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Volume 15
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Membranes, Volume 15, Issue 9 (September 2025) – 25 articles

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14 pages, 3149 KB  
Article
Effects of Surface Morphology on Mesoporous Silicon-Modified Nanofiltration Membranes for High Rejection Performances
by Ying Ding, Aifang Ding, Yuqing Liu and Dong Liu
Membranes 2025, 15(9), 274; https://doi.org/10.3390/membranes15090274 - 10 Sep 2025
Viewed by 29
Abstract
A novel approach was developed in this work in which composite nanofiltration (NF) membranes were directly and efficiently fabricated with control of the membrane pore structure and surface morphology. The fabrication of mesoporous silicon-modified polysulfone blend membranes is achieved via a phase inversion [...] Read more.
A novel approach was developed in this work in which composite nanofiltration (NF) membranes were directly and efficiently fabricated with control of the membrane pore structure and surface morphology. The fabrication of mesoporous silicon-modified polysulfone blend membranes is achieved via a phase inversion method. The structural morphology, surface functional group analysis, elemental analysis, hydrophilicity, chargeability, and nitrogen pollutant (ammonia nitrogen, nitrate nitrogen, total nitrogen) rejection properties of the modified membranes were found to be dependent on the amount of mesoporous silicon incorporated. The combination of the mesoporous silicon framework layer can not only effectively improve the surface structure of the modified membrane with a narrow pore size distribution but also increase the rejection of nitrogen pollutants compared with pure NF membranes. The mesoporous material interlayer can absorb and store the aqueous amino solution to facilitate the subsequent interfacial polymerization as well as induce changes in the pore radius and surface structure. Compared with pure NF composite membranes, the modified blend membranes exhibit increased water permeation flux as high as 29.09 L m−2 h−1 at 0.2 MPa. The results show that the optimum doping amount of mesoporous silicon is in the range of 0.5–1.0%. Characterization studies demonstrated that the addition of mesoporous silicon leads to a decreased membrane pore size. Then the retention of nitrogen pollutants was enhanced because of a combination of hydrophilicity enhancement from the carboxylic and hydroxyl functional groups present in their surfaces leading to electrostatic repulsion between functional groups present in the membranes and the nitrogen pollutant molecules. Full article
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27 pages, 4692 KB  
Article
Hydrogen Solubility in Metal Membranes: Critical Review and Re-Elaboration of Literature Data
by Giuseppe Prenesti, Alessia Anoja, Pierfrancesco Perri, Abdulrahman Yaqoub Alraeesi, Shigeki Hara and Alessio Caravella
Membranes 2025, 15(9), 273; https://doi.org/10.3390/membranes15090273 - 9 Sep 2025
Viewed by 161
Abstract
This study undertakes a thorough examination of hydrogen solubility within various metal-alloy membranes, including those based on palladium (Pd), vanadium (V), niobium (Nb), tantalum (Ta), amorphous alloys and liquid gallium (Ga). The analysis aims to outline the strengths and weaknesses of each material [...] Read more.
This study undertakes a thorough examination of hydrogen solubility within various metal-alloy membranes, including those based on palladium (Pd), vanadium (V), niobium (Nb), tantalum (Ta), amorphous alloys and liquid gallium (Ga). The analysis aims to outline the strengths and weaknesses of each material in terms of solubility and permeability performance. The investigation began by acknowledging the dual definitions of solubility found in literature: the “secant method”, which calculates solubility based on the hydrogen pressure corresponding to a specific sorbed hydrogen loading, and the “tangent method”, which evaluates solubility as the derivative (differential solubility) of the sorption isotherm at various square root values of hydrogen partial pressure. These distinct methodologies yield notably different outcomes. Subsequently, a compilation of experimental data for each membrane type is gathered, and these data are re-analysed to assess both solubility definitions. This enabled a clearer comparison and a deeper analysis of membrane behaviour across different conditions of temperature, pressure, and composition in terms of hydrogen solubility in the metal matrix. The re-evaluation presented in this study serves to identify the most suitable membranes for hydrogen separation or storage, as well as to pinpoint the threshold of embrittlement resulting from hydrogen accumulation within the metal lattice. Lastly, recent research has indicated that particularly promising membranes are those fashioned as “sandwich” structures using liquid gallium. These membranes demonstrate resistance to embrittlement while exhibiting superior performance characteristics. Full article
(This article belongs to the Special Issue Membranes and Membrane Reactors for Gas Purification and Production: Towards More Sustainable Processes)
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21 pages, 7619 KB  
Article
Investigations on the Particle Fouling and Backwash Efficiency During Microplastic Microfiltration–Particle Size Aspects
by Saeedeh Saremi, Leonie Marie Scheer, Gerhard Braun, Marcus Koch, Markus Gallei and Matthias Faust
Membranes 2025, 15(9), 272; https://doi.org/10.3390/membranes15090272 - 9 Sep 2025
Viewed by 172
Abstract
The characteristics of polystyrene (PS) microplastic (MP) microfiltration by a cellulose acetate (CA) membrane were investigated within this study. Particle sizes and pore sizes were selected in a comparable range in order to challenge the dead-end microfiltration. Backwashing experiments round up the investigations. [...] Read more.
