Chicken meat may suffer rapid deterioration because of spoilage microorganisms. The type and number of microorganisms define quality of the product. Many stuidies show the use of slight acid electrolyzed water (sAEA) with high free clorine concentration (FCC) has been investigated to control and reduce the microbial growth of chiken meat. However sAEA with low levels of free clorine were not studied. In the current study, the stability of sAEA with low free clorine concentration and its application in chicken breast meat was assessed by evolution of microorganisms and lipid oxidation during storage. To acess the stability, sAEA with pH 6 and 10 mg/L of FCC was diluted for 2 and 5 mg/L and its oxidation-redution potential (ORP), pH and FCC were determining over 5 days of storage at 4 °C. The sAEA was applied in chicken breast meat by immersion and by the combination of spray and immersion to evaluate the shelf-life during storad 4 °C for 6 days. The shelf-life was evaluated by mesophilic and psychotrophic bacteria growth, pH value and lipi oxidation by TBARS levels. All of sAEA maintained their ORP, pH and FCC characteristics during the storage. The chicken breast meat showed varied initial number of microorganisms, which influence the redution promoted by sAEA treatment. Higher mesophilic bacteria number show lower redution by sAEA. In general, sAEA was more effective in reducing mesophilic than psychotrophic bacteria after treatment application. The chicken breast pH were not affected by sAEFA. However, anyone sAEA application mode increase the shelf-life of chicken breast meat. TBARS values were confuse, and further studies are necessary to clarify the sAEA action mechanism front lipid oxidation. | Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq | Devido à sua composição, a carne de frango pode sofrer rápida deterioração pela presença de microrganismos, sendo que o tipo e número de microrganismos definem a qualidade higiênico-sanitária do produto. O uso da água eletrolisada fracamente ácida (AEFA) com alta concentração de cloro livre tem sido investigado na redução da carga microbiana de frangos de corte, mas com baixa concentração não se tem relatos. Esse trabalho teve como objetivo avaliar a estabilidade e método de aplicação da AEFA com 2, 5 e 10 mg/L de cloro livre em peitos de frango, e acompanhar a evolução dos microrganismos deteriorantes e a oxidação dos lipídios durante o armazenamento refrigerado. Estudou-se a estabilidade da AEFA com pH 6,0 com 2, 5 e 10 mg/L de cloro livre, determinando o potencial de oxirredução (POR), pH e concentração de cloro livre (CCL) ao longo de 5 dias de armazenamento a 4 °C. As AEFAs foram aplicadas nos peitos de frango pelo método de imersão e pela combinação de spray e imersão para avaliação da vida-útil de peitos de frango armazenados a 4 °C durante 6 dias. A vida-útil foi acompanhada pelo crescimento de bactérias mesófilas e psicrotróficas, valor de pH e a evolução da oxidação lipídica foi acompanhada pelos níveis de TBARS. As AEFAs elaboradas mantiveram suas características de POR, pH e CCL durante o período de armazenamento estudado. Os peitos de frango apresentaram número inicial de microrganismos variado, o que influenciou na redução promovida pelo tratamento com AEFA, sendo que quanto maior a carga de bactérias mesófilas, menor a percentagem de redução promovida pela AEFA. Notou-se, em todos os métodos de aplicação, que a AEFA foi mais efetiva frente às bactérias mesófilas do que as psicrotróficas logo após a aplicação dos tratamentos, e que o pH dos peitos de frango não foram influenciados pela aplicação da AEFA. Entretanto, os diferentes tratamentos de AEFA aplicados não aumentaram o tempo de vida-útil dos peitos de frango, pois apresentaram carga microbiológica e pH considerados impróprios para o consumo no sexto dia de armazenamento. Mais estudos são necessários para esclarecer melhor o mecanismo de ação da AEFA frente às reações de oxidação lipídica

Se presenta un método para la descontaminación de aguas contaminadas por fungicidas. El método se basa en una reacción de oxidación catalítica para el tratamiento de derivados de los tiocarbamatos, seguida por adsorción mediante carbón activo granular. Se presentan rendimientos superiores al 94% en DQO

