948 resultados para Processos químicos : Separação


Relevância:

80.00% 80.00%

Publicador:

Resumo:

Aluminum cans has wide uses and Brazil is among one of the world's largest country at recycling, to provide an option that adds value to raw materials, this paper uses aluminum cans as aluminum source for the production of alumina. Evaluating the use of acid digestions (hydrochloric acid, sulfuric acid and aqua regia) and basic (potassium hydroxide) to solubilize the aluminum after which will be complexed with 8-hydroxyquinoline at different pH's. By calcination, the complex produces an oxide with metal components with varying proportions depending on the digestion process. The thermal behavior of the complex varies with the morphology and metals present, occurring different events due to these characteristics.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Lasiodiplodan is an exocellular β-glucan with biological functionalities such as antioxidant, antiproliferative, hypocholesterolemic, protective activity against DNA damage induced by doxorubicin and hypoglycemic activity. Chemical derivatization of polysaccharide macromolecules has been considered as a potentiating mechanism for bioactivity. In this context, this work proposes the derivatization of lasiodiplodan by acetylation. Acetic anhydride was used as derivatizing agent and pyridine as catalyst and reaction medium. The derivatives obtained were evaluated by its water solubility, degree of substitution (DS), antioxidant potential, and characterized by infrared spectroscopy (FT-IR), thermal analysis, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Acetylated derivatives with different degrees of substitution (1.26; 1.03; 0.66 and 0.48) were obtained, and there was correlation between the concentration of derivatizing agent and DS. FT-IR spectroscopy analysis confirmed the insertion of acetyl groups into derivatized macromolecules (LAS-AC) through of specific bands concerning to carbonyl group (C = O) and increase in C-O vibration. SEM analysis indicated that native lasiodiplodan presents morphological structure in the form of thin films with translucent appearance and folds along its length. Derivatization led to morphological changes in the polymer, including aspects thickness, translucency and agglomeration. Thermal analysis indicated the native sample and derivative with DS 0.48 presented three weight loss stages. The first stage occurred until 125 ° C (loss of water) and there were two consecutive events of weight loss (200 ° C - 400 ° C) attributed to molecule degradation. Samples with DS 1.26; 1.03 and 0.66 demonstrated four weight loss stages. The first stage occurred until 130 ° C (loss of water), following by two consecutive events of weight loss (200 ° C - 392 ° C) attributed to degradation of the biopolymer. The fourth stage was between 381 ° C and 532 ° C (final decomposition) with exothermic peaks between 472 ° C and 491 ° C. X-ray diffraction patterns showed that native and acetylated lasiodiplodan have amorphous structure with semicrystalline regions. Derivatization did not contribute to increased solubility of the macromolecule, but potentiated its antioxidant capacity. Acetylation of lasiodiplodan allowed to obtaining a new macromolecule with higher antioxidant potential than the native molecule and with technological properties applicable in various industrial sectors.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The environmental pollution caused by industries has increased the concentration of pollutants in the environment, especially in water. Among the most diverse contaminants, there is the metals, who may or may not to be heavy/toxic, causing effluent of difficult treatment when in low concentrations. The search for alternative measures of wastewater effluent treatment has led to studies using phytoremediation technique through the various matrices (plant, fungi, bacteria) as means of polishing treatment to remove contaminants by means of biosorption/bioaccumulation. In order to use the phytoremediation technique for removing metals of the environmental, it have been performed bioassay with the macrophyte Pistia stratiotes. The bioassays were realized with healthy plants of P. stratiotes acclimatized in a greenhouse, at room temperature and lighting conditions during 28 days of cultivate. The cultivations were performed in glass vessels containing 1 L of the hydroponic solution with chromium (VI) in the potassium dichromate form with concentration range 0.10 to 4.90 mg L-1. The experiments were performed by Outlining Central Composite Rotational (OCCR), where the kinetics of bioaccumulation and chlorophyll a fluorescence were monitored in plants of P. stratiotes during cultivation. The collections of the samples and cultive solution were performed according to the OCCR. The chromium levels were measured in samples of P. stratiotes and the remaining solutions by the methodology of atomic absorption spectrometry by flame. The tolerance of P. stratiotes in relation to exposure to chromium (VI) was analyzed by parameters of physiological activity by means of chlorophyll a fluorescence, using the portable fluorometer PAM (Pulse Amplitude Modulation). The development of P. stratiots and their biomass were related to the time factor, while bioaccumulation capacities were strongly influenced by factors of time and chromium concentration (VI). The chlorophyll fluorescence parameters were affected by chromium and the exposure time at the bioassays. It was obtained an higher metal removal from the root in relation to the sheet, reaching a high rate of metal removal in solution. The experimental data removal kinetics were represented by kinetic models Irreversibly Langmuir, Reversible Langmuir, Pseudo-first Order and Pseudo-second Order, and the best fit for the culture solution was the Reversible Langmuir model with R² 0.993 and for the plant the best model was Pseudo-second order with R² 0.760.