The characteristics of polystyrene (PS) microplastic (MP) microfiltration by a cellulose acetate (CA) membrane were investigated within this study. Particle sizes and pore sizes were selected in a comparable range in order to challenge the dead-end microfiltration. Backwashing experiments round up the investigations. Microfiltration characteristics and particle size measurements, as well as a particle fouling analysis by different methods, were applied in the study in order to provide a comprehensive picture of particle deposition and particle fouling structuring. The particle removal efficiency was particle-size-dependent, and especially small particles were further reduced during the proceeding filtration, while the larger particles were already removed within the first minutes of filtration. This observation was attributed to the pore blocking (internal and/or complete) and build-up of the filter cake. The difference in the particle-fouling structure at low and elevated filtration pressure significantly influences the backwashing efficiency. The particle fouling resulting from low-pressure filtration was completely removed due to the backwashing procedure applied, while an increased filtration pressure resulted in a different particle-fouling structure, which negatively influenced the backwashing efficiency. This knowledge of the formation and structure of the MP particle fouling and its removal by backwashing is a prerequisite for further process development. Full article
(This article belongs to the Special Issue Membrane Distillation and Other Membrane-Related Applications for Water Cleaning and Desalination)
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14 pages, 3431 KB  
Article
Synergistic Adsorption–Membrane Distillation for Heavy Metal Extraction and Water Reclamation from Saline Waste Streams
by Jie Xu, Jinxin Liu, Mei-Ling Liu, Guangze Nie and Dong Zou
Membranes 2025, 15(9), 271; https://doi.org/10.3390/membranes15090271 - 8 Sep 2025
Viewed by 321
Abstract
Membrane distillation demonstrates ideal separation performance towards saline water; however, it fails to accomplish the classification and recovery of multiple components from complex saline solutions (i.e., heavy metal ion-laden saline water in process industries). Herein, an adsorption–membrane distillation (MD) coupling process was proposed, [...] Read more.
Membrane distillation demonstrates ideal separation performance towards saline water; however, it fails to accomplish the classification and recovery of multiple components from complex saline solutions (i.e., heavy metal ion-laden saline water in process industries). Herein, an adsorption–membrane distillation (MD) coupling process was proposed, as an example of a Pb(II)/NaCl mixed solution, in which the prepared adsorption membrane was firstly employed to adsorb heavy metal ions in the mixed solution and then the brine was concentrated by the MD process to realize water source recovery and utilization. Firstly, an FeOOH@PVDF adsorptive membrane was fabricated to adsorb Pb(II) ions. It was demonstrated that chemical adsorption was identified as the dominant mechanism, and the composite membrane showed excellent selective adsorption for Pb(II). Following this, the omniphobic membrane was then employed to concentrate the Pb(II)-removed saline solution, maintaining a water flux of 16.12 kg·m−2·h−1 at a concentration factor of 7.7, demonstrating excellent MD concentration performance. Through this coupled process, the saline wastewater containing heavy metal ions was successfully separated into purified water and concentrated brine without heavy metal ions, providing a novel approach for the treatment and recycling of complex saline wastewater. Full article
(This article belongs to the Special Issue Membrane Processes for Water Recovery in Food Processing Industries)
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22 pages, 661 KB  
Review
Current Trends and Biotechnological Innovations in Biofouling Control of RO Membranes in Desalination Systems
by Victoria Cruz-Balladares, Hernán Vera-Villalobos, Carlos Riquelme and Fernando Silva Aciares
Membranes 2025, 15(9), 270; https://doi.org/10.3390/membranes15090270 - 5 Sep 2025
Viewed by 463
Abstract
Background: Water scarcity is a pressing global challenge increasingly addressed by advanced desalination that converts seawater into potable water. Reverse osmosis and ultrafiltration dominate because they deliver permeate with very low impurities. Their principal limitation is membrane biofouling, which causes clogging, raises energy, [...] Read more.
Background: Water scarcity is a pressing global challenge increasingly addressed by advanced desalination that converts seawater into potable water. Reverse osmosis and ultrafiltration dominate because they deliver permeate with very low impurities. Their principal limitation is membrane biofouling, which causes clogging, raises energy, operation, and maintenance costs, and shortens membrane life. Multiple approaches mitigate biofouling—most notably pretreatment trains and engineered surface coatings—but cleaning remains the most decisive remediation pathway. Current practice distinguishes physical, chemical, and biological cleaning. Biological cleaning has gained momentum by exploiting microorganisms that inherently counter biofilms. These strategies include targeted secretion of enzymes and antifouling metabolites, and the application of whole-cell culture supernatants containing the full suite of secreted components. In addition, predatory bacteria can infiltrate established biofilms and eradicate them by lysing prey, thereby accelerating the removal of adherent biomass. Progress across these bio-based approaches signals meaningful advances in fouling control and could substantially improve the efficiency, reliability, and sustainability of desalination facilities. Collectively, they underscore the transformative potential of biological antifouling agents in operational systems. Realizing that potential will require rigorous evaluation of technical performance, long-term stability, compatibility with polyamide membranes, regulatory acceptance, and environmental safety, ultimately alongside scalable production and cost-effective deployment in full-scale plants. Full article
(This article belongs to the Special Issue Applications of Membrane Filtration and Separation)
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23 pages, 3511 KB  
Article
Modelling of Diffusion and Reaction of Carbon Dioxide and Nutrients in Biofilm for Optimal Design and Operation of Emerging Membrane Carbonated Microalgal Biofilm Photobioreactors
by Meilan Liu and Baoqiang Liao
Membranes 2025, 15(9), 269; https://doi.org/10.3390/membranes15090269 - 4 Sep 2025
Viewed by 304
Abstract
The biological performance and carbon dioxide (CO2) flux of the novel and emerging concept of a membrane carbonated microalgal biofilm photobioreactor (MC-MBPBR) for wastewater treatment were investigated using mathematical modelling in conjunction with the finite-difference method. A set of differential equations [...] Read more.
