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Updated water directives and ambitious targets like the United Nations’ Sustainable Development Goals (SDGs) have emerged in the last decade to tackle water scarcity and contamination. Although numerous strategies have been developed to remove water pollutants, it is still necessary to enhance their effectiveness against toxic and biorefractory organic molecules. Comprehensive reviews have highlighted the appealing features of the electrochemical technologies, but much progress has been made in recent years. In this timely review, a critical discussion on latest innovations and perspectives of the most promising electrochemical tools for wastewater treatment is presented. The work describes the performance of electrocatalytic anodes for direct electrochemical oxidation, the oxidation mediated by electrogenerated active chlorine, the electrocatalytic reduction as well as coupled approaches for synchronous anodic and cathodic processes combined with homogeneous and heterogeneous catalysis. The last section is devoted to the assessment of scale-up issues and the increase in the technology readiness level.

Ozone (O3) is a powerful oxidant widely used in disinfection and wastewater treatment. In this work, a novel 3-D printed casing for electrochemical cells has been specially designed and manufactured for Proton-Exchange Membrane (PEM) electro-ozonizers, trying to promote an improved fluid dynamic including an efficient evacuation of gases produced during the electrolysis and aiming to minimize the interaction among ozone and scavengers. It is demonstrated that reaching high efficiencies in the electrochemical production of ozone is limited by the action of electrogenerated scavengers, among which cathodically formed hydrogen peroxide outstands. This explains the effects observed regarding current density (higher efficiencies at higher current densities applied, because hydrogen peroxide production is prevented), electrolyte composition (better efficiencies with lower concentrations of non-reacting electrolytes) and operation pressure (better results at lower pressures, because hydrogen peroxide formation depends more importantly on dissolved oxygen than ozone production). A very good performance is obtained, with ozone productions as high as 0.240 mg/(Ah cm2) and maximum current efficiencies of 5.9% under the best operation conditions (1.0 mM of HClO4, 330 mA/cm2 and 1 bar), which demonstrate the suitability of the technology tested and the good perspectives of 3D printing to improve performance of electrochemical processes., Ozono (O 3) es un poderoso oxidante ampliamente utilizado en desinfección y tratamiento de aguas residuales. En este trabajo, se ha diseñado y fabricado especialmente una carcasa impresa en 3D para celdas electroquímicas para electro-ozonizadores de membrana de intercambio de protones (PEM), tratando de promover una dinámica de fluidos mejorada que incluya una evacuación eficiente de los gases producidos durante la electrólisis y con el objetivo de minimizar la interacción entre el ozono y los secuestrantes. Se demuestra que alcanzar altas eficiencias en la producción electroquímica de ozono está limitado por la acción de secuestrantes electrogenerados, entre los que destaca el peróxido de hidrógeno formado catódicamente. Esto explica los efectos observados con respecto a la densidad de corriente (mayores eficiencias a mayores densidades de corriente aplicadas, porque se evita la producción de peróxido de hidrógeno), composición de electrolitos (mejores eficiencias con concentraciones más bajas de electrolitos que no reaccionan) y presión de operación (mejores resultados a presiones más bajas, porque la formación de peróxido de hidrógeno depende más del oxígeno disuelto que de la producción de ozono). Se obtiene un muy buen rendimiento, con producciones de ozono de hasta 0,240 mg/(Ah cm2 ) y eficiencias de corriente máximas del 5,9% en las mejores condiciones de operación (1,0 mM de HClO 4 , 330 mA/cm 2 y 1 bar), que demuestran la idoneidad de la tecnología probada y las buenas perspectivas de la impresión 3D para mejorar el rendimiento de procesos electroquimicos.

FLK North (FLK N) (Bed I, Olduvai Gorge, Tanzania) is one of the best examples of a palimpsest where felids, hyenids and hominins made use of the same space without or with minimal interaction between hominins and the other two carnivores. Felids have been interpreted as the main accumulators and carcass consumers followed by frequent hyenid intervention. The presence of hominins at this site has been documented through the discovery of stone tools. Here, we test previous taphonomic interpretations of this site through the application of Artificial Intelligence (AI) tools (computer vision applied to bidimensional images of tooth pits) to taxonomically discriminate carnivore-made tooth marks. The bones we analyzed constitute a small sample, being a preliminary study of bone surface modifications (BSM) through the application of AI to a sample of the FLK N archaeofaunal assemblage (mostly to Level 3 fossils), pending access to the larger excavated collections. The results obtained in the present study show that the marks analyzed have been generated both by hyenids and felids. The slight predominance of hyena tooth marks is expected, since the bone sample used is dominated by long limb bones, and hyenas are the most likely agent causing long bone breakage, although felids also break bones of carcasses smaller than 150 kg as documented in the site. Felid impact, in at least three cases, is documented with tooth marks imprinted by felids and hyenas occurring on the same specimens. Felid-hyenid interaction is, thus, documented though the deep learning methods applied. The limited number of specimens where both agents are documented suggest that both hyenids and felids were independently breaking a substantial part of the bones at FLK N. This preliminarily modifies previous interpretations that attributed most long bone fragmentation exclusively to hyenas.

Here, we present a thorough taphonomic analysis of the 1.84 million-year-old site of Phillip Tobias Korongo (PTK), Bed I, Olduvai Gorge. PTK is one of the new archaeological sites documented on the FLK Zinj paleolandscape, in which FLK 22 level was deposited and covered by Tuff IC. Therefore, PTK is pene- contemporary with these sites: FLK Zinj, DS, AMK and AGS. The occurrence of these sites within a thin clay unit of ~20 cm, occupying not only the same vertically discrete stratigraphic unit, but also the same paleosurface, with an exceptional preservation of the archaeological record in its primary depositional locus, constitutes a unique opportunity to explore early hominin behavioral diversity at the most limited geochronological scale possible. The Olduvai Bed I sites have been the core of behavioral modelling for the past half a century, and the newly discovered sites, excavated with 21st century technology, will increase significantly our understanding of early human adaptive patterns. Here, we present PTK as another assemblage where faunal resources were acquired by hominins prior to any carnivore, and where stone-tool assisted bulk defleshing was carried out. The abundance of juvenile individuals extends our understanding, as in Kanjera (Kenya), about the hunting skills of early Homo sensu lato. The increasing number of sites, where bulk defleshing of small and medium-sized carcasses took place is underscoring the importance of meat in the diets of some of the early hominins, and their patterned use of the space for food processing and consumption. The patterning emerging has a profound importance for the evolution of some of the features that have traditionally been used to identify the behavior of the genus Homo., This work was supported by the Swedish Research Council (Vetenskapsrådet) (AR-HS 2018-01045-3). We also thank the Spanish Ministry of Science and Innovation for funding this research (PID 2020-115452 GB-C21), and the Ministry of Culture for their funding through the program of Archaeology Abroad. Our thanks also to the Palarq Foundation and E2in2 for financial support.

