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This work reports a comprehensive kinetic analysis and modelling of the electrochemically assisted ammonia removal from marine aquaculture waters (RAS). The proposed model combines the kinetics of chlorine electrogeneration, experimentally determined, with the mechanism and kinetic parameters, taken from literature, of break point chlorination reactions involving aqueous chlorine (HClO and ClO−), total ammonia nitrogen (TAN as NH3 and NH4+), and the chlorinated derivatives of ammonia (monochloramine (NH2C1), dichloramine (NHC12), and nitrogen trichloride (NC13)). The model has been validated with laboratory experiments, obtained in an electrochemical cell provided with Ti/RuO2 anode and Ti cathode, and working with model sea water in the range of operating variables [TAN]0 = 10–60 mg L−1 and j = 5 – 20 A m−2; good agreement between simulated and experimental data for the progress of ammonia and combined chlorine concentrations assesses the validity and robustness of the kinetic model. Thus, this study provides the tools to analyse, predict and explain ammonia removal performance in the electrochemical treatment of marine RAS water.
Alba Romano; Inmaculada Ortiz; Ane M. Urtiaga. Comprehensive kinetics of electrochemically assisted ammonia removal in marine aquaculture recirculating systems. Journal of Electroanalytical Chemistry 2021, 897, 115619 .
AMA StyleAlba Romano, Inmaculada Ortiz, Ane M. Urtiaga. Comprehensive kinetics of electrochemically assisted ammonia removal in marine aquaculture recirculating systems. Journal of Electroanalytical Chemistry. 2021; 897 ():115619.
Chicago/Turabian StyleAlba Romano; Inmaculada Ortiz; Ane M. Urtiaga. 2021. "Comprehensive kinetics of electrochemically assisted ammonia removal in marine aquaculture recirculating systems." Journal of Electroanalytical Chemistry 897, no. : 115619.
Interest in recovering and reclaiming refrigerant gases is growing as a consequence of increasing concern about the high global warming potential of some hydrofluorocarbons (HFCs). However, advanced separation processes, like extractive distillation, are required to selectively separate azeotropic and close-boiling refrigerant mixtures. In this regard, ionic liquids (ILs) arise as promising entrainers because of their favorable properties, including nonvolatility and good HFC solubility selectivity. The aim of this review is to become a reference text for the research and design of novel separation processes for mixtures of fluorinated gases based on the use of ILs. We include an extensive compilation of publications on equilibrium, mass transport, and absorption and membrane separation related to the use of ILs to selectively separate, not only the most relevant refrigerants employed nowadays, namely, HFCs, hydrofluoroolefins, and hydrochlorofluoroolefins, but also other relevant refrigerant families, such as chlorofluorocarbons, hydrochlorofluorocarbons, and perfluorocarbons. The UC-RAIL database provided as Supplementary Information compiles more than 5000 data points that are comprehensively analyzed in the review focusing on process design. Finally, we provide a set of directions that lead to the recovery of fluorinated refrigerant gases, to shift the refrigeration and air conditioning sector towards a more circular economy.
Salvador Asensio-Delgado; Fernando Pardo; Gabriel Zarca; Ane Urtiaga. Absorption separation of fluorinated refrigerant gases with ionic liquids: Equilibrium, mass transport, and process design. Separation and Purification Technology 2021, 276, 119363 .
AMA StyleSalvador Asensio-Delgado, Fernando Pardo, Gabriel Zarca, Ane Urtiaga. Absorption separation of fluorinated refrigerant gases with ionic liquids: Equilibrium, mass transport, and process design. Separation and Purification Technology. 2021; 276 ():119363.
Chicago/Turabian StyleSalvador Asensio-Delgado; Fernando Pardo; Gabriel Zarca; Ane Urtiaga. 2021. "Absorption separation of fluorinated refrigerant gases with ionic liquids: Equilibrium, mass transport, and process design." Separation and Purification Technology 276, no. : 119363.
The restrictions imposed to the production of high-global warming potential refrigerant gases have boosted the search of novel separation processes for the selective recovery of hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFO) from exhausted refrigerant mixtures. Membrane materials functionalized with ionic liquids can offer an effective techno-economical response to the challenging separation of HFC/HFO blends. In this work, we provide for the first time a thorough characterization of the gas solubility and permeation properties of three of the most relevant compounds for the future of the refrigeration and air conditioning sector, that is, difluoromethane (HFC-R32), 1,1,1,2-tetrafluoroethane (HFC-R134a), and 2,3,3,3-tetrafluoropropene (HFO-R1234yf), through composite ionic liquid–polymer membranes (CILPMs) that were prepared combining the Pebax 1657 copolymer with several ILs, [C2mim][SCN], [C2mim][BF4], [C2mim][OTf], and [C2mim][Tf2N], varying the IL content in the range of 20–60 wt %. The CILPMs with the best separation performance and mechanical stability against feed pressure were those with 40 wt % of [C2mim][BF4] and [C2mim][SCN]. For the 40 wt % [C2mim][BF4] CILPM, the addition of IL promoted the permeability of the smallest molecules R32 and R134a and reduced the permeability of the largest molecule R1234yf, which resulted in 120 and 75% selectivity enhancement relative to that of the pristine polymer for R32/R1234yf and R134a/R1234yf mixtures, respectively. Finally, this CILPM was stable in the separation of two commercial HFC/HFO refrigerant blends (R513A and R454B) over a wide pressure range (up to 12 bar). These results indicate that CILPMs can be used for separating azeotropic and near-azeotropic exhausted HFC/HFO mixtures, which could stimulate the recovery and reuse of their components and thus avoid their emissions and pull down the demand for virgin refrigerants.
