Olga Rodríguez

Concerns on liquid mercury and mercury-containing wastes: a review of the treatment technologies for the safe storage.

Due to the adverse effects of mercury on human health and the environment, restrictive legislations and world-wide common efforts are now under way to reduce both the supply and demand of mercury. As a result, all excess Hg must be stored in safe conditions in secure places. This paper is an attempt to review the various treatment technologies types of liquid mercury (Hg(0)) and mercury-containing wastes, which can be used to store these residues in a safe way. The different treatments were classified as a function of the waste treated. The main treatments described are amalgamation, formation of sulfides, thermal treatments, vitrification, soil washing, sulfur polymer stabilization solidification, chemically bonded phosphate ceramics and other encapsulation processes, being highlighted the stabilization/solidification processes that are the treatments that provide better results, according to the consulted bibliography.

Preparation and characterization of activated carbon from the char produced in the thermolysis of granulated scrap tyres

The char produced in the thermolysis of granulated scrap tyres has few market outlets, reducing the economic viability of the thermolytic process. This paper reports the potential of this char as a low-cost precursor of porous carbons. The tyre-derived char was demineralized in either alkaline or acidic media to reduce its ash, zinc, sulfur, and silica contents. The lowest impurity content was achieved with an HNO3/H2O treatment. The resulting demineralized char was then subjected to activation by KOH or CO2. The Brunauer-Emmett-Teller (BET)-specific surface area of the activated carbon produced by the KOH treatment was 242 m2/g, whereas that of the CO2-activated carbon was 720 m2/g. The textural properties of the latter product were similar to those of some commercial activated carbons. The use of tyre-derived char as a precursor of porous carbons could render the thermolytic treatment of scrap tyres more economically attractive. Implications: Char produced in thermolysis of granulated scrap tyres has a few market outlets; in this paper an alternative for its use is presented. The char was converted into activated carbon with textural properties similar to those of some commercial activated carbons. This process could render the thermolytic treatment of scrap tyres more economically attractive.

Membrane-based extraction with strip/organic dispersion methodologies for metals removal and recovery from wastewaters

Abstract The generation of liquid effluents containing organic and inorganic residues from industries presented a potential hazardousness for environment and human health, being mandatory the elimination of these pollutants from the respective solutions containing them. In order to achieve this goal, several techniques are being used, and among them, supported liquid membranes technologies are showing their potential for their application in the removal of metals contained in liquid effluents. Supported liquid membranes are a combination between conventional polymeric membranes and solvent extraction. Several configurations are used: flat-sheet supported liquid membranes, spiral wounds and hollow fiber modules. In order to improve their effectiveness, smart operations have been developed: pseudo-emulsion membrane based strip dispersion (PEMSD), pseudo-emulsion based hollow fiber strip dispersion (PEHFSD), hollow fiber renewal liquid membrane (HFRLM) and double strip dispersion hybrid liquid membrane (SDHL...

Sorption of indium (III) onto carbon nanotubes.

Indium has numerous applications in different industrial sectors and is not an abundant element. Therefore appropriate technology to recover this element from various process wastes is needed. This research reports high adsorption capacity of multiwalled carbon nanotubes (MWCNT) for In(III). The effects of pH, kinetics, isotherms and adsorption mechanism of MWCNT on In(III) adsorption were investigated and discussed in detail. The pH increases improves the adsorption capacity for In(III). The Langmuir adsorption model is the best fit with the experimental data. For the kinetic study, the adsorption onto MWCNT could be fitted to pseudo second-order. The adsorption of indium(III) can be described to a mechanism which consists of a film diffusion controlled process. Metal desorption can be achieved with acidic solutions.

Mercury leaching from hazardous industrial wastes stabilized by sulfur polymer encapsulation

European Directive 2013/39/EU records mercury as a priority hazardous substance. Regulation n° 2008/1102/EC banned the exportation of mercury and required the safe storage of any remaining mercury compounds. The present work describes the encapsulation of three wastes containing combinations of HgS, HgSe, HgCl2, HgO2, Hg3Se2Cl2, HgO and Hg(0), according to patent of Spanish National Research Council WO2011/029970A2. The materials obtained were subjected to leaching tests according to standards UNE-EN-12457 and CEN/TS 14405:2004. The results are compared with the criteria established in the Council Decision 2003/33/EC for the acceptance of waste at landfills. The Hg concentrations of all leachates were <0.01mgHg/kg for a liquid/solid ratio of 10l/kg. All three encapsulated materials therefore meet the requirements for storage in inert waste landfills.

