943 resultados para Sewage and anaerobic reactor effluent


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We report on measurements of neutrino oscillation using data from the T2K long-baseline neutrino experiment collected between 2010 and 2013. In an analysis of muon neutrino disappearance alone, we find the following estimates and 68% confidence intervals for the two possible mass hierarchies: Normal Hierarchy: sin²θ₂₃= 0.514+0.055−0.056 and ∆m²_32 = (2.51 ± 0.10) × 10⁻³ eV²/c⁴ Inverted Hierarchy: sin²θ₂₃= 0.511 ± 0.055 and ∆m²_13 = (2.48 ± 0.10) × 10⁻³ eV²/c⁴ The analysis accounts for multi-nucleon mechanisms in neutrino interactions which were found to introduce negligible bias. We describe our first analyses that combine measurements of muon neutrino disappearance and electron neutrino appearance to estimate four oscillation parameters, |∆m^2|, sin²θ₂₃, sin²θ₁₃, δCP , and the mass hierarchy. Frequentist and Bayesian intervals are presented for combinations of these parameters, with and without including recent reactor measurements. At 90% confidence level and including reactor measurements, we exclude the region δCP = [0.15, 0.83]π for normal hierarchy and δCP = [−0.08, 1.09]π for inverted hierarchy. The T2K and reactor data weakly favor the normal hierarchy with a Bayes Factor of 2.2. The most probable values and 68% 1D credible intervals for the other oscillation parameters, when reactor data are included, are: sin²θ₂₃= 0.528+0.055−0.038 and |∆m²_32| = (2.51 ± 0.11) × 10⁻³ eV²/c⁴.

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A novel protein superfamily with over 600 members was discovered by iterative profile searches and analyzed with powerful bioinformatics and information visualization methods. Evidence exists that these proteins generate a radical species by reductive cleavage of S-adenosylmethionine (SAM) through an unusual Fe-S center. The superfamily (named here Radical SAM) provides evidence that radical-based catalysis is important in a number of previously well- studied but unresolved biochemical pathways and reflects an ancient conserved mechanistic approach to difficult chemistries. Radical SAM proteins catalyze diverse reactions, including unusual methylations, isomerization, sulfur insertion, ring formation, anaerobic oxidation and protein radical formation. They function in DNA precursor, vitamin, cofactor, antibiotic and herbicide biosynthesis and in biodegradation pathways. One eukaryotic member is interferon-inducible and is considered a candidate drug target for osteoporosis; another is observed to bind the neuronal Cdk5 activator protein. Five defining members not previously recognized as homologs are lysine 2,3-aminomutase, biotin synthase, lipoic acid synthase and the activating enzymes for pyruvate formate-lyase and anaerobic ribonucleotide reductase. Two functional predictions for unknown proteins are made based on integrating other data types such as motif, domain, operon and biochemical pathway into an organized view of similarity relationships.