Fernando Pardo; Sergio V. Gutiérrez-Hernández; Gabriel Zarca; Ane Urtiaga. Toward the Recycling of Low-GWP Hydrofluorocarbon/Hydrofluoroolefin Refrigerant Mixtures Using Composite Ionic Liquid–Polymer Membranes. ACS Sustainable Chemistry & Engineering 2021, 9, 7012 -7021.
AMA StyleFernando Pardo, Sergio V. Gutiérrez-Hernández, Gabriel Zarca, Ane Urtiaga. Toward the Recycling of Low-GWP Hydrofluorocarbon/Hydrofluoroolefin Refrigerant Mixtures Using Composite Ionic Liquid–Polymer Membranes. ACS Sustainable Chemistry & Engineering. 2021; 9 (20):7012-7021.
Chicago/Turabian StyleFernando Pardo; Sergio V. Gutiérrez-Hernández; Gabriel Zarca; Ane Urtiaga. 2021. "Toward the Recycling of Low-GWP Hydrofluorocarbon/Hydrofluoroolefin Refrigerant Mixtures Using Composite Ionic Liquid–Polymer Membranes." ACS Sustainable Chemistry & Engineering 9, no. 20: 7012-7021.
In this work, polymeric membranes functionalized with ionic liquids (ILs) and exfoliated graphene nanoplatelets (xGnP) were developed and characterized. These membranes based on graphene ionanofluids (IoNFs) are promising materials for gas separation. The stability of the selected IoNFs in the polymer membranes was determined by thermogravimetric analysis (TGA). The morphology of membranes was characterized using scanning electron microscope (SEM) and interferometric optical profilometry (WLOP). SEM results evidence that upon the small addition of xGnP into the IL-dominated environment, the interaction between IL and xGnP facilitates the migration of xGnP to the surface, while suppressing the interaction between IL and Pebax®1657. Fourier transform infrared spectroscopy (FTIR) was also used to determine the polymer–IoNF interactions and the distribution of the IL in the polymer matrix. Finally, the thermodynamic properties and phase transitions (polymer–IoNF) of these functionalized membranes were studied using differential scanning calorimetry (DSC). This analysis showed a gradual decrease in the melting point of the polyamide (PA6) blocks with a decrease in the corresponding melting enthalpy and a complete disappearance of the crystallinity of the polyether (PEO) phase with increasing IL content. This evidences the high compatibility and good mixing of the polymer and the IoNF.
Carolina Hermida-Merino; Fernando Pardo; Gabriel Zarca; João Araújo; Ane Urtiaga; Manuel Piñeiro; Ana Pereiro. Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part I: Membrane Synthesis and Characterization. Nanomaterials 2021, 11, 607 .
AMA StyleCarolina Hermida-Merino, Fernando Pardo, Gabriel Zarca, João Araújo, Ane Urtiaga, Manuel Piñeiro, Ana Pereiro. Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part I: Membrane Synthesis and Characterization. Nanomaterials. 2021; 11 (3):607.
Chicago/Turabian StyleCarolina Hermida-Merino; Fernando Pardo; Gabriel Zarca; João Araújo; Ane Urtiaga; Manuel Piñeiro; Ana Pereiro. 2021. "Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part I: Membrane Synthesis and Characterization." Nanomaterials 11, no. 3: 607.
Membrane technology can play a very influential role in the separation of the constituents of HFC refrigerant gas mixtures, which usually exhibit azeotropic or near-azeotropic behavior, with the goal of promoting the reuse of value-added compounds in the manufacture of new low-global warming potential (GWP) refrigerant mixtures that abide by the current F-gases regulations. In this context, the selective recovery of difluorometane (R32, GWP = 677) from the commercial blend R410A (GWP = 1924), an equimass mixture of R32 and pentafluoroethane (R125, GWP = 3170), is sought. To that end, this work explores for the first time the separation performance of novel mixed-matrix membranes (MMMs) functionalized with ioNanofluids (IoNFs) consisting in a stable suspension of exfoliated graphene nanoplatelets (xGnP) into a fluorinated ionic liquid (FIL), 1-ethyl-3-methylpyridinium perfluorobutanesulfonate ([C2C1py][C4F9SO3]). The results show that the presence of IoNF in the MMMs significantly enhances gas permeation, yet at the expense of slightly decreasing the selectivity of the base polymer. The best results were obtained with the MMM containing 40 wt% IoNF, which led to an improved permeability of the gas of interest (PR32 = 496 barrer) with respect to that of the neat polymer (PR32 = 279 barrer) with a mixed-gas separation factor of 3.0 at the highest feed R410A pressure tested. Overall, the newly fabricated IoNF-MMMs allowed the separation of the near-azeotropic R410A mixture to recover the low-GWP R32 gas, which is of great interest for the circular economy of the refrigeration sector.