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Brazil is a country that is characterized by its low consumption of fish. With consumption records of 10.6 kg/ inhabitant/ year, it is lower than the recommended by the UN, that is 12 kg/ inhabitant/ year. The regular consumption of fish provides health gain for people and their introduction into the school feeding is an important strategy for the insertion of this food consumption habits in a population. In this context, the objective of this study was to understand the perception of fish with children from the public school system through the technical Projective Mapping (MP) and Association of Words (AP); and evaluate the acceptability of fish derivative in school meals. In the first instance with the intention to better understand the perception of children from different ages about the fish-based products, Projective Mapping techniques were applied through the use of food figures and word association. A total of 149 children from three public schools from Pato Branco, Paraná State, Brazil, took part in this study. Three groups of children aged 5-6, 7-8 and 9-10 years old were interviewed individually by six monitors experienced in applied sensory methods. Ten figures with healthy foods drawings (sushi, salad, fruit, fish, chicken), and less healthy foods (pizza, pudding, cake, hamburger, fries) were distributed to the children, who were asked to paste the figures in A3 sheet, so that the products they considered similar stayed near each other, and the ones considered very different stayed apart. After this, the children described the images and the image groups (Ultra Flash Profile). The results revealed that the MP technique was easily operated and understood by all the children and the use of images made its implementation easier. The results analysis also revealed different perceptions came from children from different ages and hedonic perceptions regarding the fish-based products had a greater weight in the percentage from older children. AP technique proved to be an important tool to understand the perception of fish by children, and strengthened the results previously obtained by the MP. In a second step it was evaluated the acceptance of fish burger (tilapia) in school meals. For this task, the school cooks were trained to prepare the hamburgers. For the evaluation of acceptance, the hedonic scale was used with 5 facial ratings (1 = disliked very much to 5 = liked a lot). Students from both genders, between 5 to 10 years old (n = 142) proved the burgers at lunchtime, representing the protein portion of the meal. The tilapia derivative products shown to be foods with important nutritional value and low calorie value. For the application of the multinomial logistic regression analysis there was no significant effect from the age and gender variation in the acceptance by children. However, statistical significance was determined in the interaction between these two variables. With 87 % acceptance rate there was potential for consumption of fish burgers in school meals.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Química, 2015.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Química, 2015.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Este relatório de estágio foi elaborado no âmbito da unidade curricular dissertação/projeto/estágio do Mestrado em Processos Químicos e Biológicos no Departamento de Engenharia Química e Biológica (DEQB) no Instituto Superior de Engenharia de Coimbra (ISEC). O presente relatório reflete o estágio que decorreu na Associação para a Inovação Tecnológica e Qualidade (AEMITEQ), um laboratório acreditado pelo Instituto Português de Acreditação (IPAC) cuja atividade principal consiste na realização de análises físico-químicas de águas, efluentes e solos, entre outros. O principal objetivo deste estágio consistiu na revalidação e na estimativa da incerteza de acordo com a norma ISO 11352:2012 do procedimento laboratorial: “Método de Análise de Azoto Amoniacal em Águas”. A proposta de revalidação de um método teve origem na alteração no modo de identificação dos documentos normativos nos anexos técnicos de acreditação. Em consequência desta alteração houve a necessidade de evidenciar perante o IPAC que o método em questão permanecia validado. A necessidade de estimar a incerteza de acordo com a norma ISO 11352:2012 teve origem na suspensão do guia do IPAC - OGC007, uma vez que a incerteza estimada pelo laboratório baseava-se neste guia. Estes objetivos foram realizados com sucesso. Outro dos objetivos deste estágio consistiu na integração nas atividades correntes do laboratório e na familiarização e execução das técnicas analíticas adotadas pela AEMITEQ com supervisão, tanto no âmbito da acreditação como fora do âmbito da acreditação. Este objetivo foi concretizado com sucesso, uma vez que obtive qualificação em vários ensaios acreditados. De uma forma generalizada, o estágio permitiu a integração num ambiente empresarial, designadamente num laboratório acreditado como a AEMITEQ. Desta forma, é possível concluir que o estágio foi realizado com sucesso, uma vez que no final fui convidada a realizar estágio profissional na AEMITEQ

