This page has only limited features, please log in for full access.
At the Nalón River estuary (Asturias, Northern Spain), the occurrence of Hg is due to historical mining activity which has resulted in environmental issues of great concern. Although several studies have investigated the sediment compartment regarding Hg contamination, no information is currently available on the fate of Hg and MeHg in the water column. Considering different hydrodynamic/seasonal conditions, water samples were collected along the estuary to evaluate Hg and MeHg distribution and partitioning behaviour between solid and aqueous phases. The complementary effect of the river discharge and tidal currents contributed to the prevalence of the dissolved (4.02 ± 1.33 ng L−1) or particulate (8.37 ± 4.20 ng L−1) Hg under different conditions of discharge in summer and autumn, respectively. Conversely, particulate MeHg prevailed when the river flow was low, especially at the estuary mouth (25.8 ± 19.1 pg L−1) and most likely due to the resuspension of fine particles promoted by a stronger tidal current. In comparison with the total Hg concentration, extremely low amounts of dissolved and particulate MeHg were observed, and strong interactions between MeHg and organic carbon highlighted a negligible risk of increased mobility and potential bioaccumulation of MeHg.
Elena Pavoni; Efren García-Ordiales; Stefano Covelli; Pablo Cienfuegos; Nieves Roqueñí. Legacy of Past Mining Activity Affecting the Present Distribution of Dissolved and Particulate Mercury and Methylmercury in an Estuarine Environment (Nalón River, Northern Spain). Applied Sciences 2021, 11, 4396 .
AMA StyleElena Pavoni, Efren García-Ordiales, Stefano Covelli, Pablo Cienfuegos, Nieves Roqueñí. Legacy of Past Mining Activity Affecting the Present Distribution of Dissolved and Particulate Mercury and Methylmercury in an Estuarine Environment (Nalón River, Northern Spain). Applied Sciences. 2021; 11 (10):4396.
Chicago/Turabian StyleElena Pavoni; Efren García-Ordiales; Stefano Covelli; Pablo Cienfuegos; Nieves Roqueñí. 2021. "Legacy of Past Mining Activity Affecting the Present Distribution of Dissolved and Particulate Mercury and Methylmercury in an Estuarine Environment (Nalón River, Northern Spain)." Applied Sciences 11, no. 10: 4396.
Elements in mining extracts can be potentially toxic if they are incorporated into soils, sediments or biota. Numerous approaches have been used to assess this problem, and these include sequential extractions and selective extractions. These two methods have limitations and advantages, and their combined use usually provides a rough estimate of the availability or (bio)availability of potentially toxic elements and, therefore, of their real potential as toxicants in food chains. These indirect speciation data are interesting in absolute terms, but in the work described here, this aspect was developed further by assessing the evolution of availability-related speciation in relation to the transport processes from the emission source, which are mainly fluvial- and wind-driven. This objective was achieved by characterizing tailings samples as the source of elements in soils and sediments at increasing distances to investigate the evolution of certain elements. The standard procedures employed included a sequential five-step extraction and a selective extraction with ammonium acetate. The results show that the highest percentages of Zn and Pb in tailings, soils and sediment samples are associated with oxyhydroxides, along with a significant presence of resistant mineralogical forms. In the case of Cd, its association with organic matter is the second-most important trapping mechanism in the area. The physicochemical mechanisms of transport did not transform the main mineralogical associations (oxyhydroxides and resistant mineralogical forms) along the transects, but they produced a chaotic evolution pattern for the other minor matrix associations for Zn and a decrease in exchangeable and carbonate-bound forms for Pb in soils. Interestingly, in sediments, these mobile forms showed a decrease in Zn and a chaotic evolution for Pb. The most probable reason for these observations is that Zn2+ can form smithsonite (ZnCO3) or hydrozincite (Zn5(CO3)2(OH)6), which explains the retention of a carbonate-bound form for Zn in the soil transect. In contrast, Pb and Cd can appear as different mineral phases. The order of (bio)availability was Pb > Zn > Cd in tailings but Cd > Pb > Zn in soils. The physicochemical processes involved in transport from tailings to soils produce an increase in Cd (bio)availability. The trend is a decrease in bioavailability on moving away from the source (tailings), with maximum values obtained for Cd near to the source area (200–400 m).
