26 resultados para COT

em Universidade Federal do Rio Grande do Norte(UFRN)


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Today a major responsibility for the contamination of soil and groundwater and surface water are establishments known as gas stations of fuel which has attracted increasing attention from both the general population as the state agencies of environmental control due to leaks in storage tanks and mainly to disruption of pipe corrosion of tanks and pumping. Other services, like oil changes and car wash are also causes for concern in this type of establishment. These leaks can cause or waste produced, and the contamination of aquifers, serious health problems and public safety, since most of these stations located in urban areas. Based on this, the work was to evaluate soil contamination of a particular service station and fuel sales in the city of Natal, through the quantification of heavy metals like Cd, Cu, Cr, Ni, Pb, Zn of total organic carbon (TOC) and organic matter using different techniques such as optical emission spectrometry with inductively coupled plasma source (ICP OES), Total Organic Carbon analyzer and gravimetric analysis respectively. And also to characterize the soil through particle size analysis. Samples were taken in 21 georeferenced points and collected in the same period. The soils sampled in sampling stations P3, P5, P6, P10, P11, P12, P13, P14, P15, P17, P18 and P20 showed the smallest size fractions ranging from fine sand to medium sand. The other study sites ranged from fine sand to medium sand, except the point P8 showed that only the type size medium sand and P19, indicating a particle size of the coarse type. The small correlation of organic matter with the elements studied in this work suggests that these are not of anthropogenic origin but geochemical support

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Dans le présent travail, nous faisons une incursion sur l'exposition de la réalité, dans une étude spécifique du programme Big Brother Brasil 9, approcher le sujet de la visibilité et de l'exposition à travers les concepts de la culture, corps, à et communication. Nous avons lié l'him/it à la théorie de pouvoir proposée par Michel Foucault. Le corps, dans notre analyse, est prisonnier à ordinateur individuel propulse, en camionnant des transformations dans le filet de rapports établis pour les participants de BBB. Nous avons cherché, à travers un plurimetodológica de l'approche, expliquer comme ils sentent les rapports de pouvoir dans ce televisivo du programme/jeu et la transformation des gens anonymes dans célébrités, raconter, avec tout ce avec la logique d'une consommation d'images. Dans l´époque contemporain, les images sont mediateurs puissants de la communication et ils servent de support au midiatique des produits, dans la fiction et banalité ou actions différentes et expériences du quotidien. Comme référence de recherche empirique, le travail est basé au Big Brother-9, a exposé par le Globe Net de Télévision, canal ouvert, dans la période du 13 janvier à avril 07, 2009. Avant que les résultats aient obtenu par l'analyse, nous avons vérifié ce BBB-9 à travers les plusieurs épreuves, les preuves et situations ont créé au-dedans parmi les participants du jeu il met à jour des rapports de pouvoir et d'exclusion, dans le différend pour le succès individuel, le tout coût. Le publique/telespectateur quand participe à travers le vote du programme travaille comme un régulateur pédagogique qu'il qualifie, Il classifique et il punit les conduites privées des joueurs, en étant responsable pour l'acceptation possible, ou pas, des gens, pendant s'écouler du jeu

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At the cashew nut processing industry it is often the generation of wastewaters containing high content of toxic organic compounds. The presence of these compounds is due mainly to the so called liquid of the cashew nut (CNSL). CNSL, as it is commercially known in Brazil, is the liquid of the cashew nut. It looks like an oil with dark brown color, viscous and presents a high toxicity index due to the chemical composition, i.e. phenol compounds, such as anacardic acid, cardol, 2-methyl cardol and monophenol (cardanol). These compounds are bio resistant to the conventional treatments. Furthermore, the corresponding wastewaters present high content of TOC (total organic carbon). Therefore due to the high degree of toxicity it is very important to study and develop treatments of these wastewaters before discharge to the environmental. This research aims to decompose these compounds using advanced oxidative processes (AOP) based on the photo-Fenton system. The advantage of this system is the fast and non-selective oxidation promoted by the hydroxyl radicals (●OH), that is under determined conditions can totally convert the organic pollutants to CO2 and H2O. In order to evaluate the decomposition of the organic charge system samples of the real wastewater od a processing cashew nut industry were taken. This industry was located at the country of the state of Rio Grande do Norte. The experiments were carried out with a photochemical annular reactor equipped with UV (ultra violet) lamp. Based on preliminary experiments, a Doehlert experimental design was defined to optimize the concentrations of H2O2 and Fe(II) with a total of 13 runs. The experimental conditions were set to pH equal to 3 and temperature of 30°C. The power of the lamps applied was 80W, 125W and 250W. To evaluate the decomposition rate measures of the TOC were accomplished during 4 hours of experiment. According to the results, the organic removal obtained in terms of TOC was 80% minimum and 95% maximum. Furthermore, it was gotten a minimum time of 49 minutes for the removal of 30% of the initial TOC. Based on the obtained experimental results, the photo-Fenton system presents a very satisfactory performance as a complementary treatment of the wastewater studied

