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
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Now showing 1 - 10 of 11
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    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, Laura
    Nanoparticles 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.
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    Selective biosorption and recovery of scandium using the alga Fucus vesiculosus
    (Minerals Engineering, 2024) Castro Ruiz, Laura; Abrahamyan, Nelly; Vardanyan, Nelly; González González, Felisa; Vardanyan, Narine; Muñoz Sánchez, Jesús Ángel
    The goal of this work was to study the viability of the application of biosorption using the brown alga Fucus vesiculosus in the recovery of scandium from red mud. The highest affinity of the biosorbent for scandium and aluminium was at pH 3. Sorption isotherms fitted to the Langmuir model for scandium and aluminium with adsorption capacities as high as 1.04 mmol·g−1 for both metals but with higher affinity for scandium than for aluminium. The performance of the biomass in fixed-bed columns was evaluated in different experimental conditions (flow rate, bed height and inlet metal concentration). Metal desorption was achieved with different inorganic and organic acids. After three consecutive sorption–desorption cycles using 0.1 N citric acid and deionized water during the regeneration step, the brown alga showed a progressive increase in scandium uptake due to the cross-linking citric acid and the alginate chains. The biomass was characterized before and after biosorption using Fourier transforms infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) coupled with an energy dispersive elemental analyser (EDS). The sorption involves different functional groups, such carboxylate and sulphonic groups by chelation and electrostatic interactions.
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    Bioleaching of Sulfide Minerals by Leptospirillum ferriphilum CC from Polymetallic Mine (Armenia)
    (Minerals, 2023) Vardanyan, Arevik; Khachatryan, Anna; Castro Ruiz, Laura; Willscher, Sabine; Gaydardzhiev, Stoyan; Zhang, Ruiyong; Vardanyan, Narine
    A strain of Leptospirillum sp. CC previously isolated from Akhtala polymetallic ore (Armenia) was studied. The main morphological and physiological characteristics of CC were revealed. The optimal growth temperature was 40 ◦C and optimal pH 1.5. A phylogenetic analysis based on 16S rRNA gene sequences (GenBank ID OM272948) showed that isolate CC was clustered with L. ferriphilum and possessed 99.8% sequence similarity with the strain L. ferriphilum OL12-2 (KF356024). The molar fraction of DNA (G + C) of the isolate was 58.5%. Bioleaching experiment indicates that L. ferriphilum CC can oxidize Fe(II) efficiently, and after 17 days, 44.1% of copper and 91.4% of iron are extracted from chalcopyrite and pyrite, respectively. The efficiency of L. ferriphilum CC in pyrite oxidation increases 1.7 times when co-cultivated with At. ferrooxidans ZnC. However, the highest activity in pyrite oxidation shows the association of L.ferriphilum CC with heterotrophic Acidocella sp. RBA bacteria. It was shown that bioleaching of copper and iron from chalcopyrite by association of L. ferriphilum CC, At. ferrooxidans ZnC, and At. albertensis SO-2 in comparison with pure culture L. ferriphilum CC for 21 days increased about 1.2 and 1.4–1.6 times, respectively.
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    Biohydrometallurgy for Rare Earth Elements Recovery from Industrial Wastes
    (Molecules, 2021) Blázquez Izquierdo, María Luisa; González González, Felisa; Muñoz Sánchez, Jesús Ángel; Castro Ruiz, Laura
    Biohydrometallurgy recovers metals through microbially mediated processes and has been traditionally applied for the extraction of base metals from low-grade sulfidic ores. New investigations explore its potential for other types of critical resources, such as rare earth elements. In recent times, the interest in rare earth elements (REEs) is growing due to of their applications in novel technologies and green economy. The use of biohydrometallurgy for extracting resources from waste streams is also gaining attention to support innovative mining and promote a circular economy. The increase in wastes containing REEs turns them into a valuable alternative source. Most REE ores and industrial residues do not contain sulfides, and bioleaching processes use autotrophic or heterotrophic microorganisms to generate acids that dissolve the metals. This review gathers information towards the recycling of REE-bearing wastes (fluorescent lamp powder, spent cracking catalysts, e-wastes, etc.) using a more sustainable and environmentally friendly technology that reduces the impact on the environment.
