foi avaliada por meio de estudos cinéticos, medindo-se a variação da concentração de ácidos graxos livres presentes antes e após a adsorção, através da determinação do Índice de Acidez.Os resultados indicaram que o aumento da concentração de ácidos iniciais diminui a capacidade de adsorção do adsorvente, mostrando que o processo é menos eficiente para concentrações mais elevadas. Para os experimentos com diferentes porcentagens de adsorventes vimos que ao se utilizar 0,5% de adsorvente obtemos a maior eficiência na remoção dos ácidos graxos, a qual vai diminuindo com o aumento da porcentagem de adsorvente.O adsorvente mais eficiente foi a Lama Vermelha ativada com 1M de HCl, onde foi obtida uma redução de 98% dos ácidos graxos para uma amostra com índice de acidez inicial 4 mg KOH/g. A modelagem matemática indicou que o modelo cinético que melhor representa o processo foi o modelo Cinético de Pseudo-2ª Ordem. Portanto, os resultados mostraram que os adsorventes utilizadossão, na sua maioria, eficientes na remoção dos ácidos graxos livres e que a concentração inicial de ácidos na amostra tem efeito direto sobre odesempenho da adsorção dos mesmos.

Nós realizamos um estudo teórico utilizando a Teoria do Funcional de Densidade, com o funcional B3LYP e o conjunto de base 6-311++g(d,p) para calcular propriedades termodinâmicas dos seguintes combustíveis e biocombustíveis: gasolina,etanol e a mistura gasolina-etanol, todos em fase gasosa. As simulações foram efetuadas através dos softwaresGaussian09W e Hyperchem 7.5 e permitiram a obtenção de propriedades dos combustíveis, as quais, foram calculadas a partir da média ponderada das propriedades de cada um de seus componentes majoritários, considerando as frações mássicas dos componentes de dois tipos de gasolina, um tipo Padrão e outro comercial Regular.As simulações foram realizadas para várias temperaturas na faixa de 0,5K - 1500K e sob a pressão de 1atm, utilizando o Modelo do Contínuo Polarizável para simular sistemas solvatados de cada componente.Foram realizadas simulações de análise conformacional, otimização de geometria molecular e cálculos de frequências Raman e Infravermelho, onde foi possível obter resultados às grandezas físicas associadasà reatividade química e ao poder calorífico dos combustíveis durante a etapa de injeção na câmara de combustão.Também foi possível comprovar e quantificaralgumas características importantes dos combustíveis, como por exemplo, o alto potencial antidetonaçãoque o etanol apresenta quando comparado à gasolina, bem como a influência causada pelo etanol quando misturado à gasolina. Estas comparaçõesforamfeitas a partirdo estudo dos potenciais termodinâmicos (energia interna, entalpia e energia livre de Gibbs) obtidos durante as simulações.Além destas propriedades foram calculasa taxa de variação da energia livre de Gibbs em relação à temperatura, o calor específico a pressão constante e a entropia dos componentes majoritários. Esta metodologia foi reproduzida utilizando os métodos computacionais semi-empíricos PM3 e PM6, com a finalidade de comparar sua precisão e o custo computacional dos mesmos no estudo de combustíveis, aosresultados obtidos a partir do funcional B3LYP.Verificamos que os métodos semi-empiricos apresentam precisão tão boa quanto o funcional B3LYP nos cálculos de propriedades termodinâmicas dos componentes majoritários, porém com um custo computacional significativamente menor, possibilitando que este trabalho se apresente como uma metodologia bastante eficaz para a caracterização termodinâmica de combustíveis e biocombustíveis na fase gasosa quando os mesmos são injetados na câmara de combustão.

This paper explores the modeling and solution of the Reynolds equation and simulate the problem of hydrodynamic lubrication in bearings of circular anchor shoes with Rayleigh and milled pad. Mathematical modeling of the problem of hydrodynamic flow in bearings with consideration of centrifugal inertial terms produces a modified generic equation Reynolds called Reynolds equation with inertial terms version. This equation is solved by the generalized integral transform technique (TTIG) method, where it transforms the Reynolds equation system for generating a common, endless and non- linear equations for obtaining the analytical and numerical solutions of the field of fluid film pressure, the charge and power consumed by the bearing, where these performance parameters depend on the geometry adopted for the bearing. Thus, four algorithms were originated by the transformed system, and the difference between them are the geometries chosen for the bearings, but all computer codes made use of the traditional way of TTIG. In all codes were implemented in Fortran 90/95 language and solved by routine BVPFD of IMSL (1987) library. The solution to said Reynolds equation expressed using the work dimensionless transfer potential P(r,q) that was found for various combinations of dimensionless coefficients that constitute the terms of this equation. The applicability of the technique was verified by comparing the results from the use of GITT the values found by the finite volume method (FVM) in a paper published by Blanco e Prata, 1998 e 2014. Behavior of pressure fields was verified by varying the sizes of the series obtained by computer codes. The results show reasonable convergence.