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Effluents from pesticide industries have great difficulty to decontaminate the environment and, moreover, are characterized by high organic charge and toxicity. The research group Center for Chemical Systems Engineering (CESQ) at the Department of Chemical Engineering of Polytechnical School of University of São Paulo and Department of Chemical Engineering, Federal University of Rio Grande do Norte have been applying the Advanced Oxidation Processes (AOP's) for the degradation of various types of pollutants. These processes are based on the generation of hydroxyl radicals, highly reactive substances. Thus, this dissertation aims to explore this process, since it has been proven to be quite effective in removing organic charge. Therefore, it was decided by photo-Fenton process applied to the degradation of the fungicide Thiophanate methyl in aqueous system using annular reactor (with lamp Philips HPLN 125W) and solar. The samples were collected during the experiment and analyzed for dissolved organic carbon (TOC) using a Shimadzu TOC (Shimadzu 5050A e VCP). The Doehlert experimental design has been used to evaluate the influence of ultraviolet radiation, the concentrations of methyl thiophanate (C12H14N4O4S2), hydrogen peroxide (H2O2) and iron ions (Fe2+), among these parameters, was considered the best experimental conditions, [Fe2+] = 0.6 mmol/L and [H2O2] = 0.038 mol/L in EXP 5 experiment and in SOL 5 experiment, obtaining a percentage of TOC removal of 60% in the annular reactor and 75% in the solar reactor

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Textile industry deals with a high diversity of processes and generation of wastewaters with a high content of pollutant material. Before being disposed of in water bodies, a pre-treatment of the effluent is carried out, which is sometimes ineffective. In order to be properly treated, physical and chemical properties of the effluent must be known, as well as the pollutant agents that might be present in it. This has turned out to be a great problem in the textile industry, for there is a variety of processes and the pollutant load is very diversified. The characterization of the effluent allows the identification of most critical points and, as a consequence, the most appropriate treatment procedure to be employed, may be chosen. This study presents the results obtained after characterizing the effluent of a textile industry that comprises knitting, dyeing and apparel sections, processing mainly polyester/cotton articles. In this work, twenty samples of the effluent were collected, and related to the changes in production. From the results, a statistical evaluation was applied, determined in function of the rate of flow. The following properties and pollutants agents were quantitatively analysed: temperature; pH; sulfides; chlorine; alcalinity; chlorides; cianides; phenols; color; COD (Chemical Oxygen Demand); TOC (Total Organic Carbon); oil and grease; total, fixed and volatile solids; dissolved, fixed and volatile solids; suspended, fixed and volatile solids; setteable solids and heavy metals such as cadmium, copper, lead, chromium, tin, iron, zinc and nickel. Analyses were carried out according to ABNT NBR 13402 norm, based upon Standard Methods for the Examination of Water and Wastewater. As a consequence, a global treatment proposal is presented, involving clean production practices as contaminant load reducer, followed by conventional (biological) treatment

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The petroleum industry deals with problems which are difficult to solve because of their relation to environmental issues. This is because amounts of residue are generated which vary in type and danger level. The soil contamination by non aqueous liquid phase mixtures, specifically hydrocarbon petroleum has been a reason for great concern, mainly the aromatic and polycyclic aromatic, which present risk to human health due to its carcinogenic and mutagenic character. The Advanced Oxidative Processes (AOP) are efficient technologies for destruction of organic compounds of difficult degradation and, often, they are present in low concentrations. They can be considered clean technologies, because there is no formation of solid by-products or the transfer of pollutor phases. This work focuses on the study of the degradation of petroleum industrial waste, by Advanced Oxidation Processes. Treatments tackling petroleum residues, contaminated soil, and water occurring in the production of petroleum reached the following Polycyclic Aromatic Hydrocarbons (PAH) degradation levels: solid residues 100% in 96 treatment hours; water residue - 100% in 6 treatment hours; soil contamination (COT degradation) - 50.3% in 12 treatment hours. AOP were effective in dealing with petroleum residues thus revealing themselves to be a promising treatment alternative

