4,074 research outputs found

    CWPO of bisphenol A with iron catalysts supported on microporous carbons from grape seeds activation

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    This accepted manuscript is available under a CC BY-NC-ND licence after the 24 months embargo periodThe catalytic wet peroxide oxidation (CWPO) of bisphenol A (BPA) with Fe catalysts supported on activated carbon from grape seeds (GS) has been studied. The GS were pyrolized (N2, 600 °C, 2 h) and subjected to activation upon partial gasification with air (400 °C, 2 h). Oxidized samples of the char and activated carbon were also obtained upon treatment with HNO3. The Fe catalysts were prepared by incipient wetness impregnation with ferric nitrate solution. They showed narrow microporosity, with surface area values ≈350–500 m2 g−1 and total iron contents between 2.8 and 4.2% wt. The CWPO experiments were carried out at 50–80 °C. The best catalyst allowed complete conversion of BPA (100 mg L−1) and a 60% TOC reduction in 3 h reaction time at 80 °C and the theoretical stoichiometric amount of H2O2 (530 mg L−1). The ecotoxicity of the effluent was negligible and the biodegradability was highly improved. In a long-term experiment (100 h), the catalyst suffered a loss of activity upon the early stages on stream (≈15 h), where about 20% of Fe was lost, followed by a highly stable behavior for the rest of the experimentThe authors wish to thank the Spanish MINECO and Comunidad de Madrid for the financial support through the projects CTM2013-43803-P and S2013/MAE-2716, respectively. I. F. Mena wishes to thank the MINECO and the ESF for a research gran

    Producción de largometrajes en Uruguay: un análisis desde la Teoría General del Costo

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    The present work, using concepts from the Cost General Theory and its connection with the culture economy, analyzes the viability of the film productions in Uruguay, focusing on the cost factors of the projects and their financing. The research is based on the study of fiction films released between 2012 and 2016. The results show that, with the current level of ticket sales, Uruguayan films can hardly be economically viable without a significant support from public funds. The high costs in a prototype industry and high risks makes it essential to know the alternatives for the viability of these projects

    Producción de largometrajes de ficción en Uruguay: Aproximación desde la Teoría General Del Costo

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    The subject of the paper is the analysis of the fiction feature films production and the production inputs, and the financing and marketing of these products too. The theoretical framework is the General Cost's Theory, linking it with Arts Economics, or Cultural Economics The research is based in the study of fiction feature films, between 2009 and 2015. The results shown that with the current level of ticket sales, Uruguayan feature films can hardly be economically viable without significant support from public funds or sales abroad

    A spectroscopic study to assess the photogeneration of singlet oxygen by graphene oxide

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    [EN] The photogeneration of singlet oxygen (O-1(2) ) during short irradiation times of graphene oxide (GO) is assessed under visible light with soft irradiation conditions either directly monitoring the phosphorescence emission of O-1(2) at ca. 1275 nm, or indirectly by means of the fluorescent probe 9, 10-anthracene diyl-bis(methylene)dimalonic acid (ABDA). Results obtained using both methodologies lead to the conclusion that O-1(2) generation is negligible under our experimental conditions. In the case of using ABDA very small emission changes were recorded, which could be attributed to other side reactions. Special care should be taken when using this spectroscopic probe to assess the generation of O-1(2), since ABDA and related probes based on the reactivity of the anthracene fluorophore can also detect electron transfer processes. This kind of approaches have been less explored in the field of Materials Science at the nanoscale, and we believe that the knowledge on the lack of generation of O-1(2) by irradiated GO is informative and useful, especially for the assessment of the environmental and biological toxicity of nanomaterials based on GO. (C) 2019 Elsevier B.V. All rights reserved.Ministerio de Economia y Competitividad of Spain (grant CTQ2015-71004-R) and Universitat Jaume I (grant P1.1B2015-76) are thanked for their financial support. C.F-L. thanks the Ministerio de Economia y Competitividad of Spain for a FPI fellowship. Technical support from SCIC of University Jaume I is acknowledged. The Instituto de Tecnologia Quimica (ITQ) thanks the support of the Severo Ochoa Program (SEV-2016-0683), and Consejo Superior de Investigaciones Cientificas (I-Link1063). We would like to thank Dr. Francisco Bosca for his technical assistance with the singlet oxygen emission measurements at the ITQ.Felip-León, C.; Puche Panadero, M.; Miravet, JF.; Galindo, F.; Feliz Rodriguez, M. (2019). A spectroscopic study to assess the photogeneration of singlet oxygen by graphene oxide. Materials Letters. 251:45-51. https://doi.org/10.1016/j.matlet.2019.05.001S455125

