Mestrado em Química - PPGQ

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Análise físico-química e toxicidade do material particulado (MP10) no ar atmosférico em Catalão–GO
(Universidade Federal de Goiás, 2018-04-23) Sousa, Nara Line da Silva; Romualdo, Lincoln Lucilio; http://lattes.cnpq.br/4703139616158480; Romualdo , Lincoln Lucilio; Freitas, Silvia de Sousa; Sarmento, Antover Panazzolo
Many studies have shown a close relationship between air pollution by particulate matter (PM10) and deterioration of human health. Because the particulate matter can contain a variety of chemical and biological components, in addition to its size directly influence the public health issue. Therefore, knowledge of particulate matter levels, as well as their composition, is important for preventive actions. In view of this problem, the study of the particulate material in the city of Catalão - GO was carried out in two different places (UFG-RC and Centro), and for the PM10 collection the AGV PM10 was used. We studied 30 samples collected between August 2017 and March 2018, in periods of 24 hours at a frequency of 6 days. The concentrations of PM10 of both sites did not exceed the established of 150 μg.m3 of PM10 daily, according to Resolution 003/90 of CONAMA. However, for the WHO recommendation setting 50 μg.m3 , there was extrapolation in the dry period for samples of equipment located in the city center. A correlation was observed between the meteorological conditions and the concentrations of the particulate material, because, as there was an increase in the pressure, temperature and wind speed, there was an increase in the PM and as the humidity increased, the concentration decreased. We found 13 elements in the filters through the use of EDXRF, which in turn, were associated with vehicular emissions and resuspension of the study environment. The cytotoxic study of the filters from both sites was performed, and it was possible to observe that there are microorganisms associated with the PM, but in the tests performed they were not harmful (toxic) to the microorganisms studied, since there was no halo of inhibition and there was growth of microorganisms. Therefore, the results showed that the concentration of PM10 for the city of Catalão - GO is in accordance with Brazilian legislation, thus, it presents good air quality. However, this particulate matter is small enough to penetrate the body and is harmful to human health because it has metals and microorganisms that may have a cumulative effect on the body.
Análise qualitativa da água do Ribeirão Samambaia em Catalão (GO)
(Universidade Federal de Goiás, 2018-08-21) Souza, Alynne Lara de; Sarmento, Antover Panazzolo; http://lattes.cnpq.br/4025685702530313; Santos, Maria Rita de Cássia; http://lattes.cnpq.br/2598029192393541; Santos, Maria Rita de Cássia; Sarmento, Antover Panazzolo; Paiva, Ed Carlos Rosa; Coelho, Luciana Melho
The present study had as objective to analyze qualitatively by means of physical and chemical parameters Ribeirão Samambaia in the municipality of Catalão (GO). In this work the following parameters were taken as reference: Dissolved Oxygen, Hydrogenion Potential, Temperature, Conductivity, Turbidity, Total Solids, Acidity, Alkalinity, Ammoniacal Nitrogen, Nitrite, Nitrate, Phosphorus, Chloride, Sulphate, Hardness and Hexavalent Chromium. For the analyzes of dissolved oxygen, hydrogenation potential, temperature, conductivity, turbidity and total solids, thirteen campaigns of 10/2016 to 02/2018 were performed. Analyzes of Acidity, Alkalinity, Ammoniacal Nitrogen, Nitrite, Nitrate, Phosphorus, Chloride, Sulphate, Hardness and Chrome were carried out six campaigns from 06/2017 to 02/2018. It was also collected from 11/2017 to 02/2018 sediments in the same points and was carried out the grain size test, EDX and XRD technique. Based on the results, it was verified that, in relation to the parameters: OD, pH, Nitrate, Nitrite, Sulphate, Phosphorus, Hardness, Chlorides the results were within the limits established by Resolution 357 (CONAMA, 2005) for class 1. The parameters of alkalinity and acidity do not present limits for their quantities, but indicate the buffering capacity for acids and bases in Ribeirão water. In the resolution also are not established values for temperature, however it influences in diverse chemical reactions. The turbidity values in the December and February campaigns exceeded the limit range established by Resolution and the chromium presented results below the limit of detection. The granulometric classification of the Ribeirao Samambaia sediments was characterized by the sand fraction. The average concentrations of the chemical species of sediments determined by EDX were similar in points 1 and 2, highlighting the high values for Si, Fe, Al and P. By the XRD analysis, the predominance of silicon oxide was observed. IQACCME presented a "Good" track on both points, with a score of 92 on P1 and 89 on P2. The only parameter that failed was turbidity in the collections of December 2017 and February 2018, which influenced the classification of the Samambaia stream.
Avaliação da adsorção de contaminantes emergentes pela casca de banana e folhas da Typha Angustifolia L.