The biological performance and carbon dioxide (CO2) flux of the novel and emerging concept of a membrane carbonated microalgal biofilm photobioreactor (MC-MBPBR) for wastewater treatment were investigated using mathematical modelling in conjunction with the finite-difference method. A set of differential equations was established to model the performance of an MC-MBPBR. The impacts of CO2 partial pressure, wastewater characteristics, and biofilm thickness on the concentration profiles and fluxes of CO2 and nutrients (N and P) to the biofilm of the MC-MBPBR were systematically studied. The modelling results showed profound impacts of these parameters on process efficiency (CO2 transfer and N and P removals) and the existence of an optimal biofilm thickness for maximum CO2, N, and P fluxes into the biofilm. Penetration of CO2 through the biofilm into the bulk water phase might occur under certain conditions. An increase in gaseous CO2 and increased influent N and P concentrations led to higher CO2, N, and P fluxes. The optimal biofilm thickness varied with the change in wastewater characteristics and gaseous CO2 concentration. The modelling results were in relatively good agreement with experimental results from the literature. The proposed mathematical models can be used as a powerful tool to optimize the design and operation of the novel MC-MBPBR for wastewater treatment and microalgae cultivation. Full article
(This article belongs to the Collection Feature Papers in 'Membrane Physics and Theory')
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21 pages, 4474 KB  
Article
A Validated CFD Model for Gas Exchange in Hollow Fiber Membrane Oxygenators: Incorporating the Bohr and Haldane Effects
by Seyyed Hossein Monsefi Estakhrposhti, Jingjing Xu, Margit Gföhler and Michael Harasek
Membranes 2025, 15(9), 268; https://doi.org/10.3390/membranes15090268 - 4 Sep 2025
Viewed by 401
Abstract
Chronic respiratory diseases claim nearly four million lives annually, making them the third leading cause of death worldwide. Extracorporeal membrane oxygenation (ECMO) is often the last line of support for patients with severe lung failure. Still, its performance is limited by an incomplete [...] Read more.
Chronic respiratory diseases claim nearly four million lives annually, making them the third leading cause of death worldwide. Extracorporeal membrane oxygenation (ECMO) is often the last line of support for patients with severe lung failure. Still, its performance is limited by an incomplete understanding of gas exchange in hollow fiber membrane (HFM) oxygenators. Computational fluid dynamics (CFD) has become a robust oxygenator design and optimization tool. However, most models oversimplify O2 and CO2 transport by ignoring their physiological coupling, instead relying on fixed saturation curves or constant-content assumptions. For the first time, this study introduces a novel physiologically informed CFD model that integrates the Bohr and Haldane effects to capture the coupled transport of oxygen and carbon dioxide as functions of local pH, temperature, and gas partial pressures. The model is validated against in vitro experimental data from the literature and assessed against established CFD models. The proposed CFD model achieved excellent agreement with experiments across blood flow rates (100–500 mL/min ), with relative errors below 5% for oxygen and 10–15% for carbon dioxide transfer. These results surpassed the accuracy of all existing CFD approaches, demonstrating that a carefully formulated single-phase model combined with physiologically informed diffusivities can outperform more complex multiphase simulations. This work provides a computationally efficient and physiologically realistic framework for oxygenator optimization, potentially accelerating device development, reducing reliance on costly in vitro testing, and enabling patient-specific simulations. Full article
(This article belongs to the Section Membrane Applications for Gas Separation)
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19 pages, 2878 KB  
Article
Exploration of Methods for In Situ Scale Removal During Magnesium Hydroxide Membrane Crystallization
by Ester Komačková, Lukáš Sedlák, Ivan Červeňanský and Jozef Markoš
Membranes 2025, 15(9), 267; https://doi.org/10.3390/membranes15090267 - 3 Sep 2025
Viewed by 329
Abstract
In coastal countries facing a shortage of drinking water, seawater desalination is essential for the production of potable water. During desalination, a large volume of waste stream, known as brine, is generated. This stream contains high concentrations of salts, particularly those of economic [...] Read more.
In coastal countries facing a shortage of drinking water, seawater desalination is essential for the production of potable water. During desalination, a large volume of waste stream, known as brine, is generated. This stream contains high concentrations of salts, particularly those of economic importance to the European Union, such as magnesium and calcium. By further processing this stream, these materials can be recovered. One method studied for separating magnesium from wastewater is membrane crystallization (MCr). The MCr process developed in this work utilizes ion-exchange membranes that separate the model brine solution from a precipitating agent, which is a solution of sodium hydroxide. During the process, the membrane allows the transport of anions between the two solutions, enabling the reaction between OH− anions and Mg2+ cations, which leads to the formation of a magnesium hydroxide precipitate. The formed precipitate can then be filtered out of the brine solution, which now has decreased salinity due to crystallization facilitated by the ion-exchange membrane. However, precipitation occurs near the membrane surface, resulting in the deposition of magnesium hydroxide onto the outer surface of the membrane. The aim of this study is to investigate methods for effectively removing magnesium hydroxide from the membrane surface, with a primary focus on maximizing the yield of magnesium hydroxide crystals in suspension. Crystal removal was induced by circulation of hydrochloric acid, followed by circulation of demineralized water through the membrane module after crystallization. In this study, a membrane module made of hollow-fiber anion-exchange membranes was employed. The production cost of these membranes is approximately 50% lower per square meter compared to flat-sheet membranes commonly used in electrodialysis, demonstrating strong potential for commercial application. More than 85% magnesium conversion was achieved during the process, yet the majority of the crystals remained attached to the membrane. Circulation of hydrochloric acid and demineralized water after the crystallization process caused detachment of the crystals into suspension, nearly doubling their yield. Full article
(This article belongs to the Special Issue Membrane Distillation and Other Membrane-Related Applications for Water Cleaning and Desalination)
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18 pages, 5631 KB  
Article
Large-Scale Molecular Dynamics of Anion-Exchange Membranes: Molecular Structure of QPAF-4 and Water Transport
by Tetsuro Nagai, Takumi Kawaida and Koji Yoshida
Membranes 2025, 15(9), 266; https://doi.org/10.3390/membranes15090266 - 2 Sep 2025
Viewed by 502
Abstract
Understanding the molecular structure and water transport behavior in anion-exchange membranes (AEMs) is essential for advancing efficient and cost-effective alkaline fuel cells. In this study, large-scale all-atom molecular dynamics simulations of QPAF-4, a promising AEM material, were performed at multiple water uptakes ( [...] Read more.
