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1.
Sci Total Environ ; 953: 176078, 2024 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-39244046

RESUMEN

Soil Aquifer Treatment (SAT) is a robust technology to increase groundwater recharge and to improve reclaimed water quality. SAT reduces dissolved organic carbon, contaminants of emerging concern, nutrients, and colloidal matter, including pathogen indicators, but little is known about its ability to reduce loads of antibiotic resistance genes (ARGs) from reclaimed waters. Here we test six pilot SAT systems to eliminate various biological hazards from the secondary effluents of a wastewater treatment plant (WWTP), equipped with reactive barriers (RBs) including different sorptive materials. Using flow cytometry, qPCR and 16S rRNA gene amplicon sequencing methods, we determined that all six SAT systems reduced total loads of bacteria by 80 to 95 % and of clinically relevant ARGs by 85 to 99.9 %. These efficiencies are similar to those reported for UV/oxidation or membrane-based tertiary treatments, which require much more energy and resources. The presence and composition of reactive barriers, the season of sampling (June 2020, October 2020, and September 2021), or the flow regime (continuous versus pulsating) did not affect ARG removal efficiency, although they did alter the microbial community composition. This suggests that an adequate design of the SAT reactive barriers may significantly increase their performance. Under a mechanistic point of view, we observed an ecological succession of bacterial groups, linked to the changing physical-chemical conditions along the SAT, and likely correlated to the removal of ARGs. We concluded that SAT is as cost-efficient technology able to dramatically reduce ARG loads and other biological hazards from WWTP secondary effluents.


Asunto(s)
Farmacorresistencia Microbiana , Agua Subterránea , Eliminación de Residuos Líquidos , Aguas Residuales , Aguas Residuales/microbiología , Eliminación de Residuos Líquidos/métodos , Agua Subterránea/microbiología , Agua Subterránea/química , Farmacorresistencia Microbiana/genética , Enterobacteriaceae/genética , Microbiología del Suelo , Genes Bacterianos , Farmacorresistencia Bacteriana/genética , ARN Ribosómico 16S
2.
Biomedicines ; 12(8)2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39200359

RESUMEN

BACKGROUND: Evidence suggests that aerobic training with blood flow restriction is beneficial for treating fibromyalgia. This study evaluated the feasibility, safety, and effects of an aerobic training program with blood flow restriction for women with fibromyalgia. METHODS: Thirty-seven women with fibromyalgia were included, and thirteen with an average age of 59 ± 3, a BMI of 26 ± 3, and who were polymedicated started the intervention period. The intervention group performed aerobic exercise with blood flow restriction using occlusive bands placed in the upper part of the rectus femoris, with a total duration of 14 min of restriction divided into two periods of 7 min with a rest period of 3 min and a total session duration of 17 min. Pressure intensity was measured using the visual pain scale (VAS), scoring 7 out of 10 (n = 7). The non-intervention group performed aerobic exercise without restriction of blood flow for the same periods, rest periods, and total duration of the session (n = 6). The intervention included 2 weekly sessions with 72 h between aerobic walking for 9 weeks. Walking was measured individually using the rating of perceived exertion scale (RPE) with an intensity between 6 and 7 out of 10. Visual and verbal support for the VAS and RPE scale was always provided throughout the sessions supervised by the investigator. Functional capacity was assessed using tests (six-minute walk test, incremental shuttle walk test, knee extension and handgrip test by dynamometer, 30 s chair stand test, and timed up-and-go test). Symptomatology was assessed using questionnaires (Widespread Pain Index, Symptom Severity Score, Fibromyalgia Impact Questionnaire, and Multidimensional Fatigue Inventory), and blood samples were collected. RESULTS: There were no adverse effects, and only one participant in the intervention group withdrew. Between-group and intragroup differences showed that the intervention group obtained improvements in the functional tests; CST p = 0.005; 6MWT p = 0.011; Handgrip p = 0.002; TUGT p = 0.002 with reduced impact of the disease according to the questionnaires; FIQ Stiffness p = 0.027 compared with the nonintervention group. Biochemical results remained within normal ranges in both groups. CONCLUSIONS: Blood flow-restricted aerobic training may be feasible, safe, and more effective than unrestricted aerobic training as a physical exercise prescription tool to improve cardiorespiratory fitness, strength, balance, and stiffness in women with fibromyalgia.

