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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.
The sedimentological and geochemical evolution of the internal platform located in front of the Llumeres cove (Asturias, North of Spain) has been studied, based on the analysis of selected sediment samples from 5 long corers, approximately 2 m thick, recovered for an offshore structures installation project. In each sample, a granulometric characterization has been carried out by the calculation of granulometric parameters (centile, mean, shorting, etc.) and the mineralogical composition (silica/biogenic carbonates). Geochemical analysis has also been made in the samples. The enrichment of selected heavy metals and metalloids (Zn, As, Cu, Pb and Hg) has been studied, applying the Geo-accumulation Index (Igeo) and the Enrichment Factor (EF). The results have also been subjected to multivariate and bivariate statistical analyzes that have allowed establishing the relationships between the elements and determining in a preliminary way their potential origin.
The sedimentological results point to the fact that the sediment was incorporated into the internal platform during the last stages of the sea level rise, which began some 20,000 years ago (Pleisto-Holocene transgression). At present, the zone enjoys stability, since no sedimentation is detected. These sediments are relict, without existing agreement with the siliciclastic sedimentation that is taking place at the moment in the coastal zone (Llumeres beach). Three main sandy lithologies have been analyzed: siliciclastic, mixed and carbonate sands which are distributed irregularly in the vertical. This is indicative of changes in the origin of the sediment (siliciclastic, due to the coastal drift current and bioclastic, typical from the platform), as well as the energy of the depositional agent with a clear decrease in size towards the top, detecting relatively large variations in size and the coarse sediments would correspond to moments of storm.
The geochemical results show that the area does not have a remarkable anthropic condition along the sedimentological profile. However, enrichment of some potential contaminants was detected in the more recent sediments (first centimeters of the boreholes), but the enrichment does not appear to pose an environmental risk and their origin seem to be related to nearby areas such as the Nalón River or the industrial area of Aviles that may export contaminants to the marine environment.
Germán Flor-Blanco; Efrén García-Ordiales; Raul Ruiz-Quesada; Luis Pando; Germán Flor. Sedimentological and environmental approach of the Llumeres offshore sediments (N Asturias-N Spain). 2021, 1 .
AMA StyleGermán Flor-Blanco, Efrén García-Ordiales, Raul Ruiz-Quesada, Luis Pando, Germán Flor. Sedimentological and environmental approach of the Llumeres offshore sediments (N Asturias-N Spain). . 2021; ():1.
Chicago/Turabian StyleGermán Flor-Blanco; Efrén García-Ordiales; Raul Ruiz-Quesada; Luis Pando; Germán Flor. 2021. "Sedimentological and environmental approach of the Llumeres offshore sediments (N Asturias-N Spain)." , no. : 1.
The inadequate treatment of waste materials in mine tailings, the closure stage not carried out correctly, carries risks due to the residues of potentially toxic elements (PTEs) that it may contain. In Panama, environmental regulations are recent, and even so the regulations are not strictly enforced, leaving a problem for the adjacent communities. Such is the case of the Remance Gold Mine, in Veraguas, Panama; this area has been exploited intermittently for over a hundred years, by different companies; the last period of exploitation was between 1989 and 1999, through a cyanidation process to extract the precious metal. Currently three tailing dams with mining waste are exposed to climatic conditions such as rain and wind, in addition to this, within the mine area and its surroundings live peasants who carry out subsistence activities such as agriculture and livestock. The purpose of this study was to evaluate the remaining potentially toxic elements and the persistence of cyanide in the tailings, and whether the remaining quantity represents a risk to human health and the environment, according to current environmental regulations in Panama and America. For this purpose, samples have been taken from the tailings and adjacent areas that could be directly related to the cyanidation process, geochemical analysis such as pH, CEC, conductivity, organic matter, potentially toxic elements and total cyanide have been carried out. The most concerning aspects of the results obtained here have been the contents of Ba (between 55 and 610 mg kg-1), Zn (between 12 and 153 mg kg-1), Sb (between 0.6 and 25.5 mg kg-1) and Hg (between 0.1 and 3.2 mg kg-1), which, according to the criteria of land use quality standards in Panama and American countries, correspond to values above the permissible limits for agricultural and residential land use. Meanwhile the levels of As (between 17.3 and 5030 mg kg-1) and Cu (between 5.4 and 403 mg kg-1) are higher than the legally established values for industrial land use. Far more significant are the values for total cyanide (between 1.4 and 518 mg kg-1), revealing the persistence of this chemical over time. These cyanide values are far higher than those reported in the literature for solid tailings from an abandoned gold mine and the values for gold mine tailings in the Americas, thus representing a serious threat to the environment.
