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This work focuses on the removal of perchloroethylene (PCE) from soils spiked with this hazardous chlorinated hydrocarbon and oil by a combination of two technologies: soil washing and anodic oxidation with diamond electrodes. The first attains the transfer of the pollutant from the soil to a soil washing fluid (SWF), from which the organics are then efficiently removed. Results show that high concentrations of sodium dodecyl sulphate (SDS) are required in the SWF for an efficient extraction of the chlorinated hydrocarbon and electrolysis has to be applied not only to the clarified liquid, but also to the interphase. The surfactant used interacts strongly with soil not only during the washing, but also during the electrolysis step. This interaction seems to play a protective role against the oxidation of SDS. The initial phase of the electrolysis is rather complex and there are several processes which modify the results importantly. Removal of PCE by electrolysis from soil is less efficient than its removal from synthetic solutions of this chlorinated pollutant. There are two first-order kinetic zones, which indicate an important competition for the oxidation of the different organics contained in the SWF during the electrolysis. © 2018 Society of Chemical Industry

In this work, the removal of antibiotic penicillin G by electrolysis with boron doped diamond (BDD) and mixed metal oxide (MMO) anodes in urine media is evaluated. First, electrolysis in different water matrices (sulfate, chloride and urine) were carried out with diamond anodes to shed light on the contribution of mediated mechanisms. Results showed that penicillin G was completely removed by electrolysis for electric charges below 5 Ahdm 3 , regardless of the water matrix and the current density applied (10-100 mAcm 2 ). Then, the influence of the anode material was evaluated for the degradation of penicillin G in urine media. A complete removal of the antibiotic was attained, regardless of the tested anode material, although the BDD anode was found to be more efficient than MMO. Results also showed that, at the current charges in which the antibiotic is depleted, the removal of other organics was much lower and the formation of chlorates was negligible, especially operating at low current densities. Because of this selective oxidation of the pharmaceutical compound, electrolysis can be proposed to be used as a pretreatment technology for later and cheaper biological treatment.

The design of new approaches that help to decrease both the environmental impact of industrial activities and the cost of existing water treatment technologies is becoming a key aspect of research. In the present work, an efficient and easy-to-use electrochemical device designed to dose iron coagulants is presented. The proposed device (the Electrochemically-assisted Coagulant – production & dosing Unit, ECU) exhibits an efficient performance in the dosing of coagulants regardless of the ionic conductivity of the water matrixes tested (within the range 100 to 1000 µS cm−1), covering a wide range of potential real surface waters. The behaviour of the ECU device was compared to that of a conventional chemical dosing of iron, and showed better pH (pH ≈ 8 for ECU but < 4 for equivalent chemical dosing) and conductivity (decrease for ECU but increase up to 60% for equivalent chemical dosing) control. Moreover, the ECU unit produced a noticeable amount of Fe2+ ions, due to the limited access of atmospheric oxygen inside the device. The device developed overcomes traditional chemical iron dosing and could be potentially applied in uses different from electrocoagulation, as it is the case of Fenton-related technologies.

This work focuses on the application of electrolysis with diamond anodes for the disinfection of urine. To do this, a synthetic human urine was polluted with Escherichia coli and Pseudomonas aeruginosa and then, it was electrolyzed at current densities within the range 0–100 A m−2. Results show that it is possible to disinfect completely the effluent even at applied electric charges lower than 2 kAh m−3, regardless the current density applied. This good performance is related to the production of powerful oxidants from the oxidation of the ions present in synthetic urine. Likewise, these species also react with the organics contained in urine (urea, creatinine and uric acid), favoring their degradation. The process efficiency for both microorganisms and organics is higher when working at low current densities. The removal of organics leads to the release of significant amounts of nitrogen in the form of nitrate which are later electroreduced to ammonium, that, in turn, reacts with the electrogenerated hypochlorite, favoring the production of chloramines (which can also contribute to the disinfection process). Regarding the mineralization, TOC removal higher than 90% can be achieved but higher applied electric charges than those required for disinfection have to be applied (around 30 kAh m−3).

