15 research outputs found
Occurrence and Treatment of Antibiotic-Resistant Bacteria Present in Surface Water
Funding Information: This research was funded by Fundação para a Ciência e a Tecnologia through the grants PTDC/EAM-AMB/30989/2017 and CEECIND/02912/2018, the Associate Laboratory for Green Chemistry—LAQV (UIDB/50006/2020 and UIDP/50006/2020). iNOVA4Health (UIDB/04462/2020, UIDP/04462/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020), a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior through national funds, is also acknowledged. Publisher Copyright: © 2023 by the authors.According 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.publishersversionpublishe
Development of highly selective composite polymeric membranes for Li+/Mg2+ separation
Associate Laboratory for Green Chemistry-LAQV, which is financed by Portuguese national funds from FCT/MCTES (UID/QUI/50006/2019).
This work was also supported by "Programa Operacional Regional de Lisboa, na componente FEDER" and "Fundacao para a Ciencia e Tecnologia, I.P." through research project PTDC/EQU-EPQ/29579/2017. S. Pawlowski acknowledges Fundacao para a Ciencia e Tecnologia, I.P. for his contracts CEECIND/01617/2017 and CEECIND/00340/2018.
iNOVA4Health UIDB/Multi/04462/2020, a program financially supported by Fundacao para a Ciencia e Tecnologia is acknowledged. Funding from INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), is also gratefully acknowledged. The authors acknowledge Professor Vitor D. Alves, from Instituto Superior de Agronomia, Universidade de Lisboa, for the support to analysing mechanical properties.To 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.preprintauthorsversionpublishe
Elimination of Total Bacteria and Antibiotic Resistance Genes from the Discharged Effluent of a Full-Scale Wastewater Treatment Plant
Funding Information: This research was funded by Fundação para a Ciência e a Tecnologia (FCT) (PhD scholarship no. PD/BD/128203/2016), AgriWWater Project (PTDC/CTA-AMB/29586/2017), INTERFACE Pro-gramme, through the Innovation, Technology and Circular Economy Fund (FITEC), iNOVA4Health (UID/Multi/04462/2019) and the European Union’s Horizon 2020 Research and Innovation Pro-gramme under the Marie Sklodowska-Curie Grant, Agreement No. 794315. This work was also supported by the Associate Laboratory for Green Chemistry—LAQV, which is financed by national funds from FCT/MCTES (UIDB/50006/2020). Funding Information: Funding: This research was funded by Fundação para a Ciência e a Tecnologia (FCT) (PhD scholarship no. PD/BD/128203/2016), AgriWWater Project (PTDC/CTA-AMB/29586/2017), INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), iNOVA4Health (UID/Multi/04462/2019) and the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant, Agreement No. 794315. This work was also supported by the Associate Laboratory for Green Chemistry—LAQV, which is financed by national funds from FCT/MCTES (UIDB/50006/2020). Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Wastewater reuse for agricultural irrigation still raises important public health issues regarding its safety, due to the increasing presence of emerging contaminants, such as antibiotic resistant bacteria and genes, in the treated effluents. In this paper, the potential for a commercial Desal 5 DK nanofiltration membrane to be used as a tertiary treatment in the wastewater treatment plants for a more effective elimination of these pollutants from the produced effluents was assessed on laboratory scale, using a stainless steel cross-flow cell. The obtained results showed high concentrations of total bacteria and target carbapenem and (fluoro)quinolone resistance genes (blaKPC, blaOXA-48, blaNDM, blaIMP, blaVIM, qnrA, qnrB and qnrS) not only in the discharged, but also in the reused, effluent samples, which suggests that their use may not be entirely safe. Nevertheless, the applied nanofiltration treatment achieved removal rates superior to 98% for the total bacteria and 99.99% for all the target resistance genes present in both DNA and extracellular DNA fractions, with no significant differences for these microbiological parameters between the nanofiltered and the control tap water samples. Although additional studies are still needed to fully optimize the entire process, the use of nanofiltration membranes seems to be a promising solution to substantially increase the quality of the treated wastewater effluents.publishersversionpublishe
Characterization of poly(acrylic) acid-modified heterogenous anion exchange membranes with improved monovalent permselectivity for RED