Spray application of electrolysed water (EW) different types was studied with objective of verify effects in bacterial growth, lipid and protein oxidation, also color. Temperature (18 and 30°C) and applied volume of water (100 and 200 mL of EW to 250 g of pork loin), as well pressure (30 and 45 psi) was tested variables in six experiments. From the beginning the experiments was based in water and energy saving, grounded in resources saving. Acid electrolysed water (AEW), slightly acid electrolised water (SAEW) and basic electrolysed water (BEW) was applied individual, and had less effect than alternate (BEW +AEW and BEW+SAEW) applications regarding mesophylls, lactic acid bacterias, Enterobacteriaceaes, with little effect on psychrotrophics. Lactic acid bacterias growth was favored in vacuum environment and interfered on meat pH, while EW treatments had no interferences in meat pH along six experiments. Bacterial effects of different EW types and combinations presented decrease tendencies until 15th storage day. Along storage BEW + AEW and BEW + SAEW at 45 psi was more significant in reduce bacterias than individual treatments. Still, EW temperature had no influence in results of realized analysis. Lipid oxidation with AEW and SAEW was higher than BEW that had values according to control. When AEW and SAEW was applied in alternate form, the application of BEW applied first provided fats and protein protection from AEW and SAEW attack, and this fact don t occurred when EW was individually applied. Color had no significant changes for individual EW applications, but in alternate applications, 45 psi promote little changes in color. Correlations with carbonyl and thiol indicated protecin oxidation evolution in pig meat long storage period in all experiments. Redo x potential demonstrated be a good analysis that can be contributed to comprehension of oxidative aspect of meat. Hexanal was more detected in BEW + AEW than BEW +SAEW in storage time. Different types of EW spraying application can be a good alternative with use potential and decrease quantity of utilized water, being alternate form of application more advantageous than individual application about quality attributes of pig meat, like bacterias and physic-chemical. | Coordenação de Aperfeiçoamento de Pessoal de Nível Superior | A aplicação na forma de spray de diferentes tipos de água eletrolisada (AE) foi estudada com o objetivo de verificar seus efeitos no desenvolvimento de bactérias, na oxidação de lipídios e proteínas, e também na cor. A temperatura (18°C e 30°C) e o volume aplicado (100 e 200 ml em 250 g de lombo suíno) das AE, bem como a pressão (30 psi e 45 psi) foram variáveis testadas em seis experimentos. Os experimentos desde o princípio tiveram como base a economia de água e energia, fundamentados na economia de recursos. A água eletrolisada ácida (AEA), água eletrolisada fracamente ácida (AEFA) e água eletrolisada básica (AEB) foram aplicadas de maneira individual, e tiveram menor efeito do que a aplicação das AE de maneira alternadas (AEB + AEA e AEB + AEFA) em mesófilos, bactérias lácticas, Enterobacteriaceaes, com pouco efeito em bactérias psicrotróficas. As bactérias lácticas tiveram crescimento favorecido em ambiente à vácuo e interferiram no pH da carne, enquanto os tratamentos com AE não interferiram no pH da carne em todos os experimentos. O efeito frente às bactérias dos diferentes tipos e combinações de AE apresentaram a tendência de diminuir até o dia 15 de armazenamento. Ao longo do tempo de armazenamento a aplicação de AEB + AEA e AEB + AEFA em 45 psi foram mais significativos em manter a redução das bactérias do que os tratamentos individuais. Ainda, a temperatura da AE aplicada não pareceu influenciar nos resultados das análises realizadas. Ocorreu maior evolução da oxidação lipídica com AEA e AEFA, enquanto com a AEB os valores ficaram mais próximos ao controle. Quando AEA e AEFA foram aplicadas de forma alternada, a AEB ao ser aplicada primeiro proporcionou proteção à gorduras e às proteínas do ataque da AEA e AEFA, fato este que não ocorreu quando estas foram aplicada de maneira individual. O atributo cor não foi alterado de maneira significativa pelos diferentes tipos de AE individuais, mas em aplicações alternadas a pressão de 45 psi promoveu pequena alteração na cor. Correlações entre o tiol e o carbonil indicaram a evolução da oxidação proteica na carne suína durante o período de armazenamento em todos os experimentos realizados. O potencial redox (POR) demonstrou ser uma análise que pode contribuir para compreensão do aspecto oxidativo da carne. O hexanal foi mais detectado na combinação de AEB + AEA do que AEB + AEFA no tempo de armazenamento. A aplicação de spray de diferentes tipos de AE mostrou-se uma alternativa com potencial de uso e redução de quantidade de água utilizada, sendo a forma alternada de aplicação mais vantajosa do que a aplicação individual sobre atributos de qualidade da carne de porco, como bactérias e físico-química.

