Person: García Lorenzo, María De La Luz
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First Name
María De La Luz
Last Name
García Lorenzo
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Mineralogía y Petrología
Area
Petrología y Geoquímica
Identifiers
9 results
Search Results
Now showing 1 - 9 of 9
Item Geogenic distribution of Arsenic (As) and Antimony (Sb) in soils of the Murcia Region in Spain(Environmental forensics, 2015) García Lorenzo, María De La Luz; Martínez-Sánchez, María José; Pérez-Sirvent, Carmen; López-Sánchez, Joaquín; Molina-Ruiz, José; Tudela, Mari LuzThe objective of this study was to determine the As and Sb contents in soils from the Murcia Region of Spain and the possible relationship between the mineralogical composition, soil properties, and As and Sb concentrations. In this study, 490 samples were selected from areas with different characteristics in order to study As and Sb variability. Results show that As and Sb concentrations are positively correlated with the phyllosilicate and quartz content but negatively correlated with the calcite content. The generic reference level (GRL) for these elements was determined according to the Spanish legislation. Established GRL values vary according to the established mineralogical groups, suggesting that GRL has to be determined considering the lithological characteristics of the study areaItem Impact of climate risk materialization and ecological deterioration on house prices in Mar Menor, Spain(Scientific reports, 2023) Lamas Rodríguez, Matías; García Lorenzo, María De La Luz; Medina Magro, Manuel; Pérez-Quirós, GabrielThe frequency and severity of extreme events related to climate change have intensified worldwide in the last decades. It is documented that increasing extreme rainfall and flooding cause more nutrient runoff into waterbodies, initiating numerous harmful algal bloom (HAB) events, especially in fragile ecosystems. We analyze the dramatic economic damage of one of these episodes in Mar Menor, the largest salt-water lagoon in Europe. We show that when the public perceived the severity of environmental degradation, the return on housing investment was 43% lower in the surroundings than in similar neighboring zones 6 years after the HAB (2015). This represents a loss in housing wealth of more than 4000 million euros, around ten times the gains of changing from dry-farming to irrigated crops, which makes this ecosystem fragile. Hence, we quantify some of the economic consequences of ecological deterioration linked to episodes of Global Climate Change.Item Use of limestone filler as a sorbent for the removal of As(V), Pb(II), Cu(II), Zn(II) and Cd(II) in contaminated sites(Geophysical Research Abstracts, 2017) Martínez Sánchez, Maria José; Veiga, José Manuel; García Lorenzo, María De La Luz; Hernández Córdoba, Manuel; Martínez López, Salvadora; Pérez Sirvent, CarmenMany of the approaches used to treat soils contaminated by heavy metals are invasive, and do not restore the natural equilibrium of the environment [1]. For this reason, one of procedures used to stabilise heavy metal-contaminated soils in situ is to directly add amendments, which, while they may not totally eliminate toxic elements, help natural retention mechanisms, induce sorption and reduce mobility and bioavailability. In this respect, the use of calcareous materials may be an excellent, eco-friendly way for recovering this type of soils [2], and this communication reports studies made in our laboratory for such a purpose. The influence of different variables in the preparation of mixtures used to stabilize contaminated soils (soil pH, temperature and composition of the contaminated soil / limestone filler) was studied by means of a factorial experimental design. The main interaction effects of the factors obtained on different contaminated soils were used along with the results of the physicochemical and mineralogical characterization in the same data matrix to be analyzed by principal components analysis (PCA). To evaluate the optimal values of the variables, spectroscopic techniques were used to measure the level of leached metals (Pb, Cd, Cu, As, Zn and Fe). The environmental conditions were simulated and controlled by means of a climatic chamber to evaluate simultaneously the processes of geochemical alteration and passivation of the mixture. The results obtained showed that the corresponding factors of the experimental design may be an important source of information to show correlations on some of the most significant variables such as the concentration of metals and, in this way, optimize the use of the in situ stabilizer.Item Isotope geochemistry of waters affected by mining activities in Sierra Minera and Portman Bay (SE, Spain)(Applied Geochemistry, 2014) García Lorenzo, María De La Luz; Martínez Sánchez, María José; Pérez Sirvent, Carmen; Agudo, Inés; Recio, ClementeThe objective of this work was to evaluate processes affecting waters from Portman Bay by way of stable isotopic analysis, particularly H and O stable isotopes from water and S and O from dissolved sulfates. In addition, surface waters from Sierra Minera were examined for the purpose of determining if these waters are affected by similar processes. The results obtained indicate that Portman Bay waters are meteoric, and marine infiltration only takes place in the deepest layers near the shore or if water remains stagnated in sediments with