(Universidade Federal de Goiás, 2015-04-10) Sousa, Priscila Afonso Rodrigues de; Coelho, Luciana Melo; http://lattes.cnpq.br/0074807107314789; Coelho, Luciana Melo; Richter, Eduardo Mathias; Freitas, Sílvia de Sousa
This paper describes the use of analytical methodology for removal of emerging contaminants sulfamethoxazole (SMX), 17α-ethinylestradiol (EE2) and estrone (E1) in water samples. Was used to remove the natural adsorbents Banana and Typha angustifolia L.in raw and treated in acidic medium. The detection and quantification was performed by high performance liquid chromatography (English, HPLC). There was a characterization of bioadsorventes by Infrared Spectroscopy East and X-ray diffraction The point of zero charge of in natura banana peels and treated with HCl was approximately 5.6 and 4.3, respectively, while point of zero charge of Typha angustifolia in natura leaves and treated with HCl was approximately 5.5 and 4.5, respectively. It was determined that the pH only influences the adsorption exerted SMX, and the pH 2 and 8 were most suitable. However, we chose to work with natural pH of the mixtures of the compounds (pH = 5.25). This study used multivariate methods (full 23 factorial design and response surface) to verify the best chemical variables. The optimized and used for construction of isotherms conditions were: cattail in kind (m = 0.38 g; t = 65 min), cattail HCl (m = 0.75 g; t = 64 min), fresh banana (m = 0, 55g, t = 62 min) and banana HCl (m = 0.76g; t = 66 min). There was the determination of LD figures of merit (SMX = 0.02 mg L-1, EE2 = 0.03 mg L-1, E1 = 0.03 mg L-1) QL (SMX = 0.05 mg L-1, EE2 = 0.05 mg L-1, E1 = 0.05 mg L-1), the selectivity was determined by building fortified calibration curves with water samples. The linearity was determined by the correlation coefficient (r = 0.99), recovery values were between 59.9% and 93.6% for the compounds and accuracy of results presented at most 14.7%. The proposed methodology has been applied to real matrix with removal percentages close to 100%.
Avaliação da fibra da bucha vegetal (Luffa cylindrica) e das folhas de taboa (Typha angustifolia L.) como materiais adsorventes para a remoção do agrotóxico tebuconazol de água contaminada
(Universidade Federal de Goiás, 2019-03-18) Silva, Thiago Felipe; Freitas, Silvia de Sousa; http://lattes.cnpq.br/4503172443143993; Freitas, Silvia de Sousa; Alves, Vanessa Nunes; Sarmento, Antover Panazzolo
Agrochemicals are industrialized products made up of a broad junction of chemicals used to combat pest resistance in plantations. The high consumption and the inappropriate disposal of these products can generate great environmental impacts. Adsorption processes employing alternative materials have been evaluated to remove them from the environment, especially from water sources for human consumption. In this work, the adsorption capacity of the materials: bush (Luffa cylindrica) and taboa (Typha angustifolia L.) was evaluated for the removal of the tebuconazole pesticide from aqueous medium. The analytical methodology used to quantify the pesticide in the solution, after the removal, was High Performance Liquid Chromatography with UV-vis detector (HPLC-UV). The values of LD and LQ in the chromatographic method were 0.01 mg L-1 and 0.10 mg L-1 , respectively. The materials were characterized by the FTIR technique, being observed in both materials the presence of functional groups characteristic of lignocellulosic compounds. The micrographs (SEM) indicated the heterogeneity and irregularity of the surface in both materials. The pH at the zero charge point (pHPCZ) was 6.15 for bush (Luffa cylindrica) and 6.62 for taboa (Typha angustifolia L.). The ability to remove tebuconazole from the aqueous medium by the materials was evaluated as a function of the adsorbent dosage, contact time and concentration of the pesticide. The dosages of 20 and 10 g L-1 were used in the adsorption tests with the bush (Luffa cylindrica) and taboa (Typha angustifolia L.), respectively. The kinetic study showed that the adsorption equilibrium was obtained after 40 minutes of contact and the experimental data were better adjusted by the Avrami model, for both materials. Regarding the study of tebuconazole concentration, it was observed that the removal is little influenced by the increase in tebuconazole concentration in the medium, remaining relatively constant in the concentration range evaluated, for both materials. The experimental data were well adjusted by all models of isotherms evaluated (Langmuir, Freundlich and Sips), with R 2> 0.99. The maximum adsorption capacity (Qmax) of tebuconazole was 8.5651 mg g-1 for bush (Luffa cylindrica) and 13.6419 mg g-1 for taboa (Typha angustifolia L.).The use of the adsorbents to remove the pesticide in natural water sample presented results very similar to those observed when using deionized water, showing that the removal efficiency of these materials is not affected by the type of aqueous matrix. The alternative column adsorption process showed satisfactory removal results (~ 51% removal for bush and ~ 75% removal with taboa), in a significantly shorter time (3-4 min) in relation to the batch process (40 min). Thus, it can be concluded that the adsorbent materials evaluated, bush (Luffa cylindrica) and the taboa (Typha angustifolia L.) can be used for the removal of the tebuconazole pesticide from aqueous medium.