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    Arsenate and Arsenite Sorption Using Biogenic Iron Compounds: Treatment of Real Polluted Waters in Batch and Continuous Systems
    (Metals, 2021) Ayala, Lesly Antonieta; Vardanyan, Arevik; Zhang, Ruiyong; Muñoz Sánchez, Jesús Ángel; Castro Ruiz, Laura
    Arsenic pollution in waters is due to natural and anthropogenic sources. Human exposure to arsenic is associated with acute health problems in areas with high concentrations of this element. Nanometric iron compounds with large specific surface areas and higher binding energy produced by some anaerobic microorganisms are thus expected to be more efficient adsorbents for the removal of harmful metals and metalloids than chemically produced iron oxides. In this study, a natural consortium from an abandoned mine site containing mainly Clostridium species was used to biosynthesize solid Fe(II) compounds, siderite (FeCO3) and iron oxides. Biogenic precipitates were used as adsorbents in contact with solutions containing arsenate and arsenite. The adsorption of As(V) fitted to the Langmuir model (qmax = 0.64 mmol/g, KL = 0.019 mmol/L) at the optimal pH value (pH 2), while the As(III) adsorption mechanism was better represented by the Freundlich model (KF = 0.476 L/g, n = 2.13) at pH 10. Water samples from the Caracarani River (Chile) with high contents of arsenic and zinc were treated with a biogenic precipitate encapsulated in alginate beads in continuous systems. The optimal operation conditions were low feed flow rate and the up-flow system, which significantly improved the contaminant uptake. This study demonstrates the feasibility of the application of biogenic iron compounds in the treatment of polluted waters.
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    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 Ángel
    Fixed-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.
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    Design of remediation pilot plants for the treatment of industrial metal-bearing effluents (BIOMETAL DEMO project): Lab tests
    (Hydrometallurgy, 2017) Ballester Pérez, Antonio; Castro Ruiz, Laura; Clara Costa, Maria; Carlier, Jorge; García-Roig, Manuel; Pérez-Galende, Patricia; Alvarez, Angela; Bertagnolli, Caroline; Guibal, Eric
    Current research is the first part of the BIOMETAL DEMO project, funded by the European Union, focusing on the development of complementary and modular biotreatment processes for the removal of metal ions from industrial effluents (issued from mining industry, surface treatment and ceramics). Metal bio-precipitation (in form of metal sulfides and metal phosphates) using sulfate-reducing bacteria (SRB), phytase and phosphatase enzymes, biosorption using sugar-beet pulp, algal biomass and alginate- or chitosan-based composites (immobilizing polyethyleneimine derivatives by encapsulation) have been extensively studied using synthetic and industrial effluents. These preliminary results allow designing a treatment flow-sheet including pre-treatment of the effluent using biologically-assisted precipitation followed by biosorption (for mining effluents that contain sulfate anions). For surface treatment and ceramics effluents, bio-precipitation combined with biosorption processes and physicochemical pretreatment followed by biosorption process represent, respectively, a promising solution. The carbon-source for the SRB process, the optimization of process parameters and the biosorbents have been selected taking into account both the technical performance and the economic viability.
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    Colonization and biofilm formation of the extremely acidophilic archaeon Ferroplasma acidiphilum
    (Hydrometallurgy, 2014) Zhang, Ruiyong ; Bellenberg, Sören; Castro Ruiz, Laura; Neu, Thomas; Sand, Wolfgang ; Vera, Mario
    Ferroplasma spp. are widely distributed in acid mine drainage (AMD) and biomining environments at mesophilic and moderately elevated temperatures, at low pH and high concentrations of iron and other metal ions. Microbial attachment and biofilm formation on metal sulfides are of great importance during bioleaching. In this work, several cultivation and microscopical techniques were applied to investigate the biofilm development of Ferroplasma acidiphilum. Biofilms were heterogeneously distributed on filters over time, and varied within the different growth conditions such as supplementation with glucose. Additionally, cell distribution, biofilm formation as well as EPS production of F. acidiphilum cells forming biofilms on pyrite were observed by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) combined with epifluorescence microscopy (EFM). Cells formed a monolayer biofilm and were preferably attached to the cracks/defects of pyrite surfaces. Biofilm and planktonic cells exhibited significant morphological differences. Capsular EPS were observed in both biofilm and planktonic cells.
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    Effectiveness of anaerobic iron bio-reduction of jarosite and the influence of humic substances
    (Hydrometallurgy, 2013) Castro Ruiz, Laura; García Balboa, María Del Camino; González González, Felisa; Ballester Pérez, Antonio; Blázquez Izquierdo, María Luisa; Muñoz Sánchez, Jesús Ángel
    Nowadays there is a growing interest in developing clean mining processes free of toxic chemicals. Biotechnology could be a cost-effective and environmentally friendly alternative to traditional leaching methods. Jarosite is an important sulfate mineral that occurs naturally and also can be produced as a waste in industrial processes. In this work, bioreduction of jarosite using Shewanella putrefaciens and a natural consortium under anaerobic conditions is presented as an acceptable bioleaching method. Moreover, the influence of humic substances that appear in natural environments acting as electron shuttles between microorganisms and insoluble oxides has been investigated. One key factor for the industrial implementation of anaerobic bioleaching is the metal recovery from minerals. The precipitates formed as products of dissimilatory iron reduction, the bacterial ability to obtain ferrous ions in solution and the stimulation of insoluble Fe(III) ores reduction by electron shuttles have been examined in this research.
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    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, Antonio
    Sugar 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.