The performance of anion-exchange membranes (AEMs) in Reverse Electrodialysis is hampered by both presence of multivalent ions and fouling phenomena, thus leading to reduced net power density. Therefore, we propose a monolayer surface modification procedure to functionalize Ralex-AEMs with poly(acrylic) acid (PAA) in order to (i) render a monovalent permselectivity, and (ii) minimize organic fouling. Membrane surface modification was carried out by putting heterogeneous AEMs in contact with a PAA-based aqueous solution for 24 h. The resulting modified membranes were firstly characterized by contact angle, water uptake, ion exchange capacity, fixed charge density, and swelling degree measurements, whereas their electrochemical responses were evaluated through cyclic voltammetry. Besides, their membrane electro-resistance was also studied via electrochemical impedance spectroscopy analyses. Finally, membrane permselectivity and fouling behavior in the presence of humic acid were evaluated through mass transport experiments using model NaCl containing solutions. The use of modified PAA-AEMs resulted in a significantly enhanced monovalent permselectivity (sulfate rejection improved by >35%) and membrane hydrophilicity (contact angle decreased by >15%) in comparison with the behavior of unmodified Ralex-AEMs, without compromising the membrane electro-resistance after modification, thus demonstrating the technical feasibility of the proposed membrane modification procedure. This study may therefore provide a feasible way for achieving an improved Reverse Electrodialysis process efficiency.This research was funded by “Programa Operacional Regional de Lisboa, na componente FEDER” and “Fundação para a Ciência e Tecnologia, I.P.”. (FCT) through research project PTDC/EQU-EPQ/29579/2017. This work was also supported by the Associate Laboratory for Green Chemistry-LAQV, which is financed by national funds from FCT/MCTES (UID/QUI/50006/2019)
Donnan Dialysis for Recovering Ammonium from Fermentation Solutions Rich in Volatile Fatty Acids
Funding Information: Universitat Politècnica de València and Ministerio de Universidades de España (Plan de Recuperación, Transformación y Resiliencia—financed by European Union—Next GenerationEU) are acknowledged for the post-doctoral research grant attributed to Kayo Santana Barros. Funding Information: This work was financed by Fundação para a Ciência e a Tecnologia, I.P., Lisbon, Portugal in the scope of the projects UIDP/04378/2020, UIDB/04378/2020 and PTDC/BTA-BTA/30902/2017 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB. The work was also supported through the projects UIDB/50006/2020 and UIDP/50006/2020, funded by FCT/MCTES through national funds. Publisher Copyright: © 2023 by the authors.For the production of polyhydroxyalkanoates (PHA) using nitrogen-rich feedstocks (e.g., protein-rich resources), the typical strategy of restricting cell growth as a means to enhance overall PHA productivity by nitrogen limitation is not applicable. In this case, a possible alternative to remove the nitrogen excess (NH4+/NH3) is by applying membrane separation processes. In the present study, the use of Donnan dialysis to separate ammonium ions from volatile fatty acids present in the media for the production of PHA was evaluated. Synthetic and real feed solutions were used, applying NaCl and HCl receiver solutions separated by commercial cation-exchange membranes. For this specific purpose, Fumasep and Ralex membranes showed better performance than Ionsep. Sorption of ammonium ions occurred in the Ralex membrane, thus intensifying the ammonium extraction. The separation performances with NaCl and HCl as receiver solutions were similar, despite sorption occurring in the Ralex membrane more intensely in the presence of NaCl. Higher volumetric flow rates, NaCl receiver concentrations, and volume ratios of feed:receiver solutions enhanced the degree of ammonium recovery. The application of an external electric potential difference to the two-compartment system did not significantly enhance the rate of ammonium appearance in the receiver solution. The results obtained using a real ammonium-containing solution after fermentation of cheese whey showed that Donnan dialysis can be successfully applied for ammonium recovery from such solutions.publishersversionpublishe
Occurrence of antibiotics, antibiotic resistance genes and viral genomes in wastewater effluents and their treatment by a pilot scale nanofiltration unit
Funding Information: Funding: This research was funded by Fundação para a Ciência e a Tecnologia through the project PTDC/CTA-AMB/29586/2017. We also acknowledge the financial support from Fundação para a Ciência e Tecnologia and Portugal 2020 to the Portuguese Mass Spectrometry Network (LISBOA-01-0145-FEDER-402-022125). iNOVA4Health-UIDB/04462/2020, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência, through national funds, is gratefully acknowledged. Associate Laboratory for Green Chemistry-LAQV, which is financed by national funds from FCT/MCTES (UID/QUI/50006/2019), is gratefully acknowledged. Funding from INTERFACE Program, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged. Funding Information: This research was funded by Funda??o para a Ci?ncia e a Tecnologia through the project PTDC/CTA-AMB/29586/2017. We also acknowledge the financial support from Funda??o para a Ci?ncia e Tecnologia and Portugal 2020 to the Portuguese Mass Spectrometry Network (LISBOA-01-0145-FEDER-402-022125). iNOVA4Health-UIDB/04462/2020, a program financially supported by Funda??o