Avaliação da fibra de coco (mesocarpo do fruto de Cocos nucifera L.) como adsorvente para remoção do agrotóxico parationa metílica de meio aquoso
(Universidade Federal de Goiás, 2017-04-07) Cardoso, Josiane Moreira; Freitas, Silvia de Sousa; http://lattes.cnpq.br/4503172443143993; Freitas, Silvia de Sousa; http://lattes.cnpq.br/4503172443143993; Alves, Vanessa Nunes; Coltro, Wendell Karlos Tomazelli
In this work, experiments were performed to study the potential of coconut fiber (Cocos nucifera L.) as adsorbent for removing the pesticide parathion methyl from water. The analytical methodology used to quantify the pesticide in the adsorption studies was based on solid phase extraction (SPE) and gas chromatography with electron capture detection (GC/ECD). The method were validated and showed good analytical features in terms of selectivity, linearity, accuracy (recovery: 100.4%), precision (coefficient of variation: 9.63%;), limit of detection (0.003 mg L-1 ) and quantification (0.010 mg L-1 ). The matrix effect in pesticide quantification was evaluated and the results showed an enhanced chromatographic response for the parathion methyl in all the concentrations evaluated due to interference of endogenous coconut fiber compounds present in the solution after adsorption tests, therefore, the quantification was made using matrix-standard calibration solutions to compensate for matrix-induced effects and to obtain more accurate results. The adsorbent characterization (FTIR, MEV, surface area and pHpcz) showed that coconut fiber surface is composed of very irregular particles, with many cavities (pore diameter: 3.48 nm) and external surface area of 3.64 m2 g -1 . The presence of several functional groups: carboxylate, hydroxyl, carboxyl, among others was observed. The pH at point of zero charge (pHpcz) for the adsorbent was 5.85. The adsorption capacity of the coconut fiber was evaluated under different parameters: adsorbent treatment, adsorbent dosage, contact time and concentration of the pesticide. The adsorbent treatment with water, HCl or NaOH did not affect the adsorption capacity (75.6% of removal was obtained, independently of the treatment). The increasing in the adsorbent dosage of 5 to 20 g L-1 caused an increasing in the adsorption capacity from 25.0% to 76.6%. The adsorption equilibrium process was reached after 90 minutes of contact, with 86.1% of removal. The kinetic study showed that the Avrami kinetic model was the best fit for the experimental data. The adsorption capacity improved as function of the pesticide concentration increasing. The experimental data were fitted to Langmuir, Freundlich and Sips isotherm models and the best fit was obtained with Freundlich and Sips models. The maximum adsorption capacity (Qmax) were 39.8547 mg g-1 . Additional tests showed that the adsorption capacity was slightly affected when using real samples (natural water) in the adsorption experiments (82.24% removal) and presented excellent adsorption capacity when used in an alternative column adsorption procedure (85.73% removal). The results indicate that the coconut fiber has a great potential to be used as adsorbent material for the treatment of water contaminated with the pesticide methyl parathion.
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.
Avaliação do uso de serragem de madeira tratada com ácido como bioadsorvente para a remoção de Diclofenaco de Sódio em meio aquoso
(Universidade Federal de Goiás, 2015-08-13) Silva, Lícia Aparecida; Coelho, Luciana Melo; http://lattes.cnpq.br/0074807107314789; Coelho, Luciana Melo; Rezende, Hélen Cristine de; Freitas, Silvia de Sousa
The present work describes the development of an analytical method for the removal of contaminant emerging Sodium Diclofenac (DCF) present in aqueous solutions. For the removal thereof, it is used as a natural adsorbent sawdust treated in acid medium. The detection and quantification of the analyte were Performed by High-Performance Liquid Chromatography (English, HPLC). The material was characterized according to the techniques of Infrared Spectroscopy and X-Ray Diffraction. The Point of Zero Charge (PZC) was obtained both for the sawdust treated in acid medium, and for the same in kind, obtaining values of 4.8 and 5.5, respectively. We chose to work with the adsorbent treated with acid in natural pH of the solution (6.43), since the adsorption was quite satisfactory (86%). It was determined the LD figures of merit (0.06 mg L-1) and LQ (0.2 mg L-1). The linearity was determined by construction of standard curves prepared in solvent and prepared curves with water samples fortified with the DCF standard. The obtained correlation coefficient was quite satisfactory (r = 0.9999) and the recovery values were between 86% and 117% to the study drug. It used Full Factorial Planning 23 for optimization of chemical variables that can have an effect on the adsorption process. The results obtained by the Pareto chart showed that the only variable that exerted influence on the adsorption was the mass of adsorbent. Therefore, it was determined by univariate optimization, as being 600 mg. To study the adsorption kinetics, it was determined the equilibration time of 180 min, and following the adsorption pseudosegunda-order model. The isotherm obtained was linearized and the result indicated that the adsorption follows the Langmuir model, ie, chemical adsorption occurs monolayer.