Recycling of copper flue dust via leaching-solvent extraction processing

AbstractA laboratory-/bench-scale investigation relating to copper recovery from Chilean copper flue dust is described. Since the dust contained a high amount of copper (nearly 24%), the considered option consisted in the leaching of the metallic material with ammonium chloride solution, thus enabling the dissolution of copper via its ammoniacal complexes, and also rendering, due to the almost neutral conditions of the leaching solution, a near complete lean solution with respect to the presence of other metal accompanying in the dust. Results obtained show that with ammonium chloride solutions, nearly 90% of the copper contained in the dust can be leached at 20°C. Copper enters the solvent extraction-electrowinning circuit due to the following equilibria:regenerating both the leaching and the solvent extraction reagents. In the above equation, HR represented the active substance of the extractant (Acorga PT5050) used in the solvent extraction circuit; the first of the above equilibria is related to the e...

Estudio cinético, en condiciones no-isotérmicas, de la desorción térmica del mercurio en suelos contaminados

The Almadén mining district (Ciudad Real, Spain) was the largest cinnabar (mercury sulphide) mine in the world. Its soils have high levels of mercury a consequence of its natural lithology, but often made much worse by its mining history. The present work examines the thermal desorption of two contaminated soils from the Almadén area under non-isothermal conditions in a N2 atmosphere, using differential scanning calorimetry (DSC). DSC was performed at different heating rates between room temperature and 600 °C. Desorption temperatures for different mercury species were determined. The Friedman, Flynn-Wall-Ozawa and Coasts–Redfern methods were employed to determine the reaction kinetics from the DSC data. The activation energy and pre-exponential factor for mercury desorption were calculated.

New Construction Materials: Calcined Paper Sludges as Active Additions

This paper shows the possibility of reutilize paper sludge waste as supplementary cementing material for the cement manufacture. This industrial waste consists essentially of a mixture of organic matter (30%) and inorganic compound, such as calcite and clay minerals. The raw paper sludge does not present pozolanic properties, but once calcined at 650°C during 2 hours, exhibits a good pozolanic activity. Calcined paper sludge was used as partial Portland cement replacements of 0 and 10%. It was a sligth increment in compressive strength for 10 % of substitution from 7 days on. Furthermore, calcined paper sludge reduces the initial and final setting times of cement paste.

Industrial aluminum hazardous waste as a new raw material for zeolite synthesis

In Spain, the secondary aluminum industry is a mature activity which produces 35% of the total aluminum production. This industry generates slag (black dross) with a valuable content of aluminum which is recovered by dry milling processes in the aluminum tertiary industry. The powdered fine solid is trapped in the sleeve filter suction system of the aluminum slag milling process. This solid is considered as a hazardous waste within the 10 03 21 group in the European Waste Catalogue (EWC), because of the very fine grain size (x50 < 50 µm) and the presence of dangerous substances (metallic aluminum, AlN, heavy metals, etc.). The high aluminum nitride content, ranging between 2 and 24%, is remarkable and it releases ammonia gas in the presence of environmental humidity. The aim of this work was to evaluate the complete recovery of the fine powders coming from the sleeve filters in the aluminum tertiary industry, as a zeolite. Two types of zeolite, analcime and NaP were obtained by hydrothermal processes from the aluminum waste and silica as raw materials. Different compositions of wastes and parameters such as time and temperature were assayed to study their effects on the obtained zeolites. The materials were characterized by X-ray diffraction and scanning electron microscopy.

