Papers by Isabel Villaescusa
Resum Partint de que els alumnes que arriben a l'Escola Politècnica Superior ja han assolit l... more Resum Partint de que els alumnes que arriben a l'Escola Politècnica Superior ja han assolit la decisió prèvia de seguir estudis tècnics, i porten un semestre després d'haver iniciat el curs, els proposem una reflexió sobre els seus estudis i la possibilitat d'exposar les seves il·lusions i els seus desencisos respecte al que n'esperaven de la universitat. Aprofitem per a remarcar-los-hi la disponibilitat dels recursos que proporciona el Centre per facilitar-los-hi la integració a la Universitat, a l'Escola i concretament al seu estudi. Aquesta part del procés s'inicia amb l'oportunitat de respondre una enquesta preparada per fer el seguiment de la seva inserció universitària amb preguntes de resposta oberta que al mateix temps d'ajudar a la verificació del funcionament de les diferents activitats de suport que els dóna l'escola, serveixen d'invitació a la reflexió tant per als alumnes matriculats per primera vegada com per als professors i equ...
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Journal of Environmental Chemical Engineering, 2013
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Reactive and Functional Polymers, 2013
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Coordination Chemistry Reviews, Sep 1, 2010
After an overview of environmental pollution and the environmental threat posed by metals, this p... more After an overview of environmental pollution and the environmental threat posed by metals, this paper focuses on a literature survey of the different analytical methodologies and techniques used to investigate the functional groups involved in metal sorption onto biomass derived from agricultural waste. The recent literature has mainly focused on identifying the binding groups on the biomass surface through the
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Journal of Hazardous Materials, Mar 15, 2010
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The Science of the total environment, Jan 19, 2015
In the last decades Cr(VI) sorption equilibrium and kinetic studies have been carried out using s... more In the last decades Cr(VI) sorption equilibrium and kinetic studies have been carried out using several types of biomasses. However there are few researchers that consider all the simultaneous processes that take place during Cr(VI) sorption (i.e., sorption/reduction of Cr(VI) and simultaneous formation and binding of reduced Cr(III)) when formulating a model that describes the overall sorption process. On the other hand Cr(VI) scarcely exists alone in wastewaters, it is usually found in mixtures with divalent metals. Therefore, the simultaneous removal of Cr(VI) and divalent metals in binary mixtures and the interactive mechanism governing Cr(VI) elimination have gained more and more attention. In the present work, kinetics of Cr(VI) sorption onto exhausted coffee from Cr(VI)-Cu(II) binary mixtures has been studied in a stirred batch reactor. A model including Cr(VI) sorption and reduction, Cr(III) sorption and the effect of the presence of Cu(II) in these processes has been develo...
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The increasing application and the immutable nature of heavy metals has made of this kind of poll... more The increasing application and the immutable nature of heavy metals has made of this kind of pollution one of the most serious environmental problems nowadays. As they are no degradable, they can accumulate in the components of the environment where their toxicity is expressed. Due to the special concern of heavy metal pollution in waters, there is an increasing interest towards the development of sustainable, environmentally friendly and cheap technologies for water treatment. Among the different materials that can be used for the detoxification of heavy metal polluted effluents, grape stalks (GS) has demonstrated an excellent performance. GS are the branches that connect the grape grains in the compact structure of the bunch. The material, mainly composed by cellulose and lignin, is an industrial by-product of wine elaboration industries that is generated in huge amounts in several countries worldwide. The management of these wastes, in many cases, involves an important extra cost...
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Science of The Total Environment
The most frequently encountered forms of organic arsenic, namely, dimethylarsinic acid, monomethy... more The most frequently encountered forms of organic arsenic, namely, dimethylarsinic acid, monomethylarsonic acid, arsenobetaine, arsenocholine and Roxarsone (4-hydroxy-3-nitrobenzene arsonic acid) were tested for toxicity either by using the Microtox bioassay, based on the rapid (within 15 min) fading of luminescence emitted by Vibrio fischeri marine bacteria, or by monitoring growth rate of the same bacteria for 3 days. Organic arsenic was generally found to be less toxic to these biological models than inorganic arsenic. In many cases, EC50 values for DMA, MMA or HNAA when using luminescence or growth inhibition assays could not be determined because of the low toxicity of the compounds. Nevertheless, results from the luminescence inhibition assay, which was found to be more sensitive than the growth inhibition assay, allowed to rank toxicity as follows: arsenate at pH 8>HNAA at pH 5>arsenate at pH 5>MMA at pH 5>HNAA at pH 8>DMA at pH 5. Arsenobetaine and monomethylar...