As argilas têm alta viabilidade técnico-econômica para diversas aplicações industriais. Em certas regiões do estado do Pará as argilas são abundantes e sua extração ocorre de forma intensiva, sendo geralmente empregadas na fabricação de artefatos cerâmicos. A utilização de argilas modificadas como adsorventes na remediação de água contaminada tem sido objeto de diversas pesquisas. Neste trabalhofoi estudada uma argila caulinitica suacaracterização e sua aplicação como adsorvente na forma “in natura” tratada termicamente na adsorção de BTX e após a modificação de sua superfície por surfactante catônico (HDTMA_Br), como adsorvente de oxiânions de cromo hexavalente.A argila proveniente do Distrito de Icoarací (PA) foi classificada por peneiramento, conforme a (NBR 7181). As frações “in natura” (FR-NAT) e modificadas (FR-ORG) e (FR-TR), partículas menores do que 44 µm foram submetidas às análises: difração de raios-X (DRX), fluorescência de raios-X, ATG/ATD, Microscopia Eletrônica de Varredura (MEV), determinação da área superficial (S_BET), porosimetria de mercúrio, CTC e pH_PCZ. Na composição do material argiloso identificaram-se: quartzo, caulinita e illita / muscovita; SiO₂ (59,6%) e Al₂O₃ (17,5%). Os valores das propriedades: S_BET de 21,8 m²/g; distribuição de tamanho de poros na região de mesoporos e macroporos; CTC de 17 (meq/100g) e valor do pH_PCZigual a 4,3. As análises de ATG/ATD das amostras de argilas organofilizadasmostraram quehouve o carregamento da superfície da argila pelo surfactante (HDTMA-Br).Amostras de argila natural e modificada termicamente não apresentaram afinidade pelos compostos orgânicos (BTX). No estudo de adsorção de cromo hexavalente foi utilizado um planejamento fatorial (DCCR) utilizando como variáveis pH e concentrações de surfactante. A adsorção de cromo hexavalente pela argila natural não foi satisfatória, porém a argila modificada quimicamente atingiu valores satisfatórios. A partir da análise estatística dos dados de adsorção, somente a concentração de surfactante catiônico produziu efeitos estatisticamente significativos na remoção do adsorbato.

Bacuri, Açaí, Priprioca, supercritical extraction, carbon dioxide, mathematical modeling

Grandes aplicações utilizando fluidos supercríticos relacionados ao fracionamento de produtos naturais têm sido estudadas nas últimas décadas. Este trabalho teve como objetivo a modelagem termodinâmica do equilíbrio de fases de sistemas binários e multicomponentes de constituintes relacionados a indústria de óleos vegetais (ácidos graxos, triglicerídeos, esqualeno, α-tocoferol e ésteres etílicos e metílicos de ácidos graxos) com dióxido de carbono supercrítico, utilizando as equações de estado cúbicas de Soave-Redich-Kwong (SRK) e Peng-Robinson (PR) com as regras de misturaQuadrática e de Mathias-Klotz-Prausnitz, para construir uma base de dados de parâmetros de interação binária entre estes constituintes e entre estes constituintes com o dióxido de carbono, com destaque para as interações relacionadas aos compostos bioativos. As equações de PR e SRK mostraram eficiência na correlação dos dados de equilíbrio dos sistemas binários. Para a maioria dos sistemas binários o ajuste dos dados experimentais com as regras de mistura com dois parâmetros de interação binária obtiveram bons resultados e equivalentes quando comparados com as regras de mistura com três parâmetros. Para sistemas multicomponentes, quando a correlação dos dados experimentais com o programa PE, empregando ambas as equações com a regra de mistura quadrática obteve convergência, foram obtidos melhores resultados para descrição do equilíbrio de fases e para a representatividade da análise termodinâmica da separação através dos coeficientes de distribuição. Para o sistema CO₂ (1)/Ácido Oleico (2)/Ácido Linoleico (3)a predição do equilíbrio com a utilização de uma matriz de parâmetros de interação de sistemas binários se mostrou equivalente em relação ao uso de parâmetros de interação de sistemasmulticomponentes. Em relação ao sistema CO₂ (1)/ Metil Miristato (2)/ Metil Palmitato (3) os resultados obtidos a partir do cálculo do equilíbrio utilizando a matriz de parâmetros de interação de sistemas binários, quanto com os parâmetros de interação do sistema multicomponente, apresentaram desvios médios semelhantes para a temperatura de 323,15K. Para o sistema CO₂ (1)/ Esqualeno (2)/ Trioleína (3)/ Ácido Oleico (4), os melhores resultados foram obtidos pela regra de mistura Quadráticacom os parâmetros de interação do sistema multicomponentes. Em relação ao sistema PFAD0 (CO₂ (1)/ Ácido Oleico (2)/ Ácido Palmítico (3)/ Esqualeno (4), os resultados obtidos utilizando a matriz de parâmetros de interação de sistemas binários mostraram desvios médios abaixo de 8%. O cálculo do ELV para o sistema CO₂ (1)/ Metil Miristato(2)/ Metil Palmitato (3)/ Metil Oleato (4)/ Metil Estearato(5) ,com os programas PE2000 e EDEflash utilizando a EDE SRK com a regra de mistura Quadrática,utilizando a matriz de parâmetros de interação obtidos de sistemas binários mostraram resultados similares. Em relação ao sistemas multicomponente CO₂ (1)/ Etil Palmitato (2)/ Etil Estearato (3)/ Etil Oleato (4)/ Etil Linoleato (5) (ésteres etílicos do óleo de dendê), a predição do ELV, utilizando a matriz de parâmetros de interação dos sistemas binários, ajustados com a EDE SRK combinada com a regra de mistura Quadrática, apresentaram resultados com desvios abaixo de 4%, em ambas as fases, para a isoterma de 333,15 K.