3.
Environ Sci Technol ; 58(12): 5472-5482, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38466321

RESUMEN

The fate of selected UV filters (UVFs) was investigated in two soil aquifer treatment (SAT) systems, one supplemented with a reactive barrier containing clay and vegetable compost and the other as a traditional SAT reference system. We monitored benzophenone-3 (BP-3) and its transformation products (TPs), including benzophenone-1 (BP-1), 4,4'-dihydroxybenzophenone (4DHB), 4-hydroxybenzophenone (4HB), and 2,2'-dihydroxy-4-methoxybenzophenone (DHMB), along with benzophenone-4 (BP-4) and avobenzone (AVO) in all involved compartments (water, aquifer sediments, and biofilm). The reactive barrier, which enhances biochemical activity and biofilm development, improved the removal of all detected UVFs in water samples. Among monitored UVFs, only 4HB, BP-4, and AVO were detected in sediment and biofilm samples. But the overall retained amounts were several orders of magnitude larger than those dissolved. These amounts were quantitatively reproduced with a specifically developed simple analytical model that consists of a mobile compartment and an immobile compartment. Retention and degradation are restricted to the immobile water compartment, where biofilm absorption was simulated with well-known compound-specific Kow values. The fact that the model reproduced observations, including metabolites detected in the biofilm but not in the (mobile) water samples, supports its validity. The results imply that accumulation ensures significant biodegradation even if the degradation rates are very low and suggest that our experimental findings for UVFs and TPs can be extended to other hydrophobic compounds. Biofilms act as accumulators and biodegraders of hydrophobic compounds.


Asunto(s)
Suelo , Contaminantes Químicos del Agua , Porosidad , Protectores Solares/análisis , Benzofenonas/química , Agua/química , Contaminantes Químicos del Agua/análisis
4.
J Hazard Mater ; 465: 133377, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-38237439

RESUMEN

The regeneration of wastewater has been recognized as an effective strategy to counter water scarcity. Nonetheless, Wastewater Treatment Plant (WWTP) effluents still contain a wide range of contaminants of emerging concern (CECs) even after water depuration. Filtration through Soil Aquifer Treatment (SAT) systems has proven efficient for CECs removal although the attenuation of their associated biological effects still remains poorly understood. To evaluate this, three pilot SAT systems were monitored, two of them enhanced with different reactive barriers. SATs were fed with secondary effluents during two consecutive campaigns. Fifteen water samples were collected from the WWTP effluent, below the barriers and 15 m into the aquifer. The potential attenuation of effluent-associated biological effects by SATs was evaluated through toxicogenomic bioassays using zebrafish eleutheroembryos and human hepatic cells. Transcriptomic analyses revealed a wide range of toxic activities exerted by the WWTP effluents that were reduced by more than 70% by SAT. Similar results were observed when HepG2 hepatic cells were tested for cytotoxic and dioxin-like responses. Toxicity reduction appeared partially determined by the barrier composition and/or SAT managing and correlated with CECs removal. SAT appears as a promising approach to efficiently reduce effluent-associated toxicity contributing to environmental and human health preservation.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Purificación del Agua , Animales , Humanos , Pez Cebra , Suelo , Contaminantes Químicos del Agua/análisis , Agua/análisis , Monitoreo del Ambiente , Eliminación de Residuos Líquidos
5.
J Hazard Mater ; 448: 130876, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36736215