A large scale electro-bioremediation test is carried out in a prototype composed by an electrokinetic soil remediation reactor with soil-treatment capacity of 32 m3. Soil polluted with a mixture of Oxyfluorfen and 2,4-Dichlorophenoxyacetic acid undergoes a combined treatment in which the electrochemically assisted remediation produced by six electrodes placed in a hexagonal alternating configuration is aimed to be enhanced with the addition of concentrated activated sludge in a central position of the prototype. Results demonstrate that this technology can remove pollutants down to a very low concentration although, as compared to a previous study, its performance does not differ significantly of that followed in a process in which bioremediation was not included. In both studies, volatilization was found to be the key mechanisms to explain the removal of both herbicides. After a treatment period slightly over month, only 7.10% of the 2,4-D and 9.22% of the oxyfluorfen remained in soil and these values are very similar to those obtained by applying a non biological electrokinetic remediation fence process in which 10.10% of the 2,4-D and 13.03% of the oxyfluorfen remained in the soil after the treatment. Results pointed out that it is very difficult to optimize simultaneously electrokinetic and biological processes because most of the processes caused by the electric field affect negatively to the microorganisms viability. Results also pointed out the significance of the sampling procedure to characterize an electro-bioremediation process at full scale.

BACKGROUND A comparison between different carbon-based anodes used in microbial fuel cells (MFCs) has been carried out. Five different carbonaceous anodes were studied: carbon paper, carbon cloth, carbon foam 30 ppi, carbon foam 80 ppi and carbon felt. RESULTS The current density generated was higher for the MFCs with porous anodes compared with the flat ones, generating up to 14.5 A m−2. However, when the superficial surface was higher than 7500 m2 m−2 the performance did not increase further due to microorganisms transport and mass transfer limitations. Regarding the biochemical performance, a linear relationship between the generated current density and the coulombic efficiency was found. This relationship indicates selection of the electrogenic microbial population when the superficial surface increases. From Illumina MiSeq analyses, it was observed that Shewanella population in the biofilm was c. 14%, while its population was negligible in the planktonic culture. This population distribution can be explained by the low growth rate of the Shewanella. CONCLUSIONS These results demonstrate that the main driving force of the carbonaceous materials performance is the ease of biofilm formation and subsequent population selection, but not on specific electronic properties of the carbon materials. © 2018 Society of Chemical Industry

RESUMEN El presente trabajo describe el desarrollo e implementación de varios sensores en una boya oceanográfica que permitan la toma de medidas de algunas magnitudes físicas, y en base a ellas predecir el momento y comportamiento del siguiente tren de olas. El dispositivo contará con un acelerómetro-giroscopio, un barómetro, GPS y un módulo LoRa. Todos estos sensores serán gestionados con un microcontrolador Arduino UNO, que se encargará de procesar todos los datos recogidos por los sensores y enviarlos a través el modulo LoRa. Para la adquisición y transmisión de datos en la boya, se utilizara el software nativo de Arduino, y para el procesado de los datos en la estación de tierra, se utilizará el software Matlab, que permitirá realizar numerosas operaciones al mismo tiempo. ABSTRACT This project describes the developement and implementation of various sensors into an oceanographic buoy which aims to measure the surge. The device will count with an accelerometer-gyroscope, a barometer, GPS and one LoRa module. All of these sensors will be managed by an Arduino UNO microcontroller, wich will take care of processing all of data collected by the sensors, and they will be sent through the LoRa module. For the acquisition and transmission of data in the buoy, the native Arduino software will be used, and for the processing of the data in the ground station, the Matlab software will be used, which will allow numerous operations at the same time. Grado en Ingeniería de Tecnologías de Telecomunicación