A Técnica da Transformada Integral Generalizada é aplicada na solução das equações de Navier-Stokes para um duto de geometria irregular na forma senoidal em um escoamento incompreensível e laminar. Para isso, foi utilizada a formulação em termos de função corrente. Um filtro geral foi adotado que se adapta ao contorno irregular para aumentar a convergência da solução. Foram analisadas diversas geometrias modificando-se a razão de comprimento (λ/a) e a razão de altura (H_min/H_max) para número de Reynolds na faixa de 25 a 400. Para o mesmo número de Reynoldselevando um dos dois parâmetros geométricos a recirculação do escoamento é menor e a diminuição de um dos parâmetros eleva a recirculação do escoamento. A recirculação no caso onde λ/a = 16 e H_min/H_max = 0.7 é pouco acentuada em Reynolds = 400. Considerando a configuração onde λ/a = 4 e H_min/H_max = 0.3 é possível gerar vorticidade em números de Reynolds de baixovalor (Re = 25). O fator de atrito, baseado nas forças viscosas, calculado apresentou o mesmo comportamento dos trabalhos da literatura.

O objetivo deste trabalho foi estudar o comportamento reológico do biodiesel do óleo de andiroba e suas misturas com diesel. A caracterização físico-química da amêndoa foi determinada através do teor de água, proteínas, cinzas e lipídeos. As análises físico-químicas realizadas no óleo foram: índice de acidez, índice de saponificação, índice de peróxido, índice de refração, massa específica, viscosidade e teor de água. Através da cromatografia gasosa a composição química em termos de ácidos graxos foi identificada e observou-se que 60,49 % são insaturados e 37,09 % são saturados, sendo composto basicamente pelos ácidos graxos: oléico (49,1 %), palmítico (28,15 %), linoléico (11,39 %) e esteárico (8,54 %). Para o estudo reológico foram feitas misturas biodiesel/diesel chamados de B0, B5, B10, B20, B50, B75 e B100. As medidas reológicas foram realizadas em viscosímetro Brookfield, modelo LV, utilizando temperaturas na faixa de 293,15 a 343,15 K. Os dados reológicos foram ajustados pelo modelo de Andrade, mostrando que o biodiesel de andiroba e suas misturas apresentam comportamento Newtoniano na faixa de temperatura estudada. Observou-se que a viscosidade decresce acentuadamente com o aumento da temperatura.

