Estudo do aproveitamento do rejeito da mineração de esmeraldas na produção de refratários conformados isolantes

Emerald mining is an important area of the economy in Brazil, country which is in second place among the exporting nations of this gem. Due to the process of extraction, a great amount of reject is generated. Since there is no appropriate destination, the reject is abandoned around the mining industries, contributing to environment degradation. Nowadays, some of the most relevant things to an industry in general are: energy conservation, cost reduction, quality and productivity enhancement. The production of isolating, transformed refractory materials achieves the sustainability dimension when protection of the environment is incorporated to such process. This work investigates the use of emerald mining rejects in the ceramic body of refractory materials, aiming at obtaining a product whose characteristics are compatible with commercial products and, at the same time, allow the use of such rejects to solve the environmental issue caused by its disposal in nature. X-ray fluorescence analysis show that the emerald reject obtained after the flotation to extract molybdenum and mica has 70% of silica and alumina (SiO2+Al2O3) and 21% of a basic oxides and alkaline metals and earthy alkaline mixture (Na2O, K2O, CaO e MgO). Because of the significant amount of silica and alumina present in the reject, four refractory ceramic bodies were prepared. Samples with a rectangular shape and dimensions 100x50x10 mm were pressed in a steel mold at 27,5 MPa and sintered at 1200ºC for 40 min. under environment atmosphere in a resistive oven. The sintered samples were characterized in relation to the chemical composition (FRX), mineralogical composition (DRX), microstructure (MEV) and physical and mechanical properties. The results indicate that the mixture with 45% of reject, 45% of alumina and 10% of kaolin presents a refractory quality of 1420ºC, dimensional linear variation below 2.00%, apparent specific mass of 1,56 g/cm3 and porosity of 46,68%, which demonstrates the potential use of the reject as raw material for the industry of isolating transformed refractory materials

Desenvolvimento de sistemas a base de tensoativos para recuperação avançada de petróleo

Petroleum is a complex combination of various classes of hydrocarbons, with paraffinic, naphtenic and aromatic compounds being those more commonly found in its composition. The recent changes in the world scenario, the large reserves of heavy oils and also the lack of new discoveries of large petroleum fields are indications that, in the near future, the oil recovery by conventional methods will be limited. In order to increase the efficiency of the extraction process, enhanced recovery methods are cited in applications where conventional techniques have proven to be little effective. The injection of surfactant solutions as an enhanced recovery method is advantageous in that surfactants are able to reduce the interfacial tensions between water and oil, thus augmenting the displacement efficiency and, as a consequence, increasing the recovery factor. This work aims to investigate the effects of some parameters that influence the surfactant behavior in solution, namely the type of surfactant, the critical micelle concentration (CMC) and the surface and interface tensions between fluids. Seawater solutions containing the surfactants PAN, PHN and PJN have been prepared for presenting lower interfacial tensions with petroleum and higher stability under increasing temperature and salinity. They were examined in an experimental apparatus designed to assess the recovery factor. Botucatu (Brazil) sandstone plug samples were submitted to assay steps comprising saturation with seawater and petroleum, conventional recovery with seawater and enhanced recovery with surfactant solutions. The plugs had porosity between 29.6 and 32.0%, with average effective permeability to water of 83 mD. The PJN surfactant, at a concentration 1000% above CMC in water, had a higher recovery factor, causing the original oil in place to be recovered by an extra 20.97%, after conventional recovery with seawater

Obtenção e caracterização de extrato microencapsulado de resíduo agroindustrial de acerola