Ana Cristina González Valoys; Tisla Monteza-Destro; José María Esbrí; Miguel Vargas-Lombardo; Efrén Garcia-Ordiales; Jonatha Arrocha; Raimundo Jiménez-Ballesta; Francisco Jesús Garcia-Navarro; Pablo Higueras. Risks associated with the presence of cyanide in waste materials in an abandoned gold mine, Panama. 2021, 1 .
AMA StyleAna Cristina González Valoys, Tisla Monteza-Destro, José María Esbrí, Miguel Vargas-Lombardo, Efrén Garcia-Ordiales, Jonatha Arrocha, Raimundo Jiménez-Ballesta, Francisco Jesús Garcia-Navarro, Pablo Higueras. Risks associated with the presence of cyanide in waste materials in an abandoned gold mine, Panama. . 2021; ():1.
Chicago/Turabian StyleAna Cristina González Valoys; Tisla Monteza-Destro; José María Esbrí; Miguel Vargas-Lombardo; Efrén Garcia-Ordiales; Jonatha Arrocha; Raimundo Jiménez-Ballesta; Francisco Jesús Garcia-Navarro; Pablo Higueras. 2021. "Risks associated with the presence of cyanide in waste materials in an abandoned gold mine, Panama." , no. : 1.
Juncus maritimus is the dominant halophyte in the marshes of the Nalón estuary, a Spanish area contaminated by mercury (Hg) as a consequence of mining activities. With the purpose of clarifying the Hg bioaccumualtion of this halophyte in this contaminated Hg salt marsh, sediments and Juncus maritimus samples were collected from seven locations. Hg uptake and allocation in the plant parts were evaluated in addition to the available, organic, and total concentrations in the buried sediments. The results showed that the presence of J. maritimus can modify the physico-chemical conditions of the salt marsh sediments where they grow, with an increase in the amount of potentially available Hg for uptake. In plants, most of the absorbed Hg (76.2to 97.3%) was retained in the root system, phytostabilising the element. J. maritimus accumulates high concentration of mercury in its organs, mainly in the buried parts, with enrichments from 3 to 24 times in the bioavailable Hg metal concentration detected in the sediments. Thus, J. maritimus could be used to stabilise Hg and hold it in the root system which could be useful in phytoremediation and phytostabilisation of saltmarsh areas contaminated by this problematic element.
Efren Garcia-Ordiales; Nieves Roqueñí; Jorge Loredo. Mercury bioaccumulation by Juncus maritimus grown in a Hg contaminated salt marsh (northern Spain). Marine Chemistry 2020, 226, 103859 .
AMA StyleEfren Garcia-Ordiales, Nieves Roqueñí, Jorge Loredo. Mercury bioaccumulation by Juncus maritimus grown in a Hg contaminated salt marsh (northern Spain). Marine Chemistry. 2020; 226 ():103859.
Chicago/Turabian StyleEfren Garcia-Ordiales; Nieves Roqueñí; Jorge Loredo. 2020. "Mercury bioaccumulation by Juncus maritimus grown in a Hg contaminated salt marsh (northern Spain)." Marine Chemistry 226, no. : 103859.
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.
Soil pollution associated with potentially toxic elements (PTEs) from mining residues is a significant problem worldwide. The decommissioned Jebal Trozza mine, located in central Tunisia, may pose a serious problem because of the possible high concentrations of PTEs present in its wastes. This mine is a potential source of contamination for agriculture in this area due to both direct causes (pollution of agricultural soils) and indirect causes (pollution of sediments that accumulate in a dam used for irrigation). The aim of the study reported here was to assess the effects of local mining activity in two respects: (1) in terms of soil quality, as determined by soil edaphological parameters and PTEs contents in the mining wastes and local soils; and (2) in terms of biological quality, as evaluated by quantification of enzymatic activity as an indicator of bacterial activity in soils and wastes. The mine tailings contained high levels of Pb (1.83–5.95%), Zn (7.59–12.48%) and Cd (85.95–123.25 mg kg−1). The adjacent soils were also highly contaminated with these elements, with average concentrations of Pb, Zn and Cd that exceeded the European standard values for agricultural soils (3, 300 and 300 mg kg−1 for Cd, Pb and Zn, respectively). Enzymatic dehydrogenase showed zero activity in waste piles and very low activity in PTE-contaminated soils, but this activity returned to normal values as the pollution decreased, thus demonstrating the effect that the contamination load had on the health of the studied soils. A Statistical Factor Analysis clearly distinguished three groups of samples, and these are related to the influence that mining on the soils and sediments had on the PTE concentrations and their effects on the biological quality of the soil. An environmental assessment based on the enrichment factor criteria indicated risk levels that varied from strongly to severely polluted. The risk appears to be greater close to the mine, where the highest PTE levels were determined.