    Removal of imidazolium- and pyridinium-based ionic liquids by Fenton oxidation

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    This is peer-post-review, pre-copyedit version of an article published in Environmental Science and Pollution Research. The final authenticated version is avilable online at: https://doi.org/10.1007/s11356-017-0867-4The oxidation of imidazolium (1-hexyl-3-methylimidazolium chloride, HmimCl) and pyridinium (1-butyl-4-methylpyridinium chloride, BmpyrCl) ionic liquids (ILs) by Fenton’s reagent has been studied. Complete conversion was achieved for both ILs using the stoichiometric H2O2dose at 70 °C, reaching final TOC conversion values around 45 and 55% for HmimCl and BmpyrCl, respectively. The decrease in hydrogen peroxide dose to substoichiometric concentrations (20–80% stoichiometric dose) caused a decrease in TOC conversion and COD removal and the appearance of hydroxylated oxidation by-products. Working at these substoichiometric H2O2doses allowed the depiction of a possible degradation pathway for the oxidation of both imidazolium and pyridinium ILs. The first step of the oxidation process consisted in the hydroxylation of the ionic liquid by the attack of the ·OH radicals, followed by the ring-opening and the formation of short-chain organic acids, which could be partially oxidized up to CO2and H2O. At H2O2doses near stoichiometric values (80%), the resulting effluents showed non-ecotoxic behaviour and more biodegradable character (BOD5/COD ratio around 0.38 and 0.58 for HmimCl and BmpyrCl, respectively) due to the formation of short-chain organic acids. [Figure not available: see fulltext.]The authors wish to thank the Spanish MINECO and Comunidad de Madrid for the financial support through the projects CTM2016-76564-R and S2013/MAE-2716, respectivel

    Imaging the Inner and Outer Gaps of the Pre-Transitional Disk of HD 169142 at 7 mm

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    We present Very Large Array observations at 7 mm that trace the thermal emission of large dust grains in the HD 169142 protoplanetary disk. Our images show a ring of enhanced emission of radius ~25-30 AU, whose inner region is devoid of detectable 7 mm emission. We interpret this ring as tracing the rim of an inner cavity or gap, possibly created by a planet or a substellar companion. The ring appears asymmetric, with the western part significantly brighter than the eastern one. This azimuthal asymmetry is reminiscent of the lopsided structures that are expected to be produced as a consequence of trapping of large dust grains. Our observations also reveal an outer annular gap at radii from ~40 to ~70 AU. Unlike other sources, the radii of the inner cavity, the ring, and the outer gap observed in the 7 mm images, which trace preferentially the distribution of large (mm/cm sized) dust grains, coincide with those obtained from a previous near-infrared polarimetric image, which traces scattered light from small (micron- sized) dust grains. We model the broad-band spectral energy distribution and the 7 mm images to constrain the disk physical structure. From this modeling we infer the presence of a small (radius ~0.6 AU) residual disk inside the central cavity, indicating that the HD 169142 disk is a pre-transitional disk. The distribution of dust in three annuli with gaps in between them suggests that the disk in HD 169142 is being disrupted by at least two planets or substellar objects.Comment: Accepted by ApJ Letters, 16 pages, 3 figures, ApJ Letters 201

    Valorisation of the liquid fraction from hydrothermal carbonisation of sewage sludge by anaerobic digestion

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    This is the peer reviewed version of the following article: Journal of Chemical Technology and Biotechnology 93.2 (2018): 450-456, which has been published in final form at https://doi.org/10.1002/jctb.5375. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsBACKGROUND: The mesophilic anaerobic digestion of the liquid fraction from hydrothermal carbonisation (208°C, 1 h) of dehydrated sewage sludge has been studied. Two initial inoculum concentrations (IC) (10 and 25 g COD L-1) and four inoculum to substrate ratios (ISR) (2, 1, 0.5 and 0.4 on a COD basis) have been selected to analyse their influence on the evolution of the anaerobic digestion process. RESULTS: The substrate is characterised by a high COD (95.5 g L-1) and TKN (8.7 g N L-1) values. High inoculum concentration (25 g COD L-1) and/or low ISR (≤ 0.5) inhibited methanogenesis due to the high ammonia nitrogen (1.4 g TAN L-1) and VFA (>4 g COD L-1) released. For the inhibited samples final COD removals lower than 15% and IA/TA ratios higher than 0.3 were found. The greatest methane yield (177±5 mL CH4 STP g-1 CODadded) was achieved at 25 g COD L-1 of IC and at an ISR of 2. CONCLUSION: During anaerobic digestion of the liquid fraction from the hydrothermal carbonisation of sewage sludge, the IC and ISR must be adequately selected for proper operation of the process and successful valorisation. According to the results, working at an ISR ≥ 1 is recommendedThe authors wish to express their gratitude to the UAM-Santander (Project CEAL-AL/2015-29) and Spanish MINECO (CTM2016-76564-R) for providing financial support. MA de la Rubia acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (RYC-2013-12549
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