Acerola (Malpighia emarginata D.C.) is a red fruit widely cultivated in Brazil, especially in the Northeastern region. Its increasing demand is attributed to its high ascorbic acid contents. Besides ascorbic acid, widely known by its health-benefit effects, acerola is rich in anthocyanins, which contribute for the antioxidant power of the fruit. Acerola processing produces a bright-red pomace, usually discarded. The further processing of this pomace, in order to explore its antioxidant compounds, could enhance acerola market value and rentability of its processing. Both ascorbic acid and anthocyanins are highly susceptible to degradation, that can be delayed by microencapsulation, which consists on packing particles (core) in an edible matrix (wall material). This work has been made with the purpose of producing a microencapsulated acerola pomace extract, which could be used by the food industry as a functional ingredient with antioxidant and coloring properties. Antioxidant compounds were recovered by pressing the pomace diluted in a solvent (a citric acid aqueous solution), by using a central composite design, with two variables: citric acid concentration in the solvent (0-2%), and solvent: pomace mass ratio (2:1-6:1). The acerola pomace extract was then microencapsulated by spray drying. A central composite design was adopted, with three variables: inlet temperature of the spray dryer (170o-200oC), wall material: acerola solids mass ratio (2:1-5:1), and degree of maltodextrin replacement by cashew tree gum as wall material (0-100%). The cashew tree gum was used because of its similarity to arabic gum, which is regarded as the wall material by excellence. The following conditions were considered as optimal for extraction of anthocyanins and ascorbic acid: solvent/pomace ratio, 5:1, and no citric acid in the solvent. 82.47% of the anthocyanins were recovered, as well as 83.22% of the ascorbic acid. Anthocyanin and ascorbic acid retentions were favored by lower inlet temperatures, higher wall material: acerola solids mass ratio and higher maltodextrin replacement by cashew tree gum, which was presented as a promising wall material. The more adequate microencapsulation conditions, based not only on retention of antioxidant compounds but also on physical properties of the final powder, were the following: inlet temperature, 185oC; wall material: acerola solids mass ratio, 5:1, and minimum degree of maltodextrin replacement by cashew tree gum, 50%

Seletividade e absorção radicular do sulfentrazone em clones de eucalipto

O objetivo deste trabalho foi avaliar a seletividade e a absorção do sulfentrazone em clones de eucalipto. O primeiro experimento foi instalado em casa de vegetação, em delineamento inteiramente casualizado, com quatro repetições, no esquema fatorial 2 x 4, sendo duas doses do sulfentrazone (400 e 600 g ha-1) e quatro clones de eucalipto, híbridos de Eucalyptus grandis x E. urophylla (FB1, FB2, FB3 e FB4). Foram realizadas avaliações visuais de intoxicação das plantas de eucalipto e, no final do estudo, determinou-se a massa seca da parte aérea dos clones. No segundo experimento, foram utilizados os mesmos clones, sendo estes acondicionados em tubos falcon com 50 mL da solução contendo o sulfentrazone na concentração de 129 mM. As plantas de eucalipto permaneceram por 24 horas com as raízes imersas na solução e, em seguida, foi realizada a extração da seiva do xilema das plantas por meio de uma câmara de pressão. A concentração de sulfentrazone na seiva das plantas foi determinada através de cromatografia líquida e espectrometria de massas. O clone FB3 apresentou menor acúmulo de massa seca em relação aos demais, o que pode estar diretamente associado aos altos níveis de intoxicação observados. O clone FB2, apesar de mostrar elevada intoxicação, não apresentou níveis tão elevados de redução de massa seca em relação à testemunha. No tocante às concentrações de sulfentrazone nas plantas, elas foram proporcionais ao acúmulo de massa seca, o que indica que as variações na seletividade dos clones de eucalipto podem estar relacionadas à absorção diferenciada do herbicida.

Boro disponível e resposta da soja em latossolo vermelho-amarelo do Mato Grosso

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

Efeito da idade e do repouso pós-colheita de frutos de pepino na semente armazenada

Para avaliar os efeitos da idade e do repouso pós-colheita de frutos de pepino (Cucumis sativus L.) de duas cultivares, Pérola (espinhos escuros) e Rubi (espinhos claros), sobre as alterações na qualidade fisiológica das sementes durante o armazenamento, conduziu-se um experimento em Botucatu, SP e Bandeirantes, PR, durante quatro anos. Os frutos foram colhidos desde os 15 ('Rubi') ou 20 ('Pérola') dias até 45 dias após a antese, permanecendo em repouso pós-colheita por 0, 5, 10 e 15 dias, antes da extração das sementes. Antes e após dois e três anos de armazenamento (sacos de papel em ambiente de laboratório), foram retiradas amostras para avaliação do potencial germinativo e do vigor. Os resultados revelaram que sementes imaturas, retiradas de frutos colhidos precocemente (até 30 dias após a antese) e sem repouso pós-colheita, perderam totalmente a capacidade germinativa no segundo ano de armazenamento. Sementes que apresentavam valores iniciais de germinação mais elevados, as colhidas de frutos maduros (com ou sem repouso pós-colheita) ou de imaturos (30 e 35 dias de idade) com 10 a 15 dias de repouso pós-colheita, mantiveram valores acima de 70% após três anos de armazenamento.