Intissar Elmayel; José M. Esbrí; Efrén García-Ordiales; Zouheir Elouaer; Eva M. Garcia-Noguero; Jalel Bouzid; Juan Antonio Campos; Pablo L. Higueras. Biogeochemical assessment of the impact of Zn mining activity in the area of the Jebal Trozza mine, Central Tunisia. Environmental Geochemistry and Health 2020, 42, 3529 -3542.
AMA StyleIntissar Elmayel, José M. Esbrí, Efrén García-Ordiales, Zouheir Elouaer, Eva M. Garcia-Noguero, Jalel Bouzid, Juan Antonio Campos, Pablo L. Higueras. Biogeochemical assessment of the impact of Zn mining activity in the area of the Jebal Trozza mine, Central Tunisia. Environmental Geochemistry and Health. 2020; 42 (11):3529-3542.
Chicago/Turabian StyleIntissar Elmayel; José M. Esbrí; Efrén García-Ordiales; Zouheir Elouaer; Eva M. Garcia-Noguero; Jalel Bouzid; Juan Antonio Campos; Pablo L. Higueras. 2020. "Biogeochemical assessment of the impact of Zn mining activity in the area of the Jebal Trozza mine, Central Tunisia." Environmental Geochemistry and Health 42, no. 11: 3529-3542.
The Nalón estuary (Asturias, NW Spain) provides a highly varied information about natural and anthropic changes along more of one century since it received the contributions from the major coal basin of Spain and it was the most important coal port of the north of the Iberian Peninsula during 20th century. As a consequence of these factors, the estuary has undergone important transformations for port uses such as port basin, jetties in the mouth, intense dredging, etc.. These changes triggered the progradation of the dune field of the confining barrier, erosion in neighbouring eastern dune fields, joint to the subsequent changes in the morphology and sedimentary in the most part of the estuary. On the other hand, the historical exploitation in the hydrographic basin of numerous mines, mainly coal mines and some metallic such as Hg, Cu, Fe and Au, with null environmental control, has produce the contribution of carbonaceous mineralogy to the fractions of quartz sands and the modification of the natural geochemistry by the contribution of metals and metalloids along the entire estuary. Furthermore, some borecores and samples throughout the estuary were studied to assess the impact of the historical human footprint on the sedimentary sequence.
Since 70´s of 20th century, the mining activity decreased and in parallel the intensive dredging decreased until today when they are scare and small definitive interruption of the intensive dredging in the estuary. Nowadays, the role of the sea-level rise and the recurrence of a series of strong wave storms since 2009 has caused the retreat of the dune fields of the confining barrier of the Nalón estuary and eastern beach/dune system of Bayas and the gradual filling of the external sector of the estuary. In addition, the management of the port is complicated because a serious navigation problem in the mouth occurred due to restrictions on dredging activities as a consequence of the high trace element concentration in the sediments and the ongoing inputs of As, Hg, Pb, and Zn into the coastal zone.
Germán Flor-Blanco; Efrén García-Ordiales; Germán Flor; Julio López Peláez; Nieves Roqueñí; Violeta Navarro-García. Environmental change assesments in response to anthropogenic human footprint in the Nalón estuary (Asturias-NW Spain). 2020, 1 .
AMA StyleGermán Flor-Blanco, Efrén García-Ordiales, Germán Flor, Julio López Peláez, Nieves Roqueñí, Violeta Navarro-García. Environmental change assesments in response to anthropogenic human footprint in the Nalón estuary (Asturias-NW Spain). . 2020; ():1.
Chicago/Turabian StyleGermán Flor-Blanco; Efrén García-Ordiales; Germán Flor; Julio López Peláez; Nieves Roqueñí; Violeta Navarro-García. 2020. "Environmental change assesments in response to anthropogenic human footprint in the Nalón estuary (Asturias-NW Spain)." , no. : 1.