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The wet oxidation of organic compounds with CO2 and H2O has been demonstrated to be an efficient technique for effluent treatment. This work focuses on the synthesis, characterization and catalytic performance of Fe-MnO2/CeO2, K-MnO2/CeO2/ palygorskite and Fe/ palygorskite toward the wet oxidative degradation of phenol. The experiments were conducted in a sludge bed reactor with controlled temperature, pressure and stirring speed and sampling of the liquid phase. Experiments were performed on the following operating conditions: temperature 130 ° C, pressure 20.4 atm, catalyst mass concentration of 5 g / L initial concentration of phenol and 0.5 g / L. The catalytic tests were performed in a slurry agitated reactor provided with temperature, pressure and agitation control and reactor liquid sampling. The influences of iron loaded on the support (0.3; 7 and 10%, m/m) and the initial pH of the reactant medium (3.1; 6.8; 8.7) were studied. The iron dispersion on the palygorskite, the phase purity and the elemental composition of the catalyst were evaluated by X-Ray Difraction (XRD), Scanning Electron Microscopy (SEM) and X-Ray Flourescence (XRF). The use of palygorskite as support to increase the surface area was confirmed by the B.E.T. surface results. The phenol degradation curves showed that the Fe3+ over palygorskite when compared with the other materials tested has the best performance toward the (Total Organic carbonic) TOC conversion. The decrease in alkalinity of the reaction medium also favors the conversion of TOC. The maximum conversion obtained from the TOC with the catalyst 3% Fe / palygorskite was around 95% for a reaction time of 60 minutes, while reducing the formation of acids, especially acetic acid. With products obtained from wet oxidation of phenol, hydroquinone, p-benzoquinone, catechol and oxalic acid, identified and quantified by High Performance Liquid Chromatography was possible to propose a reaction mechanism of the process where the phenol is transformed into the homogeneous and heterogeneous phase in the other by applying a kinetic model, Langmuir-Hinshelwood type, with evaluation of kinetic constants of different reactions involved.

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Increasing concern with the environment, in addition to strict laws, has induced the industries to find altenatives to the treatment of their wastes. Actually, the oil industry has sought solutions to overcome a big environmental problem, i.e., oil field produced water being discharged to the sea. These effluents have organic compounds dissolved, such as polycyclic aromatic hydrocarbons, phenols, benzene, toluene, ethylbenzene and xylenes (BTEX). These compounds are difficult to be removed and have high toxicity. The advanced oxidation processes - AOP are effective to degradation of these organic compounds, because they generate hydroxyl radicals with high potential of oxidation. This work includes the reactor photochemical development applied in the photodegradation treatment (by photo-Fenton process) of wastewaters containing organic compounds dissolved, aiming at treatment and recovery the oil field produced water. The studied reactor allowed the evaluation of two ultraviolet radiation sources that is the main factor to describe the feasibility of the photo¬Fenton treatment, i.e., sun and black light fluorescent lamps, and other relevant variables the process: concentration of reagents, irradiated area and also various reactor configurations to maximize the use of radiation. The organic matter degradation was verified with samples collected during the experimental and analyzed with a total organic carbon analyzer (TOC), which expressed the results in terms of mgC/L. The solar radiation was more effective than radiation from the lamps. it's an important factor for the operation costs cutting. Preliminary experiments applied to oil field produced water treatment have showed satisfactory results, reducing up to 76 % of organic matter

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Increasing concern with the environment, in addition to strict laws, has induced the industries to find alternatives to the treatment of their wastes. Actually, the oil industry has sought solutions to overcome a big environmental problem, i.e., oil field produced water being discharged to the sea. These effluents have organic compounds dissolved, such as polycyclic aromatic hydrocarbons, phenols, benzene, toluene, ethylbenzene and xylenes (BTEX). These compounds are difficult to be removed and have high toxicity. The advanced oxidation processes - AOP are effective to degradation of these organic compounds, because they generate hydroxyl radicals with high potential of oxidation. This work includes the reactor photochemical development applied in the photodegradation treatment (by photo-Fenton process) of wastewaters containing organic compounds dissolved, aiming at treatment and recovery the oil field produced water. The studied reactor allowed the evaluation of two ultraviolet radiation sources that is the main factor to describe the feasibility of the photo- Fenton treatment, i.e., sun and black light fluorescent lamps, and other relevant variables the process: concentration of reagents, irradiated area and also various reactor configurations to maximize the use of radiation. The organic matter degradation was verified with samples collected during the experimental and analyzed with a total organic carbon analyzer (TOC), which expressed the results in terms of mgC/L. The solar radiation was more effective than radiation from the lamps. It's an important factor for the operation costs cutting. Preliminary experiments applied to oil field produced water treatment have showed satisfactory results, reducing up to 76 % of organic matter