The Agua Negra drainage system (30 12'S, 69 50' W), in the Argentine Andes holds several ice- and rock-glaciers, which are distributed from 4200 up to 6300 m a.s.l. The geochemical study of meltwaters reveals that ice-glaciers deliver a HCO₃⁻----Ca²⁺ solution and rock-glaciers a SO₄²⁻----HCO₃⁻----Ca²⁺ solution. The site is presumably strongly influenced by sublimation and dry deposition. The main processes supplying solutes to meltwater are sulphide oxidation (i.e. abundant hydrothermal manifestations), and hydrolysis and dissolution of carbonates and silicates. Marine aerosols are the main source of NaCl. The fine-grained products of glacial comminution play a significant role in the control of dissolved minor and trace elements: transition metals (e.g. Mn, Zr, Cu, and Co) appear to be selectively removed from solution, whereas some LIL (large ion lithophile) elements, such as Sr, Cs, and major cations, are more concentrated in the lowermost reach. Daily concentration variation of dissolved rare earth elements (REE) tends to increase with discharge. Through PHREEQC inverse modelling, it is shown that gypsum dissolution (i.e. sulphide oxidation) is the most important geochemical mechanism delivering solutes to the Agua Negra drainage system, particularly in rock-glaciers. At the lowermost reach, the chemical signature appears to change depending on the relative significance of different meltwater sources: silicate weathering seems to be more important when meltwater has a longer residence time, and calcite and gypsum dissolution is more conspicuous in recently melted waters. A comparison with a non-glacierized semiarid drainage of comparable size shows that the glacierized basin has a higher specific denudation, but it is mostly accounted for by relatively soluble phases (i.e. gypsum and calcite). Meltwater chemistry in glacierized arid areas appears strongly influenced by sublimation/evaporation, in contrast with its humid counterparts.

Bacterial cellulose films synthesized by Komagataeibacter xylinus were combined with glycerol and chitosan to obtain composite films with improved UV-barrier. In part 2, the interaction among the compounds was analyzed by scanning electron microscopy, UV-Vis and FT-IR spectra, thermogravimetry, and differential scanning calorimetry. The water permeability, water solubility and water retention capacity were analyzed by response surface methodology. The optical properties indicated that glycerol and chitosan improved the UV-barrier properties, obtaining average transmittance values in the UV regions below 5.15%. This fact opens multiple possibilities for applications in foods and products sensitive to sunlight radiation. Hence, these properties would facilitate the application of BC–glycerol–chitosan films on fresh food, with high moisture content and susceptible to oxidation by the sunlight radiation. In addition, the thermal properties of the films showed that they could be applied in heat-treated foods at temperatures until 135°C.

Stainless steel AISI 316 was coated with aluminum-silicon by Chemical Vapor Deposition in Fluidized Bed Reactor (CVD-FBR) to 540°C and subsequently heat treated to improve its mechanical properties and its behavior against oxidation, by inter diffusion of the alloying elements. Later, oxidation was performed austenitic stainless steel aluminum-silicon coated at temperatures of 700 and 750°C, in an environment with 100% steam, to evaluate their performance. Mass gain graphs were made and oxide films were analyzed by SEM and X-ray diffraction to observe the morphology of the oxides. Thermodynamic simulation was carried out during oxidation in water vapor of the substrates for possible solid phases which could be formed. The form of attack at 750°C is similar to 700°C, although the rate of oxidation is increased, because the diffusion of the alloying elements and the oxidation reactions are faster. These coatings have good resistance to oxidation in water vapor and forming an alumina surface layer which protects the substrate from corrosion attack.

