Mestrado em Química - PPGQ

URI Permanente para esta coleção

https://repositorio.ufcat.edu.br/handle/tede/66

Navegar

Agora exibindo 1 - 11 de 11

Avaliação da produção de metano no biogás frente a diferentes diluições do dejeto bovino e a influência nutricional
(Universidade Federal de Goiás, 2020-07-20) Assunção, Geiza Pereira de; Figueiredo, Alberthmeiry Teixeira de; http://lattes.cnpq.br/7026388762536003; Sarmento, Antorver Panazzolo; Barrado, Cristiano Morita; Figueiredo, Alberthmeiry Teixeira de
The effluent resulting from the confinement of ruminant animals, specifically dairy cows, exhibits a high concentration of organic matter and contaminating agents that pose a threat to the environment as a result of their improper handling. One of the solutions found to treat and minimize the amount of these residues and, consequently, the pollutants produced is to use the residual organic matter as a sustainable energy source. An example is the use of the waste of these animals as a source of energy, both thermal and electrical, through the production and use of biogas. Thus, the main object of study of this work was to evaluate the effect of anaerobic biodegradability of bovine manure in controlled conditions of temperature and agitation, testing different dilution factors, linked to the diet of dairy cows for the improvement of methane production, in scale laboratory by batch system. The work is divided into two stages. The first was the optimization of the dilution in the efficiency of methane production, where the sample of crude manure (without diluting) was studied in addition to the dilutions 1:2; 1:6 and 1:10 (manure / water) and the influence of animal nutrition as a second stage. The biodigesters were evaluated from the efficiency of removal of organic matter (O.M.) in the physical-chemical analyzes of COD, BOD, and TVS, and in the productivity of methane. It was found that the most diluted reactors were the conditions that showed the best results of O.M. removal both in the form of COD and BOD, however, the same behavior for methane production was not observed, since the higher methane production was directly proportional to the content of incubated organic load, that is, the reactors supplied with higher concentrations of bovine manure (lower% water) exhibited higher yields. With the aid of the modified Gompertz mathematical model, he verified that the excess of O.M., due to the non-dilution of bovine manure (R.1), results in long periods of adaptation of the microorganisms (lag phase), that is, a delay in production, about two months for effective start in methane production. In the second stage, it was concluded that animal feed supplementation directly influences the production of ideal residues (rich in energy and nutrients) for the biodigestion process, since the reactor (G.3) supplied with waste from the group of animals fed with greater nutritional highest load exhibited the highest methane production, about 107% more than the reactor supplied with group 1 residues lowest nutritional charge.
Conjugação das técnicas de coagulação química (Moringa oleífera) e eletroquímica (DDB) no tratamento de efluente real de indústria de tintas
(Universidade Federal de Goiás, 2018-03-15) Barbosa, Andreia Daniane; Andrade, Leonardo Santos; http://lattes.cnpq.br/5360511377400279; Andrade, Leonardo Santos; Sarmento, Antover Panazzolo; Barrado, Cristiano Morita
Treatment of a real paint industry wastewater using a natural chemical coagulant based on Moringa oleifera (MO) seeds associated with Ca 2+ salts (nitrate or chloride) in order to potentiate its coagulating effect. This method of treatment was combined with the electrochemical technique from the use of a boron doped diamond electrode in a flow reactor. The main purpose of the treatments investigated was to evaluate the possibility of reuse of treated water in the production of a new paint. The treatment of the residue was evaluated by its turbidity, DFZ (color), total solids content, chemical oxygen demand (COD), biotoxicity and microbiological tests. The optimum conditions for coagulation were obtained at pH 6.5 and with coagulant dosage (50 g/L of MO) of 80 mL for each 1.0 L of residue (80 mL/L). The optimum concentration of Ca 2+ incorporated into the coagulant was 0.125 mol/L. The viability of the treatment, evidenced by the reuse of the treated water for the production of a new paint (made by the company supplying the waste), showed compatible quality with the water used by the company (tap water) only when the treatment was carried out using MO aqueous extract in association with Ca(NO 3 ) 2 salt. For the electrochemical treatment, the limit current density of (35 mA/cm 2 ) and an electrolysis time of 90 min were used. Bio-toxicity assays (A. Salina) showed that the mortality of micro crustaceans was reduced from 100% (raw effluent) to only 11% and that 85% of the effluent organic load was eliminated at the end of the electrolysis process. In addition, microbiological assays showed that the amount of mesophiles decreased by more than six orders of magnitude and no thermotolerant coliform colony was formed.
