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Microbial Electrochemical Fluidized Bed Reactor: A Promising Solution for Removing Pollutants From Pharmaceutical Industrial Wastewater
No full textThe capacity of electroactive bacteria to exchange electrons with electroconductive materials has been explored during the last two decades as part of a new field called electromicrobiology. Such microbial metabolism has been validated to enhance the bioremediation of wastewater pollutants. In contrast with standard materials like rods, plates, or felts made of graphite, we have explored the use of an alternative strategy using a fluid-like electrode as part of a microbial electrochemical fluidized bed reactor (ME-FBR). After verifying the low adsorption capacity of the pharmaceutical pollutants on the fluid-bed electrode [7.92 ± 0.05% carbamazepine (CBZ) and 9.42 ± 0.09% sulfamethoxazole (SMX)], our system showed a remarkable capacity to outperform classical solutions for removing pollutants (more than 80%) from the pharmaceutical industry like CBZ and SMX. Moreover, the ME-FBR performance revealed the impact of selecting an anode potential by efficiently removing both pollutants at + 200 mV. The high TOC removal efficiency also demonstrated that electrostimulation of electroactive bacteria in ME-FBR could overcome the expected microbial inhibition due to the presence of CBZ and SMX. Cyclic voltammograms revealed the successful electron transfer between microbial biofilm and the fluid-like electrode bed throughout the polarization tests. Finally, Vibrio fischeri-based ecotoxicity showed a 70% reduction after treating wastewater with a fluid-like anode (+ 400 mV), revealing the promising performance of this bioelectrochemical approach
Study of surface modification of recycled ultrafiltration membranes using statistical design of experiments
No full textMembrane surface modification on recycled ultrafiltration membrane was conducted using statistical design of experiments by two levels full factorial design. Dip-coting using catechol (CA) and polyetylenimine (PEI) was chosen as the membrane surface modification method because its simplicity, energy saving characteristics and bio-based character. The factors studied were: CA and PEI concentration (1g/l and 4 g/l), temperature (30ºC and 50ºC) and reaction time (2 and 7 hours). The studied responses were the relative permeability (Pr) and the flux recovery ratio (FRR). A model with good validity was obtained for both responses. Membranes were deeply characterized using several techniques: Scanning electron microscopy (SEM); Attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy; X-ray photoelectron spectroscopy (XPS) and Atomic force microscopy (AFM). Statistical design of experiments resulted on a useful tool to understand how the factors affect the surface modification. Surface modification conducted at mild conditions (2 hours; 30 ºC and 1g/l) improved membrane permeability and flux recovery ratio. Moreover, interaction between factors turned out to be significant in the modification process which was an unexplored field in previous works. Modification of recycled membranes is an innovative process that follows a Circular Economy approach
Stereoselective separation of sulfoxaflor by electrokinetic chromatography and applications to stability and ecotoxicological studies
No full textComparative analysis of the SolWat photovoltaic performance regarding different PV technologies and hydraulic retention times
No full textAttenuation mechanisms and key parameters to enhance treatment performance in vegetation filters: A review
No full textIn times when environmental concerns are on the rise and the search of ways to reduce waste generation and to
create a circular economy is booming, Nature Based Solutions (NBSs) play a very important role. Vegetation
Filters (VFs) are a type of Land Application System (LAS) in which wastewater is used to irrigate a forestry
plantation to treat the water and produce biomass. VFs show multiple benefits that render this technology a
suitable solution for wastewater treatment, especially for scattered populations or isolated buildings that lack of
connection to sewer systems. This review aims to provide a comprehensive state of the art of VF implementation,
highlighting the do’s and don’ts for a successful performance focusing on those factors that are essential to water
treatment. Results show that VFs have a great treatment capacity when all involving factors are considered, and
their efficiency tends to increase with time, as the VF develops and “gets older”. Indeed, the presence of finetextured
soils, the selection of a proper vegetation species, the use of pre-treated wastewater and a water
balance-based irrigation schedule alternating wetting and -drying cycles are all factors that help to achieve the
best performance. However, it is necessary to design and follow a simple but rigorous operation and maintenance
schedule to avoid system failure, which could lead to NO3–N leaching towards groundwater
