Persona: Huertas Penela, Rosa María
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rosa.huertas@ccia.uned.es
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0000-0002-7411-4479
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Huertas Penela
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Rosa María
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Publicación Development of highly selective composite polymeric membranes for Li+/Mg2+ separation(Elsevier, 2021-02-15) Saif, Hafiz Muhammad; Huertas Penela, Rosa María; Pawlowski, Sylwin; Crespo, João Goulão; Velizarov, SvetlozarTo meet the exponentially rising demand for lithium, it becomes vital to develop environmentally friendly processes for its recovery from brines, salt lakes and/or seawater. In this work, novel composite lithium transport selective polymeric membranes were developed to separate lithium and magnesium ions. Hydrogen manganese oxide (HMO) (at weight percentage from 0 to 25%), polystyrene sulfonate sodium salt (PSS–Na) and lithium triflate (LiCF3SO3) were added into the sulfonated polyethersulfone (SPES) matrix to prepare composite membranes. The developed membranes showed high mechanical stability and a homogeneous distribution of HMO. The most promising membrane, containing 20% (w/w) of HMO, showed an almost 13 times higher Li+ ionic conductivity (8.28 mS/cm) compared to the control composite membrane (without HMO) and an average ideal selectivity of 11.75 for the Li+/Mg2+ pair. The composite-20% membrane had the lowest intermolecular distance between the polymer chains (according to X-ray diffraction (XRD) analysis), the most flexible structure (lowest Tg) and showed the homogeneous dispersion of HMO (SEM images), which explains its highest Li+/Mg2+ selectivity among the tested membranes. The lithium ion transport performance and separation efficiency were investigated through diffusion dialysis experiments, under different operating conditions. A binary separation factor of 9.10 for Li+/Mg2+ and Li+ molar flux of 0.026 mol/(m2.h) was achieved without applying any external potential difference. When an external potential difference of 0.2 V was applied, the binary separation factor of Li+/Mg2+ pair was 5, while the Li+ molar flux increased almost 5 times. The obtained results provide the basis to design and develop composite lithium transport selective polymeric membranes, thus representing a promising step for future implementation of such membranes to recover lithium from saline streams.Publicación Occurrence and Treatment of Antibiotic-Resistant Bacteria Present in Surface Water(MDPI, 2023-04-11) Sério, João; Marques, Ana Paula; Huertas Penela, Rosa María; Crespo, João Goulão; Pereira, Vanessa JorgeAccording to the World Health Organization, antibiotic resistance is one of the main threats to global health. The excessive use of several antibiotics has led to the widespread distribution of antibiotic-resistant bacteria and antibiotic resistance genes in various environment matrices, including surface water. In this study, total coliforms, Escherichia coli and enterococci, as well as total coliforms and Escherichia coli resistant to ciprofloxacin, levofloxacin, ampicillin, streptomycin, and imipenem, were monitored in several surface water sampling events. A hybrid reactor was used to test the efficiency of membrane filtration, direct photolysis (using UV-C light emitting diodes that emit light at 265 nm and UV-C low pressure mercury lamps that emit light at 254 nm), and the combination of both processes to ensure the retention and inactivation of total coliforms and Escherichia coli as well as antibiotic-resistant bacteria (total coliforms and Escherichia coli) present in river water at occurrence levels. The membranes used (unmodified silicon carbide membranes and the same membrane modified with a photocatalytic layer) effectively retained the target bacteria. Direct photolysis using low-pressure mercury lamps and light-emitting diode panels (emitting at 265 nm) achieved extremely high levels of inactivation of the target bacteria. The combined treatment (unmodified and modified photocatalytic surfaces in combination with UV-C and UV-A light sources) successfully retained the bacteria and treated the feed after 1 h of treatment. The hybrid treatment proposed is a promising approach to use as point-of-use treatment by isolated populations or when conventional systems and electricity fail due to natural disasters or war. Furthermore, the effective treatment obtained when the combined system was used with UV-A light sources indicates that the process may be a promising approach to guarantee water disinfection using natural sunlight.Publicación Towards a Novel Combined Treatment Approach Using Light-Emitting Diodes and Photocatalytic Ceramic Membranes(MDPI, 2022-01-19) Bernardo, Jorge; Sério, João; Oliveira, Beatriz; Marques, Ana Paula; Huertas Penela, Rosa María; Crespo, João GoulãoNatural disasters (such as earthquakes, floods, heatwaves and landslides), isolation and war affect the water access of millions of people worldwide. Developments in the areas of membrane filtration, photolysis and photocatalysis