Person: Montero González, Esperanza
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First Name
Esperanza
Last Name
Montero González
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Geodinámica Externa
Identifiers
17 results
Search Results
Now showing 1 - 10 of 17
Item Methanol-enhanced degradation of carbon tetrachloride by alkaline activation of persulfate: Kinetic model(Science of the Total Environment, 2019) Dominguez, Carmen M.; Rodríguez Gutiérrez, Vanesa; Montero González, Esperanza; Romero, Arturo; Santos, AuroraCarbon tetrachloride (CT), a chlorinated organic compound widely used in the chemical industry during the 20th century, is nowadays a ubiquitous contaminant in groundwater and in situ technologies for its destruction are required. In this work, the degradation of CT by the alkaline activation of persulfate (PS) has been studied. Among the pool of radical species generated (hydroxyl radicals, sulfate radicals and superoxide radicals), O2∙− resulted to be the only species responsible for CT abatement. It has been found that the presence of other solvents less polar than water (hydrogen peroxide, acetone, propanol and methanol) improves CT degradation. Among them, methanol was selected as the most adequate co-solvent, leading to the complete elimination of CT (100 mg L−1, 24 h) with a moderate unproductive consumption of the oxidant. The degradation of CT increased proportionally with the concentration of this solvent (from 0.1 to 10 g L−1). The ratio NaOH:PS (from 1 to 8) did not affect the degradation of CT when working with a constant concentration of PS and highly alkaline conditions were maintained. The removal rate of CT increased as the concentration of PS increased (from 20 to 60 g L−1), while the conversion of this pollutant did not depend on its initial concentration (from 10 to 100 mg L−1). A kinetic model that considers the concentration of PS, MeOH and CT and can predict the concentration of CT with reaction time at different operating conditions, has been developed from the experimental data.Item Rain-fed granite rock pools in a national park: extreme niches for protists(Limnetica, 2021) Pérez Uz, María Blanca; Velasco González, Ismael; Murciano, Antonio; Sánchez Jiménez, Abel; García-Rodriguez, M.; Centeno Carrillo, Juan de Dios; Montero González, Esperanza; Muñoz Araújo, Benito; Olmedo Salinas, Cristina; Quintela Alonso, Pablo; Refoyo Román, Pablo; Williams, Richard Alexander John; Martín Cereceda, María MercedesRain-fed granite rock pools are geological landforms with a worldwide distribution. However, their role as habitats for microorganisms has been barely explored. We carried out a detailed morphological inventory of the ciliated protists in the sediments of three granite rain-fed rock pools from a Spanish National Park. The ciliate seed bank in the rock pools comprised 54 morphospecies. The species number inferred for each pool by rarefaction analysis was similar to that observed by microscopy. The most representative species were small bacterivorous ciliates, although the distribution of ciliate groups was significantly different in each rock pool. Testate amoebae were also found to be rich in species. This study demonstrates the existence of a diverse ciliate community adapted to persist in these ephemeral and extreme rock pool habitats through species resistance structures, many of which have not been described previously. The presence of competitive species in dormant stages prevents local extinctions through a sequential excystation over time. Our results provide a benchmark for studying protist and microbial biodiversity within rain-fed granite rock pools, a unique habitat that merits bio- and geo- conservation.- Project number: 219
Item Los juegos del agua: el desafío de la gestión de las aguas subterráneas(2019) De Stefano, Lucia; Urquijo Reguera, Julia; Montero González, Esperanza; Bolinches Quero, Antonio; Villarroya Gil, Fermín IgnacioEl juego tiene una duración aproximada de 2,5 horas y ayuda a despertar el interés del alumnado sobre los retos del uso y gestión de las aguas subterráneas, haciéndoles por tanto receptivos a los contenidos teóricos relacionados que se explican en las clases siguientes (medidas de gestión del agua, normativa, etc.). Item A survey of domestic wells and pit latrines in rural settlements of Mali: Implications of on-site sanitation on the quality of water supplies(International Journal of Hygiene and Environmental Health, 2017) Martínez Santos, Pedro; Díaz