Understanding the molecular structure and water transport behavior in anion-exchange membranes (AEMs) is essential for advancing efficient and cost-effective alkaline fuel cells. In this study, large-scale all-atom molecular dynamics simulations of QPAF-4, a promising AEM material, were performed at multiple water uptakes (λ = 2, 3, 6, and 13). The simulated systems comprised approximately 1.4 to 2.1 million atoms and spanned approximately 26 nm, thus enabling direct comparison with both wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) experiments. The simulations successfully reproduced experimentally observed structure factors, accurately capturing microphase-separated morphologies at the mesoscale (~8 nm). Decomposition of the SAXS profile into atom pairs suggests that increasing water uptake may facilitate the aggregation of fluorinated alkyl chains. Furthermore, the calculated pair distribution functions showed excellent agreement with WAXS data, suggesting that the atomistic details were accurately reproduced. The water dynamics exhibited strong dependence on hydration level: At low water uptake, mean squared displacement showed persistent subdiffusive behavior even at long timescales (~200 ns), whereas almost normal diffusion was observed when water uptake was high. These results suggest that water mobility may be significantly influenced by nanoconfinement and strong interactions exerted by polymer chains and counterions under dry conditions. These findings provide a basis for the rational design and optimization of high-performance membrane materials. Full article
(This article belongs to the Special Issue Design, Synthesis and Applications of Ion Exchange Membranes)
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15 pages, 5277 KB  
Article
Application of the Transition State Theory in the Study of the Osmotic Permeabilities of AQP7, AQP10 and GlpF
by Ruth Chan and Liao Y. Chen
Membranes 2025, 15(9), 265; https://doi.org/10.3390/membranes15090265 - 2 Sep 2025
Viewed by 411
Abstract
Aquaglyceroporins, including human AQP7, AQP10, and E. coli GlpF, are known to facilitate movements of glycerol, water, and some other uncharged molecules across the cell membrane. In this study we focused on the transport of water molecules in the absence of glycerol for [...] Read more.
Aquaglyceroporins, including human AQP7, AQP10, and E. coli GlpF, are known to facilitate movements of glycerol, water, and some other uncharged molecules across the cell membrane. In this study we focused on the transport of water molecules in the absence of glycerol for AQP7, AQP10 and GlpF using the Transition State Theory for the novel application of permeability and kinetics studies. We conducted around 500 ns of in silico simulations of the aquaglyceroporins embedded in lipid bilayer membranes with intracellular-extracellular asymmetries in leaflet lipid compositions. For the water permeability analysis, we computed the transition rate constant with correction for recrossing events where the water molecules do not completely traverse the protein channel from one side of the membrane to the other side. We also studied the hydrogen bond distributions of the single-file waters and channel residues and linear water densities along the pores of the aquaglyceroporins. Interestingly, we found that there was an inverse correlation between the number of single-file water molecules in the channel and osmotic permeability. Full article
(This article belongs to the Special Issue Composition and Biophysical Properties of Lipid Membranes)
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17 pages, 13988 KB  
Article
Efficient Removal of Pb(II) Ions from Aqueous Solutions Using an HFO-PVDF Composite Adsorption Membrane
by Shuhang Lu, Qianhui Xu, Mei-Ling Liu, Dong Zou and Guangze Nie
Membranes 2025, 15(9), 264; https://doi.org/10.3390/membranes15090264 - 1 Sep 2025
Viewed by 482
Abstract
The efficient purification of Pb(II)-containing wastewater is essential for safeguarding public health and maintaining the aquatic environment. In this study, novel hydrous ferric oxide (HFO) nanoparticle-embedded poly(vinylidene fluoride) (PVDF) composite adsorption membranes were developed through a simple blending method for efficient Pb(II) removal. [...] Read more.