This work studies the effect of treatment period on remediation efficiency in an oxyfluorfen-polluted soil through electro-bioremediation technology. Five lab-scale experimental plants were started up simultaneously, operated under an electric field of 1.0 V cm−1 with a polarity reversal frequency of 2 day−1 and disconnected at different times (2, 4, 6, 11 and 24 weeks); these plants underwent post mortem characterization after their operation period. Various parameters were monitored in the electrolyte wells during the experiments. The obtained results indicate that despite the low reproducibility of pH and conductivity in the wells (not in soil), the main conclusions that can be drawn for the different plants are sound and hence have acceptable reproducibility. Polarity reversal allowed suitable conditions for microbial life in terms of pH, but nutrients were also depleted in the soil, which leads to a decrease in the total population of microorganisms during treatment. For treatment periods of less than 10 weeks, there was an appreciable population of microorganisms in the soil, which reached oxyfluorfen removal levels of up to 40%. Longer reaction times were ineffective, and this was related to the much lower concentration of microorganisms. In comparing these results to those obtained in conventional soil bioremediation technology, the application of polarity-reversed electric current led to an increase in the average removal of oxyfluorfen from 0.11 to 0.17 mg kg−1 day−1 but a much higher decrease in the active microorganism population from 88.0 ± 9.0 to 41.0 ± 6.0% of the initial seeded value.

The electrolysis with diamond anodes of synthetic urines containing different concentrations of ibuprofen and cloxacillin is evaluated in this work, with the aim of determining if this technology is effective in the mineralization of both species in urine matrix and the main characteristics of the competitive oxidation among these two products and the natural organic compounds contained in urine (uric acid, creatinine and urea). Results point out that electrolytic technology can mineralize all organic contained in the urine very efficiently and that oxidation of the two pharmaceuticals is faster than that of the natural products contained in urine, opening the possibility of a selective treatment of the urine up to the point in which it can be merged safely with domestic wastewater without generating a negative impact on environment. Occurrence of perchlorate is the main drawback of this technology, although its impact is not believed to be as serious as the impact of the pharmaceuticals on environment.

This article presents a numerical study of the transport phenomena involved in the electrokinetic remediation of soils polluted with polar pesticides. 2,4-Dichlorophenoxyacetic acid is used as a representative of this pesticide type. A one-dimensional configuration with two facing electrodes placed in electrolyte compartments and a cathodic overflow pollutant extraction system has been used for that purpose. The conventional electrokinetic remediation process is evaluated by keeping the electrode polarity constant, and to obtain acceptable yields, it is necessary to extend the treatment for more than 250 days. The application of periodic polarity reversals is proposed to improve these results. This strategy maximises the pesticide concentration in the cathodic compartment, thus maximising the pollutant extraction rate. The results show that by applying polarity reversals over 6-h periods, it is possible to accelerate the treatment, thus improving its overall efficiency up to 94.5% compared with the treatment using a constant electrode polarity.

BACKGROUND: This work is focused on the assessment of the performance of mini-scale air-breathing microbial fuel cells (MFCs),by monitoring the evolution of the bio-electrogenic activity for a period of 40 days and by comparing the microorganismspopulations developed in each of the MFCs after this period.RESULTS: Five MFCs were operated at sludge ages ranging from 1.4 to 10.0 days. Results showed the superb performance of theMFC operating under a sludge age of 2.5 days. Desulfuromonas, Syntrophothermus, Solitalea, Acholeplasma, Propionicimonas,Desulfobacula and Sphaerochaeta are proposed as potentially responsible for the bio-electrogenic activity.CONCLUSIONS: Microbial population analysis through Illumina amplicon sequencing demonstrated that despite all MFCsbeing seeded with the same mixed culture inoculum, the biological cultures developed in the suspension and the biofilm arecompletely different and depend strongly on sludge age.© 2017 Society of Chemical Industry.