Study of five hydraulic dam sludges from Argelia as pozzolanic materials

10 paginas, 2 figuras. Les applications alimentaires du chitosane es el capitulo 8 del libro.Deseamos agradecer al Instituo de Cooperacion Iberoamerican (Madrid) la ayuda economica concedida para la realizacion de este trabajo, y al Dr. Ramon Fewrreyra (Museo de Historia Natural, Universidad Mayor de San Marcos, Lima) la recoleccion y clasificacion de lna planta. Uno de nosotros, V. P. G., agradece al Cabildo Insular de La Palma la concwsion de una beca para su realizacion.Structure et diversite de la strate arbustive des forets de la Peninsule Tingitane (Maroc). Cette etude concerne les communautes vegetales arbustives des massifs forestiers sur substrat greseux couvrant la Peninsule Tingitane au nord ouest du Maroc. La structure et la diversite de ces communautes ont ete etudiees sur la base de 98 releves representatifs. Les suberaies (Quercus suber) sont les formations forestieres naturelles les plus representatives et les plus diversifiees de l?aire d?etude. L?altitude s?est revelee etre un facteur ecologique tres discriminant, en separant clairement les communautes arbustives des forets des hautes montagnes. Au niveau des zones de basses altitudes, la fertilite, l?acidite et la perturbation anthropique jouent un role determinant dans la distribution des communautes vegetales arbustives. Cette distribution semble exprimer la dynamique de la vegetation selon un gradient de conservation-perturbation. En conclusion, l?etude souligne l?interet remarquable que presentent les forets du nord du Maroc, du point de vue de leurs significations ecologiques, biogeographiques et evolutives.The effect of regrowth age (30, 45, 60, 75 and 90 d) in the content of secondary metabolites from Neonotonia wightii was evaluated through a random blocks design, with six replications. The experiment took place from January to March (dry season) and from May to July (rainy season), in a carbonated brown soil, without irrigation and fertilization. Total tannins, total phenols, total condensed tannins, total mixed condensed tannins, free condensed tannins, flavonoids, saponins, alkaloids, triterpenes and steroids increased (P < 0.05) with age and the highest values were obtained at 90 d (5.24; 10.07; 77.67; 76.72; 0.95; 3.29; 0.53; 0.30; 8.58 and 0.63 g/kg DM during May-June-July and 3.12; 8.24; 96.64; 94.68; 1.96; 3.99; 0.52; 0.30; 8.51 and 0.69 g/kg DM during January-February-March, respectively). It can be concluded that regrowth age and climatic factors had a marked effect on the concentration of secondary metabolites. It was demonstrated that while the plant was maturing, the tenors of secondary metabolites increased. Only total condensed tannins and total mixed condensed tannins surpassed the limits in which the ruminant fermentation could be affected. It is recommended not to use this plant with an regrowth age higher than 75 d old. A similar study is suggested to be conducted with this and other legumes, in different environmental conditions, and to determine the relation between these metabolites and the digestibility and intake of these plants. Key words: legumes, maturity stage, tannins, flavonoids, saponins, alkaloidsThis work was carried out as part of the AECID project, reference A/8500/07 and A/019119/08, developed between CSIC (Madrid, Spain) and the University of Granma, Cuba. BRD was supported by contracts of Junta de Comunidades de Castilla-La Mancha (POII09-0182-3834 and POII10-0211-5015).Resumen es: En el marco del actual debate sobre el sistema de cooperacion al desarrollo, suscitado por la crisis financiera y existencial que atraviesa, el articulo ...Trabajo presentado en el II Simposium Iberoamericano en Nanotecnologia y Calidad Ambiental, celebrado en Mexico del 18 al 22 de febrero de 2013.Este trabajo de investigacion ha sido financiado por el Programa de Cooperacion Interuniversitaria e Investigacion Cientifica de la AECID (A/030613/10).Se realizaron seis experimentos simultaneos para determinar la composicion bromatologica de leguminosas forrajeras en las condiciones edafoclimaticas del Valle del Cauto, Cuba. Se empleo un diseno en bloques al azar con seis replicas y los tratamientos fueron las edades de rebrote de 60, 120 y 180 dias para los arboles y arbustos ( Leucaena leucocephala, Tithonia diversifolia, Gliricidia sepium y Eritrina varie - gata ) y de 30, 45, 60, 75 y 90 dias para las leguminosas rastreras ( Neonotonia wightii y Te - ramnus labialis ), en los periodos lluvioso y poco lluvioso. Se determinaron MS, PB, Ca, P, Mg, Si, FND, FAD, LAD, celulosa, hemicelulosa, contenido celular, ceniza, MO, DIVMS, DV, DISMS, DMO, DFND, DFAD y DPB. Se realizaron analisis de conglomerados para agrupar las especies con caracteristicas simila - res. Durante el periodo lluvioso se encontraron seis grupos y en el poco lluvioso siete grupos; con los mejores resultados, de forma integral, para la Neonotonia wightii, Teramnus labialis, Gliricidia sepium y Tithonia diversifolia , en el periodo lluvioso; y en el poco lluvioso, para Tithonia diversifolia, Gliricidia sepium y Erythri - na variegata a edades tempranas. Se concluye que la edad presento un marcado efecto en la composicion bromatologica al disminuir la calidad en la medida que la madurez avanza.69 paginas.