Alcaide, Silvia; Martín Loeches, Miguel Martín; García Castro, Javier; Solera Alfonso, Diego; Montero González, Esperanza; García Rincón, J.On-site sanitation is generally advocated as a means to eradicate the health hazards associated with open defecation. While this has provided a welcome upgrade to the livelihoods of millions of people in low-income countries, improved sanitation facilities are increasingly becoming a threat to domestic groundwater-based supplies. Within this context, a survey of pit latrines, domestic wells and improved water sources was carried out in a large rural village of southern Mali. All households were surveyed for water, sanitation and hygiene habits. Domestic wells and improved water sources were georeferenced and sampled for water quality (pH, electric conductivity, temperature, turbidity, total dissolved solids, thermotolerant coliforms, chloride and nitrate) and groundwater level, while all latrines were inspected and georeferenced. A GIS database was then used to evaluate the proportion of water points within the influence area of latrines, as well as to underpin multiple regression models to establish the determinants for fecal contamination in drinking supplies. Moreover, an appraisal of domestic water treatment practices was carried out. This revealed that nearly two-thirds of the population uses bleach to purify drinking supplies, but also that domestic-scale treatment as currently implemented by the population is far from effective. It is thus concluded that existing habits could be enhanced as a means to make water supplies safer. Furthermore, population, well and latrine density were all identified as statistically significant predictors for fecal pollution at different spatial scales. These findings are policy-relevant in the context of groundwater-dependent human settlements, since many countries in the developing world currently pursue the objective of eliminating open defecation.Item Funcionamiento hidrogeológico del sistema de las Lagunas de Ruidera(2024) Montero González, Esperanza; Martínez Alfaro, Pedro EmilioEl Campo de Montiel, Unidad Hidrogeológica 04-04, se encuentra situado entre las provincias de Ciudad Real y Albacete, al sur de la Llanura Manchega, tiene una superficie aproximada de 2500 km2. Su cota topográfica varía entre los 800 metros al norte y los 1000metros al sur. Constituye un páramo calcáreo formado por calizas y dolomías del Jurásico Inferior(Lías) con una potencia media de 75 a 100 metros, que yace sobre un sustrato impermeable del Triásico Superior en facies Keuper. La recarga se produce exclusivamente a partir de la precipitación directa y la descarga a través de manantiales que dan lugar a ríos y arroyos que vierten a las cuencas del Jucar, Guadalquivir y fundamentalmente a la del Guadiana. La red fluvial, orientada preferentemente en dirección NO-SE disecta el acuífero en varias subcuencas, siendo la principal la del Guadiana Alto o Pinilla, donde se desarrollan las Lagunas de Ruidera, declaradas Parque Natural en 1984. Se trata de quince lagunas alineadas en dirección NO-SE que aparecen escalonadas a lo largo de unos 35 km, con un desnivel de 120 metros entre la primera y la última. Están separadas entre sí por barras formadas por materiales travertínicos, comunicandose a través de cascadas, canales y subterráneamente...Item La corta inundada de Aznalcóllar y su uso como vertedero de residuos mineros (Sevilla, España)(Boletín Geológico y Minero, 2011) Santofimia Pastor, Esther; López Pamo , E.; Montero González, EsperanzaDesde su cierre en 1995 y el accidente de la balsa de lodos en 1998, la corta minera de Aznalcóllar ha sido utilizada como vertedero de diversos materiales, como los suelos contaminados retirados del área del río Guadiamar o residuos mineros de estériles, lodos piríticos y cenizas de tostación de pirita. La corta minera está parcialmente inundada y contiene un lago ácido (pH 2,7) con un volumen de ~6 Mm3 de agua enriquecida en metales y sulfato. Las investigaciones detalladas realizadas en la mina durante estos últimos años, han demostrado que los vertidos y la entrada de aguas ácidas de mina están modificando de manera notable la calidad del agua del lago. La mayor afección a la calidad del agua del lago de Aznalcóllar se debió al vertido de 1,4 Mm3 de una escombrera de pirita, entre 2005 y 2006. La disolución oxidativa de este mineral ha causado (i) un consumo total de oxígeno disuelto, (ii) un aumento notable de la conductividad eléctrica (de 