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Waste stabilization ponds (WSP) have been widely used for sewage treatment in hot climate regions because they are economic and environmentally sustainable. In the present study a WSP complex comprising a primary facultative pond (PFP) followed by two maturation ponds (MP-1 and MP-2) was studied, in the city of Natal-RN. The main objective was to study the bio-degradability of organic matter through the determination of the kinetic constant k throughout the system. The work was carried out in two phases. In the first, the variability in BOD, COD and TOC concentrations and an analysis of the relations between these parameters, in the influent raw sewage, pond effluents and in specific areas inside the ponds was studied. In the second stage, the decay rate for organic matter (k) was determined throughout the system based on BOD tests on the influent sewage, pond effluents and water column samples taken from fixed locations within the ponds, using the mathematical methods of Least Squares and the Thomas equation. Subsequently k was estimated as a function of a hydrodynamic model determined from the dispersion number (d), using empirical methods and a Partial Hydrodynamic Evaluation (PHE), obtained from tracer studies in a section of the primary facultative pond corresponding to 10% of its total length. The concentrations of biodegradable organic matter, measured as BOD and COD, gradually reduced through the series of ponds, giving overall removal efficiencies of 71.95% for BOD and of 52.45% for COD. Determining the values for k, in the influent and effluent samples of the ponds using the mathematical method of Least Squares, gave the following values respectively: primary facultative pond (0,23 day-1 and 0,09 day-1), maturation 1 (0,04 day-1 and 0,03 day-1) and maturation 2 (0,03 day-1 and 0,08 day-1). When using the Thomas method, the values of k in the influents and effluents of the ponds were: primary facultative pond (0,17 day-1 and 0,07 day-1), maturation 1 (0,02 day-1 and 0,01 day-1) and maturation 2 (0,01 day-1 and 0,02 day-1). From the Partial Hydrodynamic Evaluation, in the first section of the facultative pond corresponding to 10% of its total length, it can be concluded from the dispersion number obtained of d = 0.04, that the hydraulic regime is one of dispersed flow with a kinetic constant value of 0.20 day-1

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This study is an environmental diagnosis of the Jundiaí-Potengi/RN estuarine system waters, using calculations of pollution indicator indices such as the Water Quality Index (WQI) and the Toxicity Index (TI). The samples were collected at twelve points on the estuary, at high and low tide, between August and November 2007, over four campaigns. The study area, located in a high impact region, has various activities on its banks such as: discharge of untreated or undertreated domestic and industrial sewage, shrimp farming, immunizer stabilization lakes, riverside communities, etc. All the parameters analyzed were compared to the limits of CONAMA Resolution No. 357 of 2005 for healthy and saline Class 1 waters. The results found prove the impact caused by various activities, mainly the parameters related to the presence of organic material, such as DQO, DBO, COT and thermotolerant colliforms. The IQA for most of the collection points was of medium quality. For the metals, although values above the Resolution limits were found, most of them were lower than the detection limits of ICP-OES used, indicating that they tend to be transported by the dynamic of the tides or rainfall and are deposited in bottom sediments, resulting in a TI of 1.0 in this water, when they are absent, which occurs in most cases, or 0.0, when heavy metals are found in these waters

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This work is directed to the treatment of organic compounds present in produced water from oil using electrochemical technology. The water produced is a residue of the petroleum industry are difficult to treat , since this corresponds to 98 % effluent from the effluent generated in the exploration of oil and contains various compounds such as volatile hydrocarbons (benzene, toluene, ethylbenzene and xylene), polycyclic aromatic hydrocarbons (PAHs), phenols, carboxylic acids and inorganic compounds. There are several types of treatment methodologies that residue being studied, among which are the biological processes, advanced oxidation processes (AOPs), such as electrochemical treatments electrooxidation, electrocoagulation, electrocoagulation and eletroredution. The electrochemical method is a method of little environmental impact because instead of chemical reagents uses electron through reactions of oxide-reducing transforms toxic substances into substances with less environmental impact. Thus, this paper aims to study the electrochemical behavior and elimination of the BTX (benzene, toluene and xylene) using electrode of Ti/Pt. For the experiment an electrochemical batch system consists of a continuous source, anode Ti/Pt was used, applying three densities of current (1 mA/cm2, 2,5 mA/cm2 and 5 mA/cm2). The synthetic wastewater was prepared by a solution of benzene, toluene and xylene with a concentration of 5 ppm, to evaluate the electrochemical behavior by cyclic voltammetry and polarization curves, even before assessing the removal of these compounds in solution by electrochemical oxidation. The behavior of each of the compounds was evaluated by the use of electrochemical techniques indicate that each of the compounds when evaluated by cyclic voltammetry showed partial oxidation behavior via adsorption to the surface of the Ti/Pt electrode. The adsorption of each of the present compounds depends on the solution concentration but there is the strong adsorption of xylene. However, the removal was confirmed by UV-Vis, and analysis of total organic carbon (TOC), which showed a percentage of partial oxidation (19,8 % - 99,1 % TOC removed), confirming the electrochemical behavior already observed in voltammetry and cyclic polarization curves