Small quantities of groundwater interact with hydrothermal surface water to drive in-stream geochemical processes in a silica-armored hot-spring outflow channel in Yellowstone National Park, USA. The objective of this study was to characterize the hydrology and geochemistry of this unique system in order to (1) learn more about the Yellowstone Plateau’s subsurface water mixing between meteoric and hydrothermal waters and (2) learn more about the chemical and physical processes that lead to accumulation of streambed cements, i.e., streambed armor. A combination of hydrological, geochemical, mineralogical, microscopic, and petrographic techniques were used to identify groundwater and surface-water exchange. Interaction could be identified in winter because of differences in surface water and groundwater composition but interaction at other times of the year cannot be ruled out. Dissolved constituents originating from groundwater (e.g., Fe(II) and Mg) were traced downstream until oxidation and/or subsequent precipitation with silica removed them, particularly where high affinity substrates like cyanobacterial surfaces were present. Because the stream lies in a relatively flat drainage basin and is fed mainly by a seasonally relatively stable hot spring, this system allowed study of the chemical processes along a stream without the obscuring effects of sedimentation.

A grande preocupação em estações de tratamento de água atualmente se deve a escolhas de tecnologias de tratamento inadequadas em relação às características do manancial de água explorado. Vários estudos têm mostrado que os processos que envolvem o tratamento por ciclo completo não são efetivos na eliminação dos efeitos gerados pela presença de algas e seus sub-produtos. A dupla filtração, tecnologia que emprega a filtração ascendente seguida de filtração rápida descendente, vem sendo muito estudada e utilizada no Brasil, principalmente para o tratamento de águas com altas concentrações de algas. O presente trabalho teve, como objetivo principal, verificar o tratamento da água do reservatório UHE Lajeado da cidade de Palmas-TO, utilizando a dupla filtração, a oxidação com cloro e a adsorção com carvão ativado pulverizado, visando principalmente à remoção de algas e possíveis subprodutos da oxidação. Para realização da pesquisa, foi montada uma instalação piloto de dupla filtração, composta pelas unidades de pré-cloração, adsorção em carvão ativado pulverizado, filtro ascendente em pedregulho e filtro rápido descendente de areia. Os filtros de pedregulho e de areia trabalharam com taxas de filtração de 120 e 180 m³/m².d, respectivamente. A água bruta utilizada no estudo apresentava concentrações de cianobactérias acima de 105 cel/mL. Os resultados encontrados mostraram que o sistema foi capaz de produzir água potável, atendendo aos padrões da portaria 518 do Ministério da Saúde, obtendo-se valores de turbidez na saída do filtro de areia sempre abaixo de 0,50 uT. Em todos os ensaios realizados houve remoção de cianobactérias e de clorofila-a acima de 99,0%, sendo que os filtros de pedregulho e de areia foram os principais responsáveis por esta remoção. O uso do carvão ativado pulverizado incrementou a remoção do carbono orgânico total. Não houve formação significativa dos subprodutos da desinfecção no efluente do filtro de areia, ficando os valores encontrados muito abaixo do máximo permitido pelas legislações brasileira e internacional. | One problem that frequently arises in water treatment plants is the inadequacy of the chosen treatment processes with respect to the source water quality. Several studies have shown that processes encompassing conventional water treatment have limited capability to remove compounds associated with algae and their by-products. In Brazil, a technology known as two-stage filtration has been studied and applied to the treatment of waters with high algae concentrations. The process employs two separated filters operated in sequence in the modes up and downflow. This research investigated the application of this technology, associated with chlorine oxidation and powdered activated carbon adsorption, for algae removal using water taken from UHE Lajeado, city of Palmas, TO. Also, the technology was applied for removal of potential by-products formed by reactions between chlorine and organic matter present in water. In order to carry out the research, a pilot installation was assembled. It was constituted by pre-oxidation and carbon adsorption columns, rapid-mix tank, and two-stage filtration. The gravel and sand filters operated up and downflow in sequence, with filtration rates of 120 and 180 m³/m².d, respectively. The input water had cyanobacteria concentrations higher than 105 cel/mL The observed results showed the pilot plant produced water in accordance with Brazilian standards, having turbidity levels lower than 0,5 uT. In all tests, cyanobacteria and chlorophyll removals were above 99% and the retention was achieved mostly by the gravel and sand filters. The use of powdered activated carbon caused an increase in the TOC removal. There was limited formation of by-products and those that were detected presented concentrations below international and Brazilian standards.