Cristalização hidrotérmica do gel de TiO2 obtido pelo método de decomposição de complexos e análise de suas propriedades fotocatalíticas
(Universidade Federal de Goiás, 2018-10-10) Gomes, Yagly Grasielle dos Santos; Barrado, Cristiano Morita; http://lattes.cnpq.br/1481467844050222; Barrado, Cristiano Morita; Sarmento, Antover Panazzolo; Figueiredo, Alberthmeiry Teixeira de
In recent years, titanium dioxide TiO2 has been well studied due to its various interesting physical and chemical properties, especially with regard to the application in processes of photocatalytic discoloration. These processes have always attracted the interest of the scientific community, mainly because it is possible to use sunlight as a source of energy for the reaction to happen. The present work had the objective of studying the influence of pH on the hydrothermal crystallization of the amorphous (TiO2) gel obtained by the complex decomposition method by two different routes varying temperature and time of synthesis, where in one of the routes the materials were crystallized in a reactor metal and on the other synthetic route was used a glass reactor. Such routes were used as a relatively new, promising and efficient processing method for obtaining this type of material. The obtained samples were characterized by different techniques: the X-ray diffraction confirmed the obtaining of monophasic materials and also in mixtures of phases, with tetragonal structure for the polymorphs anatase and rutile, proving that the hydrothermal method is efficient in the synthesis of the samples of interest having energy expenditure when compared to conventional crystallization methods. Using the X-ray diffraction data, the sizes of crystallites (TC), and the percentage values of phases present in each sample were measured. The (MEV/FEG) scanning electron microscopy characterization and (TEM) transmission, evidenced the changes in the size and morphology of the materials obtained, especially between anatase and rutile when single-phase. The photocatalytic tests showed the best performance of some materials, especially for the sample crystallized in pH 7 in the glass reactor, which decoloured the study dye in 99.7% due to its morphology as well as anatase / rutile composition in percentage terms.
Deposição de filmes finos de TiO2 em superfície de vidro e avaliação das suas propriedades fotocatalíticas
(Universidade Federal de Goiás, 2019-07-03) Gonçalves, Elizael de Jesus; Barrado, Cristiano Morita; http://lattes.cnpq.br/1481467844050222; Barrado, Cristiano Morita; Figueiredo, Alberthmeiry Teixeira de; Martins, Marccus Victor Almeida
Water is one of the most abundant and most important available resources for life's existence and permanence. The National Water Agency reports that there is an increasingly inversely proportional relationship between demand and the availability of freshwater, it makes necessary to reuse this natural resource so that the world population does not enter into water chaos. Thus, the main problems encountered are the population increase and the intensification of industrial activities, which contributes to the generation of possible outbreaks of water resources contamination. However, the treatment performed by the ETAs and ETEs are not prepared to remove these compounds, which are largely toxic and difficult to degradation. Thus, advanced oxidative processes (POAs) are alternative technologies that are under strong interest in the scientific environment due to the high potential of removing these recalcitrant components. Among the POAs stands out the heterogeneous photocatalysis, which consists of photoactivating an inorganic semiconductor, such as TiO2, with consequent generation of highly oxidisant species. Titanium oxide (TiO2) has three crystallographic forms, being, anatase, rutile and Brokita. The synthesis method is highly determinant in obtaining these types of structure and, consequently, in the property of oxide. This work aimed to obtain titanium dioxide in the form of films using the Peroxo-Titanium complex Method (CPT), moreover, evaluating the calcination temperature, successive layers and addition of P25 in the films, and influence on the photochemical efficiency of Discoloration of the Tartrazine organic dye. The precursor gel was obtained by solubilization of titanium isopropoxide in H2O2 28% in ice bath. The TiO2 films were deposited by manual immersion, silk screen and with the aid of a brush on the glass plate of 20x76mm previously cleaned with piranha solution (H2SO4: H2O2) ratio in mol of 4:1. The films were thermally treated at temperatures of 450 º C and 550 º C for 1h30min. The resulting material was structurally characterized in the XW, morphologically in SEM and the composition was verified in the EDX. Heterogeneous photocatalysis assays were performed, exposing the tartrazine solution to the radiation of the mercury lamp and sunlight, in the time