The depletion of blaKPC (K. pneumoniae), blaOXA-50 (P. aeruginosa) and mecA (S. aureus) genes from hospital urines is evaluated to contribute to solve the silent pandemic of antibiotic-resistance bacteria. A microfluidic flow-through reactor with MMO anode and CB/PTFE cathode working at 50 A m−2 is employed during electrodisinfection and photo-electrodisinfection processes. The electrodisinfection process only achieves an almost negligible removal of DNA and slightly log ARG increments of 0.18, 0.19 and 0.71 for blaOXA-50, mecA and blaKPC genes, respectively. Conversely, the photo-electrodisinfection process attains the complete disinfection for all ARB tested and logarithmic removals of 3.70, 2.25 and 0.82 for blaOXA-50, mecA and blaKPC genes, respectively. These outcomes emphasize the potential of the UV light coupled to the electrodisinfection process to promote the formation of not only hypochlorite but also chlorine and even nitrogen radicals, which contribute to enhance the disinfection efficiency of the target ARB and their ARGs., Se evalúa la depleción de los genes bla KPC ( K. pneumoniae ), bla OXA-50 ( P. aeruginosa ) y mec A ( S. aureus ) de orinas hospitalarias para contribuir a solucionar la pandemia silenciosa de bacterias resistentes a los antibióticos. Se emplea un reactor de flujo continuo de microfluidos con ánodo MMO y cátodo CB/PTFE que trabaja a 50 A m - 2 durante los procesos de electrodesinfección y fotoelectrodesinfección. El proceso de electrodesinfección solo logra una eliminación casi insignificante de ADN y aumentos ligeramente logarítmicos de ARG de 0,18, 0,19 y 0,71 para bla OXA-50 , mec A y bla KPCgenes, respectivamente. Por el contrario, el proceso de fotoelectrodesinfección logra la desinfección completa para todos los ARB probados y eliminaciones logarítmicas de 3,70, 2,25 y 0,82 para los genes bla OXA-50 , mec A y bla KPC , respectivamente. Estos resultados enfatizan el potencial de la luz ultravioleta junto con el proceso de electrodesinfección para promover la formación no solo de hipoclorito sino también de radicales de cloro e incluso nitrógeno, que contribuyen a mejorar la eficiencia de desinfección del ARB objetivo y sus ARG.

This paper is focused on the evaluation of the electrochemically assisted absorption process (electro-absorption) as a treatment for volatile organic compounds contained in polluted air flows. Benzene degradation was used to test the technology, using a system consisting of a packed absorption column and a single compartment electrochemical cell equipped with boron-doped diamond (BDD) as anode and steel-steal as cathode. The influence of inlet gas flow rate and operation current intensity was evaluated by monitoring the concentration of benzene and intermediates both, in the liquid absorbent / electrolyte and in the outlet gaseous stream. Results show that steady-state values reached, during benzene absorption and electro-absorption, increase when the inlet gas flow rises from 1.5 to 6.0 L h−1 and that the bare absorption process retains benzene only up to this steady-state value of the liquid and then, it has no effect on the removal of benzene. Concentrations of benzene in the absorbent/electrolyte decreases with the increase in the current density during electrochemically assisted processes. As well, mineralization was found to be very important, as expected because of the very low concentrations of benzene into the liquid and the very high efficiencies of the electrolytic degradation with BDD electrodes, and benzoquinone and carboxylic acids were identified as the primary intermediates. These species were not detected in the outlet gas flow. The decrease in the concentration and mass flow of benzene in the outlet streams confirms that electro-absorption is a functional electrochemical application to remove benzene from gaseous streams. When current density rises (10, 50 and 100 mA cm−2), the degradation percentage increases. The values obtained were 43, 61 and 75% with 1,5 L h−1 of inlet gas flow and 10, 25 and 37 % with 6 L h−1. However, the degradation percentage relative to the energy consumption decreases when the current density rises. Results were, correspondingly, 24.7, 4.2 and 2.2 % kWh−1 with 1,5 L h−1 of inlet gas flow and 7.1, 2.1 and 1.4 % with 6 L h−1. This energy efficiency trend was explained because mass transport becomes the bottleneck in the oxidation of diluted organic solutions. These results contribute to expand the understanding of the mechanisms involved in the electro-absorption of benzene and recommend for further research in the topic, due to the relevance of the treatment results., Este artículo se centra en la evaluación del proceso de absorción electroquímicamente asistido (electroabsorción) como tratamiento de compuestos orgánicos volátiles contenidos en flujos de aire contaminado. La degradación del benceno se utilizó para probar la tecnología, utilizando un sistema que consiste en una columna de absorción empacada y una celda electroquímica de un solo compartimento equipada con diamante dopado con boro (BDD) como ánodo y acero como cátodo. La influencia del caudal de gas de entrada y la intensidad de la corriente de operación se evaluó monitoreando la concentración de benceno e intermedios tanto en el líquido absorbente/electrolito como en la corriente gaseosa de salida. Los resultados muestran que los valores de estado estacionario alcanzados, durante la absorción de benceno y la electroabsorción, aumentan cuando el flujo de gas de entrada aumenta de 1,5 a 6,0 L h −1y que el proceso de absorción simple retiene benceno solo hasta este valor de estado estacionario del líquido y luego, no tiene efecto en la eliminación de benceno. Las concentraciones de benceno en el absorbente/electrolito disminuyen con el aumento de la densidad de corriente durante los procesos asistidos electroquímicamente. Además, se encontró que la mineralización era muy importante, como se esperaba debido a las concentraciones muy bajas de benceno en el líquido y las eficiencias muy altas de la degradación electrolítica con electrodos BDD, y se identificaron la benzoquinona y los ácidos carboxílicos como los intermediarios primarios. Estas especies no se detectaron en el flujo de gas de salida. La disminución de la concentración y el flujo másico de benceno en las corrientes de salida confirma que la electroabsorción es una aplicación electroquímica funcional para eliminar el benceno de las corrientes gaseosas. Cuando aumenta la densidad de corriente (10, 50 y 100 mA cm−2 ), el porcentaje de degradación aumenta. Los valores obtenidos fueron 43, 61 y 75 % con 1,5 L h -1 de caudal de gas de entrada y 10, 25 y 37 % con 6 L h -1 . Sin embargo, el porcentaje de degradación relativo al consumo de energía disminuye cuando aumenta la densidad de corriente. Los resultados fueron, correspondientemente, 24,7, 4,2 y 2,2 % kWh- 1 con 1,5 L h - 1 de caudal de gas de entrada y 7,1, 2,1 y 1,4 % con 6 L h- 1. Esta tendencia de eficiencia energética se explica porque el transporte masivo se convierte en el cuello de botella en la oxidación de soluciones orgánicas diluidas. Estos resultados contribuyen a ampliar la comprensión de los mecanismos involucrados en la electroabsorción del benceno y recomiendan para futuras investigaciones en el tema, debido a la relevancia de los resultados del tratamiento.