Fernando Pardo; Sergio Gutiérrez-Hernández; Carolina Hermida-Merino; João Araújo; Manuel Piñeiro; Ana Pereiro; Gabriel Zarca; Ane Urtiaga. Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part II: Gas Separation Properties toward Fluorinated Greenhouse Gases. Nanomaterials 2021, 11, 582 .
AMA StyleFernando Pardo, Sergio Gutiérrez-Hernández, Carolina Hermida-Merino, João Araújo, Manuel Piñeiro, Ana Pereiro, Gabriel Zarca, Ane Urtiaga. Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part II: Gas Separation Properties toward Fluorinated Greenhouse Gases. Nanomaterials. 2021; 11 (3):582.
Chicago/Turabian StyleFernando Pardo; Sergio Gutiérrez-Hernández; Carolina Hermida-Merino; João Araújo; Manuel Piñeiro; Ana Pereiro; Gabriel Zarca; Ane Urtiaga. 2021. "Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part II: Gas Separation Properties toward Fluorinated Greenhouse Gases." Nanomaterials 11, no. 3: 582.
The effect of the temperature, as a process variable in the fabrication of polymeric membranes by the non-solvent induced phase separation (NIPS) technique, has been scarcely studied. In the present work, we studied the influence of temperature, working at 293, 313 and 333 K, on the experimental binodal curves of four ternary systems composed of PVDF and PES as the polymers, DMAc and NMP as the solvents and water as the non-solvent. The increase of the temperature caused an increase on the solubility gap of the ternary system, as expected. The shift of the binodal curve with the temperature was more evident in PVDF systems than in PES systems indicating the influence of the rubbery or glassy state of the polymer on the thermodynamics of phase separation. As a novelty, the present work has introduced the temperature influence on the Flory–Huggins model to fit the experimental cloud points. Binary interaction parameters were calculated as a function of the temperature: (i) non-solvent/solvent (g12 ) expressions with UNIFAC-Dortmund methodology and (ii) non-solvent/polymer (χ13 ) and solvent/polymer (χ23 ) using Hansen solubility parameters. Additionally, the effect of the ternary interaction term was not negligible in the model. Estimated ternary interaction parameters (χ123 ) presented a linear relation with temperature and negative values, indicating that the solubility of the polymers in mixtures of solvent/non-solvent was higher than expected for single binary interaction. Finally, PES ternary systems exhibited higher influence of the ternary interaction parameter than PVDF systems.
Marta Romay; Nazely Diban; Ane Urtiaga. Thermodynamic Modeling and Validation of the Temperature Influence in Ternary Phase Polymer Systems. Polymers 2021, 13, 678 .
AMA StyleMarta Romay, Nazely Diban, Ane Urtiaga. Thermodynamic Modeling and Validation of the Temperature Influence in Ternary Phase Polymer Systems. Polymers. 2021; 13 (5):678.
Chicago/Turabian StyleMarta Romay; Nazely Diban; Ane Urtiaga. 2021. "Thermodynamic Modeling and Validation of the Temperature Influence in Ternary Phase Polymer Systems." Polymers 13, no. 5: 678.
This work presents the carbon footprint (CF) of two hot-dip galvanisation (HDG) installations located in Spain with differences in the galvanising capacity and in the manufacturing process. The study determines the influence of the direct emissions (scope 1), emissions from electricity production (scope 2), and indirect emissions from upstream and downstream processes (scope 3). The results showed that steel and primary zinc production were the principal contributors to the CF. So, efforts should be focused on reducing the impact of the raw material production included in scope 3. Furthermore, two sensitivity analyses are presented: i) the production of one kg of two types of zinc products, special high-grade and redistilled zinc; ii) the use of two coatings: zinc for galvanisation and paint for pre-printed steel. The environmental impacts in SHG zinc were higher than in redistilled zinc, for all the impact categories due to the great influence of heavy metals emission. The results for zinc and paint protections showed that under the same level of corrosion, a greater thickness of paint is needed to protect steel pieces, compared to zinc coating. This sustainability assessment of the HDG industry recommends the sought of technology alternatives aimed at resource efficiency, such as zinc recovery from spent pickling baths, that could provide the desirable reduction of the environmental impacts associated to primary resource usage and waste treatment.
Andrea Arguillarena; María Margallo; Ane Urtiaga. Carbon footprint of the hot-dip galvanisation process using a life cycle assessment approach. Cleaner Engineering and Technology 2021, 2, 100041 .
AMA StyleAndrea Arguillarena, María Margallo, Ane Urtiaga. Carbon footprint of the hot-dip galvanisation process using a life cycle assessment approach. Cleaner Engineering and Technology. 2021; 2 ():100041.
Chicago/Turabian StyleAndrea Arguillarena; María Margallo; Ane Urtiaga. 2021. "Carbon footprint of the hot-dip galvanisation process using a life cycle assessment approach." Cleaner Engineering and Technology 2, no. : 100041.