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A concentração demográfica e de sistemas coletivos de esgotamento sanitário dentro do perímetro urbano da maioria dos municípios brasileiros, dificulta a viabilização do fornecimento de serviços de tratamento de esgotos domésticos à habitações e núcleos habitacionais isolados situados em áreas periurbanas e rurais, intensificando os danos provocados pela poluição de origem antrópica ao meio ambiente e à preservação da saúde pública. Para contribuir no equacionamento deste problema, o presente estudo teve por finalidade avaliar uma wetland construída híbrida em escala real, composta por uma unidade com fluxo contínuo subsuperficial vertical seguida por uma unidade de fluxo contínuo subsuperficial horizontal, cultivadas com capim Vetiver, para o tratamento de efluente proveniente de tanque séptico. A presente configuração experimental busca uma solução de baixo custo e simplificada para o tratamento descentralizado de esgotos domésticos. A estação experimental de tratamento de esgotos, parte integrante e um dos produtos da Rede Nacional de Tratamento de Esgotos Descentralizados RENTED, foi construída no Centro Tecnológico de Hidráulica CTH / Escola Politécnica EPUSP, campus Butantã da USP, em São Paulo. O esgoto bruto foi proveniente do Conjunto Residencial da USP e do restaurante central da Cidade Universitária. As vazões média e máxima de esgoto bruto, respectivamente, de 640L.d-1 e 1600L.d-1, foram aplicadas à entrada do TS de 5.000L e deste escoaram por gravidade à entrada da wetland construída híbrida, com TDH total de 2,8d e 1,1d, respectivamente, sob aplicação das vazões média e máxima de projeto. O monitoramento do experimento em campo, incluindo o período inicial de partida, durou 6 meses consecutivos. Foram avaliados os parâmetros físico-químicos e microbiológicos do esgoto bruto e do efluente do tanque séptico e das câmaras da wetland construída híbrida durante 97 dias consecutivos. Os resultados indicaram que tanto as mudas jovens quanto as adultas de capim Vetiver adaptaram-se bem às condições ambientais. As eficiências médias de remoção no efluente tratado final quanto à matéria orgânica carbonácea foram de 96 por cento para DBO5,20 e 90 por cento para DQO, 40 por cento para N-total, 23 por cento para N-amoniacal total, 60 por cento para P-total, 52 por cento para P-PO4, 74 por cento para SST, 96 por cento para SSV, 75 por cento para sólidos sedimentáveis, 44 por cento para SDV, 88 por cento para sulfeto total, e 97 por cento para óleos e graxas totais, variando entre 73 por cento a 100 por cento . Cerca de 80 por cento da fração orgânica da matéria nitrogenada presente no esgoto bruto foi removida. A remoção de coliformes termotolerantes foi, em média, de 2 e 3 unidades log, e de Escherichia Coli, média de 1 e 3 unidades log, respectivamente, sob aplicação das vazões máxima e média, Giardia sp, média de 99,995 por cento , Cryptosporidium sp, média de 98,7 por cento , Enterovírus, média de 99,6 por cento , e Ascaris sp, média de 0,10 ovo/L. A remoção de sulfetos propiciou a geração de efluente tratado sem odores desagradáveis. A diminuição da vazão aplicada e a elevação do TDH influenciaram positivamente no desempenho do sistema com relação às remoções dos parâmetros físico-químicos e microbiológicos. Com base no presente estudo, ficou evidente o benefício da associação de wetlands construídas com fluxo vertical e horizontal no tratamento de efluente de tanque séptico. O capim Vetiver apresentou bom potencial de utilização em wetlands 8 construídas para tratamento de esgotos domésticos. O sistema experimental de tratamento apresentou flexibilidade operacional, mantendo bom desempenho inclusive nos períodos de sobrecarga. A qualidade do efluente tratado final obtido no presente estudo atende às exigências de lançamento e aos padrões de emissão de efluentes líquidos em corpos dágua e em sistemas públicos de esgotamento sanitário definidos na legislação ambiental federal e do Estado de São Paulo. A tecnologia de wetlands construídas híbridas associada ao tratamento de efluentes de tanque séptico apresentou bom potencial para o tratamento descentralizado de esgotos domésticos, inclusive em regiões com pouca disponibilidade de área livre.

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O fenômeno conhecido como Nitrificação e Desnitrificação Simultânea (SND) significa que em um mesmo reator ocorre simultaneamente a nitrificação e a desnitrificação, sob condições de operações idênticas, podendo ser justificada principalmente pela teoria de microambiente no floco ou biofilme. Assim, em um único reator, sob condições controladas de oxigênio dissolvido (OD) e elevados tempos de residênciacelular épossível que ocorra a nitrificação e a criação de zonas anóxicas no interior dos flocos ou biofilme para a ocorrência da desnitrificação. Neste sentido, a tecnologia MBBR/IFAStem como característicaelevado tempo de residência celular do biofilme formado nos meios suporte presentes no reator. Deste modo, neste estudo avaliou-se a remoção de nitrogênio via SND em um sistema IFAS quando submetido a diferentes concentrações de OD e Tempo de DetençãoHidraulica de 5,5 e 11 horas, tratando efluente sanitário e efluente sintético. Os resultados experimentais demonstraram que pode ser possível desenvolver efetiva SND com concentrações de OD média de 1,0 mg.L-1 e 1,5 mg.L-1. Sendo que, foram obtidas eficiência média de remoção de NTde cerca de 68% e concentrações médias efluente de N-NH4 de aproximadamente 5,0 mg L-1, de N-NO3 inferiores a 4,5 mg L-1 e de N-NO2 em torno de 0,1 mg L-1, e com eficiência média de remoção DQO solúvel acima de 90%, quando empregado efluente sintético. Ademais, por meio da avaliação da emissão de Óxido Nitroso (N2O), foi possível comprovar que a desnitrificação ocorreu de forma efetiva.