Here, we present the first three-dimensional taphonomic analysis of a carnivore-modified assemblage at the anatomical scale of the appendicular skeleton. A sample of ten carcasses composed of two taxa (zebra and wildebeest) consumed by wild lions in the Tarangire National Park (Tanzania) has been used to determine element-specific lion damage patterns. This study presents a novel software for the 3D spatial documentation of bone surface modifications at the anatomical level. Combined with spatial statistics, the present analysis has been able to conclude that despite variable degrees of competition during carcass consumption, lions generate bilateral patterning consisting of substantial damage of proximal ends of stylopodials and zeugopodials, moderate damage of the distal ends of femora and marginal damage of distal ends of humeri and zeugopodials. Of special interest is, specifically, the patterning of tooth marks on shafts according to element, since these are crucial to determine not only the type of carnivore involved in any given bone assemblage, but also the interaction with other agents (namely, hominins, in the past). Lions leave few tooth marks on mid-shaft sections, mostly concentrated on certain sections and orientations of stylopodials and, to a lesser extent, of the proximal tibia. Redundant occurrence of tooth marks on certain bone sections renders them as crucial to attest lion agency in carcass initial consumption. Indirectly, this can also be used to determine whether hominins ever acquired carcasses at lion kills.

This paper evaluates the combination of electrokinetic soil flushing (EKSF) with soil vapor extraction (SVE) for the removal of four hexachlorocyclohexane (HCH) isomers contained in a real matrix. Results demonstrate that the combination of EKSF and SVE can be positive, but it is required the application of high electric fields (3 V cm−1) in order to promote a higher temperature in the system, which improves the volatilization of the HCH contained in the system. Electrokinetic transport is also enhanced with the application of higher electric gradients, but these transport processes are slower than the volatilization processes, which are the primary in this system. Hence collection of species in the electrolyte wells is negligible as compared to the compound dragged with air by the SVE but the temperature increase demonstrates a good performance. Combination of EKSF with SVE can efficiently exhaust the four HCH isomers reaching a removal of more than 90% after 15 days of treatment (20% more than values attained by SVE) but it is required the application of high electric fields to promote a higher temperature in the system (to improve the volatilization) and EK transport (to improve the dragging). 1-D transport model can be easily used to estimate the average pore water velocity and the effective diffusion of each compound under the different experimental conditions tested., Este artículo evalúa la combinación de lavado electrocinético del suelo (EKSF) con extracción de vapor del suelo (SVE) para la eliminación de cuatro isómeros de hexaclorociclohexano (HCH) contenidos en una matriz real. Los resultados demuestran que la combinación de EKSF y SVE puede ser positiva, pero se requiere la aplicación de campos eléctricos elevados (3 V cm −1) con el fin de promover una mayor temperatura en el sistema, lo que mejora la volatilización del HCH contenido en el sistema. El transporte electrocinético también mejora con la aplicación de gradientes eléctricos más altos, pero estos procesos de transporte son más lentos que los procesos de volatilización, que son los principales en este sistema. Por lo tanto, la recolección de especies en los pozos de electrolito es insignificante en comparación con el compuesto arrastrado con aire por el SVE, pero el aumento de temperatura demuestra un buen desempeño. La combinación de EKSF con SVE puede agotar eficientemente los cuatro isómeros de HCH alcanzando una eliminación de más del 90 % después de 15 días de tratamiento (20 % más que los valores alcanzados por SVE) pero se requiere la aplicación de campos eléctricos elevados para promover una temperatura más alta en el sistema (para mejorar la volatilización) y transporte EK (para mejorar el arrastre). El modelo de transporte 1-D se puede usar fácilmente para estimar el promediola velocidad intersticial del agua y la difusión efectiva de cada compuesto bajo las diferentes condiciones experimentales probadas.

