Otimização do processo de flotação de emulsão óleo/água através do planejamento fatorial completo

In recent decades, the generation of solid and liquid waste has increased substantially due to increased industrial activity that is directly linked to economic growth. For that is the most efficient process, it is inevitable generation of such wastes. In the oil industry, a major waste generated in oil exploration is produced water, which due to its complex composition and the large amount generated, has become a challenge, given the restrictions imposed by environmental laws regarding their disposal, making if necessary create alternatives for reuse or treatment in order to reduce the content of contaminants and reduce the harmful effects to the environment. This water can be present in free form or emulsified with the oil, when in the form of an emulsion of oil-water type, it is necessary to use chemicals to promote the separation and flotation is the treatment method which has proved to be more efficient, for it can remove much of the emulsified oil when compared to other methods. In this context, the object of this work was to study the individual effects and interactions of some physicochemical parameters of operations, based on previous work to a flotation cell used in the separation of synthetic emulsion oil / water in order to optimize the efficiency of the separation process through of the 24 full factorial design with center point. The response variables to evaluate the separation efficiency was the percentage of color and turbidity removal. The independent variables were: concentration of de-emulsifying, oil content in water, salinity and pH, these being fixed, minimum and maximum limits. The analysis of variance for the equation of the empirical model, was statistically significant and useful for predictive purposes the separation efficiency of the floater with R2 > 90%. The results showed that the oil content in water and the interaction between the oil content in water and salinity, showed the highest values of the estimated effects among all the factors investigated, having great and positive influence on the separation efficiency. By analyzing the response surface was determined maximum removal efficiency above 90% for both measured for turbidity as a measure of color when in a saline medium (30 g/L), the high oil concentrations (306 ppm) using low concentrations of de-emulsifying (1,1 ppm) and at pH close to neutral

Utilização de uma coluna de flotação para remoção de compostos orgânicos da água de produção

Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1° order

Otimização de metodologias para determinação de hidrocarbonetos policíclicos aromáticos:aplicação em água do Rio Potengi

This work aims to detect polycyclic aromatic hydrocarbons (PAHs) through optimized analytical techniques, such as gas chromatography with flame-ionisation detector (CGFID), gas chromatography coupled to mass spectrometry (CGMS), Fluorescence Spectroscopy of Molecular and Purpot of oils and greases (POG). Apply to chemometrics, Factorial Planning 23, in the preparation of samples by liquid-liquid extraction. The sample preparation was used for liquid-liquid extraction and factors in this sample was used for the application of factorial planning 23, such as the use of ultrasound, solvents (dichloromethane, hexane and chloroform) and ratio of solvent / synthetic sample. These factors were assigned two types of levels: positive and negative. It was used to form the cube to better analyze the answers. The responses of the eight combinations were obtained in reading the spectrofluorimetric. The optimization of equipment were used, and they served in the HPA's identification of the samples collected in Rio Potengi. The optimization of the equipment was observed every 16's and PAH in the samples was found that the HPA's came from contamination of the Rio Potengi. The contamination comes through organic household waste, hospital waste, and among other contamination that comes from industries that are installed around the River The factorial design of high validity, it was observed a more effective sample preparation. The factorial design of liquid-liquid extraction showed a way to spend less solvent in less time using an ideal solvent, but also a way to extract more analyte from the matrix itself is water. In planning a smaller form factor extraction was the use of ultrasound, the ratio 1:3 corresponding to a solvent and sample 3 and the best solvent was dichloromethane who presented a viable extraction, not discarding the possibility of using also the hexane. The chloroform and may be toxic not had a good extraction

Utilização de uma coluna de flotação para remoção de compostos orgânicos da água de produção

Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1° order.

Estudo da eficiência dos adsorventes de Al2O3 e Fe/Al2O3 para remoção de BTX presente em água contaminada com gasolina

Contamination of groundwater by BTX has been featured in recent decades. This type of contamination is due to small and continuous leaks at gas stations, causing serious problems to public health and the environment. Based on these antecedents, the search for new alternatives for treating contaminated water is shown to be essential. Therefore, this study aimed to evaluate the efficiency of removal of BTX by adsorption processes employing commercial alumina (Al2O3) and alumina supported with iron (Fe/Al2O3) as adsorbents. It was prepared by a in a synthetic gasoline solution and distilled water to simulate an actual sample. Initially, the adsorbents were characterized by techniques XRD, TG / DTG, XRF, FTIR and SEM/EDS, several trials, where he was placed synthetic solution to react in the presence of Al2O3 and Fe/Al2O3 in a closed, mechanical stirring system were performed varying the catalyst concentration 2, 4 and 6 g.L-1 every 0, 10, 30 60, 90 and 120 min, aliquots were taken and brought to analysis by gas chromatography flame ionization with headspace extraction. The results indicated that the absorbent which has higher BTX removal capacity was the Fe/Al2O3 at a concentration of 6 g.L-1, pH = 4 and time of 90 minutes reaction, resulting in an efficiency, resulting in a 86,5% efficiency for benzene removal, for the 95,4% toluene, 90,8% for ɱ,ρ- xylene and 93.7% for the θ-xylenes. Subsequently, we performed a kinetic study of the reactions, the values of experimental adsorption capacity (qe) showed agreement with the values of the theoretical adsorption capacity (qc) to the pseudo-second-order model in the adsorption tests using 2 and 6 gL-1 of Al2O3 and assays using 2, 4 and 6 g.L-1 of Fe/Al2O3. A fact corroborated by the R2 values, thus indicating that the chemical interactions are present in the adsorption mechanisms of BTX.

