Tratamento de materiais contaminados com bifenilas policloradas (PCBS) via extração convencional e fluído supercrítico

The decontamination of the materials has been subject of some studies. One of the factors that it increases the pollution is the lack of responsibility in the discarding of toxic trash, as for example the presence of PCB (Polychlorinated Biphenyls) in the environment. In the Brazilian regulations, the material contaminated with PCB in concentrations higher than 50 ppm must be stored in special places or destroyed, usually by incineration in plasma furnace with dual steps. Due to high cost of the procedure, new methodologies of PCBs removal has been studied. The objective of this study was to develop an experimental methodology and analytical methodology for quantification of removal of PCBs through out the processes of extractions using supercritical fluid and Soxhlet method, also technical efficiency of the two processes of extraction, in the treatment of contaminated materials with PCBs. The materials studied were soils and wood, both were simulated contamination with concentration of 6.000, 33.000 and 60.000 mg of PCB/ kg of materials. Soxhlet extractions were performed using 100 ml of hexane, and temperature of 180 ºC. Extractions by fluid supercritical were performed at conditions of 200 bar, 70°C, and supercritical CO2 flow-rate of 3 g/min for 1-3 hours. The extracts obtained were quantified using Gas chromatography-mass spectrometry (GC/MS). The conventional extractions were made according to factorial experimental planning technique 22, with aim of study the influence of two variables of process extraction for the Soxhlet method: contaminant concentration and extraction time for obtain a maximum removal of PCB in the materials. The extractions for Soxhlet method were efficient for extraction of PCBs in soil and wood in both solvent studied (hexane and ethanol). In the experimental extraction in soils, the better efficient of removal of PCBs using ethanol as solvent was 81.3% than 95% for the extraction using hexane as solvent, for equal time of extraction. The results of the extraction with wood showed statistically it that there is not difference between the extractions in both solvent studied. The supercritical fluid extraction in the conditions studied showed better efficiency in the extraction of PCBs in the wood matrix than in soil, for two hours extractions the obtain percentual of 43.9 ± 0.5 % for the total of PCBs extracted in the soils against 95.1 ± 0,5% for the total of PCBs extracted in the wood. The results demonstrated that the extractions were satisfactory for both technical studied

Estudo da oxidação do metabissulfito de sódio contido no efluente da carcinicultura

The shrimp farming is a process of creation of shrimp that has been growing rapidly in the country, occupying a meaningful space in the Brazilian exporting. In 2003, this activity presented a volume of 60 millions of tons and 220 millions of dollars, being the main generator of employment and income of the primary sector of the northeast economy. However, it is a new activity with c.a. five years in the Rio Grande do Norte State and therefore needs investment in the technological area. Among the wastewaters of this activity, the sulphite solution is being usually applied in the process of fishing, i.e. retrieval of the shrimps from the farming. The aim of this work is to present the oxidation experimental results of the sulphite that may be and to determine what it s the most efficient method, trough laboratory experiments. The measurements were carried out in a mixing reactor inserting air and with hydrogen peroxide addition with and without UV light. The solutions were prepared synthetically with concentrations found in the wastewater of fishing and also collected in locu. The oxidation process using air was monitorated by iodometric analysis for the sulphite and the oxidation using hydrogen peroxide was evaluated with turbidimetric analysis for sulphate, by spectrophotometer. The sulphite was totally oxidized in both processes. The experimental results permit to conclude that the oxidation by hydrogen peroxide is more efficient and allowed to determine the optimum operational conditions in terms of concentration and time of treatment