The aim of this article is to review the recent progress in the coupling of membrane separation and electrochemical technologies for water treatment. Process integration strategies have been classified in three groups. The first group deals with electrocoagulation and electrooxidation as pretreatment of membrane separation, in most cases aimed at reducing membrane fouling and decay of permeate flux of porous ultrafiltration membranes. The second group is dedicated to electrooxidation as remediation treatment for nanofiltration and reverse osmosis concentrates, which accumulate priority pollutants and emerging contaminants. Finally, the article evaluates the optimal integration of technologies using process systems engineering tools, for producing a single purified water stream, considering not only the minimization of the energy consumption but also of the total costs. Overall, it is concluded that the preconcentration strategy provides a remarkable enhancement of electrooxidation performance to degrade persistent pollutants.
Ane Urtiaga. Electrochemical technologies combined with membrane filtration. Current Opinion in Electrochemistry 2021, 27, 100691 .
AMA StyleAne Urtiaga. Electrochemical technologies combined with membrane filtration. Current Opinion in Electrochemistry. 2021; 27 ():100691.
Chicago/Turabian StyleAne Urtiaga. 2021. "Electrochemical technologies combined with membrane filtration." Current Opinion in Electrochemistry 27, no. : 100691.
Hot-dip galvanisation (HDG) is the method most commonly used to protect steel surfaces from corrosion. However, HDG involves very intensive consumption of energy and resources. This paper aims to evaluate the environmental performance and hotspots in the Spanish HDG sector using cradle-to-gate life cycle assessment (LCA). Two Spanish HDG industrial plants, with different galvanisation capacities and manufacturing processes, were selected for the case study. The LCA revealed that the consumption of energy, fuels and nonrenewable resources were the most relevant environmental burdens at both plants. Steel was the main contributor, as it had the greatest influence on the plants’ environmental profiles. The consumption of primary zinc and natural gas, used to dry and heat the molten zinc bath, also contributed to the impact of the HDG plants. This work proposes a normalisation to compare the Spanish sector against a European reference based on the average of 66 companies in 14 countries. The impacts of the Spanish HDG plants being studied were generally below the EGGA values, although the results are strongly influenced by the type of steel and the degree of material reuse implemented in the steel manufacturing process. The study lays the foundations for improvements in the resource efficiency and productivity of galvanisation plants. We propose alternatives such as the use of secondary zinc or modifications that will extend the lifespan of pickling baths, which would contribute to a more sustainable use of resources in the galvanising industry.
Andrea Arguillarena; María Margallo; Ane Urtiaga; Angel Irabien. Life-cycle assessment as a tool to evaluate the environmental impact of hot-dip galvanisation. Journal of Cleaner Production 2020, 290, 125676 .
AMA StyleAndrea Arguillarena, María Margallo, Ane Urtiaga, Angel Irabien. Life-cycle assessment as a tool to evaluate the environmental impact of hot-dip galvanisation. Journal of Cleaner Production. 2020; 290 ():125676.
Chicago/Turabian StyleAndrea Arguillarena; María Margallo; Ane Urtiaga; Angel Irabien. 2020. "Life-cycle assessment as a tool to evaluate the environmental impact of hot-dip galvanisation." Journal of Cleaner Production 290, no. : 125676.
Zinc recovery from spent pickling acids (SPAs) can play an important role in achieving a circular economy in the galvanizing industry. This work evaluates the scale-up of membrane-based solvent extraction technology aimed at the selective separation of zinc from industrial SPAs as a purification step prior to zinc electrowinning (EW). The experiments were carried out at a pilot scale treating SPAs batches of 57 to 91 L in a non-dispersive solvent extraction (NDSX) configuration that simultaneously performed the extraction and backextraction steps. The pilot plant was equipped with four hollow fiber contactors and 80 m2 of total membrane area, which was approximately 30 times higher than previous bench-scale studies. Tributylphosphate diluted in Shellsol D70 and tap water were used as organic and stripping agents, respectively. Starting with SPAs with high Zn (71.7 ± 4.3 g·L−1) and Fe (82.9 ± 5.0 g·L−1) content, the NDSX process achieved a stripping phase with 55.7 g Zn·L−1 and only 3.2 g Fe·L−1. Other minor metals were not transferred, providing the purified zinc stripping with better quality for the next EW step. A series of five consecutive pilot-scale experiments showed the reproducibility of results, which is an indicator of the stability of the organic extractant and its adequate regeneration in the NDSX operation. Zinc mass transfer fluxes were successfully correlated to zinc concentration in the feed SPA phase, together with data extracted from previous laboratory-scale experiments, allowing us to obtain the design parameter that will enable the leap to the industrial scale. Therefore, the results herein presented demonstrate the NDSX technology in an industrially relevant environment equivalent to TRL 6, which is an essential progress to increase zinc metal resources in the galvanizing sector.
Andrea Arguillarena; María Margallo; Axel Arruti-Fernández; Javier Pinedo; Pedro Gómez; Ane Urtiaga. Scale-Up of Membrane-Based Zinc Recovery from Spent Pickling Acids of Hot-Dip Galvanizing. Membranes 2020, 10, 444 .
AMA StyleAndrea Arguillarena, María Margallo, Axel Arruti-Fernández, Javier Pinedo, Pedro Gómez, Ane Urtiaga. Scale-Up of Membrane-Based Zinc Recovery from Spent Pickling Acids of Hot-Dip Galvanizing. Membranes. 2020; 10 (12):444.