RESUMEN

Submarine Groundwater Discharge (SGD) is recognized as a relevant source of pollutants to the sea, but little is known about its relevance as a source of chemicals of emerging concern (CECs). Here, both the presence and distribution of a wide range of CECs have been evaluated in the most comprehensive manner to date, in a well-characterized Mediterranean coastal aquifer near Barcelona (Spain). Samples from coastal groundwater and seawater allowed for the unique spatial characterization of the pollutants present in the land-ocean interface, an outstanding research gap that required attention. The main goals were (1) to determine CECs in the aquifer, so as to evaluate the SGD as a relevant source of marine pollution, and (2) to identify new tracers to improve our understanding of SGD dynamics. To this end, 92 CECs were located in the aquifer by using wide-scope analytical target methodologies (>2000 chemicals). Among them, the perfluoroalkyl and polyfluoroalkyl substances (PFAS), along with the pharmaceuticals carbamazepine and topiramate, were revealed to be good markers for tracing anthropogenic contamination in ground- and seawater, in concrete situations (e.g., highly contaminated sites). Additionally, non-target analysis expanded the number of potential tracers, making it a promising tool for identifying both the source and the fate of pollutants.

6.
Sci Total Environ ; 867: 161466, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36626994

RESUMEN

The need and availability of freshwater is a major environmental issue, aggravated by climate change. It is necessary to find alternative sources of freshwater. Wastewater could represent a valid option but requires extensive treatment to remove wastewater-borne contaminants, such as contaminants of emerging concern (CECs). It is urgent to develop not only sustainable and effective wastewater treatment techniques, but also water quality assessment methods. In this study, we used polar organic chemical integrative samplers (POCIS) to investigate the presence and abatement of contaminants in an urban wastewater treatment plant (WWTP) and in soil aquifer treatment (SAT) systems (a conventional one and one enhanced with a reactive barrier). This approach allowed us to overcome inter-day and intraday variability of the wastewater composition. Passive sampler extracts were analyzed to investigate contamination from 56 pharmaceuticals and personal care products (PPCPs). Data from the POCIS were used to estimate PPCPs' removal efficiency along the WWTP and the SAT systems. A total of 31 compounds, out of the 56 investigated, were detected in the WWTP influent. Removal rates along WWTP were highly variable (16-100 %), with benzophenone-3, benzophenone-1, parabens, ciprofloxacin, ibuprofen, and acetaminophen as the most effectively removed chemicals. The two SAT systems yielded much higher elimination rates than those achieved through the primary and secondary treatments together. The SAT system that integrated a reactive barrier, based on sustainable materials to promote enhanced elimination of CECs, was significantly more efficient than the conventional one. The removal of the recalcitrant carbamazepine and its epoxy- metabolite was especially remarkable in this SAT, with removal rates between 69-81 % and 63-70 %, respectively.


Asunto(s)
Cosméticos , Agua Subterránea , Contaminantes Químicos del Agua , Purificación del Agua , Aguas Residuales , Suelo , Monitoreo del Ambiente/métodos , Preparaciones Farmacéuticas , Contaminantes Químicos del Agua/análisis
7.
Sci Total Environ ; 867: 160977, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36535469

RESUMEN

Wormholes are highly conductive channels that develop in high solubility rocks. They are especially important for environmental and industrial sustainability in saline karst aquifers (e.g. Salar de Uyuni, Salar de Atacama). Wormholes dynamics (i.e., the space and time evolution of these preferential flow paths) depends on the hydrodynamic and geochemical conditions during formation, as well as on wormholes competition for flow. Despite the importance of wormholes interaction for their development, experimental efforts have focused on the evolution of a single flow-path. Direct observation and quantification of wormholes dynamics is still lacking. We propose an experimental set-up to visualize and characterize the dynamics of multiple wormholes, which may help to understand the changes in flow and transport behaviour of aquifers. We performed a dissolution experiment in a 2D synthetic evaporitic aquifer, and simultaneous fluorescent tracer tests before and during wormhole growth. We visualized the growth by sequential photographs, with the fluorescent tracer highlighting the evolving structures. We quantified wormholes dynamics by measuring pressure and mass changes of the aquifer, and by image analysis. On the one hand, results show that wormholes tend to form along areas where flux was fastest prior to dissolution. They also show clear evidence of competition for water between wormholes and represent the first quantitative evidence of the amplifying factor that drives the self-organization in wormhole growth. On the other hand, we found that the competition is slower than predicted by current analytical and numerical theories, but consistent with other laboratory results. We conjecture that the discrepancy between theory and experiments can be attributed to the combined effect of non-linear kinetics and particle dragging during dissolution. We then compared experimental tracer breakthrough curves before and during the formation of preferential flow paths. They reflect wormhole growth by an accentuated non-Fickian behaviour, with reduced first arrival and increased tailing.