8,6 a 12 mS/cm), (iii) una fuerte acidificación (pH de 4,2 a 2,7) y un calentamiento debido al carácter exotérmico de la oxidación de la pirita. A pesar de la ausencia de los agentes que oxidan a la pirita en el lago, como O2 y Fe (III) (Fe (III) <5 % Fetotal), la pirita continúa oxidándose con un incremento de las concentraciones de SO4 2- y Fe. [ABSTRACT] Since its closure in 1995 and the subsequent failure of the slurry deposit dam in 1998, the Aznalcóllar pit has been used as a disposal site for diverse metal-rich materials, such as the polluted soils removed during the cleaning-up of areas along the Guadiamar river together with waste rock, pyrite sludge and ashes deriving from pyrite roasting. At present the pit is partly flooded with a highly acidic (pH 2.7) lake holding some 6 Mm3 of metal- and sulphate-rich water. Detailed research undertaken in the area during recent years has proved that the dumping of wastes and the inflow of acidic mine waters are having a dramatic effect on the quality of the water in the lake. The greatest effect upon the Aznalcóllar lake water was due to the dumping of 1.4 Mm3 of pyritic wastes during 2005 and 2006. The oxidative dissolution of this mineral has resulted firstly in the total consumption of dissolved oxygen, secondly, a notable increase in electric conductivity (from 8.6 to 12 mS/cm), thirdly, considerable acidification (from pH 4.2 to 2.7) and finally, heating due to the exothermic character of pyrite oxidation. Despite the almost total lack of oxidizing agents such as O2 and Fe(III) (Fe(III)<5% Fetotal) in the pit lake, pyrite continues to oxidize, producing a concomitant increase in SO4 2- and Fe.Item Abatement of dichloromethane using persulfate activated by alkali: A kinetic study(Separation and Purification Technology, 2020) Dominguez, Carmen M.; Rodríguez Gutiérrez, Vanesa; Montero González, Esperanza; Romero, Arturo; Santos, AuroraThe alkaline activation of persulfate (PS) has been tested in this study as in situ oxidation technology for the abatement of dichloromethane (DCM), a chlorinated volatile organic pollutant commonly found in groundwater due to its wide use as solvent in the chemical industry during the last decades. The addition of an alkali (NaOH) as persulfate activator generates hydroxyl and superoxide radicals, achieving the total degradation of the pollutant (XDCM = 99%, 96 h, CDCM = 1.2 mmol L−1, CPS = 42 mmol L−1, CNAOH = 169 mmol L−1). From the results obtained in the presence of a hydroxyl radical-scavenger (methanol, CMeOH = 313 mmol L−1), it has been concluded that only hydroxyl radicals are responsible of DCM abatement. Trichloroethylene was identified as intermediate compound and formic acid and chloride as degradation products. The conversion of DCM increased as the initial concentration of the pollutant decreased (from 1.2 mmol L−1 to 0.1 mmol L−1), whereas an increase in the oxidant concentration (from 8 to 168 mmol L−1) led to an increase in the degradation rate of the pollutant. Finally, the molar ratio NaOH:PS (in the range 1–4) did not affect the degradation of the pollutant when a pH high enough (>12) was maintained. A kinetic model, able to predict adequately the experimental DCM concentration profiles as a function of the concentration of DCM, PS and NaOH, has been developed. The kinetic model discriminated was zero order, first order and hyperbolic order for NaOH, PS and DCM concentration, respectively.Item Multiclass spatial predictions of borehole yield in southern Mali by means of machine learning classifiers(Journal of Hydrology. Regional studies, 2022) Gómez Escalonilla, Víctor; Diancoumba, Oumou; Traoré, D.Y.; Montero González, Esperanza; Martín Loeches, Miguel Martín; Martínez Santos, PedroStudy region: Regions of Bamako, Kati and Kangaba, southwestern Mali Study focus: Machine learning-based mapping of borehole yield. Three algorithms were trained on an imbalanced multiclass database of boreholes, while twenty variables were used as predictors for borehole yield. All models returned balanced and geometric scores in the order of 0.80, with area under the receiver operating characteristic curve up to 0.87. Three main methodological conclusions are drawn: (a) The evaluation of different machine learning classifiers and various resampling strategies and the subsequent selection of the best performing ones is shown to be a good strategy in this type of studies; (b) ad hoc calibration tools, such as data on borehole success rates, provide an apt