low permeability. The main source of sulfate was the oxidation of sulfides, resulting in the liberation of acid, sulfate and metals. In order to assess the mechanism responsible for sulfide oxidation, the stoichiometric isotope balance model and the general isotope balance model were tested, suggesting that the oxidation via Fe3+ was predominant in the surface, and controlled by Acidithiobacillus ferrooxidans, while at depth, sulfate reduction occurred.Item Mobility indices for the assessment of metal contamination in soils affected by old mining activities(Journal of Geochemical Exploration, 2014) García Lorenzo, María De La Luz; Pérez Sirvent, Carmen; Molina Ruiz, José; Martínez Sánchez, María JoséThis work presents a methodology to assess the environmental potential risk of soils when submitted to different conditions. The potentially toxic element (PTE) behaviour was evaluated by single chemical extractions in order to simulate four conditions: PTEs leaching under actual rainfall conditions; acid mine drainage; and an anoxic and an oxic environment. Soil pollution assessment was carried out using the contamination factor (CF) and the pollution load index (PLI) for total contents and indicators of mobility were established for each extraction: natural mobility indicator (NMI), acid mine drainage mobility indicator (AMI), oxic mobility indicator (OMI) and anoxic mobility indicator (ANMI). The total PTE content in the samples was high, and this content decreased when the distance of the sampling site to the source of contamination increased. The results obtained after the extractions suggested that the highest PTE content was extracted in the acidic medium. The mineralogical composition is an important factor that should be taken into account in the evaluation of PTE mobility, firstly because the mineral phases react differently in the proposed situations depending on their chemical nature, and secondly, because the presence of a particular phase (with different degree of reactivity) depends on the degree of weathering. The most reactive materials under oxic conditions are, in the study area, the most modern. The proposed indices may constitute a first attempt to define areas with high potential environmental risk, where urgent action is needed. In addition, the proposed methodology could be a valuable tool to prioritise these interventions.Item Impact of acid mine drainages on surficial waters of an abandoned mining site(Environmental Science and Pollution Research, 2016) García Lorenzo, María De La Luz; Marimón, Jorge; Navarro Hervás, M. C.; Pérez Sirvent, Carmen; Martínez Sánchez, María José; Molina Ruiz, JoséWeathering of sulphide minerals produces a great variety of efflorescences of soluble sulphate salts. These minerals play an important role for environmental pollution, since they can be either a sink or a source for acidity and trace elements. This paper aims to characterise surface waters affected by mining activities in the Sierra Minera of Cartagena-La Union (SE, Spain). Water samples were analysed for trace metals (Zn, Cd, Pb, Cu, As and Fe), major ions (Na+, K+, Ca2+ and Mg2+) and anions (F−, Cl−, NO3 −, CO3 2−, SO4 2−) concentrations and were submitted to an “evaporation-precipitation” experiment that consisted in identifying the salts resulting from the evaporation of the water aliquots sampled onsite. Mineralogy of the salts was studied using X-ray diffraction and compared with the results of calculations using VISUAL MINTEQ. The study area is heavily polluted as a result of historical mining and processing activities that has produced large amount of wastes characterised by a high trace elements content, acidic pH and containing minerals resulting from the supergene alteration of the raw materials. The mineralogical study of the efflorescences obtained from waters shows that magnesium, zinc, iron and aluminium sulphates predominate in the acid mine drainage precipitates. Minerals of the hexahydrite group have been quantified together with minerals of the rozenite group, alunogen and other phases such as coquimbite and copiapite. Calcium sulphates correspond exclusively to gypsum. In a semiarid climate, such as that of the study area, these minerals contribute to understand the response of the system to episodic rainfall events. MINTEQ model could be used for the analysis of waters affected by mining activities but simulation of evaporation gives more realistic results considering that MINTEQ does not consider soluble hydrated salts.Item Geochemical and biological characterisation of supergene efflorescences in pollymetallic mining wastes from Portman Bay (SE, Spain)(Geophysical Research Abstracts, 2017) García Lorenzo, María De La Luz; Herrero, María José; Martínez Sánchez, Maria José; Molina Ruiz, José; Hernández Nicolás, Carmen María; Bech, Jaume; Pérez Sirvent, CarmenIn freshly deposited sulphidic mine tailings, the pH is neutral or slightly alkaline. Due to pyrite oxidation, the pH decreases to values lower than 3 at which acidophilic iron- and sulphur-oxidizing prokaryotes prevail and accelerate the oxidation processes. Portman Bay is heavily polluted as a result of historical mining and processing activities, during which time great amounts of wastes were produced, characterised by a high potentially toxic elements (PTE) content, acidic pH and minerals resulting from supergene alteration. Three soil samples were collected from the most