In the search for a method that can remove pollutants from gases or enhance the efficiency of the treatment of liquid wastes, electrolysis of water and methanol solutions containing benzene, toluene, and xylene were carried out in this work. Using a filter-press flow electrochemical cell, the efficiency of two different anodes (diamond coatings and mixed metal oxides) were evaluated against the electrochemical oxidation of contaminants in the different solvents mentioned. Results demonstrate that these pollutants can be removed from both types of matrixes and that the nature of the electrode influences greatly on the efficiency. In aqueous medium both electrodes perform similarly but diamond overcomes metal oxide anodes in methanol. In addition to a higher mineralization rate in that case, several highly value-added products are obtained during the process. For instance, anisole, methyl anisole and dimethyl anisole were produced from electrochemical oxidation of benzene, toluene and xylene, respectively, in methanol medium. These results pointing out that a change in the paradigm of the treatment must be made in the next years, going from the destruction of the pollutants to their conversion into highly valuable products at the frame of the circular economy premises., En la búsqueda de un método que pueda eliminar los contaminantes de los gases o mejorar la eficiencia del tratamiento de desechos líquidos , en este trabajo se llevó a cabo la electrólisis de soluciones de agua y metanol que contienen benceno, tolueno y xileno . Usando una celda electroquímica de flujo de filtro prensa , se evaluó la eficiencia de dos ánodos diferentes (revestimientos de diamante y óxidos metálicos mixtos) frente a la oxidación electroquímica .de contaminantes en los diferentes disolventes mencionados. Los resultados demuestran que estos contaminantes se pueden eliminar de ambos tipos de matrices y que la naturaleza del electrodo influye mucho en la eficiencia. En medio acuoso, ambos electrodos funcionan de manera similar, pero el diamante supera a los ánodos de óxido metálico en metanol. Además de una mayor tasa de mineralización en ese caso, durante el proceso se obtienen varios productos de alto valor agregado. Por ejemplo, el anisol, el metilanisol y el dimetilanisol se produjeron a partir de la oxidación electroquímica de benceno, tolueno y xileno, respectivamente, en medio metanol. Estos resultados apuntan que se debe realizar un cambio en el paradigma del tratamiento en los próximos años, pasando de la destrucción de los contaminantes a su conversión en productos de alto valor en el marco de las premisas de la economía circular .

In this research, a bench-scale installation was tested for the heterogeneous electro-Fenton treatment of clofibric acid. The setup consists of a pressurized flow-through electrochemical cell equipped with a catalyst fluidized-bed and aerated with a jet mixer. The novelty of the research is two-fold: the use of the pressurized-jet aerator on an electro-Fenton treatment is tested and it is one of the first studies combining pressure with heterogeneous catalysis in electro-Fenton. Moderate relative pressures, up to 2 bar, were analyzed. Initially, the electrogeneration of hydrogen peroxide was tested, showing that it is remarkably boosted by the application of pressure. Then, the elimination of clofibric acid by means of an electro-Fenton treatment was carried out at 0.12 and 0.25 A, using iron-containing alginate beads as the catalyst. Regardless of the current intensity, the increase from atmospheric pressure to 1 gauge bar boosted the elimination of the pollutant and reduced the specific energy consumption of the electrochemical cell. Specifically, at 0.25 A an abatement higher than 98% was achieved in 8 h at atmospheric pressure while only 1 h was required at 1 bar of gauge pressure. However, a further increase of the pressure to 2 bar did not report a major improvement. Moreover, the effect of pressure on the catalyst was analyzed, concluding that the integrity of the alginate beads was not compromised by pressure. In fact, the iron leaching was very similar at 0, 1 and 2 bar: around 30% after 8 h of treatment. Finally, a mathematical model was developed, using the experimental data to obtain the necessary fitting parameters, which allowed to understand better the behavior of the bench-scale reaction system., En esta investigación se probó una instalación a escala de banco para el tratamiento electro-Fenton heterogéneo del ácido clofíbrico. La configuración consta de una celda electroquímica de flujo presurizado equipada con un lecho fluidizado de catalizador y aireado con un mezclador de chorro. La novedad de la investigación es doble: se prueba el uso del aireador de chorro a presión en un tratamiento de electro-Fenton y es uno de los primeros estudios que combina presión con catálisis heterogénea en electro-Fenton. Se analizaron presiones relativas moderadas, hasta 2 bar. Inicialmente se probó la electrogeneración de peróxido de hidrógeno, demostrando que se potencia notablemente con la aplicación de presión. A continuación, se realizó la eliminación del ácido clofíbrico mediante un tratamiento electro-Fenton a 0,12 y 0,25 A, utilizando como catalizador perlas de alginato con contenido de hierro. Independientemente de la intensidad de la corriente, el aumento de la presión atmosférica a 1 bar manométrico potenció la eliminación del contaminante y redujo el consumo energético específico de la celda electroquímica. Concretamente, a 0,25 A se logró una reducción superior al 98% en 8 h a presión atmosférica mientras que solo se requirió 1 h a 1 bar de presión manométrica. Sin embargo, un aumento adicional de la presión a 2 bar no reportó una mejora importante. Además, se analizó el efecto de la presión sobre el catalizador, concluyendo que la integridad de las perlas de alginato no se vio comprometida por la presión. De hecho, la lixiviación del hierro fue muy similar a 0, 1 y 2 bar: en torno al 30% tras 8 h de tratamiento. Finalmente, se desarrolló un modelo matemático, utilizando los datos experimentales para obtener los parámetros de ajuste necesarios

This work focuses on the electrochemical production of chlorate solutions for direct use and integration in the manufacture of chlorine dioxide (ClO2), from the perspective of manufacturing portable ClO2 electrochemical generators, Este trabajo se centra en la producción electroquímica de soluciones de clorato para su uso directo e integración en la fabricación de dióxido de cloro (ClO2), desde la perspectiva de la fabricación de generadores electroquímicos portátiles de ClO2

Outstanding questions about human evolution include systematic connections between critical landscape resources—such as water and food—and how these shaped the competitive and biodiverse environment(s) that our ancestors inhabited. Here, we report fossil n-alkyl lipid biomarkers and their associated δ13C values across a newly discovered Olduvai Gorge site (AGS) dated to 1.84 million years ago, enabling a multiproxy analysis of the distributions of critical local landscape resources across an explicit locus of hominin activity. Our results reveal that AGS was a seasonally waterlogged, largely unvegetated lakeside site situated near an ephemeral freshwater river surrounded by arid-adapted C4 grasses. The sparse vegetation at AGS contrasts with reconstructed (micro)habitats at the other anthropogenic sites at Olduvai Gorge, suggesting that central-provisioning places depended more heavily on water access than vegetation viz. woody plants as is often observed for modern hunter-gatherers. As hominins at AGS performed similar butchering activities as at other Bed I sites, our results suggest they did not need the shelter of trees and thus occupied a competitive position within the predatory guild.