Aviles estuary is one of the most impacted estuaries of the north of Spain. In its margins, there are several heavy industries such as steel, zinc and aluminium factories together with other little factories dedicated to secondary metallurgical products. Because of the intense metallurgical activities developed in the area, sediments of the estuary show an important metal load. Among the different heavy metals present in the estuary, Hg in one of the most important due to its toxicity and potential transference to biota. To study the Hg concentrations present in the estuary, 52 scattered samples were collected. Samples were analysed for total Hg, and other parameters such as grain size, organic matter and sulphur have been determined. Total Hg concentration in the estuary sediments ranged between 0.1 to 18.3µg g-1 with an average of 4.3 µg g-1. The particle size of the sediment governed the mercury dispersion in the estuary. In the inner part where silt and clay fraction are predominant, Hg showed the highest values while in areas where sands predominate Hg concentrations decrease. The Hg concentration in a total of 36 samples exceed the probable effect level established by NOAA, which suggest that Hg may be transferred to the biota of the estuary and could be a problem for the health status of the area. On the other hand, concentrations of 26 samples were above the C level of the Spanish dredging regulations, limiting its management to encapsulation in non-vulnerable areas or its management as waste by an authorized manager.
Efrén García Ordiales; Mario Mangas; Lorena Sanz-Prada; Elena Pavoni; Stefano Covelli; Nieves Roqueñí; Jorge Loredo; Pablo Cienfuegos. Spatial variations of mercury in sediments of Aviles Harbour and its implications on dredging. 2020, 1 .
AMA StyleEfrén García Ordiales, Mario Mangas, Lorena Sanz-Prada, Elena Pavoni, Stefano Covelli, Nieves Roqueñí, Jorge Loredo, Pablo Cienfuegos. Spatial variations of mercury in sediments of Aviles Harbour and its implications on dredging. . 2020; ():1.
Chicago/Turabian StyleEfrén García Ordiales; Mario Mangas; Lorena Sanz-Prada; Elena Pavoni; Stefano Covelli; Nieves Roqueñí; Jorge Loredo; Pablo Cienfuegos. 2020. "Spatial variations of mercury in sediments of Aviles Harbour and its implications on dredging." , no. : 1.
Four boreholes drilled at depths ranging from 9 to 27 m and retrieved from the Nalón estuary (Asturias, northern Spain) were investigated to assess the impact of the historical human footprint on the sedimentary sequence. Analytical measurements of grain size, geochemical composition (major and trace elements), and stable Pb isotopic ratios were performed. Two different sections of the sedimentary profile were identified throughout the sedimentary sequence using Pb isotopic ratios and then corroborated with grain size characteristics and As, Hg, Pb and Zn concentrations. The upper sediment layer of the boreholes (variable depth ranging between 3 and 9 m) exhibited an increase in 208Pb/206Pb ratios and a decrease in 206Pb/207Pb ratios, whereas, in the deepest layers, these ratios remained unchanged. These variations reflected the anthropogenic input of Pb into estuarine sediments, which can be attributed to mining activities when compared to Pb isotopic ratios from coal mined in the region. The anthropogenic input can be also noted on the basis of the variability of the trace element concentrations with depth. The enrichment factors of As (max 7.5), Hg (max 45.4), Pb (max 10.3), and Zn (max 8.6), calculated using local geochemical background values helped distinguish the impact of intense anthropogenic activities, which can be attributed to mining exploitation in the Nalón River drainage basin. Despite the closure of several of these mines during the second half of the 20th century, geochemical characteristics have revealed the ongoing input of As, Hg, Pb, and Zn into the coastal zone. Thus, the legacy of contamination from these elements, mainly from leaching slags and tailing dams, is still being recorded in estuarine sediments and requires careful scrutiny on the part of local authorities in terms of its possible effects on the aquatic biota.
Efrén García-Ordiales; Germán Flor-Blanco; Nieves Roqueñí; Stefano Covelli; Pablo Cienfuegos; Rodrigo Álvarez; Giorgio Fontolan; Jorge Loredo. Anthropocene footprint in the Nalón estuarine sediments (northern Spain). Marine Geology 2020, 424, 106167 .
AMA StyleEfrén García-Ordiales, Germán Flor-Blanco, Nieves Roqueñí, Stefano Covelli, Pablo Cienfuegos, Rodrigo Álvarez, Giorgio Fontolan, Jorge Loredo. Anthropocene footprint in the Nalón estuarine sediments (northern Spain). Marine Geology. 2020; 424 ():106167.