            De origem asiática, a semente de linhaça (Linum usitatissimum L.) pertence à família das Lináceas e é obtida a partir do linho. A semente da linhaça é ainda a maior fonte alimentar de lignanas, compostos fotoquímicos parecidos com o estrogênio, que podem desempenhar ação anticancerígena. Rica em fibras solúveis tem aproximadamente 40% do seu peso composto por óleos ricos em Ômega 3, entre os quais se destaca o α-linolênico. A secagem é a operação unitária segundo o qual ocorre eliminação da água por evaporação ou sublimação, presente em um material, mediante a aplicação de calor com condições controladas. Visando averiguar o comportamento das sementes de linhaça durante a operação de secagem, o presente trabalho teve como objetivo principal realizar o planejamento experimental e analisar estatísticamente os resultados empregados para quantificar a influência da temperatura do ar (T), tempo de secagem (t), velocidade do ar de fluidização (U_f) e carga de sólidos (Cs), sobre a razão de umidade (Xr), rendimento em óleo (Rend.) e os parâmetros oleoquimicos. A estimativa do ponto ótimo de operação foi determinada em função das variáveis de entrada aplicando o conceito de desejabilidade global. Dentre as condições estabelecidas neste trabalho, o valor ótimo da Função Desejabilidade é quando T é deslocada próximo ao nível alto (72 ^oC), t para o mínimo (3 h), U_f  para o ponto  próximo ao central (0,83  m/s) e a Cs para o nível alto (500 g), obtendo-se assim: 0,126 para Xr; 36,92 % para Rend.; 4,51 mg KOH/g para IA; 22,52 meqO₂/Kg IP e 0,31% para DC. Foram obtidas as isotermas de dessorção das sementes de linhaça nas temperaturas de 40, 60 e 80°C. Os dados experimentais foram avaliados usando seis modelos matemáticos. A entalpia e a entropia diferencial de dessorção foram estimadas por meio das relações de Clausius-Clapeyron e Gibbs-Helmholtz, respectivamente. Os modelos de GAB e Peleg ajustaram adequadamente os dados experimentais. A teoria da compensação entalpia-entropia foi aplicada com sucesso às isotermas de dessorção e indica que o mecanismo de dessorção de umidade das sementes de linhaça pode ser considerado como controlado pela entalpia. A secagem das sementes de linhaça previamente umidificadas foram avaliadas em um secador de leito fixo e fluidizado, as corridas experimentais foram realizadas nas temperaturas de 40, 60 e 80°C, dentre dos cinco modelos propostos, o modelo de Midilli et al, foi o melhor modelo que melhor ajustou aos dados experimentais. Foi observado que a difusividade efetiva para as sementes de linhaça aumentou com a elevação da temperatura do ar de secagem para a secagem em leito fixo e fluidizado. A dependência da difusividade em relação à temperatura foi descrita pela equação de Arrhenius, por meio da qual se estimou para ambos os processos de secagem.

The objective was to study the flocculation of residue kaolin suspension using bioflocculant produced from cells and extracellular products of Bacillus subtilis. The assays were carried out at laboratory bench scale and was employed a jar test apparatus. The study was conducted in three stages. 1) production of biofloculante, 2) bioflocculation of kaolin residue suspensions, optimization using statistical experimental design and 3) bioflocculation and coagulation/flocculation of  industrial wastewater generated from the kaolin processing. Ouvir

Ler foneticamente

Dicionário - Ver dicionário detalhado

The biofloculante was produced from a lyophilized and certified strain of  B. subtilis in culture medium TSB (Tryptic Soy Broth). The culture and determination of the cell density in the suspension (biofloculante) were performed by standard procedures. As results were obtained 50 mL bioflocculant suspension (8.7 x 10⁸ CFU/mL). The point of zero charge (PZC) of the kaolin residue was determined by potentiometric mass titration (PMT) and immersion technique (IT). Bioflocculation process was studied using central composite design (CCD), with and without addition of background electrolyte.  Independent variables: KS (g/L), BV (mL) and suspensions pH;  dependent variable: flocculating rate (FR, %). SEM images were obtained of kaolin residue flocs, after bioflocculation for checking the mode of adhesion between the mineral particles and biofloculante. The of PZC value of the kaolin residue was, around (3.2). The results obtained from the CCR: assays with addition of electrolyte, the variables: KS, BV and pH (linear and quadratic forms) and linear interactions, BV and KS; KS and pH are significant at a confidence level of 95(per cent) for the bioflocculation process; assays without addition of electrolyte, the variables: pH and BV, linear and quadratic forms are statistically significant for the (FR, per cent). Satisfactory results were obtained from the bioflocculation, maximum flocculating rate, around 80% at experimental conditions of pH (2.4 - 3.6), BV (3.7 - 8.4 mL) and lower level of KS ( g/L). Physicochemical parameters of industrial wastewater were determined by standard procedures: pH, turbidity, total alkalinity, dissolved oxygen, solids, cations and anions (Cl^-, SO₄^2-, Na⁺, K⁺, Ba²⁺ and Mn²⁺, Ca²⁺, Fe³⁺, Zn²⁺). The PZC of kaolin residue obtained from  industrial wastewater was determined by potentiometric mass titration (TPM) technique. Bioflocculation assays of samples of the industrial wastewater were carried out, under experimental conditions, obtained from later stages of this work. The bioflocculation process was more efficient and a value of flocculating rate, around  (80% ) was obtained for (IE-B203). From bioflocculation settling rate significant was obtained at process time of 2 min and settling time of 5 min., experimental conditions that may be considered a good draw for an industrial process.