The efficient purification of Pb(II)-containing wastewater is essential for safeguarding public health and maintaining the aquatic environment. In this study, novel hydrous ferric oxide (HFO) nanoparticle-embedded poly(vinylidene fluoride) (PVDF) composite adsorption membranes were developed through a simple blending method for efficient Pb(II) removal. This composite membrane (denoted as HFO-PVDF) combines the excellent selectivity of HFO nanoparticles for Pb(II) with the membrane’s advantage of easy scalability. The optimized HFO-PVDF(1.5) membrane achieved adsorption equilibrium within 20 h and exhibited excellent adsorption capacity. Moreover, adsorption capacity markedly enhanced with increasing temperature, confirming the endothermic nature of the process. The developed HFO-PVDF membranes demonstrate significant potential for real-world wastewater treatment applications, exhibiting exceptional selectivity for Pb(II) in complex ionic matrices and could be effectively regenerated via a relatively straightforward process. Furthermore, filtration and dynamic regeneration tests demonstrated that at an initial Pb(II) concentration of 5 mg/L, the membrane operated continuously for 10–13 h before regeneration, treating up to 200 L/m2 of wastewater before breakthrough, highlighting potential for cost-effective industrial wastewater treatment. This study not only demonstrates the high efficiency of the HFO-PVDF membrane for heavy metal ion removal but also provides a theoretical foundation and technical support for its practical application in water treatment. Full article
(This article belongs to the Special Issue New Trends in Membrane Technologies for Removal of Hazardous Pollutants)
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27 pages, 12231 KB  
Review
Mitochondria-Associated Membrane Dysfunction in Neurodegeneration and Its Effects on Lipid Metabolism, Calcium Signaling, and Cell Fate
by Thi Thuy Truong, Alka Ashok Singh, Nguyen Van Bang, Nguyen Minh Hung Vu, Sungsoo Na, Jaeyeop Choi, Junghwan Oh and Sudip Mondal
Membranes 2025, 15(9), 263; https://doi.org/10.3390/membranes15090263 - 31 Aug 2025
Viewed by 732
Abstract
Mitochondria-associated membranes (MAMs) are essential for cellular homeostasis. MAMs are specialized contact sites located between the endoplasmic reticulum (ER) and mitochondria and control apoptotic pathways, lipid metabolism, autophagy initiation, and calcium signaling, processes critical to the survival and function of neurons. Although this [...] Read more.
Mitochondria-associated membranes (MAMs) are essential for cellular homeostasis. MAMs are specialized contact sites located between the endoplasmic reticulum (ER) and mitochondria and control apoptotic pathways, lipid metabolism, autophagy initiation, and calcium signaling, processes critical to the survival and function of neurons. Although this area of membrane biology remains understudied, increasing evidence links MAM dysfunction to the etiology of major neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS). MAMs consist of a network of protein complexes that mediate molecular exchange and ER–mitochondria tethering. MAMs regulate lipid flow in the brain, including phosphatidylserine and cholesterol; disruption of this process causes membrane instability and impaired synaptic function. Inositol 1,4,5-trisphosphate receptor—voltage-dependent anion channel 1 (IP3R-VDAC1) interactions at MAMs maintain calcium homeostasis, which is required for mitochondria to produce ATP; dysregulation promotes oxidative stress and neuronal death. An effective therapeutic approach for altering neurodegenerative processes is to restore the functional integrity of MAMs. Improving cell-to-cell interactions and modulating MAM-associated proteins may contribute to the restoration of calcium homeostasis and lipid metabolism, both of which are key for neuronal protection. MAMs significantly contribute to the progression of neurodegenerative diseases, making them promising targets for future therapeutic research. This review emphasizes the increasing importance of MAMs in the study of neurodegeneration and their potential as novel targets for membrane-based therapeutic interventions. Full article
(This article belongs to the Section Biological Membranes)
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22 pages, 3342 KB  
Article
Interpenetrating Nanofibrous Composite Membranes for Removal and Reutilization of P (V) Ions from Wastewater
by Guibin You, Hongyang Ma and Benjamin S. Hsiao
Membranes 2025, 15(9), 262; https://doi.org/10.3390/membranes15090262 - 31 Aug 2025
Viewed by 506
Abstract
Elevated phosphorus levels in wastewater created significant environmental concerns, including the degradation of surrounding soil structure, inhibition of plant growth, and potential threats to human health. To address this issue, a self-standing nanofibrous composite membrane based on PA-66/PVA-15%La(OH)3 was fabricated via electrospinning, [...] Read more.
Elevated phosphorus levels in wastewater created significant environmental concerns, including the degradation of surrounding soil structure, inhibition of plant growth, and potential threats to human health. To address this issue, a self-standing nanofibrous composite membrane based on PA-66/PVA-15%La(OH)3 was fabricated via electrospinning, followed by glutaraldehyde (GA) crosslinking and alkali hydrolysis to create an interpenetrating structure, where PA-66 provided the overall mechanical strength of the membrane, while La served as a functional component for the adsorption of phosphate. The chemical composition, surface morphology, thermal stability, and mechanical properties of the resulting membranes were characterized using ATR-FTIR, SEM, TGA, and tensile testing, respectively. Furthermore, the adsorption performance of the membranes was evaluated systematically through static and dynamic adsorption. The Langmuir isotherm model yielded a theoretical maximum adsorption capacity of 21.39 mg/g for phosphate ions. Notably, over 96% of this capacity was retained even in the presence of interfering ions. Moreover, dynamic adsorption experiments demonstrated that the membrane can deal with 1.74 L of phosphate-containing wastewater at a low flow rate of 1.0 mL/min and 1.46 L at a high flow rate of 2.0 mL/min, respectively, while consistently maintaining a phosphate removal efficiency exceeding 90%. A controlled release of phosphate ions from a phosphate-adsorbed membrane was successfully demonstrated using Mougeotia cultivation, implying the potential for phosphorus resource recovery. Full article
(This article belongs to the Special Issue Membrane Separation and Water Treatment: Modeling and Application)
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18 pages, 4814 KB  
Article
Pore-Discriminative Pervaporation of Xylene Isomers Through In Situ Synthesized MIL-100(In) Membranes
by Jinsuo Yu, Chenyang Jiang, Yanjun Wang, Zemin Li, Yawei Gu, Rujing Hou and Yichang Pan
Membranes 2025, 15(9), 261; https://doi.org/10.3390/membranes15090261 - 29 Aug 2025
Viewed by 463
Abstract
Efficient xylene isomers’ separation remains a challenge due to their similar kinetic diameter and boiling points, particularly for the separation of the immediate size of meta-xylene (MX). A metal–organic framework (MOF) membrane offers the opportunity to realize the isomers’ separation due to the [...] Read more.
