Person: Castro Ruiz, Laura
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First Name
Laura
Last Name
Castro Ruiz
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Identifiers
5 results
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Item Batch and Continuous Chromate and Zinc Sorption from Electroplating Effluents Using Biogenic Iron Precipitates(Minerals, 2021) Rocha, Fabiana; Muñoz Sánchez, Jesús Ángel; González González, Felisa; Blázquez Izquierdo, María Luisa; Castro Ruiz, LauraNanoparticles of iron precipitates produced by a microbial consortium are a suitable adsorbent for metal removal from electroplating industry wastewaters. Biogenic iron precipitates were utilized as adsorbents for chromate and zinc in batch conditions. Furthermore, the iron precipitates were embedded in alginate beads for metal removal in fixed-bed columns, and their performance was evaluated in a continuous system by varying different operational parameters such as flow rate, bed height, and feeding system (down- and up-flows). The influence of different adsorption variables in the saturation time, the amount of adsorbed potentially toxic metals, and the column performance was investigated, and the shape of the breakthrough curves was analyzed. The optimal column performance was achieved by increasing bed height and by decreasing feed flow rate and inlet metal concentration. The up-flow system significantly improved the metal uptake, avoiding the preferential flow channels.Item Extracellular biosynthesis of gold nanoparticles using sugar beet pulp(Chemical Engineering Journal, 2010) Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa; González González, Felisa; Muñoz Sánchez, Jesús Ángel; Ballester Pérez, AntonioSugar beet pulp was used as redactor agent for the synthesis of gold nanoparticles. The method developed is environmentally friendly and allows control of nanoparticles shapes by changing the initial pH value of aqueous HAuCl4 solutions. At low initial pH values, polygonal nanoparticles were obtained, mainly triangular and hexagonal shapes. Increasing the pH value, nanorods together with polygonal nanoparticles were produced. At higher initial pH, gold nanowires were formed. Gold biosorption took place at long reaction time, especially at low pH. This procedure could be useful to remove or recover metals from aqueous wastes. The synthesis of other metallic nanostructures such as silver and platinum could be achieved following a similar procedure.Item Speeding up bioproduction of selenium nanoparticles by using Vibrio natriegens as microbial factory(Scientific Reports, 2017) Fernández-Llamosas, Helga; Díaz, Eduardo; Carmona, Manuel; Castro Ruiz, Laura; Blázquez Izquierdo, María LuisaSelenium and selenium nanoparticles (SeNPs) are extensively used in biomedicine, electronics and some other industrial applications. The bioproduction of SeNPs is gaining interest as a green method to manufacture these biotechnologically relevant products. Several microorganisms have been used for the production of SeNPs either under aerobic or anaerobic conditions. Vibrio natriegens is a non-pathogenic fast-growing bacterium, easily cultured in different carbon sources and that has recently been engineered for easy genetic manipulation in the laboratory. Here we report that V. natriegens was able to perfectly grow aerobically in the presence of selenite concentrations up to 15 mM with a significant survival still observed at concentrations as high as 100 mM selenite. Electron microscopy and X-ray spectroscopy analyses demonstrate that V. natriegens cells growing aerobically in selenite-containing LB medium at 30 °C produced spherical electron-dense SeNPs whose size ranged from 100–400 nm. Selenite reduction just started at the beginning of the exponential growth phase and the release of SeNPs was observed after cell lysis. Remarkably, V. natriegens produced SeNPs faster than other described microorganisms that were proposed as model bioreactors for SeNPs production. Thus, the fast-growing V. natriegens bacterium becomes a suitable biocatalyst for bioremediation of selenite and for speeding-up the eco-friendly synthesis of SeNPs.Item Continuous metal biosorption applied to industrial effluents: a comparative study using an agricultural by-product and a marine alga(Environmental Earth Sciences, 2017) Castro Ruiz, Laura; Bonilla, Luis; González González, Felisa; Ballester Pérez, Antonio; Blázquez Izquierdo, María Luisa; Muñoz Sánchez, Jesús ÁngelFixed-bed column experiments have been conducted to evaluate the removal of metals from real industrial wastewaters. The effluents tested were provided by two different metallurgical companies: Industrial Goñabe, a galvanizing plant, and Sao Domingos mine, an abandoned sulfide mine. Sugar-beet pulp, a by-product of the sugar industry, and brown alga Fucus vesiculosus were used as biosorbents. The influence of pH on the sorption process was insignificant for the tests using Industrial Goñabe wastewater. On the contrary, an increase of pH improved metal sorption uptake and yield and saturation rate in the case of the Sao Domingos wastewater. A lower metal concentration in Sao Domingos wastewater resulted in a higher availability of metal-binding sites on the biomass. Better sorption parameters for both real wastewaters were obtained using brown alga Fucus vesiculosus. At pH 5, Zn sorption in continuous mode increased from 36 to 48% for Industrial Goñabe wastewater and from 34 to 37% for Sao Domingos wastewater. In the latter case, copper sorption increased from 73 to 88%. Breakthrough points that determine the service time of columns were reached later using alga as biosorbent. For Zn, column adsorption performance improved substantially with alga and its service time by 5 times. In the case of Cu, the breakthrough point of the second column was not reached during 1750 min of experimentation. The results obtained reaffirm the industrial applicability of these techniques.Item Biosynthesis of gold nanowires using sugar beet pulp(Process Biochemistry, 2011) Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa; Muñoz Sánchez, Jesús Ángel; González González, Felisa; García Balboa, María Del Camino; Ballester Pérez, AntonioSugar beet pulp was used as reductor and capping agent for the synthesis of gold nanowires. Reduction of tetrachloroaurate with sugar beet pulp is a simple, room temperature and environmentally friendly method. Polysaccharides and proteins are involved in the bioreduction and synthesis of nanoparticles. Different pH and molar concentration ratios of HAuCl4 were studied for the synthesis of gold nanowires. The formation of nanowires was induced by both basic mediums, due to the competence between biomolecules and hydroxide ions, and high concentrations of gold ions, because of the lack of capping agent to stabilize the preliminary nanoparticles formed that stick together producing wire-like nanostructures instead of nanospheres. This method allowed the synthesis of crystalline gold nanowires in the absence of a surfactant or polymer to direct nanoparticle growth, and without externally added seed crystallites. The synthesis of other metallic nanostructures such as silver and platinum could be achieved following a similar procedure.