8.
J Environ Manage ; 321: 115927, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-35994957

RESUMEN

Soil Aquifer Treatment (SAT) is used to increase groundwater resources and enhance the water quality of wastewater treatment plant (WWTP) effluents. The resulting water quality needs to be assessed. In this study, we investigate attenuation pathways of nitrogen (N) compounds (predominantly NH4+) from a secondary treatment effluent in pilot SAT systems: both a conventional one (SAT-Control system) and one operating with a permeable reactive barrier (PRB) to provide extra dissolved organic carbon to the recharged water. The goal is to evaluate the effectiveness of the two systems regarding N compounds by means of chemical and isotopic tools. Water chemistry (NO3-, NH4+, Non-Purgeable Dissolved Organic Carbon (NPDOC), and O2) and isotopic composition of NO3- (ẟ15N-NO3- and ẟ18O-NO3-) and NH4+ (ẟ15N-NH4+) were monitored in the inflow and at three different sections and depths along the aquifer flow path. Chemical and isotopic results suggest that coupled nitrification-denitrification were the principal mechanisms responsible for the migration and distribution of inorganic N in the systems and that nitrification rate decreased with depth. At the end of the study period, 66% of the total N in the solution was removed in the SAT-PRB system and 69% in the SAT-Control system, measured at the outlet of the systems. The residual N in solution in the SAT-PRB system had an approximately equal proportion of N-NH4+ and N-NO3- while in the SAT-Control system, the residual N in solution was primarily N-NO3-. Isotopic data also confirmed complete NO3- degradation in the systems from July to September with the possibility of mixing newly generated NO3- with the residual NO3- in the substrate pool.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Desnitrificación , Agua Subterránea/química , Nitratos/análisis , Nitrógeno/análisis , Suelo , Aguas Residuales , Contaminantes Químicos del Agua/análisis
10.
Front Microbiol ; 13: 877990, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35685927

RESUMEN

Global water supplies are threatened by climate changes and the expansion of urban areas, which have led to an increasing interest in nature-based solutions for water reuse and reclamation. Reclaimed water is a possible resource for recharging aquifers, and the addition of an organic reactive barrier has been proposed to improve the removal of pollutants. There has been a large focus on organic pollutants, but less is known about multifunctional barriers, that is, how barriers also remove nutrients that threaten groundwater ecosystems. Herein, we investigated how compost- and woodchip-based barriers affect nitrogen (N) removal in a pilot soil aquifer treatment facility designed for removing nutrients and recalcitrant compounds by investigating the composition of microbial communities and their capacity for N transformations. Secondary-treated, ammonium-rich wastewater was infiltrated through the barriers, and the changes in the concentration of ammonium, nitrate, and dissolved organic carbon (DOC) were measured after passage through the barrier during 1 year of operation. The development and composition of the microbial community in the barriers were examined, and potential N-transforming processes in the barriers were quantified by determining the abundance of key functional genes using quantitative PCR. Only one barrier, based on compost, significantly decreased the ammonium concentration in the infiltrated water. However, the reduction of reactive N in the barriers was moderate (between 21 and 37%), and there were no differences between the barrier types. All the barriers were after 1 year dominated by members of Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria, although the community composition differed between the barriers. Bacterial classes belonging to the phylum Chloroflexi showed an increased relative abundance in the compost-based barriers. In contrast to the increased genetic potential for nitrification in the compost-based barriers, the woodchip-based barrier demonstrated higher genetic potentials for denitrification, nitrous oxide reduction, and dissimilatory reduction of nitrate to ammonium. The barriers have previously been shown to display a high capacity to degrade recalcitrant pollutants, but in this study, we show that most barriers performed poorly in terms of N removal and those based on compost also leaked DOC, highlighting the difficulties in designing barriers that satisfactorily meet several purposes.