This work focuses on the production of electricity using chloralkaline high temperature PEM fuel cells (HT-PEMFC) comparing, within the range 120–180 °C, the performance of a cell equipped with a cathode containing a novel Ru/Pt catalyst manufactured at mild temperature conditions with another cell which contains a conventional Ru based catalyst (Ru0.75Pt0.25O2). Performance of the cell equipped with the conventional electrode at 120 °C is much better, but this situation reverses at higher operation temperatures, where the novel catalyst outperforms the conventional Ru0.75Pt0.25O2 in terms of production of electricity. In addition, the new catalyst allows to operate even at 180 °C, temperature at which the cell equipped with the conventional electrode is completely deteriorated. Results pointed out that materials are the bottleneck for the chloralkaline HT-PEMFC technology but opens the window for the search of new materials that help to improve their future development., Este trabajo se centra en la producción de electricidad utilizando pilas de combustible PEM de alta temperatura cloralcalinas (HT-PEMFC) comparando, en el rango de 120-180 °C, el rendimiento de una pila equipada con un cátodo que contiene un catalizador novedoso de Ru/Pt fabricado a temperatura templada. condiciones de temperatura con otra celda que contiene un catalizador basado en Ru convencional (Ru 0.75 Pt 0.25 O 2 ). El desempeño de la celda equipada con el electrodo convencional a 120 °C es mucho mejor, pero esta situación se revierte a temperaturas de operación más altas, donde el nuevo catalizador supera al convencional Ru 0.75 Pt 0.25 O 2en términos de producción de electricidad. Además, el nuevo catalizador permite operar incluso a 180 °C, temperatura a la que la celda equipada con el electrodo convencional se deteriora por completo. Los resultados señalaron que los materiales son el cuello de botella para la tecnología cloroalcalina HT-PEMFC pero abren la ventana para la búsqueda de nuevos materiales que ayuden a mejorar su desarrollo futuro.

This work focuses on the development and testing of simple phenomenological models for understanding the behaviour of processes happening at the same time in the electro-scrubbers during the electrochemically assisted absorption of two relevant volatile organic compounds: perchloroethylene and toluene. Formulation of the model considers physical absorption of the organics into the electrolyte and reactivity according to experimental observations. Different experimental case studies have been used to validate the model obtaining regression coefficients higher than 0.9 and 0.85 for perchloroethylene and toluene, respectively. The model points out the high relevance of the absorption technology and of the presence of cobalt. In the case of perchloroethylene, the model also highlighted the important contribution of the wet decomposition of this chlorinated hydrocarbon. Results obtained clearly evidence the industrial application of the electro-scrubbers technologies.

This work intends to go a step further in the application of electrochemical technology to produce ozone, by evaluating the production of ozone with a commercial cell registered as CabECO®, which has been previously used to disinfect heavily polluted water in a successful manner, with a view to ascertaining whether this success may be related to the production of ozone. The CabECO® cell is a PEM electrolyzer; that is to say, one in which anode and cathode are connected through a PEM membrane. Since ozone production on the electrolyte is important and depends on the composition of the liquid, attention must be paid to the electrochemical production of scavengers. Dosing of oxygen as microbubbles has a very positive effect on the production of ozone, while temperature regulation is as well considerably important, as the increase in temperature generated by ohmic losses can lead to important decreases in the efficiency of ozone electrogeneration. Rates within the range 0.06–0.60 mg O3 min−1 are observed; this means that the maximum current efficiency reached is as high as 6.11% (considering oxygen as raw matter). These results are extremely promising as compared with other references in the literature, at once they also indicate there is room for further improvements and a long way to prevent the effect of scavengers and increase the efficiency of the process.

Artifcial intelligence algorithms have recently been applied to taphonomic questions with great success, outperforming previous methods of bone surface modifcation (BSM) identifcation. Following these new developments, here we try diferent deep learning model architectures, optimizers and activation functions to assess if it is possible to identify a stone tool?s raw material simply by looking at the cut marks that it created on bone. The deep learning models correctly discerned between fint, sandstone and quartzite with accuracy rates as high as 78%. Also, single models seem to work better than ensemble ones, and there is no optimal combination of hyperparameters that perform better in every possible scenario. Model fne-tuning is thus advised as a protocol. These results consolidate the potential of deep learning methods to make classifcations out of BSM?s microscopic features with a higher degree of confdence and more objectively than alternative taphonomic procedures., Agencia Estatal de Investigación

This work aims to shed light on the scale-up a combined electrokinetic soil flushing process (EKSF) with permeable reactive barriers (PRB) for the treatment of soil spiked with clopyralid. To do this, remediation tests at lab (3.45 L), bench (175 L) and pilot (1400 L) scales have been carried out. The PRB selected was made of soil merged with particles of zero valent iron (ZVI) and granular activated carbon (GAC). Results show that PRB-EKSF involved electrokinetic transport and dehalogenation as the main mechanisms, while adsorption on GAC was not as relevant as initially expected. Clopyralid was not detected in the electrolyte wells and only in the pilot scale, significant amounts of clopyralid remained in the soil after 600 h of operation. Picolinic acid was the main dehalogenated product detected in the soil after treatment and mobilized by electro-osmosis, mostly to the cathodic well. The transport of volatile compounds into the atmosphere was promoted at pilot scale because of the larger soil surface exposed to the atmosphere and the electrical heating caused by ohmic losses and the larger interelectrode gap., Este trabajo tiene como objetivo arrojar luz sobre el escalado de un proceso de lavado de suelo electrocinético combinado (EKSF) con barreras reactivas permeables .(PRB) para el tratamiento de suelos enriquecidos con clopiralid. Para ello, se han realizado pruebas de remediación a escala de laboratorio (3,45 L), banco (175 L) y piloto (1400 L). El PRB seleccionado estaba hecho de suelo fusionado con partículas de hierro cerovalente (ZVI) y carbón activado granular (GAC). Los resultados muestran que PRB-EKSF involucraba el transporte electrocinético y la deshalogenación como los principales mecanismos, mientras que la adsorción en GAC no fue tan relevante como se esperaba inicialmente. No se detectó clopiralida en los pozos de electrolito y solo en la escala piloto, cantidades significativas de clopiralida permanecieron en el suelo después de 600 h de operación. El ácido picolínico fue el principal producto deshalogenado detectado en el suelo después del tratamiento y movilizado por electro-ósmosis, principalmente al pozo catódico.