Chicago/Turabian StyleAndrea Arguillarena; María Margallo; Axel Arruti-Fernández; Javier Pinedo; Pedro Gómez; Ane Urtiaga. 2020. "Scale-Up of Membrane-Based Zinc Recovery from Spent Pickling Acids of Hot-Dip Galvanizing." Membranes 10, no. 12: 444.
This work explores the treatment of poly- and perfluoroalkyl acids (PFAAs) in groundwater by coupling membrane separation and electrochemical oxidation (ELOX). A process system engineering approach based on modelling and empirical data was followed. Two nanofiltration (NF90) and reverse osmosis (BW30) membranes were characterized for treating an electrolyte (NaCl and CaSO4) mixture of perfluorocarboxylic acids (PFCAs) containing PFOA, PFHpA, PFHxA, PFPeA and PFBA with initial concentrations of 10 µg L−1 each. Membrane surface charge shielding and concentration polarization negatively influenced NF90 performance, and the BW30 membrane was selected. Electrochemical oxidation with boron doped diamond anodes treated the PFCAs mixture amended with PFOS and 6:2 FTSA, emulating previously pre-concentrated feed and non-preconcentrated feed conditions. Working at different current densities (J) between 20 and 350 A m−2, the removal of PFOA, PFOS and 6:2 FTSA followed first order apparent kinetics, although shorter chain PFCAs initially showed increasing trends because of their simultaneous electrogeneration and degradation. Overall, ΣPFAA electrolysis followed first order kinetics linearly correlated to J in the full range of testing. Unexpectedly, PFAAs electrolysis was faster for the low conductive non-preconcentrated feed, a result that was ascribed to the enhanced direct electron transfer mechanism resulting from the higher cell voltage. For 99.9% PFAAs removal, the total specific cost of treatment was minimized using a cascade of four RO stages and ELOX treatment of the concentrate, to reach ΣPFAA below the Health Advisory Levels recommended by the USEPA in drinking water (<70 ng L−1 sum of PFOA and PFOS).
Alvaro Soriano; Charles Schaefer; Ane Urtiaga. Enhanced treatment of perfluoroalkyl acids in groundwater by membrane separation and electrochemical oxidation. Chemical Engineering Journal Advances 2020, 4, 100042 .
AMA StyleAlvaro Soriano, Charles Schaefer, Ane Urtiaga. Enhanced treatment of perfluoroalkyl acids in groundwater by membrane separation and electrochemical oxidation. Chemical Engineering Journal Advances. 2020; 4 ():100042.
Chicago/Turabian StyleAlvaro Soriano; Charles Schaefer; Ane Urtiaga. 2020. "Enhanced treatment of perfluoroalkyl acids in groundwater by membrane separation and electrochemical oxidation." Chemical Engineering Journal Advances 4, no. : 100042.
The R410A refrigerant blend (GWP = 2088), a near azeotropic and equimass mixture of difluoromethane (R32, GWP = 675) and pentafluoroethane (R125, GWP = 3500), has been included in the HFC phase down road map established worldwide. In this context, the recovery of value-added R32 from R410A using membrane technology would be a breakthrough in the refrigeration and air conditioning sector, given that conventional distillation cannot be applied to this separation. For the first time, this work has taken advantage of the combination of ionic liquids and polymeric membranes for the separation of the constituents of the R410A mixture. Results show a remarkable improvement in terms of R32 permeability and R32/R125 selectivity in the composite membranes containing 40 wt % [C2mim][SCN] (αR32/R125 up to 14.5) and [C2mim][BF4] (αR32/R125 up to 11.0) with respect to the neat polymer membranes (αR32/R125 up to 6.9). Besides, the long-term stability was successfully tested for 25 days under high pressure conditions (7 and 12 bar), which makes these composite membranes excellent candidates for the development of membrane-based R32 separation and recovery processes.
Fernando Pardo; Gabriel Zarca; Ane Urtiaga. Effect of feed pressure and long-term separation performance of Pebax-ionic liquid membranes for the recovery of difluoromethane (R32) from refrigerant mixture R410A. Journal of Membrane Science 2020, 618, 118744 .
AMA StyleFernando Pardo, Gabriel Zarca, Ane Urtiaga. Effect of feed pressure and long-term separation performance of Pebax-ionic liquid membranes for the recovery of difluoromethane (R32) from refrigerant mixture R410A. Journal of Membrane Science. 2020; 618 ():118744.
Chicago/Turabian StyleFernando Pardo; Gabriel Zarca; Ane Urtiaga. 2020. "Effect of feed pressure and long-term separation performance of Pebax-ionic liquid membranes for the recovery of difluoromethane (R32) from refrigerant mixture R410A." Journal of Membrane Science 618, no. : 118744.