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Mode of access: Internet.

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Acetohydroxy acid synthases (AHAS) are thiamin diphosphate- (ThDP-) and FAD-dependent enzymes that catalyze the first common step of branched-chain amino acid biosynthesis in plants, bacteria, and fungi. Although the flavin cofactor is not chemically involved in the physiological reaction of AHAS, it has been shown to be essential for the structural integrity and activity of the enzyme. Here, we report that the enzyme-bound FAD in AHAS is reduced in the course of catalysis in a side reaction. The reduction of the enzyme-bound flavin during turnover of different substrates under aerobic and anaerobic conditions was characterized by stopped-flow kinetics using the intrinsic FAD absorbance. Reduction of enzyme-bound FAD proceeds with a net rate constant of k' = 0.2 s(-1) in the presence of oxygen and approximately 1 s(-1) under anaerobic conditions. No transient flavin radicals are detectable during the reduction process while time-resolved absorbance spectra are recorded. Reconstitution of the binary enzyme-FAD complex with the chemically synthesized intermediate 2-(hydroxyethyl)-ThDP also results in a reduction of the flavin. These data provide evidence for the first time that the key catalytic intermediate 2-(hydroxyethyl)ThDP in the carbanionic/enamine form is not only subject to covalent addition of 2-keto acids and an oxygenase side reaction but also transfers electrons to the adjacent FAD in an intramolecular redox reaction yielding 2-acetyl-ThDP and reduced FAD. The detection of the electron transfer supports the idea of a common ancestor of acetohydroxy acid synthase and pyruvate oxidase, a homologous ThDP- and FAD-dependent enzyme that, in contrast to AHASs, catalyzes a reaction that relies on intercofactor electron transfer.

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Five rates (0, 28.0, 65.4, 83.7 and 111.7 mm) of dairy effluent were applied through irrigation to tropical grass pasture during the wet season on the Atherton Tablelands in the Far North of Queensland, Australia. Irrigation water was applied to the treatments in inverse proportion to the effluent for equivalent total water application. Pastures were harvested on a three weekly basis, dry matter yield determined and sub samples analysed for N concentration (%), and Nitrogen yield (kg ha-1) calculated. Lysimeters installed in the high effluent treatment and the no effluent treatment measured leachate volume to 50 cm. Samples of leachate were analysed for nitrogen concentration and loss below 50 cm calculated. There was no significant difference in pasture yield and nitrogen yield among treatments. Loss of nitrogen through leachate was substantial in both the high effluent treatment and the zero effluent treatment.

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AIMS: To investigate the influence of chemical and physical factors on the rate and extent of germination of Clostridium difficile spores. METHODS AND RESULTS: Germination of C. difficile spores following exposure to chemical and physical germinants was measured by loss of either heat or ethanol resistance. Sodium taurocholate and chenodeoxycholate initiated germination together with thioglycollate medium at concentrations of 0.1-100 mmol l(-1) and 10-100 mmol l(-1) respectively. Glycine (0.2% w/v) was a co-factor required for germination with sodium taurocholate. There was no significant difference in the rate of germination of C. difficile spores in aerobic and anaerobic conditions (P > 0.05) however, the initial rate of germination was significantly increased at 37 degrees C compared to 20 degrees C (P < 0.05). The optimum pH range for germination was 6.5-7.5, with a decreased rate and extent of germination occurring at pH 5.5 and 8.5. CONCLUSIONS: This study demonstrates that sodium taurocholate and chenodeoxycholate initiate germination of C. difficile spores and is concentration dependant. Temperature and pH influence the rate and extent of germination. SIGNIFICANCE AND IMPACT OF THE STUDY: This manuscript enhances the knowledge of the factors influencing the germination of C. difficile spores. This may be applied to the development of potential novel strategies for the prevention of C. difficile infection.