Efficient xylene isomers’ separation remains a challenge due to their similar kinetic diameter and boiling points, particularly for the separation of the immediate size of meta-xylene (MX). A metal–organic framework (MOF) membrane offers the opportunity to realize the isomers’ separation due to the highly tunable pore size and pore environment. Herein, an In-based hierarchic MOF (MIL-100) with a size of 0.77 nm was screened, aiming at the realization for isomer separation through pore size matching. Meanwhile, the polar microenvironment in the MOF channel built through trimesic acid ligands contributes to the higher affinity to the MX relative to the PX. With the equimolar feed mixture of MX/PX, the optimal membrane demonstrated a total flux of 7.6 kg·m−2·h−1 and an MX/PX separation factor of 2.54 at room temperature through pervaporation. Such performance highly indicates the possibility for efficient liquid xylene separation in future. Full article
(This article belongs to the Special Issue Recent Research in Pervaporation Membranes)
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14 pages, 2445 KB  
Article
Effects of Operational Parameters on Mg2+/Li+ Separation Performance in Electrodialysis System
by Zhijuan Zhao, Jianhua Yang, Dexin Kong, Yunyan Peng and Dong Jin
Membranes 2025, 15(9), 260; https://doi.org/10.3390/membranes15090260 - 29 Aug 2025
Viewed by 367
Abstract
Brine with a high magnesium-to-lithium ratio was separated by electrodialysis equipped with a monovalent cation exchange membrane under differing operational parameters. The ionic concentration variations, separation coefficients, lithium recovery ratio, permselectivity coefficient, and Li+ flux were analyzed to evaluate the effect of [...] Read more.
Brine with a high magnesium-to-lithium ratio was separated by electrodialysis equipped with a monovalent cation exchange membrane under differing operational parameters. The ionic concentration variations, separation coefficients, lithium recovery ratio, permselectivity coefficient, and Li+ flux were analyzed to evaluate the effect of the initial Li+/Mg2+ mass concentration ratio, applied voltage, and initial volume ratio between the dilute and concentrated compartments on the separation performance of magnesium and lithium. The results showed that the increase in initial Li+/Mg2+ concentration ratio significantly increased the separation coefficient, lithium recovery ratio, and Li+ flux, demonstrating an improvement in the separation performance since the Li+ migration was accelerated when less Mg2+ competed with Li+. As the applied voltage increased from 10 V to 15 V, the separation coefficient increased, and the lithium recovery ratio and Li+ flux increased within 60 min; however, as the applied voltage increased to 20 V, the separation coefficient, the lithium recovery ratio, and the Li+ flux did not increase, which indicated that an increase in the applied voltage within the limits would contribute to the separation performance. The increase in the initial volume ratio between the dilute and concentrated compartments decreased the separation coefficient and lithium recovery ratio, indicating that the separation performance had declined. Full article
(This article belongs to the Section Membrane Applications for Water Treatment)
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37 pages, 24408 KB  
Review
Molecular Dynamics Simulations of Liposomes: Structure, Dynamics, and Applications
by Ehsan Khodadadi, Ehsaneh Khodadadi, Parth Chaturvedi and Mahmoud Moradi
Membranes 2025, 15(9), 259; https://doi.org/10.3390/membranes15090259 - 29 Aug 2025
Viewed by 656
Abstract
Liposomes are nanoscale, spherical vesicles composed of phospholipid bilayers, typically ranging from 50 to 200 nm in diameter. Their unique ability to encapsulate both hydrophilic and hydrophobic molecules makes them powerful nanocarriers for drug delivery, diagnostics, and vaccine formulations. Several FDA-approved formulations such [...] Read more.
Liposomes are nanoscale, spherical vesicles composed of phospholipid bilayers, typically ranging from 50 to 200 nm in diameter. Their unique ability to encapsulate both hydrophilic and hydrophobic molecules makes them powerful nanocarriers for drug delivery, diagnostics, and vaccine formulations. Several FDA-approved formulations such as Doxil® (Baxter Healthcare Corporation, Deerfield, IL, USA), AmBisome® (Gilead Sciences, Inc., Foster City, CA, USA), and Onivyde® (Ipsen Biopharmaceuticals, Inc., Basking Ridge, NJ, USA) highlight their clinical significance. This review provides a comprehensive synthesis of how molecular dynamics (MD) simulations, particularly coarse-grained (CG) and atomistic approaches, advance our understanding of liposomal membranes. We explore key membrane biophysical properties, including area per lipid (APL), bilayer thickness, segmental order parameter (SCD), radial distribution functions (RDFs), bending modulus, and flip-flop dynamics, and examine how these are modulated by cholesterol concentration, PEGylation, and curvature. Special attention is given to curvature-induced effects in spherical vesicles, such as lipid asymmetry, interleaflet coupling, and stress gradients across the leaflets. We discuss recent developments in vesicle modeling using tools such as TS2CG, CHARMM-GUI Martini Maker, and Packmol, which have enabled the simulation of large-scale, compositionally heterogeneous systems. The review also highlights simulation-guided strategies for designing stealth liposomes, tuning membrane permeability, and enhancing structural stability under physiological conditions. A range of CG force fields, MARTINI, SPICA, SIRAH, ELBA, SDK, as well as emerging machine learning (ML)-based models, are critically assessed for their strengths and limitations. Despite the efficiency of CG models, challenges remain in capturing long-timescale events and atomistic-level interactions, driving the development of hybrid multiscale frameworks and AI-integrated techniques. By bridging experimental findings with in silico insights, MD simulations continue to play a pivotal role in the rational design of next-generation liposomal therapeutics. Full article
(This article belongs to the Collection Feature Papers in 'Membrane Physics and Theory')
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14 pages, 2868 KB  
Article
Effects of Ca Substitution in Single-Phase Sr1-xCaxTi0.8Fe0.2O3-ẟ Oxygen Transport Membranes and in Dual-Phase Sr1-xCaxTi0.8Fe0.2O3-ẟ-Ce0.8Gd0.2O2 Membranes
by Veronica Nigroni, Yuning Tang, Stefan Baumann, Doris Sebold, Enrico Malgrati and Paolo Fedeli
Membranes 2025, 15(9), 258; https://doi.org/10.3390/membranes15090258 - 29 Aug 2025
Viewed by 420
Abstract
Oxygen transport membranes (OTMs) have gained a lot of attention for their application in different innovative fields, but the development of new materials able to combine high oxygen permeability and good chemical stability is crucial to boost the exploitation of such membrane-based technologies. [...] Read more.