Classificação de água de coco processada e natural por meio de HCA, PCA e teores de íons metálicos determinados por ICP OES

Inductively Coupled Plasma Optical Emission Spectrometry was used to determine Ca, Mg, Mn, Fe, Zn and Cu in samples of processed and natural coconut water. The sample preparation consisted in a filtration step followed by a dilution. The analysis was made employing optimized instrumental parameters and the results were evaluated using methods of Pattern Recognition. The data showed common concentration values for the analytes present in processed and natural samples. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) indicated that the samples of different kinds were statistically different when the concentrations of all the analytes were considered simultaneously.

Sulfetos volatilizáveis por acidificação e metais extraídos simultaneamente na avaliação de sedimentos de água doce

This paper discusses the historical and methodological fundaments of the dynamics and quantification of acid volatile sulfides (AVS) and simultaneously extracted metals (SEM) in aquatic sediments. It also discusses the SEM/AVS relationship, which involves several controversial aspects such as sulfide stability, sulfide-organic matter interaction, and the inability to predict the toxicity of organic compounds in the environment. This relationship is an important tool for the inference of metal bioavailability. The use of ecotoxicological tests with target organisms regulated by international standards is also a relevant aspect.

Efeitos da cobertura do solo com filme de polietileno azul no consumo de água da cultura da alface cultivada em estufa

The covering of the soil is an agricultural practice that intends to control the harmful herbs, to reduce the losses of water by evaporation of the soil, and to facilitate the harvest and the commercialization, once the product is cleaner and healthier. However, when the soil is covered important microclimatic parameters are also altered, and consequently the germination of seeds, the growth of roots, the absorption of water and nutrients, the metabolic activity of the plants and the carbohydrates storage. The current trial intended to evaluate the effect of soil covering with blue colored film on consumptive water-use in a lettuce crop (Lactuca sativa, L.). The experiment was carried out in a plastic greenhouse in Araras - São Paulo State, Brazil from March 3rd, 2001 to May 5th, 2001. The consumptive water-use was measured through two weighing lysimeter installed inside the greenhouse. Crop spacing was 0.25 m x 0.25 m and the color of the film above soil was blue. Leaf area index (IAF), was measured six times (7; 14; 21; 28; 35; 40 days after transplant) and the water-use efficiency (EU) was measured at the end. The experimental design was subdivided portions with two treatments, bare soil and covered soil. The average consumptive water-use was 4.17 mm day-1 to the bare soil treatment and 3.11 mm day-1 to the covered soil treatment. The final leaf area index was 25.23 to the bare soil treatment and 24.39 to the covered soil treatment, and there was no statistical difference between then.

Teores de nutrientes na alface irrigada com água residuária aplicada por sistemas de irrigação

A trial was carried out to evaluate the chemical composition in the aerial part of lettuce, cv. 'Elisa', irrigated with wastewater treated with constructed wetland and source deposit water, grown on a Rhodic Hapludox Soil, using the irrigation systems sprinkle, subsurface drip and surface drip irrigation. The experiment was carried out from August 17th to October 3rd of 2001 and the chemical analyses of the lettuce were accomplished to 47 days after transplanting of the seedling. The aerial part of the lettuce was analyzed as for the levels of total nitrogen, nitrate, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper, zinc, sodium, boron, cobalt and molybdenum. The sodium and the sulfur presented higher levels than the maximum suitable in the aerial part of the lettuce and the smallest level of magnesium, while other chemical elements analyzed were normal and appropriate considering the standard for well-nourished plants, not being influenced by the water type. The sodium was the chemical element that presented the highest levels in the aerial part of the lettuce in the treatments irrigated with wastewater, presenting significant difference in relationship to the treatments irrigated with source deposit water in the three irrigation systems. The use of the different irrigation systems by the application of wastewater treated with constructed wetland did not interfere in the levels of nutrients in the aerial part of the lettuce.