In this work, the electrolysis of chlorsulfuron (ClSF, a sulfonylurea herbicide) with conductive-diamond anodes is studied. The influences of the nature of the supporting electrolyte (0.05 mol dm−3 NaCl and Na2SO4), the applied current density (30 and 100 mA cm−2) and the initial herbicide concentration (20,50 ad 100 mg dm−3) have been evaluated. Total mineralization of the herbicide was attained regardless of the supporting electrolyte medium used, although electrolyte clearly influenced on the efficiency and rate of the oxidation process. Likewise, the process was found to be more efficient at low current densities. Results point out the importance of mediated electrochemical processes in the removal of ClSF. This influence was confirmed by additional tests in which the electrolysis was combined with UV light or ultrasound irradiation: the use of UV irradiation results in a less efficient process, while US improves importantly the rate of the mineralization as compared to the single electrolytic process. The strong oxidation conditions of electrolysis leads to the formation of reaction intermediates (2-amino-4-methoxy-6-methyl-1,3,5-Triazine, 2-chlorobenzenesulfonamida and oxalic acid) in agreement with the mechanisms proposed in the literature for other AOPs.

BACKGROUND The aim of this work is to evaluate the effectiveness of complete treatment of soil spiked with 2,4‐D, consisting of soil washing, followed by bioadsorption with activated sludge and electrochemical and photoelectrochemical oxidation of resulting wastewater using BDD anodes combined with UV light irradiation. RESULTS Results show that 2,4‐D is very efficiently removed from synthetic soil by soil‐washing without the use of surfactants. The effluent can be treated by bioadsorption with fresh activated sludge coming from a municipal wastewater treatment plant and the maximum adsorption capacity is 0.012 mg 2,4‐D mg−1 biomass. Despite the low contact time between the biomass and the soil‐washing effluent, results fit well to a Langmuir isotherm. CONCLUSIONS Photoelectrolysis with diamond anodes is more efficient than single electrolysis and the influence of potential radicalary oxidants produced on the anode surface from sulfate and chloride and activated by UV light can explain the better results. Both electrolysis and photoelectrolysis can lead to the complete mineralization of 2,4‐D, regardless of the biomass/herbicide ratio applied in the previous bioadsorption process. © 2016 Society of Chemical Industry

BACKGROUND This work is focused on the optimization of the performances of air-cathode microbial fuel cells (MFC) by changing the solid retention time (SRT) of the suspended biomass culture. RESULTS Five MFCs inoculated with activated sludge obtained from a municipal wastewater treatment plant were fed with a highly-concentrated acetate solution (10 000 ppm COD) and operated over two-month tests in order to determine how SRT may influence the performances of the bio-electrogenic cells. The MFC operated at SRTs of 2.5 days was found to outperform the other cells, operated at SRT of 1.4, 5.0, 7.4 and 10.0 days. In order to evaluate the possibility of using SRT as a manipulated parameter for the regulation of the operation of MFC, the SRT of the other MFCs was changed from their initial value up or down to 2.5 days. CONCLUSIONS As a result of the change in the SRT, production of electricity of the cells increased significantly in all cases, highlighting the relevance of SRT control in the optimization of the performances of MFCs. By operating at SRT 2.5 days, the current density was 4.2 A m−2, the COD consumption rate was 1.53 g COD d−1 L−1 and the COD transformed by electrogenic microorganisms was estimated at 1.5%. © 2016 Society of Chemical Industry, ANTECEDENTES Este trabajo se centra en la optimización del rendimiento de las pilas de combustible microbiano (MFC) de cátodo de aire cambiando el tiempo de retención de sólidos (SRT) del cultivo de biomasa suspendida. RESULTADOS Cinco MFC inoculadas con lodo activado obtenido de una planta de tratamiento de aguas residuales municipales se alimentaron con una solución de acetato altamente concentrada (10 000 ppm DQO) y operaron durante dos meses de pruebas para determinar cómo SRT puede influir en el rendimiento del bioelectrogénico. células. Se encontró que la MFC operada a SRT de 2,5 días superaba a las otras celdas, operadas a SRT de 1,4, 5,0, 7,4 y 10,0 días. Para evaluar la posibilidad de utilizar SRT como parámetro manipulado para la regulación de la operación de MFC, se cambió el SRT de las otras MFC desde su valor inicial hacia arriba o hacia abajo a 2.5 días. CONCLUSIONES Como resultado del cambio en el SRT, la producción de electricidad de las celdas aumentó significativamente en todos los casos, destacando la relevancia del control SRT en la optimización de los rendimientos de las MFC. Al operar a SRT 2,5 días, la densidad de corriente fue de 4,2 A m -2 , la tasa de consumo de DQO fue de 1,53 g DQO d - 1 L - 1 y la DQO transformada por microorganismos electrogénicos se estimó en 1,5%. © 2016 Sociedad de la Industria Química.

