61 research outputs found

    Homogeneous degradation of the Remazol Black B dye by Fenton and photo-Fenton processes in aqueous medium

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    In this research, factorial designs have been employed to study the influence of three important factors ([H2O2], [Fe2+] and the reaction time) on the discoloration and the degradation of Remazol Black B dye by Fenton and photo-Fenton processes. For the photo-Fenton experiments, two different sources of radiation were used: UVA and visible light. This investigation reveals the importance of irradiation on the discoloration reaction and the degradation of the Remazol Black B. Based on the optimum experimental conditions the more efficient dye removal followed the sequence: UVA light photo-Fenton > Visible light photo-Fenton > Fenton. Total organic carbon (TOC) values of 36%, 27% and 16%, for the UVA light photo-Fenton, visible light photo-Fenton and Fenton processes, respectively,were obtained for the dye degradation also at the optimumexperimental conditions. Based on the observed data it was found that the visible light can be employed as an economically viable source of irradiation in comparison to the UVA light

    Remediation of petroleum contaminated soil by photo-Fenton process applying black, white and germicidal light

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    The aim of this work was to study the application of photo-Fenton process to remediate oil contaminated soil. In this work, the influence of irradiation time, hydrogen peroxide concentration and the use of visible, UV-A and UV-C light were investigated. In addition, the presence of external catalyst (Fe2+) was assessed. The photocatalytic treatment of petroleum contaminated soil was an efficient method for removing the total organic content, achieving about 50% of TOC removal at the end of the reaction time. The use of UV-A light promoted higher TOC removal than other irradiation sources, increasing 17 and 10% the TOC removal when compared to UV-C and visible light, respectively. In the case of treatment using UV lamps, the addition of external Fe was not necessary to achieve high levels of TOC removal

    Utilização do processamento digital de imagens no monitoramento de estações de tratamento de efluentes

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    Neste trabalho é proposto um procedimento para reconhecimento semi-automático das espécies de protozoários por análise de imagem. Este programa (ProtoRec v.2) foi em seguida utilizado para estudar a evolução da microfauna durante períodos de transição (paragem e arranque da estação). Os resultados obtidos foram satisfatórios em relação ao reconhecimento das espécies pelo programa e o acompanhamento da estação permitiu-nos verificar a degradação e envelhecimento da lama e o aparecimento de protozoários que evidenciam tal fato

    Óleo produzido a partir de mamona irrigada com esgoto doméstico para produção de biodiesel

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    A mamoneira (Ricinus communis L.), é uma das oleaginosas selecionadas para o fornecimento de matéria-prima visando a produção de biodiesel, e possui uma relevante importância econômica e social para o Nordeste. Este trabalho objetivou avaliar, os aspectos produtivos da cultura da mamona irrigada com esgoto doméstico. O sistema foi composto de um reator UASB, uma lagoa anaeróbia, tanque de polimento e 4 drenos com a plantação da mamona. Foi obtida a redução de matéria orgânica 68% para DQO e 77% para DBO. Os sólidos suspensos no dreno 1 apresentaram uma média de 270,17 mg/L, enquanto que no dreno 4 chegou a 40,50 mg/L. Os valores do pH ficaram entre (6-9) para todos os drenos. O teor de óleo contido nas sementes foi analisado e obteve-se um rendimento de 46-70%. O óleo obtido foi caracterizado obtendo acidez de 0.0003 mg KOH/g, sendo classificada como do tipo 1, a densidade ficou na faixa de 0,940 g/cm3 e a viscosidade cinemática foi de 248,65 mPa.s. A análise cromatográfica identificou o ácido ricinoleico em maior quantidade com 79,9% na composição dos ácidos graxos. Os experimentos mostraram que o óleo de mamona possui um grande potencial para a produção de biodiesel

    Evaluation of the adsorption process of remazol black b dye in liquid effluents by green coconut mesocarp

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    The textile industry is economically important for the development of Brazil. However, the generated effluents from this activity present a complex molecular structure that gives a recalcitrant characteristic in its residuary waters. Due to this reality, it is necessary to develop viable technologies that remove those compounds, which are mostly dyes. In this study, the green coconut mesocarp was used to remove Remazol Black B dye of an aqueous solution using the adsorption technique. To perform the experiments, the green coconut mesocarp was dried at 60ºC, ground in a grinding mill, sifted, washed with distilled water and immersed in albumin for 24 hours. The process of adsorption was optimized in a batch mode, containing 0.5 g of adsorbent and 25 mL of synthetic solution of 10 mg L -1, at 30ºC, pH 4.0, stirring speed of 700 rpm, and granulometry G £ 0.149 mm. Afterwards, the influence of the pH of the solution, adsorbent granulometry and stirring speed were evaluated by means of factorial planning. Experiments of equilibrium and kinetics of adsorption were conducted in Erlenmeyer. Results indicated that among the main effects, the pH and the adsorbent granulometry significantly influenced the process of adsorption. Besides, the adsorption equilibrium was reached in 60 minutes of contact. The Langmuir model was adjusted to experimental results (R 2=0.9953) being obtained a maximum capacity of adsorptionof 2.93 mgg-1 and equilibrium constant of 0.26 Lmg-1. With the obtained results it could be concluded that the green coconut mesocarp could be a viable alternative for the treatment of textile effluents

    Analysis of the immunological biomarker profile during acute Zika virus infection reveals the overexpression of CXCL10, a chemokine linked to neuronal damage.

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    BACKGROUND: Infection with Zika virus (ZIKV) manifests in a broad spectrum of disease ranging from mild illness to severe neurological complications and little is known about Zika immunopathogenesis. OBJECTIVES: To define the immunologic biomarkers that correlate with acute ZIKV infection. METHODS: We characterized the levels of circulating cytokines, chemokines, and growth factors in 54 infected patients of both genders at five different time points after symptom onset using microbeads multiplex immunoassay; comparison to 100 age-matched controls was performed for statistical analysis and data mining. FINDINGS: ZIKV-infected patients present a striking systemic inflammatory response with high levels of pro-inflammatory mediators. Despite the strong inflammatory pattern, IL-1Ra and IL-4 are also induced during the acute infection. Interestingly, the inflammatory cytokines IL-1β, IL-13, IL-17, TNF-α, and IFN-γ; chemokines CXCL8, CCL2, CCL5; and the growth factor G-CSF, displayed a bimodal distribution accompanying viremia. While this is the first manuscript to document bimodal distributions of viremia in ZIKV infection, this has been documented in other viral infections, with a primary viremia peak during mild systemic disease and a secondary peak associated with distribution of the virus to organs and tissues. MAIN CONCLUSIONS: Biomarker network analysis demonstrated distinct dynamics in concurrence with the bimodal viremia profiles at different time points during ZIKV infection. Such a robust cytokine and chemokine response has been associated with blood-brain barrier permeability and neuroinvasiveness in other flaviviral infections. High-dimensional data analysis further identified CXCL10, a chemokine involved in foetal neuron apoptosis and Guillain-Barré syndrome, as the most promising biomarker of acute ZIKV infection for potential clinical application
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