There is a huge interest in developing novel hollow fiber (HF) membranes able to modulate neural differentiation to produce in vitro blood–brain barrier (BBB) models for biomedical and pharmaceutical research, due to the low cell-inductive properties of the polymer HFs used in current BBB models. In this work, poly(ε-caprolactone) (PCL) and composite PCL/graphene (PCL/G) HF membranes were prepared by phase inversion and were characterized in terms of mechanical, electrical, morphological, chemical, and mass transport properties. The presence of graphene in PCL/G membranes enlarged the pore size and the water flux and presented significantly higher electrical conductivity than PCL HFs. A biocompatibility assay showed that PCL/G HFs significantly increased C6 cells adhesion and differentiation towards astrocytes, which may be attributed to their higher electrical conductivity in comparison to PCL HFs. On the other hand, PCL/G membranes produced a cytotoxic effect on the endothelial cell line HUVEC presumably related with a higher production of intracellular reactive oxygen species induced by the nanomaterial in this particular cell line. These results prove the potential of PCL HF membranes to grow endothelial cells and PCL/G HF membranes to differentiate astrocytes, the two characteristic cell types that could develop in vitro BBB models in future 3D co-culture systems.
Marián Mantecón-Oria; Nazely Diban; Maria T. Berciano; Maria J. Rivero; Oana David; Miguel Lafarga; Olga Tapia; Ane Urtiaga. Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop in vitro Blood–Brain Barrier Models. Membranes 2020, 10, 161 .
AMA StyleMarián Mantecón-Oria, Nazely Diban, Maria T. Berciano, Maria J. Rivero, Oana David, Miguel Lafarga, Olga Tapia, Ane Urtiaga. Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop in vitro Blood–Brain Barrier Models. Membranes. 2020; 10 (8):161.
Chicago/Turabian StyleMarián Mantecón-Oria; Nazely Diban; Maria T. Berciano; Maria J. Rivero; Oana David; Miguel Lafarga; Olga Tapia; Ane Urtiaga. 2020. "Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop in vitro Blood–Brain Barrier Models." Membranes 10, no. 8: 161.
There is a huge interest in developing novel hollow fiber (HF) membranes able to modulate neural differentiation to produce in vitro blood-brain barrier (BBB) models for biomedical and pharmaceutical research, due to the low cell-inductive properties of the polymer HFs used in current BBB models. In this work, poly(ε-caprolactone) (PCL) and composite PCL/graphene (PCL/G) HF membranes were prepared by phase inversion and were characterized in terms of mechanical, electrical, morphological, chemical, and mass transport properties. The presence of graphene in PCL/G membranes enlarged the pore size and the water flux and presented significantly higher electrical conductivity than PCL HFs. Biocompatibility assay showed that PCL/G HFs significantly increased C6 cells adhesion and differentiation towards astrocytes, may be attributed to their higher electrical conductivity in comparison to PCL HFs. On the other hand, PCL/G membranes produced a cytotoxic effect on the endothelial cell line HUVEC presumably related with a higher production of intracellular reactive oxygen species induced by the nanomaterial in this particular cell line. These results prove the potential of PCL HF membranes to grow endothelial cells and PCL/G HF membranes to differentiate astrocytes, the two characteristic cell types that could develop in vitro BBB models in future 3D co-culture systems.
Marián Mantecón-Oria; Nazely Diban; Maria T. Berciano; Maria J. Rivero; Oana David; Miguel Lafarga; Olga Tapia; Ane Urtiaga. Novel Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop in vitro Blood-brain Barrier Models. 2020, 1 .
AMA StyleMarián Mantecón-Oria, Nazely Diban, Maria T. Berciano, Maria J. Rivero, Oana David, Miguel Lafarga, Olga Tapia, Ane Urtiaga. Novel Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop in vitro Blood-brain Barrier Models. . 2020; ():1.
Chicago/Turabian StyleMarián Mantecón-Oria; Nazely Diban; Maria T. Berciano; Maria J. Rivero; Oana David; Miguel Lafarga; Olga Tapia; Ane Urtiaga. 2020. "Novel Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop in vitro Blood-brain Barrier Models." , no. : 1.
The phase-down of hydrofluorocarbons (HFCs) established by the Kigali Amendment to the Montreal Protocol is leading to the formulation and commercialization of new refrigerant blends containing hydrofluoroolefins (HFOs), such as 2,3,3,3-tetrafluoropropene (R1234yf), and HFCs with moderate global warming potential, namely, difluoromethane (R32) and 1,1,1,2-tetrafluoroethane (R134a). Moreover, the recycling of refrigerants is attracting attention as a means to reduce the amount of new HFCs produced and their release to the environment. To that end, the use of ionic liquids has been proposed as entrainers to separate refrigerants with close-boiling points or azeotropic blends. Thus, the vapor–liquid equilibria and diffusion coefficients of the refrigerant–ionic liquid pairs formed by R32 + [C2mim][BF4], R134a + [C2mim][BF4], R134a+ [C2mim][OTf], R1234yf + [C2mim][OTf], and R1234yf + [C2mim][Tf2N] are studied using an isochoric saturation method at temperatures ranging from 283.15 to 323.15 K and pressures up to 0.9 MPa. In addition, the solubility behavior is successfully modeled using the nonrandom two-liquid activity-coefficient method, and the Henry’s law constants at infinite dilution, solvation energies, and infinite dilution activity coefficients are calculated.
Salvador Asensio-Delgado; Fernando Pardo; Gabriel Zarca; Ane Urtiaga. Vapor–Liquid Equilibria and Diffusion Coefficients of Difluoromethane, 1,1,1,2-Tetrafluoroethane, and 2,3,3,3-Tetrafluoropropene in Low-Viscosity Ionic Liquids. Journal of Chemical & Engineering Data 2020, 65, 1 .