Longevidade de sementes de camu-camu submetidas a diferentes ambientes e formas de conservação

O camu-camu (Myrciaria dubia (H.B.K.) McVaugh) produz fruto com grande potencial para extração de ácido ascórbico, que apresenta relevante importância econômica e social, com inúmeras aplicações industriais. O objetivo deste trabalho foi avaliar o efeito de diferentes formas de conservação e ambientes de armazenamento, sobre a manutenção da viabilidade das sementes. O delineamento experimental inteiramente casualizado, utilizando parcelas subsubdivididas, onde os fatores foram: ambiente de armazenamento (ao ar livre, em água, em câmara a 5 e a 10 ºC), forma de conservação (sementes com polpa - CP, sementes sem polpa - SP e sementes lavadas e tratadas - LT) e período de armazenamento (0; 2; 4 e 6 meses). O critério de avaliação adotado foi a protrusão da raiz primária. As sementes armazenadas em água, nas formas SP e LT, apresentaram germinação maior que 90%. As sementes nas formas CP e LT, armazenadas a 5 e a 10 ºC, tiveram germinação acima de 89%. O armazenamento em água e ao ar livre não afetou a germinação, podendo as sementes serem armazenadas durante o período de seis e quatro meses, respectivamente. As sementes CP, armazenadas em água, tiveram menor tempo médio para germinação. O índice de velocidade de germinação aumentou com o período de armazenamento e foi maior nas sementes armazenadas na água em todos os períodos. As sementes com polpa apresentaram menor índice de velocidade de germinação em todo o período de armazenamento avaliado.

Desenvolvimento de iniciadores para detecção e identificação de Diaporthe phaseolorum var. meridionalis em sementes de soja

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

Begomovírus infectando a cultura de pimentão no estado de São Paulo

Vírus do gênero Begomovirus são transmitidos por mosca-branca Bemisia tabaci G., e constituem um dos problemas fitossanitários sérios em diversas culturas. Plantas de pimentão coletadas em oito regiões do Estado de São Paulo, foram submetidas a extração de DNA total e PCR com primers universais e degenerados para begomovírus, que amplificam parte da região codificadora para a proteína capsicial. Os dados indicam a presença de begomovírus em pimentão nas cinco regiões coletadas. Análise das seqüências do DNA viral e análise filogenética revelaram identidade com dois begomovírus nativo da América. Tomato severe rugose virus - ToSRV (AY029750) e com Tomato yellow vein streak virus (ToYVSV, AY829113), espécies descritas infectando tomateiro no Brasil. A presença de begomovírus em pimentão foi verificada nas regiões de Alvinlândia, Ubirajara, Botucatu, Elias-Fausto, Paulínia, Mogi Guaçu, Paranapanema e Pirajú.

Degradação luminosa e retenção foliar dos corantes azul brilhante FDC-1 e amarelo tartrasina FDC-5 utilizados como traçadores em pulverizações

Três estudos foram conduzidos no Núcleo de Pesquisas Avançadas em Matologia (NUPAM) pertencente à UNESP/FCA - campus de Botucatu-SP, com o objetivo de avaliar a estabilidade dos corantes Azul Brilhante FDC-1 e Amarelo Tartrasina FDC-5 quanto a diferentes períodos de exposição à luz solar e contato com folhas de Eichhornia crassipes. No primeiro estudo, soluções de 0,3125, 0,625, 1,25, 2,5, 5, 10 e 20 ppm dos corantes Azul Brilhante FDC-1 e Amarelo Tartrasina FDC-5 foram acondicionadas em tubos de quartzo hermeticamente fechados e submetidos a 0, 0,5, 1, 2, 4, 6 e 10 horas de exposição à luz solar e ao escuro. Ao final de cada período, amostras de 10 mL foram retiradas dos tubos e analisadas. No segundo estudo, os tratamentos foram dispostos no esquema fatorial 2x7: duas condições luminosas (escuro e pleno sol) e sete períodos de exposição (0, 0,5, 1, 2, 4, 6 e 10 horas), com seis repetições. Com o auxílio de micropipeta, oito gotas de 5 µL das soluções Azul Brilhante e Amarelo Tartrasina a 4.000 ppm foram depositadas em placas de Petri de vidro. Após o término dos períodos de exposição, as placas foram lavadas com 50 mL de água destilada, com o objetivo de extrair o corante depositado sobre elas. No terceiro estudo, adotaram-se os mesmos tratamentos do segundo experimento, com quatro repetições, porém as soluções foram depositadas sobre as folhas de plantas de Eichhornia crassipes. Foram adotados também os mesmos procedimentos de extração dos corantes após o término dos períodos de exposição. As soluções finais obtidas nos três estudos foram submetidas à leitura óptica de absorbância em espectrofotômetro UV-visível nos comprimentos de onda de 630 e 427 nm, para os corantes Azul Brilhante FDC-1 e Amarelo Tartrasina FDC-5, respectivamente. As várias concentrações das soluções de ambos os corantes não sofreram degradação pela luz solar quando submetidas aos vários períodos de incidência luminosa nos tubos de quartzo (ambiente fechado), visto que as curvas de recuperação apresentaram equações semelhantes àquelas concentrações que foram mantidas no escuro. A mesma estabilidade também foi observada quando os corantes foram submetidos à luz solar em ambiente aberto, ou seja, nas placas de Petri. O corante Amarelo Tartrasina também se apresentou muito estável quando depositado sobre as folhas de E. crassipes, independentemente da exposição ou não à luz solar. Para o corante Azul Brilhante, ocorreram significativas perdas de 7,8 e 18,6% quando esteve depositado na superfície da folha de aguapé pelo período de 10 horas sob condições de escuro e plena luz solar, respectivamente.