Chicago/Turabian StyleEfrén García-Ordiales; Germán Flor-Blanco; Nieves Roqueñí; Stefano Covelli; Pablo Cienfuegos; Rodrigo Álvarez; Giorgio Fontolan; Jorge Loredo. 2020. "Anthropocene footprint in the Nalón estuarine sediments (northern Spain)." Marine Geology 424, no. : 106167.
This study has been carried out on the Nalón estuary, a mining impacted estuarine contaminated by metals(oid), to evaluate how the metals(oids) concentrations in the sediments contributes to the toxicity and, therefore, supposes a potential risk for the biota. For this purpose, a total of 14 surface sediment samples were collected and analysed by different techniques. Estuary sediments showed a maximum high concentration of As (68.10 μg g−1), Hg (1.33 μg g−1) and Pb (189.60 μg g−1), exceeding the NOAA Effects Range Low. Likewise, these three elements were one of the most bioavailable in the sediments according to the toxicity characteristic leaching procedure performed, reaching average values of 14.28% for As, 12.81% for Hg and 9.23% for Pb. The bioavailable concentrations of As and Hg significantly correlated with toxicity (R > 0.92), suggesting that both were the main contributors to the toxicity of the sediments. Toxicity values detected (avg. 499 TU g−1) were similar to those showed by other sites considered contaminated in the Cantabrian coastline, confirming its status as a contaminated area. The location of the highest toxicity values in the estuary was restricted to the port areas where the fine sediments that act of sink of metals(oids) are mainly deposited. This result is very important if re-mobilization of sediments take place in these areas related to dredging or other human activities.
Efren Garcia-Ordiales; Nieves Roqueñí; José Manuel Rico; Pablo Cienfuegos; Rodrigo Alvarez; Almudena Ordoñez. Assessment of the toxicity toward Vibrio fischeri in sediments of a mining impacted estuary in the north of Spain. Science of The Total Environment 2019, 660, 826 -833.
AMA StyleEfren Garcia-Ordiales, Nieves Roqueñí, José Manuel Rico, Pablo Cienfuegos, Rodrigo Alvarez, Almudena Ordoñez. Assessment of the toxicity toward Vibrio fischeri in sediments of a mining impacted estuary in the north of Spain. Science of The Total Environment. 2019; 660 ():826-833.
Chicago/Turabian StyleEfren Garcia-Ordiales; Nieves Roqueñí; José Manuel Rico; Pablo Cienfuegos; Rodrigo Alvarez; Almudena Ordoñez. 2019. "Assessment of the toxicity toward Vibrio fischeri in sediments of a mining impacted estuary in the north of Spain." Science of The Total Environment 660, no. : 826-833.
Efrén Garcia-Ordiales; Pablo Higueras; Jose M. Esbrí; Nieves Roqueñí; Jorge Loredo. Seasonal and spatial distribution of mercury in stream sediments from Almadén mining district. Geochemistry: Exploration, Environment, Analysis 2018, 19, 121 -128.
AMA StyleEfrén Garcia-Ordiales, Pablo Higueras, Jose M. Esbrí, Nieves Roqueñí, Jorge Loredo. Seasonal and spatial distribution of mercury in stream sediments from Almadén mining district. Geochemistry: Exploration, Environment, Analysis. 2018; 19 (2):121-128.
Chicago/Turabian StyleEfrén Garcia-Ordiales; Pablo Higueras; Jose M. Esbrí; Nieves Roqueñí; Jorge Loredo. 2018. "Seasonal and spatial distribution of mercury in stream sediments from Almadén mining district." Geochemistry: Exploration, Environment, Analysis 19, no. 2: 121-128.
Sediments contaminated by Hg and As from two historical mining areas have been deposited in the Nalón estuary (Asturias, northern Spain) since 1850. Total mercury (Hg) concentrations in the sediments range from 0.20 μg g to 1.33 μg g, most of it in the form of sulphides. Concentrations of methylmercury (303.20-865.40 pg g) are up to two orders of magnitude lower than the concentration of Hg. Total As concentration (As) is enriched compared to the background level for the area. The relative abundance of As(V) on As(III) in the sediments ranges from 97.6% to 100%, whereas inorganic Hg accounts for more than 99% of the total Hg. The occurrence of the most toxic species, inorganic As(III) and organic methylmercury, seem to be related to redox conditions together with the amounts of sulphur which act as natural barriers which inhibit the biological and chemical speciation processes. Despite the high amounts of Hg and As present in the sediments, their transference to the water column appear to be limited thus converting sediments in an effective sink of both elements. Special attention should be paid to potential variations of the environmental conditions which might increase the element mobility and exchange between sediments and the water column.
