Andalusian Institute of Earth science

Granada, Spain

Andalusian Institute of Earth science

Granada, Spain
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Monaci F.,University of Siena | Leidi E.O.,IRNAS | Mingorance M.D.,Andalusian Institute of Earth Science | Valdes B.,University of Seville | And 2 more authors.
Journal of Environmental Sciences | Year: 2011

To assess the ecophysiological traits and the phytoremediation potential of the endemic heather Erica andevalensis, we determined the concentrations of major and trace elements in different plant parts and in rizosphere soils from Riotinto mining district (Huelva, Spain). The results showed that E. andevalensis may grow on substrates with very high As, Cu, Fe and Pb concentrations (up to 4114, 1050, 71900 and 15614 μg/g dry weight, respectively), very low availability of macro- and micronutrients and with pH values ranging from 3.3 to 4.9. In these harsh edaphic conditions E. andevalensis selectively absorbed and translocated essential nutrients and excludes potentially phytotoxic elements, which were accumulated in the root epidermis. The concentrations of major and trace elements in E. andevalensis aerial parts from the Riotinto mining district were in the normal range for plants; likewise other Erica species it accumulated Mn and only in a very polluted site we measured leaf concentrations of As and Pb within the excessive or toxic limits for plants. Differently from previous studies, which emphasized the soil pH and bioavailability of phytotoxic elements as the main stress factors, this study showed that in the Riotinto region, E. andevalensis can tolerate wide range of pH and toxic element concentrations; the harshest environments colonized by monospecific patches of this species were characterized above all by very low availability of nutrients. The extraordinary capability to adapt to these extreme habitats made E. andevalensis a priority species to promote the phytostabilization and the development of a self-sustaining vegetative cover on Riotinto mine tailings. © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Aguzzi C.,University of Granada | Capra P.,University of Pavia | Bonferoni C.,University of Pavia | Cerezo P.,University of Granada | And 5 more authors.
Applied Clay Science | Year: 2010

Biocomposites of chitosan (CS) and montmorillonite (VHS) were prepared by solid-liquid interaction of the components. The resultant composites were characterized by thermal analysis and the cation exchange capacity of the clay mineral was compared to polysaccharide retention. The composites were loaded with 5-amino salicylic acid (5-ASA), comparing the drug loading capacity and drug release behavior with those of the interaction products prepared with the drug and chitosan or montmorillonite alone. The results showed that chitosan was effectively retained by montmorillonite particles through cation exchange. In comparison with interaction products prepared using the drug and the individual components, there was a synergic effect between the clay mineral and the polysaccharide regarding both their ability to retain drug molecules, and also the control of drug release in acidic medium. In particular, the 5-ASA/CS/VHS composites showed higher drug loading and slower drug release compared to both 5-ASA/VHS and 5-ASA/CS interaction products, with almost linear release profile throughout test. According to the results, biocomposites of chitosan and montmorillonite were promising supports for modified formulations of 5-amino salicylic acid. © 2010 Elsevier B.V.

Urena C.,University of Granada | Azanon J.M.,University of Granada | Azanon J.M.,Andalusian Institute of Earth science | Corpas F.,University of Jaén | And 3 more authors.
Construction and Building Materials | Year: 2013

The improvement in physical properties of expansive soils after addition of non-conventional additives is studied. The tested agents were magnesium hydroxide, seawater and olive mill wastewater. The use of these materials, which can be obtained from natural sources or as by-products derived from industrial processes, can lead to greater sustainability of the construction process. In the case of olive mill wastewater, its management is still an issue in many regions where production of olive oil is a main economic activity. The untreated soil used was a sample of pure bentonite. To evaluate the effects of the additives, the physical properties of the soil such as compaction, consistency, bearing capacity and swelling pressure were studied. The mineral compositions of the treated soils were evaluated by XRD tests. Test results showed that the non-conventional additives tested reduced the plasticity and the swelling potential of the soil. Indeed the tested agents proved to be very effective to produce reductions in the swelling pressure of 60-87% in comparison with the original swelling pressure of the untreated bentonite. X-ray diffraction tests proved that magnesium hydroxide, seawater and olive mill wastewater promoted mineral changes within bentonite, especially smectite to illite conversion. This conversion is due to the alterations promoted by the additives on conditions such as pH and concentration of different cations (magnesium, calcium, potassium, etc.) The mineral modifications occurred are behind the sharp reductions in swelling pressure and plasticity of bentonite. © 2013 Elsevier Ltd. All rights reserved.