This work is focused on the characterization of the production of ozone, hydrogen peroxide and hydroxyl radicals (peroxone) in pressurized undivided electrochemical cells. BDD and MMO electrodes were compared as anodes and RVC, graphite and stainless steel as cathodes. Gauge pressures in the range 2–4 bar were applied. Results demonstrate the complexity in the production of oxidants in an undivided cell, allowing to propose a model of the set of reactions (both electrochemical and in the bulk) occurring in the system. A higher pressure decreases the accumulation of ozone meanwhile hydrogen peroxide production is maximized at intermediate values of pressure. Combining BDD and graphite is the best combination for enhancing the production of hydroxyl radicals for which a negligible influence of pressure was observed. These results would allow to select the proper design to maximize the efficiency in the production of each of the oxidants studied.

Humans are unique in their diet, physiology and socio‑reproductive behavior compared to other primates. They are also unique in the ubiquitous adaptation to all biomes and habitats. From an evolutionary perspective, these trends seem to have started about two million years ago, coinciding with the emergence of encephalization, the reduction of the dental apparatus, the adoption of a fully terrestrial lifestyle, resulting in the emergence of the modern anatomical bauplan, the focalization of certain activities in the landscape, the use of stone tools, and the exit from Africa. It is in this period that clear taphonomic evidence of a switch in diet with respect to Pliocene hominins occurred, with the adoption of carnivory. Until now, the degree of carnivorism in early humans remained controversial. A persistent hypothesis is that hominins acquired meat irregularly (potentially as fallback food) and opportunistically through klepto‑foraging. Here, we test this hypothesis and show, in contrast, that the butchery practices of early Pleistocene hominins (unveiled through systematic study of the patterning and intensity of cut marks on their prey) could not have resulted from having frequent secondary access to carcasses. We provide evidence of hominin primary access to animal resources and emphasize the role that meat played in their diets, their ecology and their anatomical evolution, ultimately resulting in the ecologically unrestricted terrestrial adaptation of our species. This has major implications to the evolution of human physiology and potentially for the evolution of the human brain., We thank the Spanish Ministry of Science, Innovation and Universities for funding this research (HAR2017-82463-C4-1-P) and for fellowships to JA,GCA and MVR, and the Ministry of Culture for their funding through the program of Archaeology Abroad. We also thank the Swedish Research Council (Vetenskapsrådet) (AR-HS 2018-01045-3), and the Santander Bank (AR-HS 2018-01045-3) for their funding support. Our thanks also to the Palarq Foundation and E2in2 for financial support.

This work demonstrates the viability of MEAs based on Nafion membranes for being used in reversible electrochemical cells for the chloralkali process. It also shows the effect of the operation temperature, from room temperature up to 80 °C, and humidification of the chlorine stream on the performance of these cells as fuel cell. Results demonstrate that these cells can be operated in reversible mode, yielding a current density of approximately12 mA cm−2 at a cell potential of 0.5 V, when operating as fuel cells fed with gaseous chlorine and hydrogen. The maximum power density achieved is 7.0 mW cm−2, which is much higher than that obtained with the same system fed with hydrogen and chlorine dissolved into liquid electrolytes. It is important to operate at room temperatures because efficiency decreases dramatically with temperature in an irreversible way, affecting the electrode. Humidification is necessary for the hydrogen stream and convenient for the chlorine stream, although it does not solve the irreversible cell damage caused by operation at high temperatures. Current efficiency of chlorine production is above 95 %, when operating as electrolyzer feeding a solution containing 2.0 M of NaCl. The rate of production of chlorine was 45.4 mmol h−1 at 100 mA cm−2 and the Cl2/O2 molar ratio is 9.54, which is much higher than the values obtained in previous works which are between 3 and 5., Este trabajo demuestra la viabilidad de los MEA basados ​​en membranas de Nafion para ser utilizados en celdas electroquímicas reversibles para el proceso de cloro-álcali. También se muestra el efecto de la temperatura de operación, desde temperatura ambiente hasta 80 °C, y la humidificación de la corriente de cloro sobre el desempeño de estas celdas como pila de combustible. Los resultados demuestran que estas celdas pueden operar en modo reversible, produciendo una densidad de corriente de aproximadamente 12 mA cm- 2 a un potencial de celda de 0,5 V, cuando operan como celdas de combustible alimentadas con cloro gaseoso e hidrógeno. La máxima densidad de potencia alcanzada es de 7,0 mW cm −2, que es muy superior a la obtenida con el mismo sistema alimentado con hidrógeno y cloro disueltos en electrolitos líquidos. Es importante operar a temperatura ambiente porque la eficiencia disminuye drásticamente con la temperatura de manera irreversible, afectando al electrodo. La humidificación es necesaria para la corriente de hidrógeno y conveniente para la corriente de cloro, aunque no soluciona el daño irreversible de las celdas causado por la operación a altas temperaturas. La eficiencia actual de producción de cloro es superior al 95 %, cuando opera como electrolizador alimentando una solución que contiene 2,0 M de NaCl. La tasa de producción de cloro fue de 45,4 mmol h -1 a 100 mA cm -2 y el Cl 2 /O 2relación molar es de 9,54, muy superior a los valores obtenidos en trabajos anteriores que se sitúan entre 3 y 5.

In this work, the removal of perchloroethylene (PCE) using continuous-operation electro-scrubbers is evaluated. Two types of electro-scrubbers were made by combining a jet mixer or a packed absorption column with a single flow-cell. The absorbent/electrolyte is recirculated between both devices, being electrolyzed in the cell and retaining the pollutant in the scrubber. In both scrubber’s system, an important amount of PCE was absorbed into the electrolyte and the application of electric current significantly improved the results, highlighting the efficiency of the integration of technologies. Tests in the absence of absorbent/electrolyte confirmed the reactivity of the PCE in the wet gas phase. The jet-mixer system turned out to be more efficient than the packed column, yielding better results both in absorption and electro-absorption modes, and reaching a PCE removal greater than 90%. Meanwhile, the addition of cobalt mediators did not improve the electro-scrubbing efficiency as initially expected: in the case of the packed column electro-scrubber there were no changes while in the case of the jet mixer surprisingly it is generated a negative effect.