AMA StyleSalvador Asensio-Delgado, Fernando Pardo, Gabriel Zarca, Ane Urtiaga. Vapor–Liquid Equilibria and Diffusion Coefficients of Difluoromethane, 1,1,1,2-Tetrafluoroethane, and 2,3,3,3-Tetrafluoropropene in Low-Viscosity Ionic Liquids. Journal of Chemical & Engineering Data. 2020; 65 (9):1.
Chicago/Turabian StyleSalvador Asensio-Delgado; Fernando Pardo; Gabriel Zarca; Ane Urtiaga. 2020. "Vapor–Liquid Equilibria and Diffusion Coefficients of Difluoromethane, 1,1,1,2-Tetrafluoroethane, and 2,3,3,3-Tetrafluoropropene in Low-Viscosity Ionic Liquids." Journal of Chemical & Engineering Data 65, no. 9: 1.
Photocatalytic membrane reactors (PMR), with immobilized photocatalysts, play an important role in process intensification strategies; this approach offers a simple solution to the typical catalyst recovery problem of photocatalytic processes and, by simultaneous filtration and photocatalysis of the aqueous streams, facilitates clean water production in a single unit. The synthesis of polymer photocatalytic membranes has been widely explored, while studies focused on ceramic photocatalytic membranes represent a minority. However, previous reports have identified that the successful synthesis of polymeric photocatalytic membranes still faces certain challenges that demand further research, e.g., (i) reduced photocatalytic activity, (ii) photocatalyst stability, and (iii) membrane aging, to achieve technological competitiveness with respect to suspended photocatalytic systems. The novelty of this review is to go a step further to preceding literature by first, critically analyzing the factors behind these major limitations and second, establishing useful guidelines. This information will help researchers in the field in the selection of the membrane materials and synthesis methodology for a better performance of polymeric photocatalytic membranes with targeted functionality; special attention is focused on factors affecting membrane aging and photocatalyst stability.
Marta Romay; Nazely Diban; Maria J. Rivero; Ane Urtiaga; Inmaculada Ortiz. Critical Issues and Guidelines to Improve the Performance of Photocatalytic Polymeric Membranes. Catalysts 2020, 10, 570 .
AMA StyleMarta Romay, Nazely Diban, Maria J. Rivero, Ane Urtiaga, Inmaculada Ortiz. Critical Issues and Guidelines to Improve the Performance of Photocatalytic Polymeric Membranes. Catalysts. 2020; 10 (5):570.
Chicago/Turabian StyleMarta Romay; Nazely Diban; Maria J. Rivero; Ane Urtiaga; Inmaculada Ortiz. 2020. "Critical Issues and Guidelines to Improve the Performance of Photocatalytic Polymeric Membranes." Catalysts 10, no. 5: 570.
Hydrofluorocarbons (HFCs) are powerful greenhouse gases whose production and consumption must be phased-down in order to reach the reduction goals established by the Kigali Amendment to the Montreal Protocol. However, the share of recycled refrigerant gases remains very low owing to the extremely inefficient separation of refrigerant mixtures by cryogenic distillation. In this sense, the HFCs difluoromethane (R32, GWP = 675) and 1,1,1,2-tetrafluoroethane (R134a, GWP = 1430), together with the hydrofluoroolefin (HFO) 2,3,3,3-tetrafluoropropene (R1234yf, GWP = 4), are among the most common constituents of HFC/HFO refrigerant mixtures currently employed in the refrigeration and air conditioning sector. Therefore, the feasibility of using membrane technology for the selective separation of these compounds is assessed in this work for the first time. A comprehensive study of their gas permeation through several poly(ether-block-amide) (PEBA) membranes that differ on the content and type of backbone segments is performed. Results show that PEBA membranes exhibit superior permeability of R32 (up to 305 barrer) and R134a (up to 230 barrer) coupled with reasonably high selectivity for the gas pairs R32/R1234yf (up to 10) and R134a/R1234yf (up to 8). Moreover, for the blends R32/R1234yf and R32/R134a, the membrane separation performance is not significantly affected under the mixed-gas conditions tested. Thus, results evidence that consideration should be given to membrane technology for the cost-efficient separation of HFCs/HFOs mixtures in order to boost the recycling of these compounds.
Fernando Pardo; Gabriel Zarca; Ane Urtiaga. Separation of Refrigerant Gas Mixtures Containing R32, R134a, and R1234yf through Poly(ether-block-amide) Membranes. ACS Sustainable Chemistry & Engineering 2020, 8, 2548 -2556.
AMA StyleFernando Pardo, Gabriel Zarca, Ane Urtiaga. Separation of Refrigerant Gas Mixtures Containing R32, R134a, and R1234yf through Poly(ether-block-amide) Membranes. ACS Sustainable Chemistry & Engineering. 2020; 8 (6):2548-2556.
Chicago/Turabian StyleFernando Pardo; Gabriel Zarca; Ane Urtiaga. 2020. "Separation of Refrigerant Gas Mixtures Containing R32, R134a, and R1234yf through Poly(ether-block-amide) Membranes." ACS Sustainable Chemistry & Engineering 8, no. 6: 2548-2556.