para a Ci?ncia e Tecnologia/Minist?rio da Educa??o e Ci?ncia, through national funds, is gratefully acknowledged. Associate Laboratory for Green Chemistry-LAQV, which is financed by national funds from FCT/MCTES (UID/QUI/50006/2019), is gratefully acknowledged. Funding from INTERFACE Program, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged. Publisher Copyright: © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Broad-spectrum fluoroquinolone antibiotics (ciprofloxacin and levofloxacin), carbapenem and fluoroquinolone resistance genes, as well as viral genomes, were detected in grab samples of wastewater effluents. Passive samplers, which are simpler and easier to use and provide information about the concentrations and combination of contaminants present in a certain fluid matrix over time, proved to be extremely promising devices to monitor the presence of the target antibiotics in wastewater effluents. Nanofiltration was tested with a pilot-scale unit installed at a domestic wastewater treatment facility, using a Desal 5DK membrane operated at a constant transmembrane pressure of 6 bar and 70% recovery rate. In a 24 h experimental assay, the variation of the membrane permeance was low (6.3%). High rejections of the target contaminants from the wastewater effluent were obtained by the pilot-scale treatment. Hence, nanofiltration using the Desal 5DK membrane is considered to be a promising treatment to cope with chemical and biological contaminants present in wastewater effluents.publishersversionpublishe
Protein crystallization in a microfluidic contactor with nafion®117 membranes
UIDB/50006/2020 UIDP/50006/2020 “Erasmus Mundus Doctorate in Membrane Engineering”–EUDIME (FPA 2011–2014, http://www.eudime.unical.itProtein crystallization still remains mostly an empirical science, as the production of crystals with the required quality for X-ray analysis is dependent on the intensive screening of the best protein crystallization and crystal’s derivatization conditions. Herein, this demanding step was addressed by the development of a high-throughput and low-budget microfluidic platform consisting of an ion exchange membrane (117 Nafion® membrane) sandwiched between a channel layer (stripping phase compartment) and a wells layer (feed phase compartment) forming 75 independent microcontactors. This microfluidic device allows for a simultaneous and independent screening of multiple protein crystallization and crystal derivatization conditions, using Hen EggWhite Lysozyme (HEWL) as the model protein and Hg2+ as the derivatizing agent. This microdevice offers well-regulated crystallization and subsequent crystal derivatization processes based on the controlled transport of water and ions provided by the 117 Nafion® membrane. Diffusion coefficients of water and the derivatizing agent (Hg2+) were evaluated, showing the positive influence of the protein drop volume on the number of crystals and crystal size. This microfluidic system allowed for crystals with good structural stability and high X-ray diffraction quality and, thus, it is regarded as an efficient tool that may contribute to the enhancement of the proteins’ crystals structural resolution.publishersversionpublishe
Impact of Ionic Liquid Structure and Loading on Gas Sorption and Permeation for ZIF-8-Based Composites and Mixed Matrix Membranes
CEECIND/ 00793/2018
LA/P/0008/2020
PTDC/CTM-TM/30326/2017Carbon dioxide (CO2) capture has become of great importance for industrial processes due to the adverse environmental effects of gas emissions. Mixed matrix membranes (MMMs) have been studied as an alternative to traditional technologies, especially due to their potential to overcome the practical limitations of conventional polymeric and inorganic membranes. In this work, the effect of using different ionic liquids (ILs) with the stable metal–organic framework (MOF) ZIF-8 was evaluated. Several IL@ZIF-8 composites and IL@ZIF-8 MMMs were prepared to improve the selective CO2 sorption and permeation over other gases such as methane (CH4) and nitrogen (N2). Different ILs and two distinct loadings were prepared to study not only the effect of IL concentration, but also the impact of the IL structure and affinity towards a specific gas mixture separation. Single gas sorption studies showed an improvement in CO2 /CH4 and CO2 /N2 selectivities, compared with the ones for the pristine ZIF-8, increasing with IL loading. In addition, the prepared IL@ZIF-8 MMMs showed improved CO2 selective behavior and mechanical strength with respect to ZIF-8 MMMs, with a strong dependence on the intrinsic IL CO2 selectivity. Therefore, the selection of high affinity ILs can lead to the improvement of CO2 selective separation for IL@ZIF-8 MMMs.publishersversionpublishe
Towards a Novel Combined Treatment Approach Using Light-Emitting Diodes and Photocatalytic Ceramic Membranes
Natural 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
Retention and Inactivation of Quality Indicator Bacteria Using a Photocatalytic Membrane Reactor
The 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