Oxygen transport membranes (OTMs) have gained a lot of attention for their application in different innovative fields, but the development of new materials able to combine high oxygen permeability and good chemical stability is crucial to boost the exploitation of such membrane-based technologies. Perovskite oxides are widely studied as mixed ionic-electronic conductors for the realization of OTMs. In this article, we focus on Sr1-xCaxTi0.8Fe0.2O3-ẟ (SCTF) perovskites and investigate the effect of Ca content on the A-site of the permeation properties, both in single-phase SCTF membranes and in dual-phase membranes obtained by combining SCTF and the ionic conductor Ce0.8Gd0.2O2 (CGO). In single-phase samples, we observed that the substitution of 40% Ca preserves the permeation performances of the non-substituted SrTi0.8Fe0.2O3−ẟ membrane while allowing for a substantial decrease in the sintering temperature, thus facilitating membrane manufacturing. In dual-phase membranes, the increase in the Ca content in the perovskite causes an increase in grain size. The permeation is, at least partially, controlled by the kinetics of the surface exchange reactions. This limitation can be overcome by the addition of an activation layer; however, the permeance of activated CGO-SCTF membranes still remains lower compared to the single-phase parent perovskitic membranes. Full article
(This article belongs to the Section Membrane Applications for Gas Separation)
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17 pages, 2222 KB  
Article
Hydration Fingerprints: A Reproducible Protocol for Accurate Water Uptake in Anion-Exchange Membranes
by Sandra Elisabeth Temmel, Daniel Ölschläger and Ralf Wörner
Membranes 2025, 15(9), 257; https://doi.org/10.3390/membranes15090257 - 28 Aug 2025
Viewed by 614
Abstract
Anion-exchange membranes (AEMs) not only enable the fabrication of catalyst-coated membranes without precious metals but are also projected to achieve a technology-readiness level (TRL) suitable for industrial deployment before the end of this decade. Accurate and reproducible water uptake data are essential for [...] Read more.
Anion-exchange membranes (AEMs) not only enable the fabrication of catalyst-coated membranes without precious metals but are also projected to achieve a technology-readiness level (TRL) suitable for industrial deployment before the end of this decade. Accurate and reproducible water uptake data are essential for guiding AEM design, yet conventional gravimetric methods—relying on manual blotting and loosely defined drying steps—can introduce variabilities exceeding 20%. Here, we present a standardized protocol that transforms water uptake measurements from rough estimates into precise, comparable “hydration fingerprints.” By replacing manual wiping with a calibrated pressure-blotting rig (0.44 N cm−2 for 10 s twice) and verifying both dry and wet states via ATR-FTIR spectroscopy, we dramatically reduce scatter and align our FAAM-PK-75 (Fumatech, Bietigheim, Germany) results with published benchmarks in DI water, aqueous KOH (0.1–9 M), various alcohols, and controlled humidity (39–96% RH). These uptake profiles reveal how OH− screening, thermal densification at 60 °C, and PEEK reinforcement govern equilibrium hydration. A low-cost salt-bath method for vapor-phase sorption further distinguishes reinforced from unreinforced architectures. Extending the workflow to additional commercial and custom membranes confirms its broad applicability. Ultimately, this work establishes a new benchmark for AEM hydration testing and provides a predictive toolkit for correlating water content with conductivity, dimensional stability, and membrane–ink interactions during catalyst-coated membrane fabrication. Full article
(This article belongs to the Special Issue Ion Conducting Membranes and Energy Storage)
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24 pages, 6011 KB  
Review
Recent Progress on the Development of Polyetheretherketone Membranes for Water Remediation
by Jingwen Zhou, Longjun Wang, Hong Liu, Xinhao Li, Dalong Li, Linlin Yan and Xiquan Cheng
Membranes 2025, 15(9), 256; https://doi.org/10.3390/membranes15090256 - 28 Aug 2025
Viewed by 615
Abstract
Industries containing excess acid or alkaline wastewater exacerbate water security. As a semi-crystalline engineering thermoplastic with superior chemical resistance, exceptional mechanical strength, and outstanding thermal stability, polyetheretherketone (PEEK) is a promising candidate for advanced functional membranes in water remediation. Herein, we present a [...] Read more.