Efrén Garcia-Ordiales; Stefano Covelli; Jose Manuel Rico; Nieves Roqueni; Giorgio Fontolan; Germán Flor Blanco; Pablo Cienfuegos; Jorge Loredo. Occurrence and speciation of arsenic and mercury in estuarine sediments affected by mining activities (Asturias, northern Spain). Chemosphere 2018, 198, 281 -289.
AMA StyleEfrén Garcia-Ordiales, Stefano Covelli, Jose Manuel Rico, Nieves Roqueni, Giorgio Fontolan, Germán Flor Blanco, Pablo Cienfuegos, Jorge Loredo. Occurrence and speciation of arsenic and mercury in estuarine sediments affected by mining activities (Asturias, northern Spain). Chemosphere. 2018; 198 ():281-289.
Chicago/Turabian StyleEfrén Garcia-Ordiales; Stefano Covelli; Jose Manuel Rico; Nieves Roqueni; Giorgio Fontolan; Germán Flor Blanco; Pablo Cienfuegos; Jorge Loredo. 2018. "Occurrence and speciation of arsenic and mercury in estuarine sediments affected by mining activities (Asturias, northern Spain)." Chemosphere 198, no. : 281-289.
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.
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.
Highlights•The uptake of potentially toxic elements by Holm-oak trees has been studied•Holm-oak tree in not a PHE's bioconcentrator for the six elements analysed•Uptake favours Zn, Cd and Cu with respect to Pb and As; Hg uptake is mainly foliar•Selective extraction procedures does not show good indications of bioavailability•A simple method to assess possible toxic effects on vegetation has been proposed AbstractThis work is aimed to the establishment of some clues concerning metal uptake by the holm oak (Quercus ilex L.) in abandoned base metals (Pb-Zn) mining sites from central Spain. The study is based on total contents of potentially harmful elements (PHEs), including Pb, Zn, Cu, As, Sb, Cd and Hg, in leaves from holm-oak trees as well as in the corresponding soils, in three different sites included in the Alcudia Valley Mining District. Besides, we present other analytical data for the corresponding soils: pH; electrical conductivity; organic matter; and selective extractions: i) Modified Geological Survey Field Leach Test (using deionized water); extraction with ammonium acetate solution at two different pH values; EPA Method 1312 (using a H2SO4:HNO3 solution); and extraction with an EDTA solution. This is aimed to search for relationships between PHE concentrations in the leaves and the different parameters measured in the corresponding soil, in order to determine bioavailability of PHE in this type of environments. The results show areas impacted by different degrees of PHE; in the most polluted area Pb concentrations reach 300 times the regional baseline and background values indicated by World Health Organization. Also, detected concentrations of the elements in leaves show that the holm-oak tree is a species with a very low bioaccumulation capacity, as shown by a selective uptake of PHE, favouring Zn, Cd and Cu with respect to Pb and As, and with Hg as a peculiar case, influenced by foliar uptake. However, metal concentrations in leaves reach levels above published toxicity levels thresholds, in particular for Pb and Zn. After this study, the soil to plant transfer capacity depends on different parameters for each element, being extremely difficult to generalise a common scenario favouring or preventing this process. Instead, we have found a complex case, conditioned by the soil proprieties (reactivity, salt contents and presence and concentration of organic matter) and to lesser extent, by PHE speciation in the soils.
Pablo Higueras; José María Esbrí; Efrén García-Ordiales; Beatriz González-Corrochano; Miguel Angel López-Berdonces; Eva Maria García-Noguero; Jacinto Alonso-Azcárate; Alba Martínez-Coronado. Potentially harmful elements in soils and holm-oak trees ( Quercus ilex L.) growing in mining sites at the Valle de Alcudia Pb-Zn district (Spain)–Some clues on plant metal uptake. Journal of Geochemical Exploration 2017, 182, 166 -179.