are important for safe water production and water re-use applications. This work aimed to test alternative ways to ensure effective disinfection of wastewater effluents: light-emitting diodes that emit at different wavelengths, photocatalytic membranes, and the combination of the two solutions. The different treatment processes were tested at the laboratory scale to assess their performance in the removal and inactivation of water quality indicator bacteria and fungi present in wastewater effluents. The membranes were found to be effective to retain the microorganisms (rejection values higher than 96%), while three small ultraviolet C light-emitting diodes that emitted light at 255 and 265 nm showed an excellent performance for inactivation (higher than 2.5-log inactivation of total coliforms and Escherichia coli after 10 min of exposure in real wastewater effluents). When photocatalytic membranes are used, ultraviolet A light-emitting diodes ensured effective treatment of the retentate (higher than 65%). The combination of these two processes is extremely promising since it ensures not only the production of a high quality permeate that can be reused, but also the treatment of the retentate.Publicación Stability of Polymeric Membranes to UV Exposure before and after Coating with TiO2 Nanoparticles(MDPI, 2021-12-30) Labuto, Geórgia; Sanches, Sandra; Crespo, João Goulão; Pereira, Vanessa J.; Huertas Penela, Rosa María; Fundação para a Ciência e a Tecnologia en PortugalThe combination of photocatalysis and membrane filtration in a single reactor has been proposed, since the photocatalytic treatment may degrade the pollutants retained by the membrane and reduce fouling. However, polymeric membranes can be susceptible to degradation by UV radiation and free radicals. In the present study, five commercial polymeric membranes were exposed to ultraviolet (UV) radiation before and after applying a sol–gel coating with TiO2 nanoparticles. Membrane stability was characterized by changes in hydrophilicity as well as analysis of soluble substances and nanoparticles detached into the aqueous medium, and by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and energy-dispersive X-ray spectrometry (EDS) for structural, morphological, and elemental distribution analysis, respectively. The TiO2 coating conferred photocatalytic properties to the membranes and protected them during 6 h of UV radiation exposures, reducing or eliminating chemical and morphological changes, and in some cases, improving their mechanical resistance. A selected commercial nanofiltration membrane was coated with TiO2 and used in a hybrid reactor with a low-pressure UV lamp, promoting photocatalysis coupled with cross-flow filtration in order to remove 17α-ethinylestradiol spiked into an aqueous matrix, achieving an efficiency close to 100% after 180 min of combined filtration and photocatalysis, and almost 80% after 90 min.Publicación Electropsun non-woven luminescent two-dye pH sensors: Effect of morphology on the sensing performance(Elsevier, 2024-08-24) Vieira, Tiago; Canejo, João; Huertas Penela, Rosa María; Oliveira, Hugo M.; Godinho, María H.; Crespo, João Goulão; Portugal, Carla A. M.Electrospun (ES) non-woven matrices are regarded as promising platforms for the development of miniaturized sensing systems with improved detection capacity. Their high specific surface area and void-to-volume ratio are expected to promote higher and faster interaction of the sensing molecular probes with the target stimuli increasing sensor sensitivity and response time. However, the poor light transparency of ES non-woven mats appears as the main limiting effect regarding their use as optical sensor platforms being important to determine to what extent it affects the sensor prediction accuracy. This work addresses this question providing a comparative analysis of the performance of flat cast and ES non-woven cellulose acetate luminescent platforms loaded with a pH sensitive dye-pair, i.e. fluorescein isothiocyanate (FITC) and rhodamine 6 G (R6G). This study follows a comprehensive approach aiming at clarifying the effect of the platform morphology on the sensitivity of their spectral properties to pH and to understand about the advantages of using dual dye systems for pH detection. The presence of R6G improved remarkably the sensitivity of these ES matrices extending the analytical capacity of the probes to the alkaline range. The emission of ES matrices showed stronger sensitivity to pH. However, pH prediction accuracy was found to depend crucially on a synergistic effect from the platform morphology and the signal analysis methodology. ES non-woven matrices allows for accurate pH prediction, characterized by determination errors < 10 % for pH < 10, by exponential analysis of the dye-pair emission at λExc of 450 nm and λEm of 519 nm. Furthermore, it shows a strong reduction of the determination errors, at extremely acidic conditions, resulting in values comparable to that obtained by analysis of the emission signal from flat cast platforms with more complex Förster Resonance Energy Transfer (FRET) methodologies.Publicación Retention and