Treatment of persistent perfluorocarboxylic acids in water matrixes requires of strong oxidation conditions, as those achieved by boron doped diamond (BDD) electrooxidation (ELOX). However, large scale implementation of ELOX is still hindered by its high energy consumption and economical investment. In this work, we used process systems engineering tools to define the optimal integration of a membrane pre-concentration stage followed by the BDD electrolysis of the concentrate, to drastically reduce the costs of treatment of perfluorohexanoic acid (PFHxA, 100 mg L-1) in industrial waste streams. A multistage membrane cascade system using nanofiltration (NF90 and NF270 membranes) was considered to achieve more sophisticated PFHxA separations. The aim was to minimize the total costs by determining the optimal sizing of the two integrated processes (membrane area per stage and anode area) and the optimal process variables (pre-concentration operating time, electrolysis time, input and output concentrations). The non-linear programming model (NLP) was implemented in the General Algebraic Modelling System (GAMS). The results showed that for a 2-log PFHxA abatement (99% removal), the optimal two membrane stages using the NF90 membrane obtains a 75.8% (6.4 $ m-3) reduction of the total costs, compared to the ELOX alone scenario (26.5 $ m-3). The optimized anode area and the energy savings, that were 85.3% and 88.2% lower than in ELOX alone, were the major contributions to the costs reduction. Similar results were achieved for a 3-log and 4-log PFHxA abatement, pointing out the promising benefits of integrating electrochemical oxidation with membrane pre-concentration through proper optimization for its large-scale application to waters impacted by perfluorocarboxylic acids.
Álvaro Soriano; Daniel Gorri; Lorenz T. Biegler; Ane Urtiaga. An optimization model for the treatment of perfluorocarboxylic acids considering membrane preconcentration and BDD electrooxidation. Water Research 2019, 164, 114954 .
AMA StyleÁlvaro Soriano, Daniel Gorri, Lorenz T. Biegler, Ane Urtiaga. An optimization model for the treatment of perfluorocarboxylic acids considering membrane preconcentration and BDD electrooxidation. Water Research. 2019; 164 ():114954.
Chicago/Turabian StyleÁlvaro Soriano; Daniel Gorri; Lorenz T. Biegler; Ane Urtiaga. 2019. "An optimization model for the treatment of perfluorocarboxylic acids considering membrane preconcentration and BDD electrooxidation." Water Research 164, no. : 114954.
Nowadays persistent perfluorohexanoic acid (PFHxA) ubiquity in the environment is a result of its increasing use as substitute of longer chain perfluorocarboxylic acids. In this study, five nanofiltration (NF270, NF90) and reverse osmosis (XLE, BW30 and SW30XLE) membranes were analyzed in the separation of PFHxA at elevated concentrations (100 mg L-1) relevant in industrial effluents of the production of fluorinated polymers. Experiments assessed the influence of the operation pressure, pH and ionic strength. The NF270 membrane achieved the highest permeate flux, although PFHxA rejection was typically the lowest of all membranes and was negatively affected in the acidic pH range. The NF90, XLE and BW30 membranes achieved PFHxA observed rejections over 99%, but only NF90 and XLE membranes attained suitable water permeability. Finally, both XLE and NF90 membranes were selected to provide the lowest PFHxA concentration in the permeate (0.2 mg L-1 at 10 bar). However, when the ionic strength was further increased the electrostatic repulsion to perfluorohexanoate was weakened and the size exclusion mechanism contribution increased, thus making the membranes more permeable to PFHxA. Our results demonstrate that proper selection of NF/RO membranes is a critical issue for the design of treatments for industrial effluents containing short chain PFCAs.
Álvaro Soriano; Daniel Gorri; Ane Urtiaga. Selection of High Flux Membrane for the Effective Removal of Short-Chain Perfluorocarboxylic Acids. Industrial & Engineering Chemistry Research 2019, 58, 3329 -3338.
AMA StyleÁlvaro Soriano, Daniel Gorri, Ane Urtiaga. Selection of High Flux Membrane for the Effective Removal of Short-Chain Perfluorocarboxylic Acids. Industrial & Engineering Chemistry Research. 2019; 58 (8):3329-3338.
Chicago/Turabian StyleÁlvaro Soriano; Daniel Gorri; Ane Urtiaga. 2019. "Selection of High Flux Membrane for the Effective Removal of Short-Chain Perfluorocarboxylic Acids." Industrial & Engineering Chemistry Research 58, no. 8: 3329-3338.
Enric Brillas; Vicente Montiel; Ignasi Sirés; Ane Urtiaga. Editorial of the special issue on advanced electrochemical technologies for environmental applications. Separation and Purification Technology 2019, 208, 1 -2.
AMA StyleEnric Brillas, Vicente Montiel, Ignasi Sirés, Ane Urtiaga. Editorial of the special issue on advanced electrochemical technologies for environmental applications. Separation and Purification Technology. 2019; 208 ():1-2.
Chicago/Turabian StyleEnric Brillas; Vicente Montiel; Ignasi Sirés; Ane Urtiaga. 2019. "Editorial of the special issue on advanced electrochemical technologies for environmental applications." Separation and Purification Technology 208, no. : 1-2.