-- 10 figuras.-- 47 referencias.-- Memoria preseanta en el del XLIII Curso Internacional de Edafologia y Biologia VegetalEn un diseno de bloques al azar con seis replicas se evaluo la influencia de la edad de rebrote (30 a 75 d) y los factores del clima en la calidad nutritiva del pasto Panicum maximum vc. Mombasa. El experimento se enmarco en los trimestres enero-febrero-marzo (poca lluvia) y mayo-junio-julio (lluvia), en suelo de tipo pardo con carbonato, sin riego ni fertilizacion. Las correlaciones mas altas se presentaron entre los indicadores de calidad y edad, temperatura media, humedad relativa maxima y lluvias. Las ecuaciones de regresion lineal durante el periodo lluvioso presentaron R2 que variaron entre 0.97 y 0.99. Se destacaron MS, FND, celulosa, hemicelulosa, y digestibilidad in situ. Los menores errores estandar de estimacion se obtuvieron en FND, celulosa y hemicelulosa. Se concluye que la edad de rebrote y las condiciones climaticas tuvieron efecto marcado en el valor nutritivo. Se recomienda continuar estudios de estos indicadores en diferentes tipos de suelos, en las condiciones edafoclimaticas del Valle del Cauto, con el objetivo de disponer de mas informacion10 paginas, 2 figuras. Les applications alimentaires du chitosane es el capitulo 8 del libro.Through a completely randomized design with six replicates, the effect of the re-growth age (30, 45, 60, 75 and 90 d) on the nutritive quality of Neonotonia wightii was assessed, as well as the relation between its digestibility, ME and tannins. The experiment was conducted during the trimesters January-February-March (dry season) and May-June-July (rainy season), on a brown soil with carbonate, without irrigation or fertilization. The DM, silica (Si), NDF, ADF and lignin increased (P < 0.05) with age and the highest values were obtained at 180 d, while the CP, DM in vitro digestibility and ME diminished (P < 0.05). The highest values were reached at 30 d. The total phenols, total tannins and total condensed tannins increased (P < 0.05) with the re-growth age in both seasons and reached the maximum concentrations at 90 d (10.7, 5.24 and 77.66 g/kg DM in May-June-July and 8.24, 3.12 and 96.64 g/kg DM in January-February-March, respectively). In both seasons, high negative correlations (between -0.82 and -0.99) were obtained between the total phenols, total tannins and total condensed tannins and the DM in vitro digestibility, OMD, DM in situ digestibility, true digestibility (TD) and ME. It is concluded that age had a marked effect on the indicators assessed, more highlighted in the rainy season, when the nutritive quality diminished due to the increase of the fiber fraction, diminishing of the protein, digestibility and ME, and due to the inverse relation between the two last indicators and the phenolic compounds. Studies on other legumes under different edafoclimatic and management conditions are suggested. Key words: legume, phenolic compound, tannins, digestibility, energy.Trabajo presentado en el 8th International Mesostructured Materials Symposium, celebrado en Awaji Island, Hyogo (Japon) del 20 al 24 de mayo de 2013.Los trabajos arqueologicos que se recogen en este articulo se encuadran en el Proyecto financiado por el Ministerio de Cultura del Gobierno de Espana, dentro del Programa Anual de Arqueologia en el Exterior, y la AECID.Pratylenchus goodeyi obtained from a field population, infecting banana roots at Madeira island, Portugal, was cultured on carrot discs at 25 °C in a growth chamber to determine its rate of reproduction and to compare the morphometry of the axenically produced population with that of specimens from a field population and from previous published descriptions. An initial inoculum level of 12 specimens (ten females and two males) produced, after four months, up to 39,000 specimens/single disc, in all stages of development (eggs, juveniles and adults with a sex ration between females and males of 12:1). The main morphometric features with stable value (such as stylet length, V%, spicules and gubernaculum length, etc.) of specimens from the carrot disc culture closely agreed with the original description, and the banana populations from Cameroon and Maderia.The 3rd Edition of the International Congress: Waters, Wastes and Environment. Fez, Marruecos. Nov. 2011Resumen es: Se realizo un estudio cinetico de la fotopolimerizacion de la parte organica de composites preparados en base de Bis-GMA en diferentes atmosferas (O2 y N...Trabajo presentado en el 4th Federation of African Chemical Societies (FASC) congress, celebrado en Marrakech (Marruecos) del 7 al 9 de mayo de 2013.El presente trabajo ha sido financiado por proyectos del Ministerio de Ciencia e Innovacion, la Comunidad de Madrid, la Junta de Comunidades de Castilla-La Mancha, la Fundacion Ramon Areces y la Agencia Espanola de