Devido à falta de informações técnicas sobre o tratamento de águas residuárias utilizando o sistema de aeração em cascatas, objetivou-se com a realização deste trabalho estudar o desempenho desse sistema no tratamento de águas residuárias da lavagem e descascamento/despolpa dos frutos do cafeeiro (ARC). Além disso, procurou-se determinar o coeficiente de eficiência associado à aeração em cascatas, avaliar a incorporação de oxigênio dissolvido e a capacidade do sistema em remover matéria orgânica, macronutrientes (nitrogênio, fósforo e potássio) e compostos fenólicos da ARC. O experimento foi implantado e conduzido na Área Experimental de Tratamento de Resíduos do Departamento de Engenharia Agrícola da Universidade Federal de Viçosa. O sistema de aeração em cascatas foi instalado em um talude com inclinação de 30° e com uma diferença de nível de 4,14 m. A cascata foi composta de 23 degraus, com altura, largura e comprimento de 0,18; 0,32 e 0,60 m, respectivamente. No final da cascata foi instalado um reservatório, com 2 m3 de volume, denominado recepção/detenção da ARC escoada na escada. Após ser submetida a um tempo de detenção de 3 horas, a ARC era transferida para outro reservatório denominado tanque de recirculação , de onde era recalcada para nova recirculação na cascata. Essa recirculação era feita 3 vezes ao dia e sob vazão constante de 1 L s-1. Durante os 30 dias de operação do sistema de tratamento foram utilizadas amostras de ARC coletadas em 3 diferentes ocasiões e, a cada 10 dias de operação do sistema, as mesmas eram trocadas. O experimento foi instalado seguindo um delineamento em blocos casualizados, esquema de parcelas subdivididas no tempo, consistindo de 3 blocos (3 amostras de ARC). Em relação à variável DBO, foram avaliados 6 tratamentos principais (locais de coleta da ARC na cascata) e 4 tratamentos secundários (tempo de recirculação da ARC: 0, 3, 6 e 9 dias), totalizando 72 unidades experimentais. No que se refere à análise das alterações na variável DQO, foram avaliados 6 tratamentos principais (locais de coleta da ARC na cascata) e 10 tratamentos secundários (tempo de recirculação: 0, 1, 2, 3, 4, 5, 6, 7, 8 e 9 dias), totalizando 180 unidades experimentais. Nesse caso, as unidades experimentais foram constituídas por amostras coletadas em cada dia, nos pontos pré-estabelecidos. Para estudar o decaimento da concentração de oxigênio dissolvido em função do tempo no tanque de recepção/detenção, um experimento à parte foi realizado em delineamento inteiramente casualizado com 6 repetições e 15 tratamentos (0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 minutos). Nessa avaliação, as unidades experimentais foram as alíquotas de ARC amostradas a cada 2 minutos. Com a utilização do sistema de aeração em cascatas foi possível incorporar, em média, 0,2 mg L-1 de oxigênio a cada lance de 1 m de degraus na cascata. A máxima porcentagem de saturação de oxigênio na ARC foi de 19,4%, tendo sido obtida com o escoamento em lance de escada de 4 m. A alta concentração de material orgânico não permitiu que se detectassem grandes alterações na concentração de oxigênio dissolvido na ARC. O sistema constituído pela cascata de aeração apresentou coeficiente de eficiência de 0,078. O tempo de detenção ideal no tanque de recepção/detenção foi de 26 minutos. O sistema em operação proporcionou eficiência na remoção média de DQO de 28,9%. As remoções de sólidos totais, sólidos voláteis totais; sólidos suspensos totais, sólidos suspensos voláteis, nitrogênio total, fósforo total, potássio total e compostos fenólicos foram de 57,3; 71,6; 26,5; 17,2; 35,7; 62,5; 49,5 e 55,0%, respectivamente. A cascata de aeração mostrou ser uma importante alternativa para composição de sistemas de tratamento da ARC, tendo em vista que é um meio efetivo de tratamento aeróbio do material orgânico em suspensão. | Due to lack of technical information on the treatment of wastewater using cascade aeration systems, this work aimed to study the performance of this system in the treatment of the wastewater from washing and stripping/pulping coffee (CW). In addition, it sought to determine the coefficient of efficiency associated with cascade aeration system, evaluate the incorporation of dissolved oxygen and the system s ability to remove organic matter, nutrients (nitrogen, phosphorus and potassium) and phenolic compounds from CW. The experiment was assembled and conducted in the Waste Management Experimental Area of the Agricultural Engineering from the Federal University of