Avaliação e desenvolvimento de um método para extração seletiva de cromo utilizando a luffa cylindrica como bioadsorvente
(Universidade Federal de Goiás, 2016-04-20) Sousa Neto, J. A.; Alves, Vanessa Nunes; http://lattes.cnpq.br/7058376443471599; Alves, Vanessa Nunes; http://lattes.cnpq.br/7058376443471599; Coelho, Luciana Melo; Muñoz, Rodrigo Alejandro Abarza
This work describes the development of a method in solid phase extraction for Cr (III) determination in food and environmental samples using Luffa cylindrica as bioadsorbent. In the first chapter, a characterization study to evaluate the use of Luffa cylindrica "in natura" as bioadsorbent for chromium ions (III and VI) adsorption in aqueous systems was conducted. Through characterization, specifically in relation to the determination of pH(PCZ), it became clear that the material has positively charged surface in solutions with pH below 6.0 and above this value, the surface is negatively charged. From this evidence, a study was conducted to evaluate the effect of pH solution on the chromium inorganic species adsorption has been noted that from pH = 4.0 it is possible to separate the chromium species (III and VI) and trivalent species exclusively adsorbed. Thus, we conducted several characterization tests such as Infrared Spectroscopy, X-rays Diffraction by the powder method, Elemental Analysis, Scanning Electron Microscopy and Energy Dispersive Spectroscopy to evaluate the physicochemical characteristics of Luffa cylindrica. The results of the kinetic study and the adsorption isotherms showed that the chromium III ions adsorption of Luffa cylindrica possibly occurs through an interaction of the chemical type. Furthermore, the parameters as stirring time and adsorbent mass were evaluated to obtain the best conditions of the adsorption process. Quantification of chromium before and after the adsorption process was performed by Flame Atomic Absorption Spectrometry. From the results, it was observed that requires 30 minutes to achieve sorption equilibrium and adsorption kinetics followed a pseudo-second-order. Study of possible interferences Ba2+, Co2+, Cu2+, Fe3+ and Mn2+ ions were performed in order to observe the selectivity of the material relative to the analyte of interest. The second chapter was developed a flow method of solid phase extraction for selective extraction and determination of Cr (III) ions in food and environmental samples. Multivariate techniques were used to evaluate the chemical variables and extraction flow system: adsorbent mass, separation flow rate, concentration and volume of eluent, through a 24factorial design. The results showed that the adsorbent mass and eluent volume was significantly influence in the flow system and has been used for optimization a Doehlert design of these variables indicating optimal values as 170 mg of adsorbent mass and 1348μL eluent (HNO3 1 mol L-1). The other variables, separation flow rate and eluent concentration were maintained at the values 2 mL min-1 and 1 mol L-1, respectively. The possible presence of interfering ions, Cu2+, Fe3+, Mn2+, Zn2+, Ca2+, Mg2+, Na+, K+, Cr6+ was studied in order to verify the selectivity of the analysis method. Through the calculated values for the interfering factor (IF) was determined good selectivity of the proposed method. The analytical performance was evaluated by the parameters, detection limit (LOD), quantification limit (LOQ), accuracy (D.P.R) and the values were 19.2 ug L-1; 63.99 ug L-1 and 0.19%, respectively, with the linear range of the method equal to 63.90 to 2000 ug L-1. Finally, the accuracy of the method was evaluated from analysis of water certificate reference material (APS-1071) and sediment (APS-1066). Recovery tests were performed on samples of water, energy and isotonic values having been found in the range from 87.60 to 107.35%. Keywords:Chromium, Luffa cylindrica, solid phase extraction.
Avaliação química de polissacarídeos e propriedades antimelanoma da heterogalactana proveniente do macrofungo Hypsizygus marmoreus
(Universidade Federal de Goiás, 2019-02-02) Oliveira, Ruberney da Silva de; Carbonero, Elaine Rosechrer; http://lattes.cnpq.br/7136817335979894; Carbonero, Elaine Rosecher; Freitas, Lorena Ramos de; Leal, Maria Carolina Di-Medeiros
Hypsizygus marmoreus, popularly known as "Bunashimeji" in Japan, is an edible mushroom highly valued for its medicinal properties. Several therapeutic effects have been reported for this species as immunomodulatory, antitumor, antiviral, cytotoxic, antifungal, antihypertensive, antioxidant, anti-inflammatory, antiproliferative, regulation of obesity and insulin resistance, antiatherosclerotic, which have been attributed to crude extracts, fractions and/or isolated compounds (proteins, lipids, polysaccharides, oligopeptides and secondary metabolites) obtained from the basidiocarp and/or mycelium and filtered from the submerged culture. Considering the diversity of polysaccharides present in each fungal species, as well as their importance in modifying the biological response, the H. marmoreus mushroom is unexplored in this area, representing an important species to be studied. For this, the aqueous and alkaline extractions were performed to obtain the polysaccharide extracts, which were purified by freezing/thawing and precipitation with Fehling's solution. The structural determination was performed by NMR spectroscopy, monosaccharide composition analysis and methylation by GC-MS and partial hydrolysis. From the cold aqueous extract was isolated a fucomannogalactan (fraction Hm-PF2AF, Hm-FMG; Mw = 17,670 Da) contained (-16)-linked galactopyranosyl main chain, partially substituted at O-2 with non-reducing ends of α-L-Fucp and -Manp; a branched α-glucan with glycosidic bonds of the type (1→4) and (1→6) (Hm-MRSF2) with a glycogen-like structure and a branched -glucan with a Glcp-(1→3)-linked backbone, partially substituted at O-6 by non-reducing ends of -Glcp (Hm-S2AF). Fractionation of the cold water soluble fraction obtained from the alkaline extract (Hm-SK) resulted in two fractions containing glycogen and a -glucan (Hm-SFK and Hm-PFK) distinct from that previously mentioned. After elimination of glycogen by amylase treatment, the fractions obtained (Hm-TASFK and Hm-TAPFK, respectively) probably consist of branched -glucans containing a main chain of β-Glcp (16)-linked, which are partially substituted in O-3. Further analysis of structural characterization (2D NMR, methylation, partial degradation of Smith, among others) should be performed to confirm the structure of -glucans isolated and other fractions obtained in this study. In order to prove the effects of polysaccharides as biological response modifiers, the purified fractions (fucomannogalactan and -glucans) of H. marmoreus were submitted to evaluation of the antitumoral activities, in collaboration with Prof. Dr. Edvaldo da Silva Trindade and Dr. Stellee M. P. Biscaia from the Cell Biology Department of the Federal University of Paraná. Preliminary results of fucomannogalactan (Hm-FMG) demonstrated that heterogalactan was not cytotoxic, nor altered cell morphology, but was able to reprogram B16-F10 murine melanoma cells by modifying colony formation ability and cell migration, without changing cellular proliferation. In view of the promising in vitro antimelanoma effects of the Hm-FMG polysaccharide, it can be suggested that these polymers are responsible for part of the therapeutic properties conferred by this macrofungus. To confirm these findings, additional assays should be performed to prove the possible antitumor effects of purified fractions and the mechanism of action of these compounds.