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A review of the literature of work carried out on dextransucrase production, purification, immobilization and reactions has been carried out. A brief review has also been made of the literature concerning general enzyme biotechnology and fermentation technology. Fed-batch fermentation of the bacteria Leuconostoc mesenteroides NRRL B512 (F) to produce dextransucrase has formed the major part of this research. Aerobic and anaerobic fermentations have been studied using a 16 litre New Brunswick fermenter which has a 3-12 litre working volume. The initial volume of broth used in the studies was 6 litres. The results of the fed-batch fermentations showed for the first time that yields of dextransucrase are much higher under the anaerobic conditions than during the aerobic fermentations. Dextransucrase containing 300-350 DSU/cm3 of enzyme activity has been obtained during the aerobic fermentations, while in the anaerobic fermentations, enzyme yields containing 450-500 DSU/cm3 have been obtained routinely. The type of yeast extract used in the fermentation medium has been found to have significant effects on enzyme yield. Of the different types studied, the Gistex Standard was found to be the type that favoured the highest enzyme production. Studies have also been carried out on the effect of agitation rate and antifoam on the enzyme production during the anaerobic experiments. Agitation rates of up to 600 rpm were found not to affect the enzyme yield, however, the presence of antifoam in the medium led to a significant reduction in enzyme activity (less than 300 DSU/cm3). Scale-up of the anaerobic fermentations has been performed at up to the 1000 litre level with enzyme yields containing more than 400 DSU/cm3 of activity being produced. Some of the enzyme produced at this scale was used for the first time to produce dextran on an industrial scale via the enzyme route, with up to 99% conversion of sucrose to dextran being obtained. An attempt has been made at continuous dextransucrase production. Cell washout was observed to occur at dilution rates of greater than 0.4 h-1. Dextransucrase containing up to 25 DSU/cm3/h has been produced continuously.

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The objective of this study was to design, construct, commission and operate a laboratory scale gasifier system that could be used to investigate the parameters that influence the gasification process. The gasifier is of the open-core variety and is fabricated from 7.5 cm bore quartz glass tubing. Gas cleaning is by a centrifugal contacting scrubber, with the product gas being flared. The system employs an on-line dedicated gas analysis system, monitoring the levels of H2, CO, CO2 and CH4 in the product gas. The gas composition data, as well as the gas flowrate, temperatures throughout the system and pressure data is recorded using a BBC microcomputer based data-logging system. Ten runs have been performed using the system of which six were predominantly commissioning runs. The main emphasis in the commissioning runs was placed on the gas clean-up, the product gas cleaning and the reactor bed temperature measurement. The reaction was observed to occur in a narrow band, of about 3 to 5 particle diameters thick. Initially the fuel was pyrolysed, with the volatiles produced being combusted and providing the energy to drive the process, and then the char product was gasified by reaction with the pyrolysis gases. Normally, the gasifier is operated with reaction zone supported on a bed of char, although it has been operated for short periods without a char bed. At steady state the depth of char remains constant, but by adjusting the air inlet rate it has been shown that the depth of char can be increased or decreased. It has been shown that increasing the depth of the char bed effects some improvement in the product gas quality.

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Biomass pyrolysis to bio-oil is one of the promising sustainable fuels. In this work, relation between biomass feedstock element characteristic and crude bio-oil production yield and lower heating value was explored. The element characteristics considered in this study include moisture, ash, fix carbon, volatile matter, C, H, N, O, S, cellulose, hemicellulose, and lignin content. A semi-batch fixed bed reactor was used for biomass pyrolysis with heating rate of 30 °C/min from room temperature to 600 °C and the reactor was held at 600 °C for 1 h before cooling down. Constant nitrogen flow (1bar) was provided for anaerobic condition. Sago and Napier glass were used in the study to create different element characteristic of feedstock by altering mixing ratio. Comparison between each element characteristic to crude bio-oil yield and low heating value was conducted. The result suggested potential key element characteristic for pyrolysis and provide a platform to access the feedstock element acceptance range.