11.
Sci Total Environ ; 838(Pt 1): 155978, 2022 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-35588800

RESUMEN

In coastal aquifers, two opposite but complementary processes occur: Seawater intrusion (SWI), which may salinize heavily exploited aquifers, and Submarine groundwater discharge (SGD) which transports oligo-elements to the sea. Aquifers are expected to be chemically reactive, both because they provide abundant surfaces to catalyze reactions and the mixing of very different Fresh Water (FW) and Sea Water (SW) promote numerous reactions. Characterizing and quantifying these reactions is essential to assess the quality and composition of both aquifer water, and SGD. Indeed, sampling SGD is difficult, so its composition is usually uncertain. We propose a reactive end-member mixing analysis (rEMMA) methodology based on principal component analysis (PCA) to (i) identify the sources of water and possible reactions occurring in the aquifer and (ii) quantify mixing ratios and the extent of chemical reactions. We applied rEMMA to the Argentona coastal aquifer located North of Barcelona that contains fluvial sediments of granitic origin and overlies weathered granite. The identification of end members (FW and SW) and the spatial distribution of their mixing ratios illustrate the application procedure. The extent of reactions and their spatial distribution allow us to distinguish reactions that occur as a result of mixing from those caused by sediment disequilibrium, which are relevant to recirculated saltwater SGD. The most important reaction is cation exchange, especially between Ca and Na, which promotes other reactions such as Gypsum and Fluorite precipitation. Iron and Manganese are mobilized in the SW portion but oxidized and precipitated in the mixing zone, so that Fe (up to 15 µEq/L) and Mn (up to 10 µEq/L) discharge is restricted to SW SGD. Nitrate is reduced in the mixing zone. The actual reaction amounts are site-specific, but the processes are not, which leads us to conjecture the importance of these reactions to understand the SGD discharge elsewhere.


Asunto(s)
Agua Subterránea , Monitoreo del Ambiente , Agua Dulce , Agua Subterránea/análisis , Agua de Mar/análisis , Navíos , Agua/análisis
12.
JACC Cardiovasc Interv ; 15(10): 1022-1029, 2022 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-35589232

RESUMEN

OBJECTIVES: The main objective of this study was to compare the efficacy of 3 hemostatic methods for the prevention of early radial artery occlusion (RAO): standard patent hemostasis, patent hemostasis with ulnar compression or the ulnar artery transient compression facilitating radial artery patent hemostasis (ULTRA) method, and facilitated hemostasis with a hemostatic disc. BACKGROUND: There are no prospective randomized studies that compare early RAO rates with the 3 most used nonocclusive hemostatic methods. METHODS: This was a prospective, longitudinal, comparative, and randomized study. The final population analyzed was 1,469, and they were randomized into 3 groups: 491 patients in group 1 with standard patent hemostasis, 490 patients in group 2 with the ULTRA method, and 488 patients in group 3 with facilitated hemostasis with a hemostatic disc. RESULTS: The RAO rate at 24 hours of the total population analyzed was 4.6%. By hemostasis groups, it was 3.6% for patent hemostasis, 5.5% for the ULTRA method, and 4.7% for facilitated hemostasis with a hemostatic disc, with no statistical difference among the 3 groups (P = 0.387). At 30 days, the overall rate of RAO was 1.8%, and by groups, it was 1.4% for the patent hemostasis group, 1.8% for the ULTRA method group, and 2.2% for the facilitated hemostasis with a hemostatic disc group, respectively (P = 0.185). CONCLUSIONS: The rates of RAO at 24 hours evaluated by plethysmography oximetry and confirmed by ultrasound among 3 current radial hemostasis methods (ie, patent hemostasis, the ULTRA method, and facilitated hemostasis with a hemostatic disc) are not different.