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.
Degradação do corante tartrazina utilizando o TiO2: Ce em um sistema conjugado dos processos eletroquímico/fotocatalítico
(Universidade Federal de Goiás, 2015-06-12) Souza, Cláudio Roberto de; Andrade, Leonardo Santos; http://lattes.cnpq.br/5360511377400279; Godinho Júnior, Mário; http://lattes.cnpq.br/8364676654739392; Godinho Júnior, Mário; La Porta, Felipe de Almeida; Andrade, Leonardo Santos
The effects of inclusion of cerium ions on the photocatalytic activity of TiO2 were studied in this work, so that the tartrazine dye, a food dye belongs to the class of azo compounds, it was degraded. Characterization techniques such as X-ray diffraction (XRD), diffuse reflectance (UV-VIS) and scanning electron microscopy (SEM) were used to understand the relationship between structure and photocatalytic activity for the oxides synthesized by the method of polymeric precursors with different temperatures of calcination. According to the analysis by X-ray diffraction, the crystalline anatase phase was predominant on calcinations at temperatures equal to and less than 750 ° C for the synthesized compounds. Photocatalytic degradation of the dye Tartrazine, catalyzed by the synthesized compounds was evaluated and compared to P25 (trade photocatalyst) and undoped titanium oxide. Best performance was observed in the photocatalytic activity of P25, followed by titanium oxide doped cerium ten percent and finally the non-doped titanium oxide, respectively obtaining an elimination of 100% color; 45.92% and 33.89% in 60 min, 71.18% and reaching 57% at 120 min respectively for the titanium oxide doped with ten percent of cerium and titanium oxide undoped flow reactor. Thus it is clear that doping the material improved photocatalytic performance. For coupling techniques were performed in three electrolysis current density: 10; 30 and 50 mA / cm2, yielding an elimination of color respectively 26.25%; 37.94% to 40.67%, in this case, the process efficiency is not only related to color removal also depends on the energy consumption, which was 0.26 kWh / g; 0.88 kWh / g 1.85 kWh / g for current densities of 10; 30 and 50 mA / cm2, respectively, and the current density of 30 mA / cm2 showed the most money. Having optimized the two processes, one can then perform the photoelectrochemical experiments, whereas for all three catalysts studied, the combined processes (photoelectrochemical) performed better compared to the separate processes, respectively being obtained discoloration of 100%; 48.82% and 39.00% in 60 min, reaching 73.26% and 65.54% respectively for 120 min in titanium oxide doped with ten percent of cerium and titanium oxide undoped.
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.