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Biomass pyrolysis to bio-oil is one of the promising sustainable fuels. In this work, relation between biomass feedstock element characteristic and pyrolysis process outputs was explored. The element characteristics considered in this study include moisture, ash, fix carbon, volatile matter, carbon, hydrogen, nitrogen, oxygen, and sulphur. A semi-batch fixed bed reactor was used for biomass pyrolysis with heating rate of 30 °C/min from room temperature to 600 °C and the reactor was held at 600 °C for 1 h before cooling down. Constant nitrogen flow rate of 5 L/min was provided for anaerobic condition. Rice husk, Sago biomass and Napier grass were used in the study to form different element characteristic of feedstock by altering mixing ratio. Comparison between each element characteristic to total produced bio-oil yield, aqueous phase bio-oil yield, organic phase bio-oil yield, higher heating value of organic phase bio-oil, and organic bio-oil compounds was conducted. The results demonstrate that process performance is associated with feedstock properties, which can be used as a platform to access the process feedstock element acceptance range to estimate the process outputs. Ultimately, this work evaluated the element acceptance range for proposed biomass pyrolysis technology to integrate alternative biomass species feedstock based on element characteristic to enhance the flexibility of feedstock selection.

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In this study, we carried out the study of Eriochrome black T removal using expanded perlite modified orthophenanthroline by adsorption technique. The study of the adsorption process was performed by investigating the effect of the initial dye concentration, contact time and pH range of the solution (acidic and alkaline) in the adsorption process, for a so-called synthetic effluent (aqueous solution of black eriochrome T) and a real effluent (generated from the test for determining the water hardness, by complexation titration). The materials were characterized by Thermogravimetry / Differential Thermal Analysis (TG / DTA), absorption spectroscopy in the infrared (IR), X-ray Diffraction (XRD) and scanning electron microscopy (SEM). By analysis of XRD observed thinking on orthophenanthroline the modified expanded perlite. And by IR analysis showed an increase in intensity and a detailed enlargement of the absorption band related to the axial deformation of the OH bond of silanol groups of perlite (Si-OH). In the equilibration time of the study, in the evaluated time range (5-230 min) was not possible to observe the existence of a balance of time, probably attributed to the type of interaction between the Eriochrome black-T and the expanded perlite modified orthophenanthroline, being an interaction of surface origin. In the study effect of the initial concentration of the adsorbate in the case 2,0x10-4 mol / L natural pH (pH 5) gave the highest removal percentage value of eriochrome T black color with 63.74 % removal in 20 minutes of contact. In evaluating the effect of varying the pH of Eriochrome black T solution in the adsorption process, it was found that the more acidic the environment, the greater the percentage stain removal, being a result of acid-base interaction between the adsorbate and the adsorbent. In T Eriochrome black removal study in real effluent we used the optimized conditions by studying with synthetic sewage. The dye removal at pH 10, natural pH of the effluent was no significant reaching the maximum amount of color removal percentage of 8.12%, obtained already at pH 3 with maximum color removal 100.00% of color, once more proving that eriochrome black T and effectively interact better with the adsorbent at acid pH values (pH 5 or 3), and most efficiently at pH 3. thus one can mention that the perlite expanded (an amorphous aluminosilicate naturally acid) modified with orthophenanthroline (one Bronsted base) consists of a master and effective removal of coloring material in the acid-type aqueous solution, the conditions expressed in this study, can be applied as an adsorbent of this dye also mums real effluent.

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The monograph focuses on the analysis of data addressing the problem of H2S contamination and oxic-anoxic interface in the Black Sea. Regularities of the fine structure of vertical distribution of oxygen, hydrogen sulfide, biogenic elements, organic substances, suspended matter, and metals of the iron-manganese group in the area of contact of aerobic and anaerobic waters have been revealed. Also effects of biochemical, physico-chemical and dynamic processes on their vertical distribution have been examined. Sulfate reduction in seawater and bottom sediments has been studied. Quantitative estimates of H2S fluxes at the water - bottom sediment and O2-H2S interfaces have been done. Features of H2S oxidation have been studied, its budget in the Black Sea has been calculated. Multiyear spatial-temporal variability of the oxic-anoxic interface has been investigated.