Multi-Criteria Evaluation and Sensitivity Analysis for the Optimal Location of Constructed Wetlands (METland) at Oceanic and Mediterranean Areas
No full textMETland is a new variety of Constructed Wetland (CW) for treating wastewater where gravel is replaced by a biocompatible electroconductive material to stimulate the metabolism of electroactive bacteria. The system requires a remarkably low land footprint (0.4 m2/pe) compared to conventional CW, due to the high pollutant removal rate exhibited by such microorganisms. In order to predict the optimal locations for METland, a methodology based on Multi-Criteria Evaluation (MCE) techniques applied to Geographical Information Systems (GIS) has been proposed. Seven criteria were evaluated and weighted in the context of Analytical Hierarchy Process (AHP). Finally, a Global Sensitivity Analysis (GSA) was performed using the Sobol method for resource optimization. The model was tested in two locations, oceanic and Mediterranean, to prove its feasibility in different geographical, demographic and climate conditions. The GSA revealed as conclusion the most influential factors in the model: (i) land use, (ii) distance to population centers, and (iii) distance to river beds. Interestingly, the model could predict best suitable locations by reducing the number of analyzed factors to just such three key factors (responsible for 78% of the output variance). The proposed methodology will help decision-making stakeholders in implementing nature-based solutions, including constructed wetlands, for treating wastewater in rural areas
Procedimientos para el análisis de parámetros de calidad de aguas continentales relacionados con los afloramientos de cianobacterias
No full textPhotocatalytic nanostructures coating with antimicrobial and self-cleaning properties
No full textLa contaminación microbiana y la formación de biopelículas constituyen un reto debido a la
amenaza que suponen las infecciones para la salud y al creciente desarrollo de resistencias a
los antibióticos. Los recubrimientos antimicrobianos nanoestructurados no solo inhiben la
proliferación bacteriana, sino que además pueden conferir propiedades autolimpiantes. La
fotocatálisis se considera una alternativa prometedora para la inactivación de gran variedad
de patógenos por su alta eficiencia, sostenibilidad y rentabilidad. Sin embargo, su aplicación
práctica se encuentra limitada por la rápida recombinación de los pares electrón-hueco
fotogenerados y su restricción actual a la región UV del espectro solar. En este escenario, el
objetivo de esta Tesis ha sido desarrollar superficies híbridas fotocatalíticas o
fotoelectrocatalíticas basadas en nanopartículas de óxidos metálicos /derivados de grafeno
modificadas con dopantes y en estructuras metal-orgánicas (MOFs) para su aplicación en
recubrimientos antimicrobianos y autolimpiantes.
Los recubrimientos fotocatalíticos de ZnO preparados por electrospray mostraron excelentes
propiedades autolimpiantes para la degradación del azul de metileno bajo irradiación UV y
se mantuvieron esencialmente libres de colonización bacteriana y biopelículas, lo que se
atribuyó a las especies reactivas de oxígeno (ROS) fotogeneradas y a la lixiviación de iones
zinc. También se fabricaron películas nanocompuestas de ZnO con diferentes proporciones
de óxido de grafeno reducido (rGO) mediante spin-coating, mejorando notablemente la
actividad antimicrobiana y la estabilidad frente a la lixiviación de iones zinc del ZnO debido
a la reducción de la recombinación de pares electrón-hueco fotogenerados y al contacto
íntimo entre las nanopartículas de ZnO y las láminas de rGO. Para la desinfección
fotoelectrocatalítica de aguas, se prepararon por electrospray superficies de Ce-TiO2/GO, que
mostraron una alta eficiencia junto con una sobreproducción de ROS intracelular debido a
una mejor separación de los portadores de carga. Por último, se emplearon Zr-MOFs como
fotocatalizadores estables y activados por la luz solar en desinfección fotoelectrocatalítica,
cuya alta eficiencia se atribuyó a la transferencia de carga del ligando al clúster mediante
fotones de alta energía
Impacto del uso de astillas de madera como enmienda al suelo en un filtro verde piloto: dinámica de la infiltración
No full textVegetation Filters (VFs) are a non conventional wastewater treatment that takes advantage of natural attenuation processes in the soil-plant microorganism system. The impact of amendment incorporation and irrigation management in the infiltration dynamics of a pilot VF is assessed by: i) volumetric water content in soil and ii) irrigation front drainage times in each study event. The variation of these parameters was studied in relation with the irrigation schedule (weekly or daily) and system (gravity or drip), vegetation activity, the amendment application and its incorporation mode (mix or surface layer). The amendment incorporation rise soil water contents increasing its porosity and aeration. Irrigation front drainage times are conditioned by volume and number of irrigation times in each event and the vegetation activity status