Asunto(s)
Arteriopatías Oclusivas , Cateterismo Periférico , Hemostáticos , Arteriopatías Oclusivas/diagnóstico por imagen , Arteriopatías Oclusivas/prevención & control , Cateterismo Cardíaco/efectos adversos , Cateterismo Cardíaco/métodos , Cateterismo Periférico/efectos adversos , Cateterismo Periférico/métodos , Angiografía Coronaria/efectos adversos , Angiografía Coronaria/métodos , Técnicas Hemostáticas/efectos adversos , Hemostáticos/efectos adversos , Humanos , Estudios Prospectivos , Arteria Radial/diagnóstico por imagen , Resultado del Tratamiento
13.
J Contam Hydrol ; 247: 103980, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35245819

RESUMEN

Coastal aquifers are a vital water source for the more than one billion people living in coastal regions around the globe. Due to the intensity of economic activities and density of population, these aquifers are highly susceptible not only to seawater intrusion, but also to anthropogenic contamination, which may contaminate the aquifer and submarine groundwater discharge. Identification and localization of contaminant source characteristics are needed to reduce contamination. The techniques of contaminant source identification are based on numerical models that require the knowledge of the hydrodynamic properties of aquifers. Thus, the challenging topic of contaminant source and aquifer characterization (CSAC) is widely developed in the literature. However, most of the existing studies are concerned with inland aquifers with relatively uniform groundwater flow. Coastal aquifers are influenced by density-driven seawater intrusion, tidal forces, and water injection and abstraction wells. These phenomena create complex flow and transport patterns, which render the CSAC especially challenging and may explain why CSAC has never been addressed in coastal settings. The presented study aims to provide an efficient methodology for the simultaneous identification of contaminant source characteristics and aquifer hydraulic conductivity in coastal aquifers. For this purpose, the study employs numerical modeling of density-dependent flow and multiple-species solute transport, to develop trained and validated artificial neural network metamodels, and then employs these metamodels in a version of the ensemble Kalman filter (EnKF) termed the 'constrained restart dual EnKF (CRD-EnKF)' algorithm. We show that this variant of the EnKF can be successfully applied to CSAC in the complex setting of coastal aquifers. Furthermore, the study analyzes the influence of common issues in CSAC monitoring, such as the effect of non-ideal monitoring network distributions, measurement errors, and multi-level vs. single level monitoring wells.


Asunto(s)
Agua Subterránea , Conductividad Eléctrica , Monitoreo del Ambiente , Humanos , Hidrodinámica , Agua de Mar , Agua
14.
Artículo en Inglés | MEDLINE | ID: mdl-35122581

RESUMEN

Quantitative flow ratio (QFR) is a recently proposed angiographic index that allows to assess the pressure loss in coronary arteries in a similar fashion as the fractional flow reserve (FFR). The purpose of this study was to evaluate the diagnostic performance of QFR as compared to FFR, in a Latin-American population of patients with suspected ischaemic heart disease. QFR was retrospectively derived from coronary angiograms. The association, diagnostic performance, and continuous agreement of fixed-flow QFR (fQFR) and contrast-flow QFR (cQFR) with FFR was assessed by continuous and dichotomous methods. 90 vessels form 66 patients were finally included. The study comprised coronary stenoses of intermediate severity, both angiographically (diameter stenosis: 46.6 ± 12.8%) and physiologically [median FFR = 0.83 (quartile 1-3, 0.76-0.89)]. The correlation of FFR with both fQFR [ρ = 0.841, (95% CI 0.767 to 0.893), p < 0.001] and cQFR [ρ = 0.833, (95% CI 0.755 to 0.887), p < 0.001] was strong. The diagnostic performance of cQFR was good [area under the ROC curve of 0.92 (95% CI 0.86 to 0.97, p < 0.001)], with 0.80 as the optimal cQFR cut-off against FFR ≤ 0.80. This 0.80 cQFR cut-off classified correctly 83.3% of total stenoses, with a sensitivity of 85.2% and specificity of 80.6%. QFR was strongly associated with FFR and exhibited a high diagnostic performance in this Latin-American population.