Viçosa. The cascade aeration system was installed in a slope with an inclination of 30° and with a level difference of 4.14 m. The cascade consisted of 23 steps, with height, width and length of 0.18; 0.32 and 0.60 m respectively. At the end of the cascade was installed a container with 2 m³ volume. It was called reception/detention of the CW disposed on the ladder. After a detention time of 3 hours, the CW was transferred to another tank, called recirculation tank, where it was pumped for further recycling in the cascade. This recirculation was done three times a day and under constant flow rate of 1 L s-1. During the 30 days of operation of the treatment system it was used samples of CW collected at three different occasions and it was changed every 10 days of system. The experiment was conducted following a randomized block design, split plot in time, consisting of 3 blocks (3 samples CW). Regarding to the variable BOD, it was evaluated six main treatments (location in the cascade of CW) and four secondary treatments (recirculation time of CW: 0, 3, 6 and 9 days), totalizing 72 experimental units. As regards the analysis of changes in variable COD, it was evaluated six main treatments (location in the cascade of CW) and 10 secondary treatments (recirculation time: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 days), totaling 180 experimental units. In this case, the experimental units were composed of samples collected each day, in pre-set points. To study the decay of dissolved oxygen concentration versus time in the receiving/holding tank , another experiment was conducted in a randomized design with 6 replications and 15 treatments (0, 2, 4, 6, 8, 10, 12 , 14, 16, 18, 20, 22, 24, 26, 28 minutes). In this evaluation, the experimental units were the rates of CW sampled every 2 minutes. With the cascade aeration system it was possible to incorporate an average of 0.2 mg L-1 of oxygen at each meter of stairs. The maximum percentage of oxygen saturation in the CW was 19.4% and it was obtained at flight of stairs at 4 m. The high concentration of organic material did not allow it to detect major changes in the concentration of dissolved oxygen in the CW. The system consisting of cascade aeration coefficient for efficiency of 0.078. The detention time in the tank for ideal reception/detention was 26 minutes. The system in operation provided average removal efficiency of COD was 28.9%. The removals of total solids, volatile solids, total suspended solids, volatile suspended solids, total nitrogen, total phosphorus, potassium and total phenolic compounds were 57.3; 71.6; 26.5; 17.2; 35.7; 62.5; 49.5 and 55.0% respectively. The cascade aeration proved to be an important alternative for the composition of treatment systems of CW, considering it is a very effective aerobic treatment of suspended organic material. | Conselho Nacional de Desenvolvimento Científico e Tecnológico

Selenium (Se) is an essential micro-nutrient for humans, but can be toxic at high levels of intake. Se deficiency and Se toxicity are linked with serious diseases, with some regions worldwide experiencing Se deficiency due to Se-poor rocks and soils and other areas dealing with Se toxicity due to the presence of Se-enriched geologic materials. In addition, Se is consumed primarily through plants that take up Se from soil and through animal products that consume these plants. Hence, the soil and groundwater system play important roles in determining the effect of Se on human health. This paper reviews current understanding of Se fate and transport in soil and groundwater systems and its relation to human health, with a focus on alluvial systems, soil systems, and the interface between alluvial systems and Cretaceous shale that release Se via oxidation processes. The review focuses first on the relation between Se and human health, followed by a summary of Se distribution in soil-aquifer systems, with an emphasis on the quantitative relationship between Se content in soil and Se concentration in underlying groundwater. The physical, chemical, and microbial processes that govern Se fate and transport in subsurface systems then are presented, followed by numerical modeling techniques used to simulate these processes in study regions and available remediation strategies for either Se-deficient or Se-toxic regions. This paper can serve as a guide to any field, laboratory or modeling study aimed at assessing Se fate and transport in groundwater systems and its relation to human health.