Intissar Elmayel; José María Esbrí; García-Ordiales Efrén; Efren Garcia; Zouhair Elouear; Bouzid Jalel; Alessandro Farieri; Nieves Roqueñí; Pablo Cienfuegos; Pablo Higueras. Evolution of the Speciation and Mobility of Pb, Zn and Cd in Relation to Transport Processes in a Mining Environment. International Journal of Environmental Research and Public Health 2020, 17, 4912 .
AMA StyleIntissar Elmayel, José María Esbrí, García-Ordiales Efrén, Efren Garcia, Zouhair Elouear, Bouzid Jalel, Alessandro Farieri, Nieves Roqueñí, Pablo Cienfuegos, Pablo Higueras. Evolution of the Speciation and Mobility of Pb, Zn and Cd in Relation to Transport Processes in a Mining Environment. International Journal of Environmental Research and Public Health. 2020; 17 (14):4912.
Chicago/Turabian StyleIntissar Elmayel; José María Esbrí; García-Ordiales Efrén; Efren Garcia; Zouhair Elouear; Bouzid Jalel; Alessandro Farieri; Nieves Roqueñí; Pablo Cienfuegos; Pablo Higueras. 2020. "Evolution of the Speciation and Mobility of Pb, Zn and Cd in Relation to Transport Processes in a Mining Environment." International Journal of Environmental Research and Public Health 17, no. 14: 4912.
New technological development and a best knowledge of the basin allow to have justified expectation to find coalbed methane reserves. Measurements of gas content in unexploited coal seams are made in order to estimate the CBM could revive the economic interest of the Asturian Central Coal Basin (ACCB). According to first estimations based on the studies accomplished, the minimum resources of coalbed methane in the whole of the Asturian Central Coal Basin are in the order of 25,000 Mm3 and the gas content of the coal seams range from 6 m3 to 14 m3/t. The introduction should briefly place the study in a broad context and define the purpose of the work and its significance.
Pablo Cienfuegos-Suárez; Efrén García-Ordiales; Diego Alonso-Fernández; Jorge Enrique Soto-Yen. CBM Resources Estimations for the Development of Coal Mine Methane in the Asturian Central Basin, Spain. Proceedings 2018, 2, 1404 .
AMA StylePablo Cienfuegos-Suárez, Efrén García-Ordiales, Diego Alonso-Fernández, Jorge Enrique Soto-Yen. CBM Resources Estimations for the Development of Coal Mine Methane in the Asturian Central Basin, Spain. Proceedings. 2018; 2 (23):1404.
Chicago/Turabian StylePablo Cienfuegos-Suárez; Efrén García-Ordiales; Diego Alonso-Fernández; Jorge Enrique Soto-Yen. 2018. "CBM Resources Estimations for the Development of Coal Mine Methane in the Asturian Central Basin, Spain." Proceedings 2, no. 23: 1404.
There is a number of risk issues associated with CBM/CMM operations: sealing the mine shafts; pumping the mine water; evacuating air from the mine and air ingress into the mine. Our team has investigated the details of the initial phase of the business plan and, by extrapolation of key parameters, was able to form an opinion on the larger plan. The details investigated include: the methods to calculate the volume of gas entrapped in the coal; the sealing of the mine shafts to trap the gas escape; and the process to keep the mines pumped dry by removing the underground water that drains into the mine workings.
Pablo Cienfuegos-Suárez; Diego Alonso-Fernández; Efrén García-Ordiales. Possibilities for Use of Coal Bed Methane & Coal Bed Mine in Asturias. Proceedings 2018, 2, 1495 .
AMA StylePablo Cienfuegos-Suárez, Diego Alonso-Fernández, Efrén García-Ordiales. Possibilities for Use of Coal Bed Methane & Coal Bed Mine in Asturias. Proceedings. 2018; 2 (23):1495.
Chicago/Turabian StylePablo Cienfuegos-Suárez; Diego Alonso-Fernández; Efrén García-Ordiales. 2018. "Possibilities for Use of Coal Bed Methane & Coal Bed Mine in Asturias." Proceedings 2, no. 23: 1495.
The water cycle in hydraulic fracturing shows five stages that includes, from the water supply, the manufacture of the fracturing fluid, the injection, recovery of the flowback and water produced, and the management of the same. Finally, the case applied in the Asturian coal basin (ACCB) is analyzed for the development of the exploration and production of methane gas from coal layers (CBM).
Pablo Cienfuegos-Suárez; Rocío García-Menéndez; Efrén García-Ordiales; Jorge Enrique Soto-Yen. Use & Re-Use of Water Resources in the Exploration Non-Conventional Hydrocarbons. Proceedings 2018, 2, 1405 .