Desenvolvimento de método adaptado de extração com ponteiras descartáveis para determinação de íons Pb(II) e Mn(II) utilizando taboa (Typha angustifólia L.) como adsorvente
(Universidade Federal de Goiás, 2020-12-18) Ferreira, Marina Mesquita; Alves, Vanessa Nunes; http://lattes.cnpq.br/7058376443471599; Alves, Vanessa Nunes; Lemos, Valfredo Azevedo; Freitas, Sílvia de Sousa
In this work, the extraction technique with disposable tips (DPX - from English disposable pipette extraction) was used using Typha angustifolia L. (cattail) as an adsorbent. An adapted DPX method was developed for the determination of Pb(II) and Mn(II) ions in aqueous samples, using the Flame Atomic Absorption Spectrometry (FAAS) technique for quantification. The characterization of the cattail was performed through X-Ray Diffraction, Infrared Spectroscopy, X-Ray Fluorescence Spectroscopy, Determination of the pH at the Zero Charge Point and Buoyancy, with results consistent with those observed in the literature. The zero load point of the material was determined at 6.39. The pH of the solution was univariate optimized by selecting the solutions of Pb(II) and Mn(II) ions at a concentration of 1.0 mg L-1 at pH 8. Tests to optimize the parameters that influence the adsorption and desorption of the ions were made in a multivariate manner. Through Doehlert planning, it was possible to obtain optimal values for mass of adsorbent and number of adsorption cycles, being defined in 30 mg and 7 cycles, respectively, for Pb(II) and Mn(II) ions and the concentration of HNO3 and number of desorption cycles, in 0.8 mol L-1 and 7 cycles. The kinetic study indicated that the adsorption of the Pb(II) and Mn(II) ions obey a pseudo-first order and Avrami kinetics, respectively. The maximum adsorption capacity was obtained through the construction of adsorption isotherms, with values of 29.17 and 5.64 mg g-1 being found for the Pb(II) and Mn(II) ions, respectively. Under optimized conditions the extraction method presented detection limits of 17.51 μg L-1 (Pb (II)) and 35.02 μg L-1 (Mn (II)), quantification limits of 58.37 μg L-1 (Pb (II)) and 116.7 μg L-1 (Mn (II)), and a pre-concentration factor of 10 (Pb (II)) and 2 (Mn (II)), being a linear range of 116.7 to 2000 μg L-1 method for Mn (II) and from 58.37 to 2500 μg L-1 for Pb (II). Accuracy was evaluated separately in terms of repeatability and reproducibility, obtaining D.P.R. values of 0.31 and 0.25% for Pb (II), respectively, and 7.00 and 9.88% for Mn (II), respectively. The evaluation was evaluated by means of recovery tests in river water collected near a mining company, recovery values in the range of 80-120% and through the use of certified reference materials, indicating high reliability of the method.
Desenvolvimento de metodologia analítica utilizando sistema em fluxo e casca de arroz para pré-concentração de chumbo em amostras de sedimento
(Universidade Federal de Goiás, 2018-06-20) Furtado, Liliam Quelem Tavares; Coelho, Luciana Melo; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4794563A2; Coelho, Luciana Melo; Alves, Vanessa Nunes; Silva, Sidnei Gonçalves da
The present work presents a study of use of the rice husk as adsorbent material for the determination of lead ions in sediment samples obtained at different points of Rio Doce region (Espírito Santo), using flow injection system. With detection metal determination wes used Atomic Flame Absorption Spectrometry. The physico-chemical characterization of the material was done by Infrared Region Spectroscopy, Scanning Electron Microscopy, X-ray Dispersive Energy Analysis and X-ray Diffraction and determination of the zero load point. In adsorptive processes, the pH directly influences the extraction of the ion and the study of this parameter indicated that in pH 6,00 better extraction conditions are obtained. After pH determination, a multivariate optimization 2 4 of the parameters influencing the ion adsorption process was performed. The variables evaluated were adsorbent mass, preconcentration flow, volume and eluent concentration. Subsequently, a univariate study of the mass and preconcentration flow variables was performed, as well as a study of the elution flow rate. The best responses for flow system operation were obtained using: adsorbent mass 70.0 mg, eluent concentration (HNO3) 0,50 mol L-1 , eluent volume 1000 μL, preconcentration flow 2.0 mL min-1 and elution flow 1.0 mL min-1 . From the optimized conditions, the procedure showed to be effective for the Pb2+ species, with limits of detection (LD) and quantification (LQ), respectively, equal to 0.015 and 0.05 mg L-1, with a relative standard deviation (DPR) of 6.821% and a preconcentration factor of 49.5. Recovery values were obtained between 87 - 100% for fortified sediment samples. In order to analyze the selectivity of the method, the evaluation of possible interferences was carried out, based on the calculation of the interference factor (FI). The Cu (II), Ni (II), Co (II), Fe (III) and Zn (II) ions were analyzed in different proportions. The procedure presented was satisfactory for preconcentration of Pb2+ ions, and it can be used for extraction of the same. As it proved to be fast, efficient, low cost, besides the reduction in reagent consumption and waste generation. Factors that favor the development of a system based on the principles of "Green Chemistry".
Desenvolvimento de métodos eletroquímicos para determinação de neurotransmissores utilizando eletrodos de zircônia nanoestruturada e diamante dopado com boro
(Universidade Federal de Goiás, 2014-01-28) Paranhos, Maysa de Melo; Andrade, Leonardo Santos; http://lattes.cnpq.br/5360511377400279; Andrade, Leonardo Santos; Laurindo, Edison Aparecida; Figueiredo, Alberthmeiry Teixeira de
DSA® electrodes modified with films ErYZrO2 or YZrO2 and boron-doped diamond electrodes (BDD) were tested as electrochemical sensors detect front of the neurotransmitter epinephrine and its interfering ascorbic acid (AA) and uric acid (UA), which coexist with epinephrine in biological fluids and are also electroactive, rusting in the same potential that epinephrine. The physical and morphological characterization of the films of ZrO2 were performed using the techniques of XRD, SEM / FEG, EDXS and Open circuit potential. For electrochemical characterization of the sensor in developing were used the techniques of cyclic voltammetry (CV), differential pulse voltammetry (DPV) and Flow Injection Analysis with Amperometric Detection. The analyzes used for physical and morphological characterization of the ZrO2 films demonstrated that the technique of spin coating together with the methodology used for the deposition of ZrO2 films on the surface of substrate DSA® showed films were obtained satisfactory. The BDD electrodes showed good catalytic activity for both analyzed substances (EP, AA and UA). While BDD electrode showed good sensitivity for detection of EP in the presence of AA, electrodes ZrO2 addition to good sensitivity and selectivity showed good reproducibility for the detection of EP without interference from UA and AA.