Degradação fotoquímica de hidrocarbonetos da gasolina em efluentes aquosos

Photo-oxidation processes of toxic organic compounds have been widely studied. This work seeks the application of the photo-Fenton process for the degradation of hydrocarbons in water. The gasoline found in the refinery, without additives and alcohol, was used as the model pollutant. The effects of the concentration of the following substances have been properly evaluated: hydrogen peroxide (100-200 mM), iron ions (0.5-1 mM) and sodium chloride (200 2000 ppm). The experiments were accomplished in reactor with UV lamp and in a falling film solar reactor. The photo-oxidation process was monitored by measurements of the absorption spectra, total organic carbon (TOC) and chemical oxygen demand (COD). Experimental results demonstrated that the photo-Fenton process is feasible for the treatment of wastewaters containing aliphatic hydrocarbons, inclusive in the presence of salts. These conditions are similar to the water produced by the petroleum fields, generated in the extraction and production of petroleum. A neural network model of process correlated well the observed data for the photooxidation process of hydrocarbons

Remoção conjugada de metais e óleo de água produzida

Petroleum can be associated or not with natural gas, but in both cases water is always present in its formation. The presence of water causes several problems, such as the difficulty of removing the petroleum from the reservoir rock and the formation of waterin-oil and oil-in-water emulsions. The produced water causes environmental problems, which should be solved to reduce the effect of petroleum industry in the environment. The main objective of this work is to remove simultaneously from the produced water the dispersed petroleum and dissolved metals. The process is made possible through the use of anionic surfactants that with its hydrophilic heads interacts with ionized metals and with its lipophilic tails interacts with the oil. The studied metals were: calcium, magnesium, barium, and cadmium. The surfactants used in this research were derived from: soy oil, sunflower oil, coconut oil, and a soap obtained from a mixture of 5wt.% coconut oil and 95wt.% animal fat. It was used a sample of produced water from Terminal de São Sebastião, São Paulo. As the concentration of the studied metals in produced water presented values close to 300 mg/L, it was decided to use this concentration as reference for the development of this research. Molecular absorption and atomic absorption spectroscopy were used to determine petroleum and metals concentrations in the water sample, respectively. A constant pressure filtration system was used to promote the separation of solid and liquid phases. To represent the behavior of the studied systems it was developed an equilibrium model and a mathematical one. The obtained results showed that all used surfactants presented similar behavior with relation to metals extraction, being selected the surfactant derived from soy oil for this purpose. The values of the partition coefficients between the solid and liquid phases " D " for the studied metals varied from 0.2 to 1.1, while the coefficients for equilibrium model " K " varied from 0.0002 and 0.0009. The removal percentile for oil with all metals associated was near 100%, showing the efficiency of the process

Planejamento experimental aplicada a um novo separador líquido-líquido utilizado no tratamento de águas residuais contaminadas com petróleo