In this work, H2O2 is electro-generated in the cathodic compartment of a divided filter-press cell with a carbon cloth in the configuration of a gas diffusion electrode using air as oxygen source. The effect of Teflon® content was studied and it was found that the appropriate content is within the range of 10-20%. The production was greatly enhanced after the air-brushing deposition (and subsequent annealing) of simply 0.5 mg of carbon black. Higher additions clogged the pores and resulted counterproductive in terms of H2O2 generation. At a current density of 25 mA cm-2, the production rate was 15 mg H2O2 h-1 cm-2 with a current efficiency close to 100%. Production rate increased with current density up to more than 40 mg H2O2 h-1 cm-2 at 87.5 mA cm-2. The good performance and ease of preparation of this electrode make it an interesting alternative to generate hydrogen peroxide for Electro-Fenton processes.

This work studies the feasibility of the periodic polarity reversal strategy (PRS) in a combined electrokinetic-biological process for the remediation of clayey soil polluted with a herbicide. Five two-weeks duration electrobioremediation batch experiments were performed in a bench scale set-up using spiked clay soil polluted with oxyfluorfen (20 mg kg. Additionally, two complementary reference tests were done: single bioremediation and single electrokinetic. The microbial consortium used was obtained from an oil refinery wastewater treatment plant and acclimated to oxyfluorfen degradation. Main soil conditions (temperature, pH, moisture and conductivity) were correctly controlled using PRS. On the contrary, the electroosmotic flow clearly decreased as increased. The uniform soil microbial distribution at the end of the experiments indicated that the microbial activity remained in every parts of the soil after two weeks when applying PRS. Despite the adapted microbial culture was capable of degrade 100% of oxyfluorfen in water, the remediation efficiency in soil in a reference test, without the application of electric current, was negligible. However, under the low voltage gradients and polarity reversal, removal efficiencies between 5% and 15% were obtained, and it suggested that oxyfluorfen had difficulties to interact with the microbial culture or nutrients and that PRS promoted transport of species, which caused a positive influence on remediation. An optimal, Este trabajo estudia la viabilidad de la estrategia de inversión periódica de polaridad (PRS) en un proceso combinado electrocinético-biológico para la remediación de suelos arcillosos contaminados con un herbicida. Se realizaron cinco experimentos por lotes de electrobiorremediación de dos semanas de duración en una instalación a escala de banco utilizando suelo arcilloso con púas contaminado con oxifluorfeno (20 mg kg. Adicionalmente, se realizaron dos pruebas complementarias de referencia: biorremediación simple y electrocinética simple . El consorcio microbiano utilizado fue obtenido de una planta de tratamiento de aguas residuales de una refinería de petróleo y aclimatado a la degradación del oxifluorfeno. Las principales condiciones del suelo (temperatura, pH, humedad y conductividad) se controlaron correctamente mediante PRS. Por el contrario, el flujo electroosmótico disminuyó claramente a medida que aumentado. La distribución microbiana uniforme del suelo al final de los experimentos indicó que la actividad microbiana permaneció en todas las partes del suelo después de dos semanas al aplicar PRS. A pesar de que el cultivo microbiano adaptado fue capaz de degradar el 100% del oxifluorfeno en el agua, la eficiencia de remediación en el suelo en una prueba de referencia, sin la aplicación de corriente eléctrica , fue insignificante. Sin embargo, bajo los gradientes de bajo voltaje y la inversión de polaridad, se obtuvieron eficiencias de remoción entre el 5% y el 15%, y sugirió que el oxifluorfeno tenía dificultades para interactuar con el cultivo microbiano o los nutrientes y que el PRS promovió el transporte de especies, lo que provocó una influencia positiva. sobre la remediación. Un óptimo