of 120 minutes and 390 minutes. In general, the formation of biphasic materials with photocatalytic activity was observed; The photocatalytic film that presented the best photocatalytic performance was the T3 material with 30% addition of P25 for promoting the total discoloration of the dye in 100%, with kap of 0.0693, it can be emphasized that the films have catalytic activity both in Presence in artificial and natural ultraviolet light; and have not shown to be toxic, with a small mortality rate Artemia salina less than 30%. The efficiency was related to the presence of a mixture of anatase/rutile phases similar to P25, which generates an effect of heterojunction increasing the photochemical efficiency to promote oxidative reactions and adsorption, favoring the discoloration of the organic compost resistant, and bringing advantages of TiO2 films, such as the reuse of glass spheres in various catalytic processes without the loss of photochemical efficiency, and the ease of removal of the material at the end of the photocatalytic process.
Estudo experimental e mecânico quântico “ab initio” para investigar as propriedades estruturais e eletrônicas do zirconato de cálcio
(Universidade Federal de Goiás, 2015-03-09) Oliveira, Marisa Carvalho de; Gurgel, Maria Fernanda do Carmo; http://lattes.cnpq.br/1245821448123612; Gurgel, Maria Fernanda do Carmo; Silva, Elson Longo da; Barrado, Cristiano Morita
Perovskites compounds such as calcium zirconate have the formula ABO3 and form a class of materials with optical, magnetic and electrical properties and can have various interesting scientific and technological applications. Perovskites materials will be reported in this work due to present physical and chemical stability and interesting properties studies. In the case, experimental investigations associated with theoretical calculations will be based on "ab initio" guided by the theoretical and computational chemistry based on CRYSTAL09 program. These theoretical simulations give a powerful complement to experimental techniques in order to provide structural and electronic information more detailed to the atomic level. Therefore, this search aims to study and analyze the synthesis of perovskites by the polymeric precursor method, perform characterization of the samples by X-ray diffraction (XRD), Rietveld refinement, Raman spectroscopy, spectroscopy in the UVvisible region (UV-vis), Transmission Electron Microscopy (TEM), photoluminescence spectroscopy (PL) and a computational theoretical study. The theoretical modeling will be developed using computational methods ab initio through periodic quantum mechanical method, aiming to provide information about the structural arrangement, electronic, optical and energy systems, confirming the experimental data, FL obtaining emission spectra for CZO doped to 900 °C and 1000 °C pure, as well as density of states diagrams band structure and charge density
Síntese do Fe3O4@SiO2:phen:Eu3+: um nanocompósito magnético luminescente visando aplicações biomédicas
(Universidade Federal de Goiás, 2017-03-03) Silva, Raphael Lucas de Sousa e; Figueiredo, Alberthmeiry Teixeira de; http://lattes.cnpq.br/7026388762536003; Figueiredo, Alberthmeiry Teixeira de; Sousa, Marcelo Henrique; Barrado, Cristiano Morita
Among the various iron oxides studied, a magnetite (Fe3O4) stands out due to its superparamagnetic behavior and its high biocompatibility. Luminescent properties working cooperatively in magnetic nanoparticles with which the material converts certain types of energy into emission of electromagnetic radiation at the same time, which enables an interaction by magnetic fields. In the present work, an investigation and structural, elemental and morphological analysis of superparamagnetic / luminescent particles formed by coating of iron oxide by an SiO2 base network was carried out. The Fe3O4 oxide was synthesized by the coprecipitation method, and in the Eu3+ rare earth together with the 1,10-phenanthroline linker in the network, were responsible for energy transfer processes in systems that checked as optical materials for materials. The nanocomposites synthesized obeyed the formation of a core-shell system and was verified by micrographs obtained by Electron Transmission Electron Microscopy, evidencing a formation of nanoparticles of varied sizes. As the compositions of the phases of the materials were characterized by X-ray Diffraction, Radiated Spark Energy and Absorption Spectroscopy in the Infrared region, showing a crystal phase of the magnetic oxide and a formation of nanocomposite. The properties of interest (magnetism and photoluminescence) were evaluated and the respective results presented agreed with each other, with characteristic emissions of Eu3+ emitting a pink coloration, and an emission intensity for a concentration of this species in the material. The materials presented a superparamagnetic behavior, evidencing that the oxide coating did not change as Fe3O4 magnetic characteristics, and is in turn presented in a saturation magnetization of 55 emu / g with a magnetic domain of 8.9 nm. As nanoparticles have dimensions that indicate that a part has a magnetic domain.