Cooperacion Internacional para el Desarrollo.En el macizo de Moa se encuentran lateritas ricas en cobalto y niquel que estan siendo explotadas por las companias mineras debido a su gran interes economico. Pero existen tambien grandes volumenes de minerales no metalicos, que no han sido estudiados. En este trabajo se aborda la evolucion de las fases a alta temperatura de estos materiales que presentan diferentes relaciones gibsita/caolinita para su posterior aplicacion en la industria ceramica. Se ha realizado su caracterizacion granulometrica, quimica (ICP-OES, fotometria de llama), mineralogica (DRX) y microestructural (MEB-EDS). La caolinita es la fase arcillosa mayoritaria, especialmente en una de las muestras con una relacion SiO2/Al2O3 de 1,16; el resto de las muestras presentan un exceso considerable de Al2O3 (gibsita o geles). Los altos contenidos de alumina (33 � 45% en peso) y compuestos de hierro (12 - 21% en peso) de Fe2O3 en forma de hematites, goethita o geles junto con los bajos porcentajes de alcalinos y silice dan lugar a una alta refractariedad de estas arcillas. A elevadas temperaturas los compuestos de hierro reaccionan con los de aluminio, formando espinela (FeAl2O4), soluciones solidas de hierro en el corindon (Al1-xFexO) y la mullita (Al6-yFeySi2O13) y magnetita. La presencia de esta ultima fase, unida a la refractariedad de las muestras sugiere su posible aplicacion en el campo de los materiales ceramicos, como acumuladores de calor.Uno de los pilares de la dieta mediterranea son las legumbres, un alimento de renovado interes nutricional, puesto que contiene compuestos bioactivos que pueden presentar efectos beneficiosos para nuestra salud. Ademas de la presencia de compuestos fenolicos relacionados con la actividad antioxidante resultan de gran interes otros componentes con una funcionalidad prebiotica (fibra alimentaria, y almidon resistente) por los numerosos efectos positivos sobre el organismo. Sin embargo, la presencia de las leguminosas en la dieta queda cada dia mas relegada, por lo que se hace necesario encontrar nuevas formas de incorporalas a la vida moderna. Actualmente, el proceso de germinacion ha puesto en evidencia una mejora en la calidad nutricional y sensorial de las leguminosas. Este proceso puede significar una via que atraiga la atencion del consumidor con la consiguiente incorporacion de germinados en su dieta. Por este motivo el objetivo general del presente proyecto de Tesis Doctoral es avanzar en el conocimiento cientifico de compuestos de la pared celular vegetal, concretamente fibra alimentaria, y del almidon resistente, asi como de los efectos de la aplicacion de los procesos de coccion y germinacion. Se ha empleado como modelo vegetal semillas de leguminosas (judia variedad Tolosa y lenteja variedad La Armuna), para la posible utilizacion de sus harinas como ingredientes de funcionalidad mejorada en una dieta de un colectivo de personas sanas. Asimismo, surge la necesidad de evaluar las modificaciones que los procesamientos anteriormente mencionados originan sobre las propiedades fisico-quimicas y tecnofuncionales de las harinas obtenidas, que pueden resultar de gran interes para la industria alimentaria y de restauracion. Los resultados derivados de la investigacion serviran para informar al consumidor sobre los efectos beneficiosos de la inclusion de estas leguminosas procesadas en su dieta habitual. El objetivo global de este trabajo se ha desarrollado a traves de los siguientes objetivos especificos: 1. Estudio inicial de caracterizacion de leguminosas (Capitulo 1); 2. Evaluacion de la influencia de los procesos de coccion y germinacion sobre los principales componentes de leguminosas: o Fraccion de carbohidratos complejos (fibra alimentaria y almidon) (Capitulo 2); o Pared celular como origen de la fibra alimentaria (Capitulo 3); o Fraccion proteica (Capitulo 4); y o Polifenoles totales y capacidad antioxidante (Capitulo 5); 3. Evaluacion de las propiedades hipoglucemicas en harinas de leguminosas sometidas a los procesos de coccion y germinacion (Capitulo 6). 4. Estudio de la repercusion de dichos procesos sobre las propiedades tecnofuncionales de harinas de leguminosas (Capitulo 7). Este estudio forma parte del proyecto de investigacion ?Valoracion de componentes bioactivos (compuestos fenolicos y componentes de la pared celular), como criterio de calidad de leguminosas crudas y procesadas?, proyecto no AGL2008-05673-C02-02/ALI enmarcado en las Acciones Estrategicas del Programa Nacional de Alimentacion del Ministerio de Ciencia e Innovacion, en colaboracion con el Instituto de Fermentaciones Industriales. Este trabajo se ha llevado a cabo fundamentalmente en el Laboratorio de Caracterizacion de Productos Vegetales del Departamento de Produccion y Caracterizacion de Nuevos Alimentos del CIAL (Instituto de Investigacion en Ciencias de la Alimentacion) y del Departamento de Quimica Agricola de la Universidad Autonoma de Madrid. El analisis de las proteinas fue realizado en Instituto de Medicina Molecular Aplicada (IMMA) de la Universidad San Pablo CEU.