In this work, it is studied the treatment of real wastewater (intensified with two target compounds) using electro-irradiated technologies. Two types of effluents coming from an organic-synthesis pharmaceutical industry and the outlet of a municipal wastewater treatment plant were intensified with metoprolol (β-blocker) and caffeine (stimulant), respectively. Conductive diamond electrochemical oxidation (CDEO), photolysis, sonolysis and all possible combinations among these technologies were evaluated for the treatment of both wastes. Results demonstrate that complete oxidation of the target compounds, as well as mineralization of the organic compounds contained in the matrixes, can be attained by all electro-irradiated technologies and no salt addition was needed to obtain an efficient treatment. Single irradiated technologies were inefficient in the oxidation but their combination with CDEO improves significantly the efficiency of the process showing clear synergistic effects. However, due to the large energy requirement of ultrasound irradiation, this combination is only cost-effective in the case of ultraviolet irradiation.

BACKGROUND This work compares the performance of three stacked microbial fuel cells constructed with different number of single‐MFC (MFC1 with two stacked‐MFCs, MFC2 with ten stacked‐MFCs and MFC3 with twenty stacked‐MFCs), and operated under the same conditions for one month. RESULTS According to results, algae suspensions can be used as fuel for MFC‐stacks, although current efficiencies obtained are low. In comparing the effect of number of cells stacked on the performance of the stacks, it was found that the higher the number of cells stacked, the higher the energy harvested from algae. However, because of the very efficient consumption of COD in the first MFC of the stacks (not only by electrogenic but also by non‐electrogenic microorganisms) and the sequential circulation of the fuel through the different cells of the stack, in all cases the systems ran out of fuel and this was reflected in lower production of electricity, compared with that expected taking into account the number of cells stacked. Results obtained from the polarization curves and the cathodic oxygen consumption also support this explanation. CONCLUSIONS Results demonstrate that algal biomass is a suitable fuel for energy generation using MFC technology and provides microorganisms not only of a carbon source but also with the required nutrients. However, the low coulombic efficiencies obtained in the three stacks indicate that feeding algae to MFC also promotes the formation of an important amount of non‐electrogenic microorganisms that compete successfully with bioelectrogenic microorganisms for the substrate provided. © 2017 Society of Chemical Industry

In this research, the treatment of soil spiked with petroleum was studied using a surfactant-aided soil-washing (SASW) process followed by sonolysis (US), photolysis and boron doped diamond electrolysis (BDD-electrolysis) for washing liquid treatment. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing completely the petrochemical compounds by using dosages about 5 g of extracting surfactant (sodium dodecyl sulfate (SDS)) per kg of soil. The main characteristics of the effluents produced in this soil remediation technology as well as the efficiency of the treatment (US, photolysis and BDD-electrolysis) depend on the dosage of SDS. Depollution of the effluents (degradation and mineralization of the organic matter) is related to the reduction in size of micelles formed by SDS and petroleum, and it depends on the treatment used. US and photolysis were inefficient decontamination processes, while BDD-electrolysis favors the complete depletion of micelles. However, the intensification of the efficiency was attained by synergic degradation effects when UV light irradiation and US were coupled with BDD-electrolysis, US/BDD-electrolysis and photo/BDD-electrolysis, respectively. Sulfate (coming from SDS) ions play an important role during the BDD-electrolysis, US/BDD-electrolysis and photo/BDD-electrolysis because persulfate and persulfate radicals are produced (by sulfate activation applying US or photolysis), improving the efficiency of the processes.