Desenvolvimento de um aptassensor para detecção do vírus da dengue
(Universidade Federal de Goiás, 2017-08-17) Souza, Evellyn Gonçalves de; Andrade, Leonardo Santos; http://lattes.cnpq.br/5360511377400279; Neves, Adriana Freitas; http://lattes.cnpq.br/2984939300978146; Neves, Adriana Freitas; Santos, Maria Rita de Cássia; Vieira, Pabline Marinho
Dengue is an endemic disease that causes wide concern both the health systems and to the patients. Thus, it is important that studies aiming at diagnoses faster and with possibility of field application can be developed for the medical intervention happens early, avoiding the worsening of the cases. Therefore, the aim of this work was to develop an electrochemical biosensor based on the use of aptamer as a bioelement for recognition on the surface of the boron doped diamond electrode (BDD) for the detection of each of the four serotypes of the dengue virus. Previously to the development of the biosensor, the dot-blot and apta-PCR techniques were used as validation methods for the interaction between aptamer B07 and target, the 5'UTR region present in the viral genome. The cyclic voltammetry technique was used in the analysis of redox reactions on the surface of the BDD electrode with and without modification of its surface with chitosan film. Ferrocene was used as the redox mediator and electroactive indicator of hybridization of the DNA strands formed in the sensor. The peaks of current indicated that the electrode with chitosan film modification on its surface presented greater stability. The redox compound had higher affinity for the double chains hybridized on the surface of the electrode, showing current values for DENV 1, 2, 3 and 4 of were 0.73; 0.69; 0.79 and 1.03 μA, respectively. These values were higher than the current found for the single-stranded aptamer (ssDNA), which was 0.62 μA, as well as for the current obtained from the aptamer hybridized with its complementary strand (dsDNA) whose value was 0.91 μA. Analyzes with time variations were performed showing a reduction in current values as a function of time, probably due to the reduction of the interaction of the electroactive material in the sensor. The aptasensor developed here showed good detection distinction between nucleic acid sequences, presenting potential for application in the detection of dengue virus.
Desenvolvimento de um método de extração e pré-concentração em fluxo para determinação de cádmio em amostras de interesse alimentício utilizando a palha do café como adsorvente
(Universidade Federal de Goiás, 2017-03-29) Soares, Maria Dalva Americano; Carvalho, Dayene do Carmo; http://lattes.cnpq.br/5513978376671756; Alves, Vanessa Nunes; http://lattes.cnpq.br/7058376443471599; Alves, Vanessa Nunes; Freitas, Silvia de Sousa; Coelho, Nívia Maria Melo
The present work presents a study on the use of dry coffee straw and straw from sticky coffee, also known as "bark" of the coffee as adsorbent for metallic ions. Initially, the experiments were carried out in batch and the metal quantification before and after the adsorption experiments was done using Atomic Flame Absorption Spectrometry (FAAS). The adsorption of the ions Cd (II), was evaluated and the results indicated that the coffee straw dried in natura, presented an outstanding performance. The optimization parameters studied in the adsorption of the corresponding ion were the pH of the solution and time of contact, presenting the maximum adsorption occurrence in the pH value between 5 to 9 and better contact time starting from 60 minutes. The physical-chemical characterization of the material was done through the use of Infrared Spectroscopy, X-ray Dispersive Energy Analysis, X-Ray Diffraction Analysis, EDX Elemental Analysis and the zero load point determination. The adsorption kinetics best fit the pseudo-second order model and the adsorption isotherms developed with the objective of determining the maximum adsorptive capacity showed a better fit to the Langmuir model. From data obtained in the batch experiments, the dry coffee straw was used in the development of a solid phase extraction method for adsorption of cadmium. In order to evaluate the chemical and flow variables that possibly influence the system, the multivariate method was used. The variables studied were adsorbent mass, eluent concentration, eluent volume and pre-concentration flow, through a factorial design 24, indicating the eluent volume and pre-concentration flow as the significant variables, which were studied later by means of Doehlert planning. Thus, the best conditions for flow system operation were: adsorbent mass 25 mg, (HCl) eluent concentration 1.0 mol L-1, eluent volume 250 μL and pre-concentration flow 2.0 mL min-1. For the purpose of analyzing the selectivity of the method, a study of the possible interferences was done, based on the calculation of the interference factor (IF). The Cu+2, Fe+2, Mn+2, Zn+2, Ca+2, Mg+2, Na+1, K+1, Cr+3 ions were analyzed in different proportions. The pre-concentration factor was calculated as being equal to 20.4; Limit of detection (LD) 7,86 μg L-1, Limit of quantification (LQ) 26,20 μg L-1, precision (DPR) 0,11, linear range between 26,20 - 2000 μg L-1. The accuracy of the method was tested through the analysis of the certified water reference material (APS - 1071).The recovery tests were carried out on samples of cashew, pineapple, orange and guava juices, and the values found were ranged from 100,72 to 109,7%. The method developed was satisfactory for pre-concentration of Cd (II) ions, for the simplicity, efficiency, low cost. Also, the used adsorbent can be easily found in nature and it can be reused.