Inactivation of Quality Indicator Bacteria Using a Photocatalytic Membrane Reactor(MDPI, 2022-06-22) Marques, Ana Paula; Huertas Penela, Rosa María; Bernardo, Jorge; Oliveira, Beatriz; Crespo, João GoulãoThe development of effective disinfection treatment processes is crucial to help the water industry cope with the inevitable challenges resulting from the increase in human population and climate change. Climate change leads to heavy rainfall, flooding and hot weather events that are associated with waterborne diseases. Developing effective treatment technologies will improve our resilience to cope with these events and our capacity to safeguard public health. A submerged hybrid reactor was used to test the efficiency of membrane filtration, direct photolysis (using ultraviolet-C low-pressure mercury lamps, as well as ultraviolet-C and ultraviolet-A light-emitting diodes panels) and the combination of both treatment processes (membrane filtration and photolysis) to retain and inactivate water quality indicator bacteria. The developed photocatalytic membranes effectively retained the target microorganisms that were then successfully inactivated by photolysis and advanced oxidation processes. The new hybrid reactor could be a promising approach to treat drinking water, recreational water and wastewater produced by different industries in small-scale systems. Furthermore, the results obtained with membranes coated with titanium dioxide and copper combined with ultraviolet-A light sources show that the process may be a promising approach to guarantee water disinfection using natural sunlight.Publicación Single solvent synthesis of lithium-selective hydrogen manganese oxide (HMO)-based mixed matrix membranes(KeAi; Elsevier, 2025-03-29) Saif, Hafiz Muhammad; Gebretatios, Amanuel Gidey; Huertas Penela, Rosa María; Crespo, João Goulão; Pawlowski, SylwinThe rising lithium-ion battery market drives lithium demand and requires efficient and selective lithium recovery methods from aqueous sources. Membrane technologies can address environmental and inherent efficiency issues in conventional lithium extraction methods. This study presents the synthesis of novel lithium-selective mixed matrix membranes (MMMs) by integrating 0–30 wt% of a lithium selective filler named hydrogen manganese oxide (HMO) into a sulfonated polyethersulfone (SPES)-Nafion polymer matrix. The membranes were produced by casting and thoroughly examined to assess their chemical, physical, morphological, thermal, and mechanical characteristics. The transport of lithium across membranes was evaluated in diffusion and electro-diffusion studies. The membrane containing 20 wt% of HMO exhibited the highest ideal selectivity values, which were 1.05 for Li+/K+, 1.20 for Li+/Na+, and 13.36 for Li+/Mg2+; and more than 97% increase in lithium-ion conductivity when compared with the control membrane without HMO. In diffusion experiments, the binary separation factors for Li+/K+, Li+/Na+, and Li+/Mg2+ were 0.71, 1.52, and 11.83, respectively, while under electro-diffusion conditions, the corresponding values were 0.82, 1.55, and 9.88. Above 20 wt% of HMO, membranes lose their separation capacity as HMO aggregates inside the membrane structure. The higher selectivity of membranes towards Li+ in the presence of Mg2+ is due to magnesium's larger hydrated radius and higher hydration energy compared to lithium. Overall, the prepared membranes demonstrated a promising potential for green lithium recovery. This study facilitates the advancement of sustainable lithium-selective MMM synthesis.Publicación On operation of reverse electrodialysis (RED) and membrane capacitive deionisation (MCDI) with natural saline streams: A critical review(Elsevier, 2020-02-15) Pawlowski, Sylwin; Huertas Penela, Rosa María; Galinha, Cláudia F.; Crespo, João Goulão; Velizarov, SvetlozarEnvironment-friendly production of power and clean water is one of the major goals of 2030 Agenda for Sustainable Development, and can be achieved by emerging electromembrane processes, such as reverse electrodialysis (RED) and membrane capacitive deionisation (MCDI). RED generates electricity from salinity gradient energy sources, while MCDI desalinates (mainly) brackish water. However, fouling, scaling, stack channels clogging and undesired uphill ionic transport can reduce the power output and salt removal efficiency in RED and MCDI, respectively. A practical overview of current problems and challenges of operating and monitoring these processes under real conditions is provided. Appropriate mitigation approaches, which might include feed water pre-treatment, in-situ cleaning strategies and/or development of new antifouling ion-exchange membranes (IEMs) are disclosed. First, a description, analysis and (when possible) normalised comparison of the performance of available RED and MCDI stacks, employing natural saline streams, is presented. Afterwards, it is discussed how fouling formation can be detected, monitored and characterised, which is essential to implement effective pre-treatment and cleaning strategies. Finally, sustainable ways for preparation of appropriate IEMs are selected and presented.