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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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 Assessment of the Potential of Using Nanofiltration Polymeric and Ceramic Membranes to Treat Refinery Spent Caustic Effluents(MDPI, 2022-06-17) Rita, Ana Isabel; Nabais, Ana Rita; Neves, Luisa A.; Huertas Penela, Rosa María; Santos, María; Madeira, Luis M.; Sanches, SandraSpent caustic effluents are very challenging due to their very hazardous nature in terms of toxicity as well as their extreme pH (approximately 12–14). Spent caustic has presented a challenge for wastewater treatment in refineries, due to its composition rich in mercaptans, sulfides and other aromatic compounds. To address such problems, membrane filtration was studied using real effluents from Sines Refinery, in Portugal. The present study attempts to assess the potential for spent caustic treatment with nanofiltration (NF) polymeric and ceramic membranes, assessing membrane life expectancy. For that, membrane aging studies in static mode were performed with the polymeric membrane before attempting NF treatment (dynamic studies). A ceramic membrane was also tested for the first time with this type of effluents, though only in dynamic mode. Although the polymeric membrane performance was very good and in accordance with previous studies, its lifespan was very reduced after 6 weeks of contact with spent caustic, compromising its use in an industrial unit. Contrarily to expectations, the ceramic membrane tested was not chemically more resistant than the polymeric one upon direct contact with spent caustic (loss of retention capacity in less than 1 h in contact with the spent caustic). The results obtained suggest that a pH of 13.9 is very aggressive, even for ceramic membranes.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 On the role of components of therapeutic hydrophobic deep eutectic solvent-based nanoemulsions sustainably produced by membrane-assisted nanoemulsification for enhanced antimicrobial activity(Elsevier, 2022-03-15) Syed, Usman Taqui; Leonardo, Inês Carvalho; Mendoza, Gracia; Gaspar, Frédéric B.; Gámez, Enrique; Huertas Penela, Rosa María; Crespo, M. Teresa Barreto; Arruebo, ManuelStringent regulations and growing industrial interests have ensued the development of sustainable processes. Membrane assisted-nanoemulsification based on microengineered membranes has been explored for the sustainable production of therapeutic hydrophobic deep eutectic solvent (DES)-based nanoemulsions for enhanced antimicrobial applications. Hydrophobic DESs were synthesised by employing therapeutic terpenes: DL-menthol and thymol. To understand the mechanism of oil droplet detachment from the membrane when producing such nanoemulsions, the effect of hydrophilicity/hydrophobicity partition of the active membrane surface on the process performance was evaluated. Using a continuous phase cross-flow velocity of 0.32 m.s−1, a dispersed phase flowrate of 0.02 ml.min−1 and 2% (w/w) Tween 80 resulted in a DES-in-water nanoemulsion of 81.2 ± 0.9 nm droplet size. Novel observations like intrinsically reduced interfacial tension of 7.5 mN.m−1 between water and hydrophobic DES, and a hydrophobic DES wetting behaviour to both hydrophilic and hydrophobic active membrane surfaces were witnessed. Compared to DL-menthol, thymol or synthesised DES, the optimised DES-in-water nanoemulsions exhibited enhanced synergetic antimicrobial effect against Escherichia coli, Staphylococcus aureus and superior potency against Cutibacterium acnes, an acne inducing bacterial strain. These nanoemulsions were also cytocompatible with human keratinocytes and dermal fibroblasts. Lastly, membrane-assisted nanoemulsification manifested controlled size and monomodally distributed nanoemulsions compared to traditional ultrasound-driven emulsification.Publicación Treatment of a real water matrix inoculated with Aspergillus fumigatus using a photocatalytic membrane reactor(Elsevier, 2020-03-15) Oliveira, Beatriz; Sanches, Sandra; Huertas Penela, Rosa María; Barreto Crespo, Maria Teresa; Pereira, Vanessa JorgeCoupling UV photolysis, stable photoactive TiO2 layers and water filtration in a single photocatalytic membrane reactor can be beneficial to achieve high quality drinking water since the membrane retains microorganisms and chemical pollutants whereas the photocatalytic treatment decreases fouling components and treats the concentrated retentate. In this work, a newly designed photocatalytic membrane reactor combining filtration with UV photolysis/ photocatalysis under a low pressure mercury lamp (wavelength emission at 254 nm) using ceramic modified membranes was used to treat filtered surface water inoculated with Aspergillus fumigatus. The photocatalytic membranes used in this study were produced using an environmental friendly modification process. Results showed high percentages of adsorption and retention of the spores for both the unmodified and modified membrane. The lower pore size of the modified membrane has the advantage of retaining the spores at the surface instead of trapping the spores inside as observed for the unmodified membrane. Direct photolysis ach- ieved retentate treatment percentages up to 99% after 60 min of treatment. The effect of the combined treatment showed that direct photolysis and photocatalysis were able to cause the deformation of spores and led to changes in membrane permeability and enzymatic activity.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 Combination of Zinc Oxide Photocatalysis with Membrane Filtration for Surface Water Disinfection(MDPI, 2023-01-02) Martínez Sosa, Santiago; Huertas Penela, Rosa María; Pereira, Vanessa JorgeIncrease water usage has led to its deterioration. Pollutants are easily found in the aquatic environment and treatment techniques must keep improving to meet the current needs and future demands. Membranes are attractive for water treatment, but limitations like fouling and the highly concentrate produced affect their performance. Combining membrane filtration with photocatalysis provides the opportunity to integrate a self-cleaning step during membrane filtration. In this work, we studied two simple and efficient approaches to combine membrane filtration with zinc oxide nanoparticles (using the catalyst in suspension and immobilized) activated by light emitting diodes (LED) emitting light at 365 nm. Both systems were used to test the disinfection efficiency in real surface water, compared in terms of catalyst concentration in the permeate stream (below the limit of detection) and its recovery after filtration (higher that 74%). The system’s capability to retain and inactivate target bacteria (total coliforms and E. coli) in the retentate stream was tested with samples of real surface water. The results obtained show that both configurations led to an improved performance in comparison to the membrane treatment alone with a higher retention of the bacteria (not detected in the permeate samples) and higher treatment of the retentate. For the modified membranes, different catalyst concentrations and thermal treatments were tested. The performance of all the processes was evaluated in terms of the level of treatment achieved and the permeate flux. All the modified membranes showed an efficient retention of the target bacteria from surface water, with higher performances than the unmodified membrane (96.2% for total coliforms and 94.9% for E. coli). Remarkable retention and treatment of the retentate was achieved using a membrane modified with a catalyst load of 125 mg subject during two hours to a thermal treatment of 300 °C. This modification has a performance comparable to the system with the same catalyst load in suspension. During operation, the permeate flux reduction is lower with the modified membranes which could lead to longer operation times without the need of further cleaning or replacement. The combined system, ceramic membranes modified with zinc oxide and UV-A LEDs proved to be effective to retain and disinfect water quality indicator bacteria present in real surface water matrices.