Desenvolvimento de um método de extração em fase sólida in situ para determinação de Cr(III) em infusão de fitoterápicos
(Universidade Federal de Goiás, 2019-08-08) Siqueira, Alêssa Gomes; Costa, Bruno Elias dos Santos; http://lattes.cnpq.br/9995122149910490; Alves, Vanessa Nunes; http://lattes.cnpq.br/7058376443471599; Rezende, Hélen Cristine; Coelho, Luciana Melo; Alves, Vanessa Nunes; Costa, Bruno Elias dos Santos
This work presents the development of an in situ solid phase extraction method (SPE-ISS) for the determination of chromium (III) in herbal infusion samples using flame atomic absorption spectrometry (F AAS). Thus, in order to evaluate the inorganic composition of medicinal plant samples (calendula, chamomile, carqueja, green tea, leather hat, melissa and passiflora) we used the EDXRF (Dispersive Energy X-ray Fluorescence). the presence of plant essential metals in addition to toxic metals. Subsequently, a quantitative analysis of some metal ions was performed in infusion samples prepared from these plants, and Fe(III) was the only one found in considerable concentration, while Pb(II), Cr(III), and Cd(II) presented concentrations below the detection limit of the technique. Therefore, it is necessary to develop extraction and preconcentration methods that allow the determination of Cr(III) simply and safely, even when present in low concentrations. In this work, the SPE-ISS method was optimized by multivariate techniques, and the results showed that the formation of the Cr-PAN complex is favored at pH 9.5, with the complexant at 0.18 mmol L-1 concentration. For optimization of solid phase formation and extraction, factorial design and response surfaces were used, which pointed to the use of CTAB as phase transfer agent, NaClO4 0.26 mol L-1 as ionic pairer and agitation time of 7.5 minutes. Studies of possible interferents indicated negative interference of the metallic ions Al(III), Zn(II), Fe(III) and Ca(II). The analytical performance was evaluated by the parameters, preconcentration factor, detection limit (LD) and limit of quantification (LQ) and the values found were 1.66 μg L-1 and 5,5 μg L-1, respectively. The intra-day and inter-day precision (RPD) was 0.001% and 0.0004%, respectively, being the linear range of the method from 250 to 5000 μg L-1, presenting the potential to determine low chromium concentrations. Finally, the accuracy of the method was evaluated from analysis of certified reference water material (APS-1071), as well as recovery tests on water samples and herbal infusions 77.60 - 116%.
Desenvolvimento de um método por ponto nuvem dos hormônios naturais E1 e E2 em amostras de urina e determinação por CLAE/EC utilizando eletrodo de diamante dopado com boro
(Universidade Federal de Goiás, 2015-08-06) Amorim, Kamila Pereira de; Andrade, Leonardo Santos; http://lattes.cnpq.br/5360511377400279; Andrade, Leonardo Santos; Brocenschi, Ricardo Francisco; Alves, Vanessa Nunes
Cloud point extraction method (CPE) was used for the determination of estrone (E1) and 17β-estradiol (E2) hormones in human urine. The combination of the electrochemical detection techniques with high-performance liquid chromatography (HPLC-EC) was used for the detection and quantification of these hormones. A boron doped diamond electrode (BDD) pretreated cathodically was used as electrode material for all electrochemical measurements. The optimized chromatographic parameters resulted in a mobile phase composition of KH2PO4 (0.01 mol L-1; pH 5.0) / ACN (72:28 V/V), flow 1.2 ml min-1. An applied potential for electrochemical detection of 1.0 V x Ag/AgCl (3.0 mol L-1) was selected from hydrodynamic voltammograms constructed for each hormone changing the potential between 0.3 V and 1.2 V x Ag/AgCl (3.0 mol L-1). Limits of detection (S/N = 3) of 500 ng mL-1 and limits of quantification of 800 ng mL-1 were obtained for both E1 and E2 hormones without any extraction process. Urine samples at pH 5.0 and 7.0 were investigated aiming the influence of pH on the efficiency of the CPE process, and the optimum results for the most current signal of the hormones was obtained at pH 7.0. Extractor solvent volumes were changed in the 0.5-2.5 mL range, and the optimum results were obtained when using 1.0 mL of Tergitol TMN-6 surfactant (10% aqueous solution). From the equation of the calibration curves obtained with and without the CPE procedure it was possible to determine the pre-concentration factor (FC) and all the other parameters involving the efficiency of CPE method. A comparison of the efficiency of CPE method with direct liquid-liquid extraction with the organic solvent CCl4 was carried out and the results showed that the CPE method was quite superior to liquid-liquid extraction. The validation of the method was carried out from intra-day recovery experiments and inter-day and evaluated the accuracy, precision and repeatability. The proposed method was applied to individual samples of urine of 1 man, 1 pregnant woman, 1 woman in fertile age, and 1woman in lactating stage. The values of the variation coefficients of the recovery percentages were lower than 15%.