Modelagem e simulação da deposição de parafinas em escoamento turbulento

The flow assurance has become one of the topics of greatest interest in the oil industry, mainly due to production and transportation of oil in regions with extreme temperature and pressure. In these operations the wax deposition is a commonly problem in flow of paraffinic oils, causing the rising costs of the process, due to increased energy cost of pumping, decreased production, increased pressure on the line and risk of blockage of the pipeline. In order to describe the behavior of the wax deposition phenomena in turbulent flow of paraffinic oils, under different operations conditions, in this work we developed a simulator with easy interface. For that we divided de work in four steps: (i) properties estimation (physical, thermals, of transport and thermodynamics) of n-alkanes and paraffinic mixtures by using correlations; (ii) obtainment of the solubility curve and determination the wax appearance temperature, by calculating the solid-liquid equilibrium of parafinnic systems; (iii) modelling wax deposition process, comprising momentum, mass and heat transfer; (iv) development of graphic interface in MATLAB® environment for to allow the understanding of simulation in different flow conditions as well as understand the matter of the variables (inlet temperature, external temperature, wax appearance temperature, oil composition, and time) on the behavior of the deposition process. The results showed that the simulator developed, called DepoSim, is able to calculate the profile of temperature, thickness of the deposit, and the amount of wax deposited in a simple and fast way, and also with consistent results and applicable to the operation

Modelagem da transferência de massa na remoção do óleo da água produzida por flotação em coluna com uso de tensoativos de origem vegetal

The treatment of oil produced water and its implications are continually under investigation and several questions are related to this subject. In the Northeast Region Brazil, the onshore reservoirs are, in its majority, mature oil fields with high production of water. As this oil produced water has high levels of oil, it cannot be directly discarded into the environment because it represents a risk for contamination of soil, water, and groundwater, or even may cause harm to living bodies. Currently, polyelectrolytes that promote the coalescence of the oil droplets are used to remove the dispersed oil phase, enhancing the effectiveness of the flotation process. The non-biodegradability and high cost of polyelectrolytes are limiting factors for its application. On this context, it is necessary to develop studies for the search of more environmentally friendly products to apply in the flotation process. In this work it is proposed the modeling of the flotation process, in a glass column, using surfactants derived from vegetal oils to replace the polyelectrolytes, as well as to obtain a model that represents the experimental data. In addition, it was made a comparative study between the models described in the literature and the one developed in this research. The obtained results showed that the developed model presented high correlation coefficients when fitting the experimental data (R2 > 0.98), thus proving its efficiency in modeling the experimental data.

Vinicius de Moraes e Shelley: um exercício de desleitura .

Using Harold Bloom s methodology known as dialectical revisionism we undertake the task of misreading of Vinícius de Moraes (1913- 1980) poems Poética (1950), Operário em construção (1955), Poética II (1960) against Percy Bysshe Shelley (1792-1822) and his poem A Song: Men of England, suggesting that the Brazilian poet trammeled a battle with his poetic triad, in which Operário em Construção is Vinicius s main weapon. It is suggested here that each one of Vinícius´poem represents a step of what Bloom calls anxiety of influence . The misreading proposed confronts the themes and the imagery of the poems, arguing that Shelley and Vinícius are similar when they approach exploitation and working class consciousness according to the Dialectic Marxism pattern, and that Vinícius´s poem was not only inspired by Shelley s, but using one of the strategies suggested by Bloom, he corrects the ideological flaws of Shelley s poem. It is also discussed the possibility that both poems are inspired by Plato´s (428-7 a 348-7 a.C.) allegory of the cave, his concept of justice and the moral construction of the polis defended in A República. Thus, considering the process of misreading, these five poems constitute what Bloom calls a family romance , which is characterizes the phenomenon of melancholy of creativity

O corpo no pensamento de Epicuro: limites e possibilidades

The theme that fits the perspective of this thesis comes from the interest of treating, in the Epicurean corpus, about the importance of the body and its manners of realization for understanding the thought of Epicurus of Samos. Based on the inferences contained in the texts that remained from Epicurus, we did an analysis of the aspects that characterize Epicurism as a thought that makes repeated references to the body as an instance of sensitivity. It was necessary, therefore, to discuss how the body is linked to the possibility of thought, and how the latter can be admitted as a body element. It is further understood that the atomistic physics converges to the idea that asserts natural phenomena as likely to be contained and explained by the observations that come from the senses which are manifested through the body. For this reason, it was also pertinent to reflect on the admission of the body as a key element for the interpretation of Epicurean thought, even under the constitution of language. The Epicurean construction about body image was also used for the interpretation and questioning of the dynamics that define the relationships between individuals, characterizing the koinonía of the garden through the notion of corporeal unity. It was defined, therefore, that the characterization of the action field of individuals who lived in the Epicurean garden revolves around the use of logos, with the dialogues coming from the exercise of philosophy for therapeutic purposes, which were able to introduce a specific mode of political action marked by the absence of strange interests of the notion of philía