15.
Chemosphere ; 240: 124826, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31561164

RESUMEN

The processes that control water quality improvement during artificial recharge (filtering, degradation, and adsorption) can be enhanced by adding a reactive barrier containing different types of sorption sites and promoting diverse redox states along the flow path, which increases the range of pollutants degraded. While this option looks attractive for renaturazing reclaimed water, three issues have to be analyzed prior to broad scale application: (1) a fair comparison between the system with and without reactive barrier; (2) the role of plants in prevention of clogging and addition of organic carbon; and (3) the removal of pathogens. Here, we describe a pilot installation built to address these issues within a waste water treatment plant that feeds on water reclaimed from the secondary outflow. The installation consists of six systems of recharge basin and aquifer with some variations in the design of the reactive barrier and the heterogeneity of the aquifer. We report preliminary results after one year of operation. We find that (1) the systems are efficient in obtaining a broad range of redox conditions (at least iron and manganese reducing), (2) contaminants of emerging concern are significantly removed (around 80% removal, but very sensitive to the compound), (3) pathogen indicators (E. coli and Enterococci) drop by some 3-5 log units, and (4) the recharge systems maintained infiltration capacity after one year of operation (only the system without plants and the one without reactive barrier displayed some clogging). Overall, the reactive barrier enhances somewhat the performance of the system, but the gain is not dramatic, which suggests that barrier composition needs to be improved.


Asunto(s)
Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Calidad del Agua/normas , Contaminantes Químicos del Agua/análisis
16.
Sci Total Environ ; 612: 985-994, 2018 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-28892850

RESUMEN

A reactive barrier that consisted of vegetable compost, iron oxide and clay was installed in an infiltration basin to enhance the removal of emerging organic compounds (EOCs) in the recharge water. First-order degradation rates and retardation factors were jointly estimated for 10 compounds using a multilayer reactive transport model, whose flow and conservative transport parameters were previously estimated using hydraulic head values and conservative tracer tests. Reactive transport parameters were automatically calibrated against the concentration of EOCs measured at nine monitoring points. The degradation rate of each compound was estimated for three zones defined according to the redox state, and retardation coefficients were estimated in two zones defined according to the organic matter content. The fastest degradation rates were obtained for the reactive barrier, and the estimated values were similar to or higher than those estimated in column and/or field experiments for most of the compounds (8/10). Estimated retardation coefficients in the reactive barrier were higher than in the rest of the aquifer in most cases (8/10) and higher than those values estimated in previous studies. Based on the results obtained in this study the reactive barrier seems to be able to enhance the removal of EOCs.

17.
Salud pública Méx ; 60(supl.1): 65-82, 2018. tab, graf
Artículo en Español | LILACS | ID: biblio-979183

RESUMEN

Resumen El sismo del 19 de septiembre de 2017 en México causó daños catastróficos en el estado de Morelos que afectaron a más de 23 000 inmuebles en prácticamente todos los municipios del estado. Después de un sismo, resultan de gran importancia las acciones de emergencia existentes en la región para dar apoyo a la sociedad, tanto en el rescate de personas atrapadas como en la evaluación de la condición estructural que presentan los inmuebles, y de esta manera, mitigar sus efectos. Las acciones de emergencia requieren de planeación, organización, recursos económicos y materiales y, sobre todo, de trabajo en equipo. Desafortunadamente muchas sociedades no están preparadas para contener grandes desastres, por lo que puede resultar muy difícil hacer frente a una gran emergencia sin las condiciones adecuadas. Durante la emergencia del 19 de septiembre se vivió una situación jamás esperada en el estado de Morelos por los daños provocados por el sismo de magnitud 7.1, con epicentro a menos de 75 km de distancia, que puso a prueba al sistema de emergencia del estado. De manera particular, investigadores del Instituto Nacional de Electricidad y Energías Limpias (INEEL) iniciaron acciones de inspección en los inmuebles de su propio instituto, y posteriormente se pusieron a las órdenes de Protección Civil del Estado de Morelos para realizar inspecciones post-sísmicas de los inmuebles de gobierno, escuelas y, en general, de las viviendas de Morelos. La tarea principal del apoyo del INEEL consistió en dictaminar si los inmuebles debían continuar operando o ser habitables, si debían ser desalojados para hacer una revisión detallada o incluso si debían ser demolidos debido al alto riesgo de colapso que presentaban. El apoyo proporcionado por el INEEL no sólo se concentró en la evaluación post-sísmica de los inmuebles, sino que ha sido el inicio de una mayor colaboración con las autoridades del Estado, que resultará en el mejoramiento de los planes de emergencia y, sobre todo, en la actualización de las normas de diseño.