The present work had as objective to apply an experimental planning aiming at to improve the efficiency of separation of a new type of mixer-settler applied to treat waste water contaminated with oil. An unity in scale of laboratory, was installed in the Post-graduation Program of Chemical Engineering of UFRN. It was constructed in partnership with Petrobras S.A. This called device Misturador-Decantador a Inversão de Fases (MDIF) , possess features of conventional mixer-settler and spray column type. The equipment is composed of three main parts: mixing chamber; chamber of decantation and chamber of separation. The efficiency of separation is evaluated analyzing the oil concentrations in water in the feed and the output of the device. For the analysis one used the gravimetric method of oil and greases analysis (TOG). The system in study is a water of formation emulsified with oil. The used extractant is a mixture of Turpentine spirit hydro-carbons, supplied for Petrobras. It was applied, for otimization of the efficiency of separation of the equipment, an experimental planning of the composite central type, having as factorial portion fractionary factorial planning 2 5-2, with the magnifying of the type star and five replications in the central point. In this work, the following independents variables were studied: contents of oil in the feed of the device; volumetric ratio (O/A); total flowrate ; agitation in the mixing chamber and height of the organic bed. Minimum and maximum limits for the studied variables had been fixed according previous works. The analysis of variance for the equation of the empirical model, revealed statistically significant and useful results for predictions ends. The variance analysis also presented the distribution of the error as a normal distribution and was observed that as the dispersions do not depend on the levels of the factors, the independence assumption can be verified. The variation around the average is explained by 98.98%, or either, equal to the maximum value, being the smoothing of the model in relation to the experimental points of 0,98981. The results present a strong interaction between the variable oil contents in the feed and agitation in the mixing chamber, having great and positive influence in the separation efficiency. Another variable that presented a great positive influence was the height of the organic bed. The best results of separation efficiency had been obtained for high flowrates when associates the high oil concentrations and high agitation. The results of the present work had shown excellent agreement with the results carried out through previous works with the mixer-settler of phase inversion

Reciclagem de material asfáltico fresado utilizando solventes e microemulsões

With the increase of asphalt milling services was also a significant increase in recycling services pavements. The techniques used today are basically physical processes in which the milled material is incorporated into new asphalt mixtures or executed on site, with the addition of virgin asphalt and rejuvenating agent. In this paper seeks to analyze the efficiency of extraction of CAP (Petroleum Asphalt Cement) mixtures from asphalt milling, using commercial solvents and microemulsions. The solvents were evaluated for their ability to solubilize asphalt using an extractor reflux-type apparatus. Pseudoternary diagrams were developed for the preparation of microemulsion O/W surfactant using a low-cost coconut oil saponified (OCS). Microemulsions were used to extract the CAP of asphalt through physicochemical process cold. Analysis was performed concentration of CAP in solution by spectroscopy. The data provided in the analysis of concentration by the absorbance of the solution as the basis for calculating the percentage of extraction and the mass flow of the CAP in the solution. The results showed that microemulsions prepared with low concentration of kerosene and butanol/OCS binary has high extraction power of CAP and its efficiency was higher than pure kerosene, reaching 95% rate of extraction

Otimização do processo de recuperação do cromo de efluentes de curtumes por microemulsões no extrator Morris

The tanning industries are those which transform animal hide or skin into leather. Due to the complexity of the transformation process, greater quantities of chemicals are being used which results in the generation of effluents with residual solids. The chromium in the residual waters generated by tanning tend to be a serious problem to the environment, therefore the recovery of this metal could result in the reduction of manufacturing costs. This metal is usually found in a trivalent form which can be converted into a hexavalent compound under acidic conditions and in the presence of organic matter. The present study was carried out with the objective to recover chromium through an extraction/re-extraction process using micro emulsions. Micro emulsions are transparent and thermodynamically stable system composed of two immiscible liquids, one forming the continuous phase and the other dispersed into micro bubbles, established by an interfacial membrane formed by surface active and co-surface active molecules. The process of recovering the chromium was carried out in two stages. The first, an extraction process, where the chromium was extracted in the micro emulsion phase and the aqueous phase in excess was separated. In the second stage, a concentrated acid was added to the micro emulsion phase rich in chromium in order to obtain a Winsor II system, where the water that formed in the micro emulsion phase separates into a new micro emulsion phase with a higher concentration of chromium, due to the lowering of the hydrophiles as well as the ionisation of the system. During the experimental procedure, a study was initiated with a synthetic solution of chromium sulphate passing onto the effluent. A Morris extractor was used in the extraction process. Tests were carried out according to the plan and the results were analysed by statistical methods in order to optimise the main parameters that influence the process: the total rate of flow (Q), stirring speed (w) and solvent rate (r). The results, after optimization, demonstrated that the best percentuals in relation to the chromium extraction (99 %) were obtained in the following operational conditions: Q= 2,0 l/h, w= 425 rpm and r= 0,375. The re-extraction was carried out at room temperature (28 °C), 40 °C and 50°C using hydrochloric acid (8 and 10 M) and sulphuric acid (8 M) as re-extracting agents. The results obtained demonstrate that the process was efficient enough in relation to the chromium extraction, reaching to re-extraction percentage higher than 95 %.