AMA StylePablo Cienfuegos-Suárez, Rocío García-Menéndez, Efrén García-Ordiales, Jorge Enrique Soto-Yen. Use & Re-Use of Water Resources in the Exploration Non-Conventional Hydrocarbons. Proceedings. 2018; 2 (23):1405.
Chicago/Turabian StylePablo Cienfuegos-Suárez; Rocío García-Menéndez; Efrén García-Ordiales; Jorge Enrique Soto-Yen. 2018. "Use & Re-Use of Water Resources in the Exploration Non-Conventional Hydrocarbons." Proceedings 2, no. 23: 1405.
The geological storage of CO2 in coal seams is an emerging option in the portfolio of mitigation actions for reduction of atmospheric greenhouse gas concentrations. A background study focused to the selection of favorable sites for CO2 geological storage are necessary steps, and in the selection of reservoirs for CO2 sequestration a complete petrophysical characterization of the sample is necessary. To complement the classical petrophysical parameters measured on the rocks of the geological formation with potential to be used to store the injected CO2, a new equipment has been designed and constructed to simulate at a laboratory scale the inter-action between the rock and the injected CO2, at different pressure conditions simulating depths of the geological formations up to 1000 m. The design and construction of this equipment allows us to investigate known physical and chemical processes that occur between the rocks store/seal and the fluid injected into geological storage. Essays focused to study the alterability of the rock in contact with CO2 either in subcritical or supercritical state, as well as essays for CO2 injectivity on the rock can be accomplished.
Pablo Cienfuegos-Suárez; Efrén García-Ordiales; Jorge Enrique Soto-Yen. New Equipment for Complementary Petrophysical Characterization of Rocks for Deep Geological Storage. Proceedings 2018, 2, 1494 .
AMA StylePablo Cienfuegos-Suárez, Efrén García-Ordiales, Jorge Enrique Soto-Yen. New Equipment for Complementary Petrophysical Characterization of Rocks for Deep Geological Storage. Proceedings. 2018; 2 (23):1494.
Chicago/Turabian StylePablo Cienfuegos-Suárez; Efrén García-Ordiales; Jorge Enrique Soto-Yen. 2018. "New Equipment for Complementary Petrophysical Characterization of Rocks for Deep Geological Storage." Proceedings 2, no. 23: 1494.
In this article we present a geostatistical approach to the transmission tomographic inverse problem, which is based on consideration of the inverse problem variables (velocity and traveltime errors) as regionalized variables (R.V.). Their structural analysis provides us with a new method to study the geophysical anisotropy of the rock, an important source of a priori information in order to design the anisotropic corrections. The underlying idea is that the geophysical structure can be deduced from the spatial structure of the regionalized variables which result from solving the tomographic problem with an isotropic algorithm. Also, the application of the structural analysis technique to the anisotropic corrected velocity field allows us to characterize the reliability of these corrections (model quality analysis). Geostatistical formalism also provides us with different techniques (parametric and non-parametric) to estimate and even simulate the velocity in the areas where this field has been considered anomalous based on field studies and on geophysical and statistical criteria. The kriging acts as a low-pass smoothing filter for the anomalous model parameters (velocities), but is not a substitute for an adequate filtering of the outliers before the inversion. This methodology opens the possibility of considering the inverse problem variables as stochastic processes, an important feature in cases where the tomogram is to be used as a tool of assessment to quantify the rock heterogeneities.
Juan L. Fernández Martínez; César O. Menéndez Pérez; Luis Mariano Pedruelo González; José Paulino Fernández Álvarez; Pablo Cienfuegos Suarez. Geostatistical Analysis of Inverse Problem Variables: Application to Seismic Tomography. Mathematical Geosciences 2003, 35, 953 -969.
AMA StyleJuan L. Fernández Martínez, César O. Menéndez Pérez, Luis Mariano Pedruelo González, José Paulino Fernández Álvarez, Pablo Cienfuegos Suarez. Geostatistical Analysis of Inverse Problem Variables: Application to Seismic Tomography. Mathematical Geosciences. 2003; 35 (8):953-969.
Chicago/Turabian StyleJuan L. Fernández Martínez; César O. Menéndez Pérez; Luis Mariano Pedruelo González; José Paulino Fernández Álvarez; Pablo Cienfuegos Suarez. 2003. "Geostatistical Analysis of Inverse Problem Variables: Application to Seismic Tomography." Mathematical Geosciences 35, no. 8: 953-969.