AMA StylePablo Higueras, José María Esbrí, Efrén García-Ordiales, Beatriz González-Corrochano, Miguel Angel López-Berdonces, Eva Maria García-Noguero, Jacinto Alonso-Azcárate, Alba Martínez-Coronado. Potentially harmful elements in soils and holm-oak trees ( Quercus ilex L.) growing in mining sites at the Valle de Alcudia Pb-Zn district (Spain)–Some clues on plant metal uptake. Journal of Geochemical Exploration. 2017; 182 ():166-179.
Chicago/Turabian StylePablo Higueras; José María Esbrí; Efrén García-Ordiales; Beatriz González-Corrochano; Miguel Angel López-Berdonces; Eva Maria García-Noguero; Jacinto Alonso-Azcárate; Alba Martínez-Coronado. 2017. "Potentially harmful elements in soils and holm-oak trees ( Quercus ilex L.) growing in mining sites at the Valle de Alcudia Pb-Zn district (Spain)–Some clues on plant metal uptake." Journal of Geochemical Exploration 182, no. : 166-179.
The extensive extraction activity of mercury ores in Asturias (northwest Spain), also rich in As and Sb, has impacted the Nalón river estuary. The objective of this research was to assess the historical evolution of As-Hg-Sb accumulation in the salt marsh sediments of this area. For this purpose, sediment cores were collected from two different salt marshes (eastern and western river banks) in the estuarine environment to evaluate the degree of anthropogenic enrichment and the geochronology of As-Hg-Sb accumulation. Core subsampling was performed by cutting 2-cm-thick slices of sediments. The subsamples were then analysed for several physical and chemical parameters. Sedimentation rate was assessed by measuring short-lived radionuclides (excess (210)Pb and (137)Cs). Pre-mining levels of As-Hg-Sb were observed at core depths below 50 cm. In the less extended salt marsh (eastern river bank), maximum As-Hg-Sb concentrations of 87.48, 3.66, and 5.75 μg·g(-1), respectively, were found at the core top as a consequence of long-term mining activity in the area. The vertical distribution of As-Hg-Sb was influenced by the single-point contamination sources, whereas grain-size variability and diagenetic remobilisation did not seem affected. Geochronological measurements showed that the depositional fluxes of As-Hg-Sb were influenced by anthropogenic input after 1900, when mining activity in the area was most intense. Hg mining ceased in 1969; however, the corresponding core profiles did not show a drastic decreasing trend in element fluxes, implying that the river drainage basin retains some "memory" of contamination which affects riverine sediments. A preliminary gross estimation of total As-Hg-Sb "trapped" in the Nalón river salt marsh sediments amounted to approximately 18.7, 1.0, and 0.7 t, respectively. These morphological structures suffer erosive processes, thus representing a potential source of these elements associated with sediments; consequently, management conservation and monitoring of salt marshes should be taken into consideration from this environmental point of view.
Efrén Garcia-Ordiales; Pablo Cienfuegos; Nieves Roqueñí; Stefano Covelli; Germán Flor Blanco; Giorgio Fontolan; Jorge Loredo. Historical accumulation of potentially toxic trace elements resulting from mining activities in estuarine salt marshes sediments of the Asturias coastline (northern Spain). Environmental Science and Pollution Research 2017, 26, 3115 -3128.
AMA StyleEfrén Garcia-Ordiales, Pablo Cienfuegos, Nieves Roqueñí, Stefano Covelli, Germán Flor Blanco, Giorgio Fontolan, Jorge Loredo. Historical accumulation of potentially toxic trace elements resulting from mining activities in estuarine salt marshes sediments of the Asturias coastline (northern Spain). Environmental Science and Pollution Research. 2017; 26 (4):3115-3128.
Chicago/Turabian StyleEfrén Garcia-Ordiales; Pablo Cienfuegos; Nieves Roqueñí; Stefano Covelli; Germán Flor Blanco; Giorgio Fontolan; Jorge Loredo. 2017. "Historical accumulation of potentially toxic trace elements resulting from mining activities in estuarine salt marshes sediments of the Asturias coastline (northern Spain)." Environmental Science and Pollution Research 26, no. 4: 3115-3128.