recent exploitation stage, stored in containers for a year and moistened simulating rainfall events. The percolates obtained were collected and naturally evaporated, obtaining three efflorescence samples. The existence of bacterial activity was evaluated by scanning electron microscopy (SEM). C15 sample is characterised by copiapite small crystals generating an homogeneous, porous mass. Inside the mass of copiapite crystals, both pyrite and gypsum were also found. In this sample, a laminae of material fills the pore space. The high carbon content shown in the spectrum of this material permits to characterise it as a biofilm. In the cross section sample of C15, a noticeable lamination of copiapite crystals has been observed, probably originated by dissolution processes. A clear limit between the lamination zone and the upper zone of the efflorescence was noticed, and here arborescent forms are developed. C17 and C18 also presented copiapite crystals, but, unlike C15, they do not present lamination and are characterized by an irregular shape and massive fabric. In C17, small crystals growing in the surface of this material were observed, generating small crusts. According to the spectrum analysis, these crusts are formed by alunogen. In C18, crystals of acicular morphology are present, and appear grouped at certain points. Therefore, out of the three natural efflorescences, biotic activity was only found in C15. This efflorescence differs significantly in morphology and fabric from samples C17 and C18. Besides the morphology, the PTEs content is also different, suggesting that chemical properties of this soil favoured the organic activity. An important factor could be related to a high iron content, since, as demonstrated in similar materials, iron performs a fundamental factor for bioinducted nucleation.Item Geochemical characterisation of surface waters, topsoils and efflorescences in a historic metal-mining area in Spain(Journal of Soils and Sediments, 2016) Pérez Sirvent, Carmen; Hernández Pérez, Carmen; Martínez Sánchez, Maria José; García Lorenzo, María De La Luz; Bech, JaumePurpose Mining activities generate large amounts of wastes that may contain potentially toxic elements (PTE), which, if released into the environment, may cause air, water and soil pollution long after mining operations have ceased. This paper describes the environmental relevance of efflorescences, topsoils and surface waters from the abandoned mine of Sierra Minera of Cartagena-La Unión, SE Spain. The exposure of the population to arsenic and the associated risk were also assessed. Materials and methods A total of 10 topsoils and surface waters and 11 efflorescences affected at varying degrees by mining activities were studied. The total potentially toxic element content (As, Cd, Cu, Fe, Pb and Zn) was determined in all samples. In addition, the mineralogical composition of solid samples was determined by X-ray diffraction and some efflorescences were also analysed using a scanning electron microscopy-energy dispersive X-ray spectrometer. Finally, an arsenic-intake risk assessment was carried out, both as regards carcinogenic and non-carcinogenic effects and considering the total and the bioaccesible As content. Results and discussion The study area is heavily polluted as a result of historical mining and processing activities, during which time great amounts of wastes were produced, characterised by a high PTE content, acidic pH and minerals resulting from supergene alteration. The supergene mineralogical assemblages include soluble metal salts, mainly sulphates, iron hydroxysulphates and iron oxyhydroxides, all of which form ochreous precipitates. Topsoil samples showed risk values and hazard quotients higher than the reference levels, particularly for children. In the efflorescences, these values were lower but still unacceptable. Conclusions The efflorescences are of significance for monitoring purposes because they are involved in cycles of retention release of hydrogen ions, sulphate and potentially toxic elements. In addition, in a semi-arid climate, such as the study area, these minerals contribute to our understanding of the response of the system to episodic rainfall events. In general, it was observed that the arsenic in collected samples represent a potential risk for human health through ingestion.Item Use of bioassays for the assessment of areas affected by phosphate industry wastes(Journal of Geochemical Exploration, 2014) Martínez Sánchez, Maria José; Pérez Sirvent, Carmen; García Lorenzo, María De La Luz; Martínez López, S.; Bech Serra, Joan J; García Tenorio, R.; Bolívar, J. M.Phosphogypsum (PG) is a waste product of the phosphoric acid production process and contains, generally, high activity concentrations of uranium series radionuclides. This study is a contribution towards a risk assessment in areas affected by phosphate industry in SW Spain, integrating information from soil physicochemical characteristics, total and soluble potentially toxic elements (Zn, Pb, Cd, Cu, As and Fe), mineralogical composition and ecotoxicological evaluation. The applied bioassays confirmed the soil toxicity categorisation and then, it is highly recommended to complement the results from environmental chemistry with results from bioassays, in order to provide a more complete and relevant information on the bioavailability of contaminants and to characterise the risk of contaminated areas.