Influência da temperatura do ar de secagem no calor latente de vaporização de água em feijão macassar (Vigna unguiculata (L.) Walp.), variedade sempre-verde

In order to determine the energy needed to artificially dry an agricultural product the latent heat of vaporization of moisture in the product, H, must be known. Generally, the expressions for H reported in the literature are of the form H = h(T)f(M), where h(T) is the latent heat of vaporization of free water, and f(M) is a function of the equilibrium moisture content, M, which is a simplification. In this article, a more general expression for the latent heat of vaporization, namely H = g(M,T), is used to determine H for cowpea, always-green variety. For this purpose, a computer program was developed which automatically fits about 500 functions, with one or two independent variables, imbedded in its library to experimental data. The program uses nonlinear regression, and classifies the best functions according to the least reduced chi-squared. A set of executed statistical tests shows that the generalized expression for H used in this work produces better results of H for cowpea than other equations found in literature.

Adequação de engates rápidos de aspersores como conectores de mangueira para distribuição de água em sulcos de irrigação

As a way to reduce water losses in furrow irrigation systems, used in fresh market tomato production, farmers are improperly distributing water into the field using plastic hose. The objective of this work was to study the suitability of using quick coupler sprinkler as hose connectors for water distribution in tomato plantation. The first step of the study was to assess the current hose field operation for tomato growers. Subsequently, four models of quick couplers sprinklers available in the market were tested in laboratory to determine the coefficient of resistance, the equivalent tube length, the head loss curve and the linking efficiency. As result, a structural design for hose connectors was presented using the model of coupling with the best hydraulic performance. Additionally, some technical recommendations on its use in irrigation water distribution are highlighted. Despite the requirement for additional field trials, the proposed system has potential to optimize the water use efficiency, to improve workers ergonomic conditions, and ensure good profitability to the producer.

TEORIA SINTÁTICA: DE UMA PERSPECTIVA DE -ISMOS PARA UMAPERSPECTIVA DE PROGRAMAS

This paper tries to show that the developments in linguistic sciences are better viewed as stages in a single research program, rather than different ideological -isms. The first part contains an overview of the structuralistas' beliefs about the universality and equivalence of human languages, and their search for syntactic universals. In the second part, we will see that the generative program, in its turn, tries to answer why language is a universal faculty in the human species and addresses questions about its form, its development and its use. In the second part, we will see that the paper gives a brief glimpse of the tentative answers the program has been giving to each of these issues.

Variação sazonal da fotossíntese, condutância estomática e potencial da água na folha de laranjeira 'Valência'

Seasonal variation in environmental conditions may influence gas exchange rates as well as water relations in perennial species. This work was carried out to evaluate photosynthetic rates (A), transpiration (E), stomatal conductance (g) and leaf water potential (psi f ) in 'Valencia' orange trees grafted on four different rootstocks. Measurements were made twice a day: from 9h00 to 11h00 a.m. and from 1h00 to 3h00 p.m., during January, March and July. A and g were significantly lower and psif was significantly more negative, in the afternoon. The decrease in A may be related to the reduction in g, due to the increase in the vapor pressure deficit between the air and the leaf (VPDair-leaf ) in the afternoon, when temperatures are higher. In spite of the partial stomatal closure in the afternoon, the values for E were approximately the same as those measured in the morning, due to the increase in the VPDair-leaf . A decrease in A and g could also be noted from January to July, that is, from the hot and humid summer months, to the colder and drier winter ones. It was suggested that the decrease in A and g observed from January through March, may be related to the decrease in plant growth rates, which could have influenced the source-sink relationships, since the climatic conditions for both months were similar. The decrease in A and g showed in July, seems to be related to the decrease in both the night temperature and the growth rate of plants.

PREDIÇÃO DA ATIVIDADE DE ÁGUA E RELAÇÃO ENTRE A ATIVIDADE DE ÁGUA E A DEPRESSÃO DO PONTO DE CONGELAMENTO DE SUCOS DE FRUTAS

This work proposes to determine the water activity and the freezing point depression of tangerine, pineapple and lemon juices at various concentrations (10-55oBrix) and to achieve a correlation between these properties. The freezing point depression was determined with a LAKTRON cryoscope and common laboratory materials. The water activity was determined with a DECAGON CX-2 hygrometer in the temperature range of 15 to 30oC. With the results, the adjustment to CHEN (1987) water activity prediction equation to non-electrolyte mixtures was verified, through the calculation of the variation coefficient (CV). Being CV smaller than 3% for the proposed model, it can be said that the experimental data have adjusted well to the prediction equation. The water activity and the freezing point depression was correlated for tangerine, pineapple and lemon juices and r2 values were higher than 99%. Therefore, it is possible to obtain the water activity by knowing the freezing point depression of studied juices.

Educação para a água

A água como tema no contexto educacional é abordada a partir de diversas perspectivas. Diante das discussões em relação à crise socioambiental atual, acreditamos que a educação para a água deva ser realizada a partir da abordagem das dimensões espacial e temporal, considerando nesta última o tempo geológico e a história humana, sem a qual não é possível enfrentar a fragmentação do conhecimento que predomina no ambiente escolar. A abordagem do local, tendo como unidade de estudo a bacia hidrográfica, auxiliada pelos conteúdos das geociências e por metodologias interdisciplinares, proporciona uma visão integrada e contextualizada do tema para a construção do conhecimento.