Castilla-La Mancha (central Spain) is a region characterized by significant agricultural production aimed at high-quality food products such as wine and olive oil. The quality of agricultural products depends directly on the soil quality. Soil geochemistry, including dispersion maps and the recognition of baselines and anomalies of various origins, is the most important tool to assess soil quality. With this objective, 200 soil samples were taken from agricultural areas distributed among the different geological domains present in the region. Analysis of these samples included evaluation of edaphological parameters (reactivity, electrical conductivity, organic matter content) and the geochemistry of major and trace elements by X-ray fluorescence. The dataset obtained was statistically analyzed for major elements and, in the case of trace elements, was normalized with respect to Al and analyzed using the relative cumulative frequency (RCF) distribution method. Furthermore, the geographic distribution of analytical data was characterized and analyzed using the kriging technique, with a correspondence found between major and trace elements in the different geologic domains of the region as well as with the most important mining areas. The results show an influence of the clay fraction present in the soil, which acts as a repository for trace elements. On the basis of the results, of the possible elements related with clay that could be used for normalization, Al was selected as the most suitable, followed by Fe, Mn, and Ti. Reference values estimated using this methodology were lower than those estimated in previous studies.
Sandra Bravo; Efrén García-Ordiales; Francisco Jesus Garcia Navarro; Jose Angel Amorós; Caridad Pérez-De-Los-Reyes; Raimundo Jiménez-Ballesta; José María Esbrí; Eva María García-Noguero; Pablo Higueras. Geochemical distribution of major and trace elements in agricultural soils of Castilla-La Mancha (central Spain): finding criteria for baselines and delimiting regional anomalies. Environmental Science and Pollution Research 2017, 26, 3100 -3114.
AMA StyleSandra Bravo, Efrén García-Ordiales, Francisco Jesus Garcia Navarro, Jose Angel Amorós, Caridad Pérez-De-Los-Reyes, Raimundo Jiménez-Ballesta, José María Esbrí, Eva María García-Noguero, Pablo Higueras. Geochemical distribution of major and trace elements in agricultural soils of Castilla-La Mancha (central Spain): finding criteria for baselines and delimiting regional anomalies. Environmental Science and Pollution Research. 2017; 26 (4):3100-3114.
Chicago/Turabian StyleSandra Bravo; Efrén García-Ordiales; Francisco Jesus Garcia Navarro; Jose Angel Amorós; Caridad Pérez-De-Los-Reyes; Raimundo Jiménez-Ballesta; José María Esbrí; Eva María García-Noguero; Pablo Higueras. 2017. "Geochemical distribution of major and trace elements in agricultural soils of Castilla-La Mancha (central Spain): finding criteria for baselines and delimiting regional anomalies." Environmental Science and Pollution Research 26, no. 4: 3100-3114.
Abandoned and flooded mine networks provide underground reservoirs of mine water that can be used as a renewable geothermal energy source. A complete hydrochemical characterization of mine water is required to optimally design the geothermal installation, understand the hydraulic behavior of the water in the reservoir and prevent undesired effects such as pipe clogging via mineral precipitation. Water pumped from the Barredo-Figaredo mining reservoir (Asturias, NW Spain), which is currently exploited for geothermal use, has been studied and compared to water from a separate, nearby mountain mine and a river that receives mine water discharge and partially infiltrates into the mine workings. Although the hydrochemistry was altered during the flooding process, the deep mine waters are currently near neutral, net alkaline, high metal waters of Na-HCO type. Isotopic values suggest that mine waters are closely related to modern meteoric water, and likely correspond to rapid infiltration. Suspended and dissolved solids, and particularly iron content, of mine water results in some scaling and partial clogging of heat exchangers, but water temperature is stable (22°C) and increases with depth, so, considering the available flow (>100Ls), the Barredo-Figaredo mining reservoir represents a sustainable, long-term resource for geothermal use.
C. Loredo; A. Ordóñez; Efren Garcia; R. Álvarez; Nieves Roqueni; P. Cienfuegos; A. Peña; Neil Burnside. Hydrochemical characterization of a mine water geothermal energy resource in NW Spain. Science of The Total Environment 2017, 576, 59 -69.
AMA StyleC. Loredo, A. Ordóñez, Efren Garcia, R. Álvarez, Nieves Roqueni, P. Cienfuegos, A. Peña, Neil Burnside. Hydrochemical characterization of a mine water geothermal energy resource in NW Spain. Science of The Total Environment. 2017; 576 ():59-69.
Chicago/Turabian StyleC. Loredo; A. Ordóñez; Efren Garcia; R. Álvarez; Nieves Roqueni; P. Cienfuegos; A. Peña; Neil Burnside. 2017. "Hydrochemical characterization of a mine water geothermal energy resource in NW Spain." Science of The Total Environment 576, no. : 59-69.