Aguzzi C.,University of Granada | Ortega A.,Pablo De Olavide University | Bonferoni M.C.,University of Pavia | Sandri G.,University of Pavia | And 6 more authors.
Carbohydrate Polymers | Year: 2011

Microspheres based on the interaction between 5-amino salicylic acid (5-ASA) and chitosan were designed as a new colonic delivery system. Microspheres were prepared by a spray drying technique and characterised by physical properties, morphology and drug dissolution characteristics. Effects of the microspheres over inflamed Caco-2 cells were also evaluated, by determining cell viability and expression of mRNA levels of biomarkers involved in the pathogenesis of Inflammatory Bowel Diseases (IBD) (IL-1β and IL-8). Results showed that chitosan improved dissolution properties of 5-ASA. The amount of free drug released over 120 min did not exceed 9 mg/cm2, while microspheres showed a high dissolution rate reaching approximately 50 mg/cm 2 of drug released. Contact of inflamed cells with free 5-ASA reduced mRNA levels of IL-1β and IL-8. Microspheres did not show cytotoxic activity and maintained ILs levels observed in non-inflamed cells, mimicking the anti-inflammatory effect of 5-ASA alone. © 2011 Elsevier Ltd. All rights reserved.

Cruz-Hernandez P.,University of Huelva | Perez-Lopez R.,University of Huelva | Parviainen A.,Andalusian Institute of Earth science | Lindsay M.B.J.,University of Saskatchewan | Nieto J.M.,University of Huelva
Catena | Year: 2016

Iron-rich sediments commonly cover riverbeds that have been affected by acid drainage associated with sulfide-mineral oxidation. Freshly-formed precipitates correspond to poorly-crystalline oxyhydroxysulfates that recrystallize over time. This study examined the distribution and mineral association of trace elements (e.g., As, Cu, Zn) in modern and ancient (~ 6 Ma) Fe terraces in the Tinto river basin, Spain. The mineral composition of the terraces was determined by Raman μ-spectroscopy. Chemical digestions, electron probe microanalyses, and synchrotron-based μ-X-ray fluorescence mapping were used to examine As, Cu, and Zn distribution and corresponding mineral associations. Fresh precipitates at modern terrace surfaces were dominated by schwertmannite, which contained high As, Cu, Mn, and Zn concentrations. However, schwertmannite transforms into goethite at short-time (weeks) in the deeper part of the current terraces and into hematite at century-time scale. Affinity for trace elements was generally highest in schwertmannite and lowest in hematite, which suggests that their retention by Fe terraces decreases during mineral transformation. Hence, schwertmannite acts as temporary sink for contaminants, which are again released at long-term during the maturation. These findings should be considered for management and treatment of possible water resources affected by acid mine drainage. © 2016 Elsevier B.V.

Rebelo M.,University of Aveiro | Viseras C.,University of Granada | Viseras C.,Andalusian Institute of Earth science | Lopez-Galindo A.,Andalusian Institute of Earth science | And 2 more authors.
Applied Clay Science | Year: 2011

In order to be used in therapeutics, geological materials must comply with a number of specifications. In particular, clays used as pharmaceutical raw materials must be safe. As a product to be manipulated during the manufacture of drug dosage forms, they are also required to satisfy a number of technological features, including flowability and texture. With these premises, this work aimed to characterize mineralogical, textural and technical properties of Portuguese clayey raw materials belonging to well known formations (from Upper Jurassic to Miocene in age). Some of these materials are used in particular beaches for their therapeutic properties. The present study showed that mineralogical and chemical compositions of the samples allow for their safe therapeutic application. Nevertheless, in some particular samples, it could be necessary to reduce the quartz content and coarse particles before use. Bulk samples showed better flow patterns than the < 63-μm samples. For that, the use of bulk samples is preferred over separated samples. The most suitable materials for medical hydrology applications were those belonging to Freixial, Aveiro, Barracão, Luz, Xabregas and Serra de Dentro Bentonite formations. © 2010 Elsevier B.V.