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This work presents a proposal to detect interface in atmospheric oil tanks by installing a differential pressure level transmitter to infer the oil-water interface. The main goal of this project is to maximize the quantity of free water that is delivered to the drainage line by controlling the interface. A Fuzzy Controller has been implemented by using the interface transmitter as the Process Variable. Two ladder routine was generated to perform the control. One routine was developed to calculate the error and error variation. The other was generate to develop the fuzzy controller itself. By using rules, the fuzzy controller uses these variables to set the output. The output is the position variation of the drainage valve. Although the ladder routine was implemented into an Allen Bradley PLC, Control Logix family it can be implemented into any brand of PLCs

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This work aims to obtain a low-cost virtual sensor to estimate the quality of LPG. For the acquisition of data from a distillation tower, software HYSYS ® was used to simulate chemical processes. These data will be used for training and validation of an Artificial Neural Network (ANN). This network will aim to estimate from available simulated variables such as temperature, pressure and discharge flow of a distillation tower, the mole fraction of pentane present in LPG. Thus, allowing a better control of product quality

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Engenharia Sanitária

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The oil industry has several segments that can impact the environment. Among these, produced water which has been highlight in the environmental problem because of the great volume generated and its toxic composition. Those waters are the major source of waste in the oil industry. The composition of the produced water is strongly dependent on the production field. A good example is the wastewater produced on a Petrobras operating unit of Rio Grande do Norte and Ceará (UO-RNCE). A single effluent treatment station (ETS) of this unit receives effluent from 48 wells (onshore and offshore), which leads a large fluctuations in the water quality that can become a complicating factor for future treatment processes. The present work aims to realize a diagnosis of a sample of produced water from the OU - RNCE in compliance to certain physical and physico-chemical parameters (chloride concentration, conductivity, dissolved oxygen, pH, TOG (oil & grease), nitrate concentration, turbidity, salinity and temperature). The analysis of the effluent is accomplished by means of a MP TROLL 9500 Multiparameter probe, a TOG/TPH Infracal from Wilks Enterprise Corp. - Model HATR - T (TOG) and a MD-31 condutivimeter of Digimed. Results were analyzed by univariated and multivariated analysis (principal component analysis) associated statistical control charts. The multivariate analysis showed a negative correlation between dissolved oxygen and turbidity (-0.55) and positive correlations between salinity and chloride (1), conductivity, chloride and salinity (0.70). Multivariated analysis showed there are seven principal components which can explain the variability of the parameters. The variables, salinity, conductivity and chloride were the most important variables, with, higher sampling variance. Statistical control charts have helped to establish a general trend between the physical and chemical evaluated parameters

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Nowadays, bamboo is being studied because of their strength properties according with their specific mass and speed of growth, which makes it an important alternative as a new resource that will help reduce pressure on forests and helpping them favoring the minimization of uncontrolled deforestation in many regions of Brazil. This study aimed, in general, to analyze physical and mechanical properties of the material with the divulgation of its potential for industrial application. To do so, in this research were determined in relation to the physical properties, moisture content, dimensional stability and the apparent densities and the mechanics and basic, just a tension parallel to grain, in order to observe the interference of various kinds of treatments (chemical, thermal and natural) on the strength and modulus of elasticity in this request. The species used was the Guadua angustifolia, a species native of Brazil. All tests were performed at Universidade Estadual Paulista - Campus Experimental Itapeva in the laboratory of Materials Properties. The methodology used for testing of moisture, density and tension parallel to grain were based on NBR 7190/1997 for the wood, and dimensional stability tests were based on much the same as in COPANT 462/1972 (South American) . The preservative treatments conducted followed the recommendation of each manufacturer. The values obtained in tests of physical properties were satisfactory especially with respect to density and dimensional stability analyzed by the coefficient of anisotropy, showed that, compared to wood, excellent quality for the shrinkage test, obtaining a coefficient of 1.2. With respect to parallel tensile tests to fibre results showed, in most cases, that test specimens with the presence of us have lower values of resistance and modulus of elasticity when compared with those without us. In the treatment of thermal-treatment there was an apparent treatment there was an apparent increase in...

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The unbridled consumption of electronic equipment associated with fast immersion of new technologies on the market leads to the accelerated growth of electronic waste. Such waste mostly contains printed circuit boards in its structure. Printed circuit boards have many metals, including heavy metals, being highly toxic. Electronic waste is discarded improperly and indiscriminately, usually without any previous treatment and with other municipal waste, contaminating the environment and causing serious problems to human health. Beyond these metals, there are also precious metals and high value-added basis, that can be recovered and recycled, reducing the exploration of natural resources. Thus, due to the high growth potential and reuse of these waste treatment processes, characterization and separation were applied to the printed circuit boards. The printed circuit boards were subjected to physical treatments such as dismantling, crushing, sizing separation, magnetic separation and chemical treatments such as pyrolysis and leaching. Through characterization process (pyrolysis and leaching) the proportions of the components of the granulometric range were determined: 46,08% of metals; 23,32% of polymers and 30,60% of ceramics. It was also observed by particle size separation that metal components tend to concentrate in coarse fractions, while polymeric and ceramic components in fine fractions. From the magnetic separation process was obtained 12,08% of magnetic material and 82,33% of non-magnetic material.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

O objetivo deste estudo foi analisar o desempenho de um sistema de captação e tratamento de água do rio Sarapuí, por meio de uma estação de tratamento composta por um sistema de pré-tratamento convencional, ligado a um sistema de separação por membranas de osmose inversa, no Município de Belford Roxo RJ, instalado para fornecer água de processo a instalações industriais. Foi verificado que a água captada encontra-se em condição bastante degradada e que a unidade de tratamento removeu, em média, 97% do teor dos poluentes presentes na água, enquadrando-a nos parâmetros requeridos pelo processo industrial. Foi possível comprovar que o processo de separação por osmose inversa pode ser utilizado em escala industrial, proporcionando ganhos econômicos consideráveis, além de evitar o consumo de água potável para fins de processos industriais e, ainda, contribuir para a retirada de carga orgânica de uma fonte degradada