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Reviews in Environmental Science and Bio/Technology
Because dramatic cases of arsenic contamination of water resources, soils, vegetables, humans and... more Because dramatic cases of arsenic contamination of water resources, soils, vegetables, humans and animals increase, this review has focussed on the fate and behaviour of this element and what kind of health impacts are related with its release in surface or ground waters. In a first part, we point out how the primary minerals can lead to As mobilization and exportation by surface waters and suspended matter. We also emphasize the particular key role for As retention through both adsorption onto natural Fe(III) (hydr)oxides, Mn oxides and/or precipitation as Fe(III) arsenates. Nowadays, numerous and efficient systems for arsenic removal from any natural resources are available to produce good quality drinking water (with <10μg/l As); however it is not within the scope of the present review. In a second part we focus on recent knowledge about the human toxicity of the various arsenic species. Chronic exposure to As in drinking water lead to many health diseases and, although the me...
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Bioresources
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International Journal of Biological Macromolecules, 2015
Selected biosorbents, brewers draff and grape waste, have been encapsulated in calcium alginate b... more Selected biosorbents, brewers draff and grape waste, have been encapsulated in calcium alginate beads and used for the removal of Cr(VI) from aqueous solutions. The effects of encapsulation variables, including the type of waste, the percentage of waste in the beads and the curing time of the beads in CaCl2, on the diameters of the beads and Cr(VI) sorption kinetics have been evaluated. In total, 21 different types of beads were produced. The diameters of the beads increased with increasing amounts of encapsulated biomaterial. Beads that contained grape waste were larger than those containing brewers draff. The most efficient beads for Cr(VI) removal were beads that contained 4% w/w of grape waste. No significant differences in the kinetics of Cr(VI) sorption were found with respect to the curing time variable in the case of grape waste calcium alginate beads. Statistical analysis confirmed that the type and percentage of waste are the critical parameters influencing the diameters of the beads and Cr(VI) removal. It was proven that the sorption efficiencies of the beads containing draff and grape waste encapsulated under the optimum conditions were much higher than the efficiencies obtained when using both wastes in their native states.
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The Science of the total environment, Jan 7, 2015
Understanding the role of biomacromolecules and their interactions with pollutants is a key for e... more Understanding the role of biomacromolecules and their interactions with pollutants is a key for elucidating the sorption mechanisms and making an accurate assessment of the environmental fate of pollutants. The knowledge of the sorption properties of the different constituents of these biomacromolecules may furnish a significant contribution to this purpose. Suberin is a very abundant biopolymer in higher plants. In this study, suberin monomers isolated from cork were analyzed by thermally-assisted methylation with tetramethylammonium hydroxide (TMAH) in a pyrolysis unit coupled to gas chromatography-mass spectrometry (GC/MS). The isolated monomer mixture was used to study the sorption of three pesticides (isoproturon, methomyl and oxamyl). The modes of pesticide-sorbent interactions were analyzed by means of two modeling calculations, the first one representing only the mixture of suberin monomers used in the sorption study, and the second one including glycerol to the mixture of s...
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Biomass - Detection, Production and Usage, 2011
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Comptes Rendus Chimie, 2015
ABSTRACT The performance of a microporous activated carbon prepared chemically from olive stones ... more ABSTRACT The performance of a microporous activated carbon prepared chemically from olive stones for removing Cu(II), Cd(II) and Pb(II) from single and binary aqueous solutions was investigated via the batch technique. The activated carbon sample was characterized using N2 adsorption-desorption isotherms, SEM, XRD, FTIR, and Boehm titration. The effect of initial pH and contact time were studied. Adsorption kinetic rates were found to be fast and kinetic experimental data fitted very well the pseudo-second-order equation. The adsorption isotherms fit the Redlich-Peterson model very well and maximum adsorption amounts of single metal ions solutions follow the trend Pb(II) &gt; Cd(II) &gt; Cu(II). The adsorption behavior of binary solution systems shows a relatively high affinity to Cu(II) at the activated carbon surface of the mixture with Cd(II) or Pb(II). An antagonistic competitive adsorption phenomenon was observed. Desorption experiments indicated that about 59.5% of Cu(II) and 23% of Cd(II) were desorbed using a diluted sulfuric acid solution.
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International Journal of Chemical Engineering and Applications, 2012
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Chemical Speciation and Bioavailability, 2004
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Arabian Journal of Chemistry, 2013
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Fresenius Journal of Analytical Chemistry, 1998
ABSTRACT The toxicity of nickel and lead compounds has been evaluated in NaCl and NaClO4 solution... more ABSTRACT The toxicity of nickel and lead compounds has been evaluated in NaCl and NaClO4 solutions by using the MicrotoxR bioassay. The aim of this work was to assess the toxicity of the different species in solution when varying the concentration of the medium. A modified Microtox protocol which enables the pH to be constant in all the cuvettes during analysis has been used. The positively charged species (Ni2+, Pb2+, PbCl+) were found to contribute more to the toxicity of Ni and Pb in NaCl while in NaClO4 solutions free metal was the responsible species. In all media studied, Pb compounds were the most toxic and provoked a quick response of the bacteria.
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Papers by Isabel Villaescusa