DS (David’s site) is one of the new archaeological sites documented in the same paleolandscape in which FLK 22 was deposited at about 1.85 Ma in Olduvai Gorge. Fieldwork in DS has unearthed the largest vertically-discrete archaeological horizon in the African Pleistocene, where a multi-cluster anthropogenic accumulation of fossil bones and stone tools has been identified. In this work we present the results of the techno-economic study of the lithic assemblage recovered from DS. We also explore the spatial magnitude of the technological behaviors documented at this spot using powerful spatial statistical tools to unravel correlations between the spatial distributional patterns of lithic categories. At DS, lavas and quartzite were involved in different technological processes. Volcanic materials, probably transported to this spot from a close source, were introduced in large numbers, including unmodified materials, and used in percussion activities and in a wide variety of reduction strategies. A number of volcanic products were subject to outward fluxes to other parts of the paleolandscape. In contrast, quartzite rocks were introduced in smaller numbers and might have been subject to a significantly more intense exploitation. The intra-site spatial analysis has shown that specialized areas cannot be identified, unmodified materials are not randomly distributed, percussion and knapping categories do not spatially overlap, while bipolar specimens show some sort of spatial correlation with percussion activities.

Deep learning models are based on a combination of neural network architectures, optimization parameters and activation functions. All of them provide exponential combinations whose computational fitness is difficult to pinpoint. The intricate resemblance of the microscopic features that are found in bone surface modifications make their differentiation challenging, and determining a baseline combination of optimizers and activation functions for modeling seems necessary for computational economy. Here, we experiment with combinations of the most resolutive activation functions (relu, swish, and mish) and the most efficient optimizers (stochastic gradient descent (SGD) and Adam) for bone surface modification analysis. We show that despite a wide variability of outcomes, a baseline of relu–SGD is advised for raw bone surface modification data. For imbalanced samples, augmented datasets generated through generative adversarial networks are implemented, resulting in balanced accuracy and an inherent bias regarding mark replication. In summary, although baseline procedures are advised, these do not prevent to overcome Wolpert’s “no free lunch” theorem and extend it beyond model architectures.

The electro-oxidation of tetracycline (TeC) in methanol medium containing chloride or sulfate ions was evaluated using a DSA®-Cl2 in a flow reactor and compared with BDD. The results show that after 30 min of electrolysis no TeC is detected by liquid chromatography when chloride is used as supporting electrolyte. On the other hand, after 90 min of electrolysis using a BDD anode only 61% of TeC was removed from solutions with chloride, but in the presence of sulfate the removal reaches 94%. This evidences that the oxidizing species generated during electrochemical oxidation control the process and the mechanism of degradation of the TeC. Besides that, it was possible to infer that only a small amount of methanol might convert to formaldehyde or formic acid, although they were not detected according to the nil changes in the FTIR spectra or in the HPLC chromatograms recorded., La electrooxidación de tetraciclina (TeC) en medio metanol que contiene iones cloruro o sulfato se evaluó utilizando un DSA®-Cl 2en un reactor de flujo y comparado con BDD. Los resultados muestran que después de 30 min de electrólisis no se detecta TeC por cromatografía líquida cuando se usa cloruro como electrolito de soporte. Por otro lado, después de 90 min de electrólisis utilizando un ánodo BDD, solo se eliminó el 61% de TeC de las soluciones con cloruro, pero en presencia de sulfato la eliminación alcanza el 94%. Esto evidencia que las especies oxidantes generadas durante la oxidación electroquímica controlan el proceso y el mecanismo de degradación del TeC. Además de eso, fue posible inferir que solo una pequeña cantidad de metanol podría convertirse en formaldehído o ácido fórmico, aunque no se detectaron de acuerdo con los nulos cambios en los espectros FTIR o en los cromatogramas HPLC registrados.

This work aims at the formulation of simple and pragmatic models to predict the behaviour of a photovoltaic solar electrochemical oxidation treatment assisted by an energy storage system. Those models will be later integrated in a software tool that allows the optimization and the management of the energy provided by solar panels to power electrochemical advanced oxidation processes coupled with a redox flow battery as energy storage system. Models for a PV panel, a redox flow battery stack and a conductive diamond electrochemical oxidation electrolyzer have been proposed and fitted to experimental data. Results showed a huge accuracy of the models to predict the electric and remediation parameters. Validation analyses reported high regression coefficients above 0.96 which confirm the precision of all the proposed models. Thus, once known the solar radiation in a located place, the level of remediation of a wastewater effluent treated by electrolysis may be estimated. Furthermore, it must be pointed out that the operational conditions of the treatment could be optimized and adjusted by means of an energy storage in the redox flow battery. Considering those facts, the sustainability and efficiency of electrochemically-assisted remediation processes could be highly increased.

In this work, the production of ozone at mild pH conditions using a commercial electrochemical PEM cell CONDIAPURE Ⓡ is evaluated, at once a phenomenological model is proposed to understand the basis of the processes that occur inside the cell. At these pH conditions, the production of ozone can be explained from the oxidation of water, while the decomposition of ozone is found to be extremely important to explain the global experimental behavior observed. Not only is this decomposition a chemical but also an electrochemically assisted process which, in turn, can be related to the production of other oxidants in the cell which interact with ozone behaving as predators. The model formulated explains and satisfactorily reproduces the influence of the operation mode, the current intensity applied and presence and destruction of organics, with regression coefficients (r2) ranging from 0.88 to 0.99, helping to understand how the production of ozone should be promoted during electrochemical processes.