Síntese e caracterização de hidróxidos e óxidos nanométricos de gadolínio e samário, pelo sistema hidrotérmico assistido por micro – ondas (HTMW)
(Universidade Federal de Goiás, 2013-07-26) Almeida, Maciel Salomão de; Godinho Júnior, Mário; http://lattes.cnpq.br/8364676654739392; Godinho Júnior, Mário; Figueiredo, Alberthmeiry Teixeira de; Barrado, Cristiano Morita
The method of obtaining nanorods was conducted by precipitation of hydroxides of samarium and gadolinium weak base with ammonium hydroxide at room temperature and subsequent calcination of hydroxides to oxides. For the nanosized powders hydroxide with nanorods morphology was used hydrothermal system assisted by microwave (HTMW). The products obtained were characterized by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The application of X-ray diffraction identified crystalline phases, quantitation of phases, determining the parameters of the unit cell, the crystallite size and orientation. The scanning electron microscopy and transmission contributed to the morphological observations in the post hydroxide nanorods. Obtaining oxides occurred after the thermal analysis: Thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The gadolinia and samaria, are known as oxides of these elements were obtained by dehydration of the respective hydroxides. During calcination of the hydroxides, the porosity of the nanorods became increasingly smaller due to reduction of surface free energy of the nanorods, maintaining the morphology.
Síntese e caracterização de nanocompósitos ocos de Y2O3:Eu3+ revestidos com Fe3O4
(Universidade Federal de Goiás, 2020-07-24) Caldas, Maylura Morais; Figueiredo, Alberthmeiry Teixeira de; http://lattes.cnpq.br/7026388762536003; Figueiredo, Alberthmeiry Teixeira de; Tranquilin, Ricardo Luís; Barrado, Cristiano Morita
The study of hollow structures has stood out for being considered functional materials and due to their properties such as high load capacity, low density and high surface area. This set of factors allows the hollow structures to gain space in research for the production of new materials. Combined with these factors, luminescent and magnetic properties in a single material have been explored for their ability to track and visualize. Among the materials with luminescent properties, Y2O3:Eu3+ is highlighted as an important luminophore with red emission, easy to produce and with good stability. Among the magnetic materials, Fe3O4 stands out due to its compatibility with biological systems and its superparamagnetic behavior. In the present study, the synthesis and structural and morphological characterization for the production of hollow double hull spheres Y2O3:Eu3+@Fe3O4 was verified. To obtain these hollow structures of spherical morphology, the hard templating method was used, using carbon spheres obtained by the hydrothermal method, as a hard templating. The coprecipitation synthesis was used to coat the carbon spheres with Y2O3:Eu3+ and Fe3O4, and the resulting materials were subjected to heat treatment to remove carbon. The composites obtained have spherical and hollow morphology, based on the micrographs obtained by scanning electron microscopy with field emission (FEG), according to the X-ray diffraction, the structures were crystalline and presented phases related to Y2O3 and Fe3O4. The crystallite sizes were calculated providing evidence that Y2O3:Eu3+ and Fe3O4 nanoparticles covered the rigid model. The luminescent and magnetic properties were investigated and their results show compliance, the luminescent emissions characteristic of the Eu3+ ion in the 612nm region corresponding to the orange/red emission of the electromagnetic spectrum and superparamagnetic character due to the magnetic characteristics of Fe3O4.
Síntese e caracterização do core-shell ZrO2:Y3+@TiO2
(Universidade Federal de Goiás, 2016-03-21) Silva, P. D. G.; de Figueiredo, A. T.; http://lattes.cnpq.br/7026388762536003; de Figueiredo, A. T.; Zampiere, Marcelo; Barrado, Cristiano Morita
Since the early 90's researchers have investigated the combination of nanocomposites comprised of multilayers, which have better efficiency than their corresponding individual particles, may present in certain cases, new properties. The resulting structure is called a core-shell. In this study, were synthesized ZrO2:Y 3+ coated with TiO2, obtaining nanocomposites ZrO2:Y 3+ @TiO2 with a thickness of 10, 20 and 50% shell. The photoluminescent property (FL) of the nanocomposites was studied. Such interest is due to the fact that the order/disorder structural at the interface of the core-shell type systems may be possible recombination processes responsible for the photoluminescence emission of these materials. Nanoparticles of the core and the shell were obtained by the Method of Polymeric Precursors. The samples were characterized by X-ray diffraction (XRD) to identify the formation