Em nome da cidade vencida: a São Luís republicana em José do Nascimento Moraes (1889 1920)

Cette dissertation a pour but d´analyser la ville de São Luís do Maranhão pendant la Première Republique, d´après le roman Vencidos e Degenerados, de José do Nascimento Moraes, publié en 1915. À partir des rapports entre l´Histoire et la Littérature, nous nous intéressons à la façon dont l´auteur écrit l´histoire d´une ville qui, après la fin de l´esclavage et l´installation de la Republique, conserve des anciens préjugés de race et reste plongée dans l´immobilité economique. Le roman fait partie d´un ensemble d´oeuvres scientifiques et littéraires d´une géneration connue sous le nom de Novos Atenienses (nouveaux athéniens), laquelle discutait la crise économique et culturelle vécue par le Maranhão au tournant des XIXe et XXe siècles. Le discours formulé par les nouveaux-athéniens comprennait des eléments nostalgiques associés au culte des lettres envisageant la conquête de la réconaissance littéraire et le désir d´adapter la ville de São Luis aux modèles de progrès et modernisation de la période républicaine. Dans ce contexte, Moraes introduit les thèmes liés à la discrimination raciale qui demerait après la fin de l´esclavage, qu´il considérait un obstacle au progrès de la capitale de Maranhão, et aussi la cause des pérsecutions littéraires dont il était victime. On a analisé le roman en cherchant compreendre les rapports entre les individus et les rapports qui´ils entretienent avec les spaces de la ville, à partir de questions d´ordre littéraire, raciale et urbaine. En guise de conclusion, la narration de l´oeuvre est dévellopée de façon que la ville, peuplée de gens de couleurs, sert à legitimée l´oeuvre littéraire de Moraes, dont le nom a été oublié dans les principaux cercles littéraires de la capitale pendant la période examinée

Experiências maternas de perda de um filho com câncer infantil: uma compreensão fenomenológico-existencial

Death due to childhood cancer reflects an early outcome of life, which can cause a strong repercussion in the mother s existence - figure to whom the greatest part of responsibilities during the child s illness is commonly allocated. The aim of this study is to understand the experience of mothers who have lost a kid as a consequence of childhood cancer, approaching the personal senses of this fact. Following a qualitative research design, with an exploratory and comprehensive approach, the study used the narrative method, which was obtained from a semi-structured interview, as the data generation procedure. The research counted on the participation of three adult mothers who had lost their kids because of childhood cancer, after - at least - a six-month period of oncologic treatment. The proposal of analysis follows the parameters of the phenomenological method and the data are based on Martin Heidegger s existential analytic. The results were structured into three thematic axes: previous History, child illness and its repercussions; The network of support and care; Loss and after loss: facing and signifying. It was possible to comprehend that the emergence of cancer in childhood promotes, since the diagnosis, a disruption of everyday meanings, accentuating the fragile condition of human life. In this specific circumstance of childhood illness, all the participants restricted their possibilities of being-in-the-world, dedicating exclusively to the practice of maternity. Concerning their relationship with their children in treatment, the narratives unveiled, in a convergent manner, the existence of care in a substitutive mode. In the network of support - primarily constituted by family, the health team and the support institutions - the relations were marked by proximity and detachment movements. With the child s death, mothers began to live a way of being-with the absent child , ensuring the continuity of the relationship with the dead infant. From the results exposed above, we can understand the motherly mourn as a singular experience in constant resignification, in which the subjective time overlaps the cronological time. The increment of anguish, resulting from the mother s confrontation to the question of finitude, mobilizes a process of change in their way of being-in-the-world, promoting an openness to new possibilities in their lives. Singular attention to the mother, during the process of illness and child loss, turns out to be fundamental