The TD6 unit of the Gran Dolina contains an assemblage of the Early Pleistocene, interpreted firstly as a home base. Morerecently has been proposed a transported origin of the remains according to the sedimentology. Following this model, the remainsshould be dragged or lagged in a predictable pattern related to their weight, density, shape, and size. Conversely, the debrisgenerated in an undisturbed residential camp should retain spatial relations of codependence caused by the depositional process,not related to inherent variables of materials. To check if the remains were recovered in their original depositional place(aggregated) or are the product of transportation (segregated or random spatial relation), we have evaluated different variables:the spatial arrangement between osteological and lithic tools; the integrity of the bones and their structural characters (shape andtissue composition); postdepositional modifications; and the specimen size distribution. The combined results indicate that thelayers that conform the TD6.2 subunit were undisturbed, while TD6.1 was affected by postdepositional processes, probablywater flows, resulting in a lagged assemblage. In conclusion, TD6.2 is best interpreted as a well-preserved home base and shouldplay a key role in studies of the behavior of the first European populations., The Ministry of Science, Innovation and Universities (MICINN-FEDER) of the Spanish Government financed the research, project no. PGC2018-093925-B-C32 and project no. FJCI-037447-I (Subprograma Juan de la Cierva) and, also, the AGAUR (project no. 2017 SGR-1040) and the URV (project no. 2018PFR-URV-B2-91). IPHES research is framed in CERCA Programme/Generalitat de Catalunya. The funding for fieldwork came from the Cultural and Tourism Council of Castilla y León and the Atapuerca Foundation. This research was supported by the Spanish Ministry of Science and Innovation through the “Maríade Maeztu” excellence accreditation (CEX2019-000945-M).

Bone surface modifications (BSMs) in faunal assemblages are frequently used to infer past agency and actions of hominins and carnivores, with implications for the emergence of key human behaviours. Patterning of BSMs has mostly been defined as a combination of the intensity of marks per bone portion and sometimes per element. Numerous variables involved in butchery can condition cut mark anatomical distribution, so much so that these variables are widely assumed to be stochastic. Here, we present a new methodological approach using a novel geospatial tool (Ikhnos) which combines the three-dimensional spatial documentation of cut mark patterns with spatial statistics based on wavelets, applied to three experimental and ethnoarchaeological faunal assemblages. We use wavelets to identify patterning of multiple longitudinal series of cut mark distributions on bones, and to establish similarities or differences in patterning within and across different assemblages. This method demonstrates the existence of general and behaviour-specific butchery patterns. It can also be used to effectively assess the proportion of mark clustering that is due to randomness, versus that which is conditioned by the butchery process.

Bioelectrochemical systems (BESs) are regarded as effective green technologies for wastewater treatment, with low associated energy costs. This work studies the influence of the cathode pH and operational mode, as microbial fuel cell (MFC) or microbial electrolysis cell (MEC), on the electrocatalytic hydrodechlorination (ECH) of 2,4-dichlorophenol (2,4-DCP) in an abiotic cathode. When operating as MFC, the results showed that more acid cathode pH enhances the ECH reactions. Practically a total dechlorination was obtained after 72 h at cathode pH=5, whereas only an 88% dechlorination was obtained at pH=7. Also, ECH was further enhanced by operating under MEC mode, where the cathode was poised towards more negative potentials and higher current densities were achieved. The MEC presented a faster kinetics, reaching an 81% of dechlorination after 24 h of operation in batch mode and the full dechlorination after 48 hours. Additionally, when operating as MEC, the phenol obtained after the dechlorination reaction was further hydrogenated to cyclohexanone under these mild operating conditions, which would drastically reduce the toxicity of the effluent.

Electro-Fenton process is considered a very promising tool for the treatment of waste waters contaminated by organic pollutants refractant or toxic for microorganisms used in biological processes [1-6]. In these processes H2O2 is continuously supplied to an acidic aqueous solution contained in an electrolytic cell from the two-electron reduction of oxygen gas, directly injected as pure gas or bubbled air. Due to the poor solubility of O2 in aqueous solutions, two dimensional cheap graphite or carbon felt electrodes give quite slow generation of H2O2, thus resulting in a slow abatement of organics. In this context, we report here a series of studies [7-9] on the effect of air pressure on the electro-generation of H2O2 and the abatement of organic pollutants in water by electro-Fenton process. The effect of air pressure, current density, mixing and nature of the organic pollutant was evaluated. [1] E. Brillas, I. Sirés, M.A. Oturan, Chem. Rev., 109 (2009) 6570-6631. [2] C.A. Martínez-Huitle, M.A. Rodrigo, I. Sirés, O. Scialdone, Chem. Rev. 115 (2015) 13362–13407. [3] M. Panizza, G. Cerisola, Chem. Rev. 109 (2009) 6541–6569. [4] I. Sirés, E. Brillas, M.A. Oturan, M.A. Rodrigo, M. Panizza, Environ. Sci. Pollut. Res. 21 (2014) 8336–8367. [5] C.A. Martínez-Huitle, S. Ferro, Chem. Soc. Rev. 35 (2006) 1324–1340. [6] B.P.P. Chaplin, Environ. Sci. Process. Impacts. 16 (2014) 1182–1203. [7] O. Scialdone, A. Galia, C. Gattuso, S. Sabatino, B. Schiavo, Electrochim. Acta, 182 (2015) 775-780. [8] J.F. Pérez, A. Galia, M.A. Rodrigo, J. Llanos, S. Sabatino, C. Sáez, B. Schiavo, O. Scialdone, Electrochim. Acta, 248 (2017) 169-177. [9] A.H. Ltaïef, S. Sabatino, F. Proietto, A. Galia, O. Scialdone, O. 2018, Chemosphere, 202, 111-118.

In this work, the cathodic electro-dechlorination of 2,4-DCP in a Microbial Fuel Cell (MFC) was studied. To do that, an MFC externally connected with a 120 Ω load was operated by feeding a synthetic wastewater with 300 ppm of 2,4-DCP to the abiotic cathode compartment and sodium acetate to the biotic anode with electroactive bacteria. During the experiments, all the intermediates (2-chlorophenol and 4-chlorophenol) and final products (phenol and Cl−) from the dechlorination of 2,4-DCP were monitored. Results show that the bio-assisted electroreductive treatment achieved a cathodic dechlorination yield of a 57% after 24 h, which increases up to 88% after 72 h. In addition, because of the dechlorination of 2,4-DCP, the biodegradability of the synthetic wastewater, expressed as the ratio BOD/COD, was increased from negative values (corresponding to toxic effluents) up to 0.568. Meanwhile, the toxicity decreased drastically, with EC50 values that increased from 0.021 to 0.228 mmol L−1. Operation current densities during the bio-assisted electro-dehalogenation process were significant and decreased from initial values of 0.14 down to 0.04 mA cm−2. These results indicate that the bioelectrochemical technology can produce small amounts of energy while dechlorinating an extremely hazardous waste.