of the nanocomposite and evaluate the structural order in the synthesized materials. The core was obtained with tetragonal structure and the shell with anatase structure. From the diffractograms have been carried out calculations of the crystallite size and lattice parameters. The characterization by Transmission Electron Microscopy (TEM), it was not possible to differentiate the core of the shell by the images, since both are structurally ordered, requiring analysis by Energy Dispersive X-ray (EDX), which was verified the presence of Zr and Ti elements that comprise the core-shell nanocomposite. The FL emission results were explained as a function of the shell thickness, as well as the effect of calcination temperature on the order-disorder structural material. To evaluate the performance of the FL issuing nanocomposites were calculated chromaticity coordinates, based on the FL emission spectra.
Síntese, caracterização e investigação da propriedade luminescente do ZnO e do ZrO 2 dopados com európio e suas aplicações na ciência forense
(Universidade Federal de Goiás, 2018-09-28) Bernardes, Yasmim Rafaella Caixeta Pinto; Figueiredo, Alberthmeiry Teixeira de; http://lattes.cnpq.br/7026388762536003; Figueiredo, Alberthmeiry Teixeira de; Sousa, Marcelo Henrique; Barrado, Cristiano Morita
Recently, luminescent materials have aroused interest in the scientific and expert community due to their unique properties. These luminescent materials are being used in the production of papillary developers with excellent advantages over the commonly employed methods. These materials are based on inorganic matrices doped with TR 3+ ions. In the present work, zinc oxide (ZnO) and zirconium dioxide (ZrO 2 ) matrices with different concentrations of the earth-rare ion europium (III) were synthesized for the development of fingerprints. The materials were obtained by the sol-gel process and characterized by X-ray diffraction, photoluminescence and scanning electron microscopy to evaluate the structural properties. The XRD results showed ZnO hexagonal and ZrO 2 with different tetragonal and monoclinic phase compositions. The photoluminescent results indicated that the percentage of europium directly influences the optical properties of the synthesized materials. The synthesized materials revealed the fingerprint with clear contours that enable identification. The microscopic magnification allows visualizing the adherence of the materials by the residues of the fingerprints. Finally, the luminescent processes of Eu 3+ doped in different matrices provide the widening of the range of papillary developers. The results found contribute to the development of new materials for the development of fingerprints.
Tratamento de efluente real de indústria de tintas pelo uso de métodos conjugados de coagulação química e eletroquímico
(Universidade Federal de Goiás, 2016-03-09) Silva, Larissa Ferreira da; Andrade, Leonardo Santos; http://lattes.cnpq.br/5360511377400279; Andrade, Leonardo Santos; Paula, Heber Martins de; Barrado, Cristiano Morita
In the last years problems regarding the availability and quality of water are gaining a lot of attention once the latest water crisis that occurred in Brazil were not restricted to arid and semiarid regions, but in regions with higher population density and industrial activity. Some types of industry activities have called more attention because its consume large volumes of water and contaminate lakes, rivers and groundwater. In this sense, the search for new wastewater treatments has become very promising, since this process can allows the reuse of the water and then reducing the consumption. The present work describes and discusses an investigation into the treatment of paint manufacturing wastewater (water-based acrylic texture) by coagulation (aluminum sulfate) coupled to electrochemical methods (BDD electrode). Two proposals are put forward, based on the results. The first proposal considers the feasibility of reusing wastewater treated by the methods separately and in combination, while the second examines the possibility of its disposal into water bodies. To this end, parameters such as toxicity, turbidity, color, organic load, dissolved aluminum, alkalinity, hardness and odor are evaluated. In addition, the proposal for water reuse is strengthened by the quality of the water-based paints produced using the wastewater treated by the two methods (combined and separate), which was evaluated based on the typical parameters for the quality control of these products. Under optimized conditions, the use of the chemical coagulation (12 mL/L of Al2(SO4)3 dosage) treatment, alone, proved the feasibility of reusing the treated wastewater in the paint manufacturing process. However, the use of the electrochemical method (i = 10 mA/cm2 and t = 90 min) was required to render the treated wastewater suitable for discharge into water bodies.

Navegar

Navegando Mestrado em Química - PPGQ por Autor "Barrado, Cristiano Morita"

Resultados por página

Opções de Ordenação