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The textile industry is one of the most polluting in the world (AHMEDCHEKKAT et al. 2011), generating wastewater with high organic loading. Among the pollutants present in these effluents are dyes, substances with complex structures, toxic and carcinogenic characteristics, besides having a strong staining. Improper disposal of these substances to the environment, without performing a pre-treatment can cause major environmental impacts. The objective this thesis to use a technique of electrochemical oxidation of boron doped diamond anode, BDD, for the treatment of a synthetic dye and a textile real effluent. In addition to studying the behavior of different electrolytes (HClO4, H3PO4, NaCl and Na2SO4) and current densities (15, 60, 90 and 120 mA.cm-2 ), and compare the methods with Rhodamine B (RhB) photolysis, electrolysis and photoelectrocatalytic using H3PO4 and Na2SO4. Electrochemical oxidation studies were performed in different ratio sp3 /sp2 of BDD with solution of RhB. To achieve these objectives, analysis of pH, conductivity, UV-visible, TOC, HPLC and GC-MS were developed. Based on the results with the Rhodamine B, it was observed that in all cases occurred at mineralization, independent of electrolyte and current density, but these parameters affect the speed and efficiency of mineralization. The radiation of light was favorable during the electrolysis of RhB with phosphate and sulfate. Regarding the oxidation in BDD anode with different ratio sp3 /sp2 (165, 176, 206, 220, 262 e 329), with lower carbon-sp3 had a longer favoring the electrochemical conversion of RhB, instead of combustion. The greater the carbon content on the anodes BDD took the biggest favor of direct electrochemical oxidation

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In this work the degradation of real and synthetic wastewater was studied using electrochemical processes such as oxidation via hydroxyl radicals, mediated oxidation via active chlorine and electrocoagulation. The real effluent used was collected in the decanter tank of the Federal University of Rio Grande do Norte (ETE-UFRN) of Effluent Treatment Plant and the other a textile effluent dye Ácido Blue 113 (AB 113) was synthesized in the laboratory. In the electrochemical process, the effects of anode material, current density, the presence and concentration of chloride as well as the active chlorine species on site generated were evaluated. Electrodes of different compositions, Ti/Pt, Ti/Ru0,3Ti0,7O2, BDD, Pb/PbO2 and Ti/TiO2-nanotubes/PbO2 were used as anodes. These electrodes were subjected to electroanalytical analysis with the goal of checking how happen the anodic and cathodic processes across the concentrations of NaCl and supporting electrolyte used. The potential of oxygen evolution reaction were also checked. The effect of active chlorine species formed under the process efficiency was evaluated by removing the organic matter in the effluent-ETE UFRN. The wastewater treatment ETE-UFRN using Ti/Pt, DDB and Ti/Ru0,3Ti0,7O2 electrodes was evaluated, obtaining good performances. The electrochemical degradation of effluent-UFRN was able to promote the reduction of the concentration of TOC and COD in all tested anodes. However, Ti/Ru0,3Ti0,7O2 showed a considerable degradation due to active chlorine species generated on site. The results obtained from the electrochemical process in the presence of chloride were more satisfactory than those obtained in the absence. The addition of 0.021 M NaCl resulted in a faster removal of organic matter. Secondly, was prepared and characterized the electrode Ti/TiO2-nanotubes/PbO2 according to what the literature reports, however their preparation was to disk (10 cm diameter) with surface area and higher than that described by the same authors, aiming at application to textile effluent AB 113 dye. SEM images were taken to observe the growth of TiO2 nanotubes and confirm the electrodeposition of PbO2. Atomic Force Microscope was also used to confirm the formation of these nanotubes. Furthermore, was tested and found a high electrochemical stability of the electrode Ti/TiO2-nanotubes/PbO2 for applications such as long-term indicating a good electrocatalytic material. The electrochemical oxidation of AB 113 using Ti/Pt, Pb/PbO2 and Ti/TiO2-nanotubes/PbO2 and Al/Al (electrocoagulation) was also studied. However, the best color removal and COD decay were obtained when Ti/TiO2-nanotubes/PbO2 was used as the anode, removing up to 98% of color and 92,5% of COD decay. Analysis of GC/MS were performed in order to identify possible intermediates formed in the degradation of AB 113.