complement to standard machine learning metrics; and (c) a multiclass approach with an unbalanced database represents a greater challenge than predicting a bivariate outcome, but potentially results in a finer depiction of field conditions. New hydrological insights for the region: Alluvial sediments were found to be the most productive areas, while the Mandingue Plateau has the lowest groundwater potential. The piedmont areas showcase an intermediate groundwater prospect. Elevation, basement depth, slope and geology rank among the most important variables. Lower values of clay content, slopes and elevations, and higher values of basement depth and saturated thickness were linked to the most productive class.Item Clustering Groundwater Level Time Series of the Exploited Almonte-Marismas Aquifer in Southwest Spain(Water, 2020) Naranjo Fernández, Nuria; Guardiola-Albert, Carolina; Aguilera Alonso, Héctor; Serrano Hidalgo, Carolina; Montero González, EsperanzaGroundwater resources are regularly the principal water supply in semiarid and arid climate areas. However, groundwater levels (GWL) in semiarid aquifers are suffering a general decrease because of anthropic exploitation of aquifers and the repercussions of climate change. Effective groundwater management strategies require a deep characterization of GWL fluctuations, in order to identify individual behaviors and triggering factors. In September 2019, the Guadalquivir River Basin Authority (CHG) declared that there was over-exploitation in three of the five groundwater bodies of the Almonte-Marismas aquifer, Southwest Spain. For that reason, it is critical to understand GWL dynamics in this aquifer before the new Spanish Water Resources Management Plans (2021–2027) are developed. The application of GWL series clustering in hydrogeology has grown over the past few years, as it is an extraordinary tool that promptly provides a GWL classification; each group can be related to different responses of a complex aquifer under any external change. In this work, GWL time series from 160 piezometers were analyzed for the period 1975 to 2016 and, after data pre-processing, 24 piezometers were selected for clustering with k-means (static) and time series (dynamic) clustering techniques. Six and seven groups (k) were chosen to apply k-means. Six characterized types of hydrodynamic behaviors were obtained with time series clustering (TSC). Number of clusters were related to diverse affections of water exploitation depending on soil uses and hydrogeological spatial distribution parameters. TSC enabled us to distinguish local areas with high hydrodynamic disturbance and to highlight a quantitative drop of GWL during the studied period.Item Methanol-enhanced degradation of carbon tetrachloride by alkaline activation of persulfate: kinetic model(Science of The Total Environment, 2019) Domínguez Torre, Carmen María; Rodriguez, Vanesa; Montero González, Esperanza; Romero Salvador, Arturo; Santos López, AuroraCarbon tetrachloride (CT), a chlorinated organic compound widely used in the chemical industry during the 20th century, is nowadays a ubiquitous contaminant in groundwater and in situ technologies for its destruction are required. In this work, the degradation of CT by the alkaline activation of persulfate (PS) has been studied. Among the pool of radical species generated (hydroxyl radicals, sulfate radicals and superoxide radicals), O2∙− resulted to be the only species responsible for CT abatement. It has been found that the presence of other solvents less polar than water (hydrogen peroxide, acetone, propanol and methanol) improves CT degradation. Among them, methanol was selected as the most adequate co-solvent, leading to the complete elimination of CT (100 mg L−1, 24 h) with a moderate unproductive consumption of the oxidant. The degradation of CT increased proportionally with the concentration of this solvent (from 0.1 to 10 g L−1). The ratio NaOH:PS (from 1 to 8) did not affect the degradation of CT when working with a constant concentration of PS and highly alkaline conditions were maintained. The removal rate of CT increased as the concentration of PS increased (from 20 to 60 g L−1), while the conversion of this pollutant did not depend on its initial concentration (from 10 to 100 mg L−1). A kinetic model that considers the concentration of PS, MeOH and CT and can predict the concentration of CT with reaction time at different operating conditions, has been developed from the experimental data.