Rebelo M.,University of Aveiro | Viseras C.,University of Granada | Viseras C.,Andalusian Institute of Earth science | Lopez-Galindo A.,Andalusian Institute of Earth science | And 2 more authors.
Applied Clay Science | Year: 2011

Tailored peloids are prepared by the maturation of selected clay minerals mixed with thermo-mineral waters. These dispersions are topically applied to the skin to treat different ailments because of their unique rheological and thermal properties. Colloidal dimensions of the dispersed clay mineral particles yielded stable and viscous dispersions capable of flowing when spread and stand in the area to be treated without flowing away. To be easily handled and cause a pleasant sensation during application, the clay mineral dispersions must have good consistency and cause no abrasion. As thermotherapeutic agents, these systems are heated before application being important to ensure that the clay paste has heat retention capacity and adequate cooling kinetics.On the basis of a previous detailed characterization of Portuguese clayey materials for medical hydrology applications, six clay raw materials were selected as candidates to be used in the preparation of tailored peloids. This study aims to obtain tailored peloids with suitable technical, rheological and thermal properties. Samples from "Serra de Dentro" and "Barracão Clays" formations exhibited adequate abrasivity and consistency. Regarding sedimentation volume and apparent viscosity, the majority of samples showed some difficulties as they were coagulated in the absence of a dispersing agent. Specific heat and cooling rate were adequate in samples from "Serra de Dentro" and "Luz Clays" formations. © 2011 Elsevier B.V.

Driussi O.,French National Center for Scientific Research | Maillard A.,French National Center for Scientific Research | Ochoa D.,University of Salamanca | Lofi J.,Montpellier University | And 6 more authors.
Marine and Petroleum Geology | Year: 2014

The current interpretation of the Messinian Salinity Crisis (MSC) involves the deposition of peripheral or marginal evaporites in onshore basins as well as the erosion of the margin and the deposition of thick evaporites in deep basins. The so-called intermediate basins are formed in domains between the onland outcrops and the deep basins. The Balearic Promontory is a bathymetric high located between the deep Algerian and Liguro-Provençal basins and the onland Spanish basin. The SIMBAD project aims to investigate the spatial variability of the MSC-related deposits and to assess the extent of post-MSC reactivation over the Balearic Promontory. We present here the first results of the SIMBAD high-resolution seismic survey (January 2013) which imaged for the first time a thin MSC-related unit widely distributed in small sub-basins over the Balearic Promontory.Borehole analyses have shown that this unit could be correlated with primary gypsum formations linked to the peripheral evaporites. Locally, in the Central Depression between Mallorca and Ibiza islands, a thicker MSC unit is observed whose lowermost transparent part could correspond to a salt layer. Geometrical relationships suggest that the MSC in the Central Depression could postdate the primary gypsum. The occurrence of a halite layer in the Central Depression, at depths of 1000 to 1500 m, favours the hypothesis that the evaporites precipitated passively in closed or partially closed perched sub-basins, possibly as a result of evaporative drawdown at different depths and possibly diachronously, at least with respect to the deep-basin evaporites. © 2014 Elsevier Ltd.

Aguzzi C.,University of Granada | Viseras C.,University of Granada | Viseras C.,Andalusian Institute of Earth science | Cerezo P.,University of Granada | And 3 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2013

This paper investigates desorption of 5-aminosalicilyc acid (5-ASA) adsorbed onto halloysite (HL). Desorption isotherms were fitted according to kinetic laws obtained considering release of 5-ASA from HL as the phase of desorption of the previously adsorbed drug molecules both inside the nanotubes of HL as onto the surface of clay particles and/or in the inter-particle spaces of their aggregates [28]. Desorption isotherms has been also fitted with other equations frequently used in drug release kinetics studies. The best fitting corresponded to the kinetic model proposed; in agreement with the results of adsorption [28]. © 2013 Elsevier B.V.

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