Abstract The earthquake of September 19, 2017 in Mexico caused catastrophic damage in the state of Morelos to more than 23 thousand structures in almost all municipalities. After an earthquake, emergency actions in the area are of great importance to support society, rescue trapped people as well as to assess the structural condition of the structures, and in this way, mitigate the negative effects. Unfortunately, society is not prepared to contain major disasters, and it can be very difficult to face a major emergency without the right conditions. The earthquake of September 19, with magnitude 7.1 and epicenter less than 75 km away, caused an emergency never expected in the state of Morelos, because of the damage it produced, which put Morelos' emergency system to the test. In particular, researchers from the National Institute of Electricity and Clean Energies (INEEL) initiated inspection actions in the buildings of their own institute, and subsequently placed themselves under the orders of the Civil Protection office of the State of Morelos to carry out post-seismic inspections of government buildings, schools and, in general, the homes of Morelos. The main task was to decide if the buildings were able to be inhabited again, if they should be evicted for a detailed review or if they should be demolished due to their high risk of collapse. The support was not only oriented to the post-seismic evaluation of the buildings, but was the beginning of working days with the State authorities, which will result in the improvement of the emergency plans and, above all, in the update of the design standards.

18.
Sci Total Environ ; 592: 391-402, 2017 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-28324856

RESUMEN

Groundwater management in urban areas requires a detailed knowledge of the hydrogeological system as well as the adequate tools for predicting the amount of groundwater and water quality evolution. In that context, a key difference between urban and natural areas lies in recharge evaluation. A large number of studies have been published since the 1990s that evaluate recharge in urban areas, with no specific methodology. Most of these methods show that there are generally higher rates of recharge in urban settings than in natural settings. Methods such as mixing ratios or groundwater modeling can be used to better estimate the relative importance of different sources of recharge and may prove to be a good tool for total recharge evaluation. However, accurate evaluation of this input is difficult. The objective is to present a methodology to help overcome those difficulties, and which will allow us to quantify the variability in space and time of the recharge into aquifers in urban areas. Recharge calculations have been initially performed by defining and applying some analytical equations, and validation has been assessed based on groundwater flow and solute transport modeling. This methodology is applicable to complex systems by considering temporal variability of all water sources. This allows managers of urban groundwater to evaluate the relative contribution of different recharge sources at a city scale by considering quantity and quality factors. The methodology is applied to the assessment of recharge sources in the Barcelona city aquifers.

20.
Proc Natl Acad Sci U S A ; 112(19): 5938-43, 2015 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-25902501

RESUMEN

Zoback and Gorelick [(2012) Proc Natl Acad Sci USA 109(26):10164-10168] have claimed that geologic carbon storage in deep saline formations is very likely to trigger large induced seismicity, which may damage the caprock and ruin the objective of keeping CO2 stored deep underground. We argue that felt induced earthquakes due to geologic CO2 storage are unlikely because (i) sedimentary formations, which are softer than the crystalline basement, are rarely critically stressed; (ii) the least stable situation occurs at the beginning of injection, which makes it easy to control; (iii) CO2 dissolution into brine may help in reducing overpressure; and (iv) CO2 will not flow across the caprock because of capillarity, but brine will, which will reduce overpressure further. The latter two mechanisms ensure that overpressures caused by CO2 injection will dissipate in a moderate time after injection stops, hindering the occurrence of postinjection induced seismicity. Furthermore, even if microseismicity were induced, CO2 leakage through fault reactivation would be unlikely because the high clay content of caprocks ensures a reduced permeability and increased entry pressure along the localized deformation zone. For these reasons, we contend that properly sited and managed geologic carbon storage in deep saline formations remains a safe option to mitigate anthropogenic climate change.

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