Industries containing excess acid or alkaline wastewater exacerbate water security. As a semi-crystalline engineering thermoplastic with superior chemical resistance, exceptional mechanical strength, and outstanding thermal stability, polyetheretherketone (PEEK) is a promising candidate for advanced functional membranes in water remediation. Herein, we present a comprehensive overview of recent advances in PEEK materials, encompassing PEEK membrane fabrication, strategies for membrane hydrophilic modification, and applications in wastewater treatment. Specifically, research efforts have focused on membrane preparation methods such as nonsolvent-induced phase separation (NIPS), thermally induced phase separation (TIPS), and chemical-induced crystallization (CIC), which aim to address the critical challenge of forming solvent-resistant PEEK membranes while maintaining membrane performance. Additionally, various hydrophilic modification strategies (pretreatment, co-blending, and post-treatment) for PEEK membranes are discussed to alleviate membrane fouling problems, with in-depth discussions of diverse applications in wastewater treatment (such as the removal and purification of synthetic dyes, organic solvents, natural organic matter removal, and oil–water mixture). The review concludes with an emphasis on the current challenges and potential of PEEK membrane for wastewater treatment. Full article
(This article belongs to the Special Issue Preparation, Characterization, and Application of Advanced Separation Membrane Materials)
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13 pages, 4452 KB  
Article
Characterization of TMEM16F-Specific Affibodies and Their Cellular Effects
by Eunyoung Kim, Jinho Bang, Sunghyun Kim and Byoung-Cheol Lee
Membranes 2025, 15(9), 255; https://doi.org/10.3390/membranes15090255 - 28 Aug 2025
Viewed by 456
Abstract
The TMEM16 (Anoctamin) family comprises a group of transmembrane proteins involved in diverse physiological processes, including ion transport and phospholipid scrambling. TMEM16F (Anoctamin 6), a phospholipid scramblase and nonselective ion channel, plays a central role in membrane remodeling, blood coagulation, immune responses, and [...] Read more.
The TMEM16 (Anoctamin) family comprises a group of transmembrane proteins involved in diverse physiological processes, including ion transport and phospholipid scrambling. TMEM16F (Anoctamin 6), a phospholipid scramblase and nonselective ion channel, plays a central role in membrane remodeling, blood coagulation, immune responses, and cell death pathways through its ability to externalize phosphatidylserine in response to elevated intracellular calcium levels. Consequently, modulating TMEM16F activity has emerged as a promising strategy for the development of new therapeutic applications. Despite the functional importance of TMEM16F, TMEM16F modulators have received little study. In a previous study, we generated TMEM16F-specific affibodies by biopanning a phage display library for affibodies that bind to brain-specific TMEM16F (hTMEM16F) variant 1. In this study, we selected six other affibodies from among the 38 previously sequenced affibody candidates and characterized them. After purification, we confirmed that two of these affibodies bound to human TMEM16F with high affinity. To provide functional insights into how these affibodies modulate TMEM16F activity, we tested whether they could exert functional effects at the cellular level. Finally, we show that TMEM16F affibody attenuated the neuronal cell death induced by glutamate and microglial phagocytosis, suggesting that these affibodies might have potential therapeutic and diagnostic applications. Full article
(This article belongs to the Special Issue Membrane Proteins: New Insights into Structure, Dynamics and Functions)
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12 pages, 2615 KB  
Article
Poly(Ionic Liquid)-Based Composite Electrolyte Membranes: Additive Effect of Silica Nanofibers on Their Properties
by Yoshiki Kawai, Yirui Lu, Shaoling Zhang, Gen Masuda and Hidetoshi Matsumoto
Membranes 2025, 15(9), 254; https://doi.org/10.3390/membranes15090254 - 27 Aug 2025
Viewed by 622
Abstract
Poly(ionic liquids) (PILs) show great promise as a new class of solid electrolytes for energy applications, including high-temperature polymer electrolyte fuel cells, owing to their combination of the unique electrochemical properties of ionic liquids and macromolecular architecture. In this study, we prepared and [...] Read more.
Poly(ionic liquids) (PILs) show great promise as a new class of solid electrolytes for energy applications, including high-temperature polymer electrolyte fuel cells, owing to their combination of the unique electrochemical properties of ionic liquids and macromolecular architecture. In this study, we prepared and characterized PIL-based composite polymer electrolyte membranes containing silica nanofibers (SiO2NFs). The SiO2NFs were prepared via electrospinning, followed by calcination, and were used as a thermally and mechanically stable, porous substrate. The crosslinked protic PIL was synthesized via in situ radical polymerization of imidazolium hydrogensulfate-based reagents (one monomer and one crosslinker). It was then used as the membrane matrix. The prepared freestanding PIL membranes remained thermally stable at temperatures of up to 180 °C. Furthermore, the PIL/SiO2NF composite electrolyte membranes demonstrated improved mechanical properties due to reinforcement by the NF framework. These composite membranes also exhibited relatively high proton conductivity (approximately 0.1 to 1 mS/cm) in the 100–150 °C temperature range. Full article
(This article belongs to the Special Issue Design, Synthesis and Applications of Ion Exchange Membranes)
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31 pages, 7470 KB  
Article
Evaluation of a Non-Stagnant Water Gap in Hollow-Fiber Membrane Distillation and Multistage Performance Limitations
by Mohamed O. Elbessomy, Kareem W. Farghaly, Osama A. Elsamni, Samy M. Elsherbiny, Ahmed Rezk and Mahmoud B. Elsheniti
Membranes 2025, 15(9), 253; https://doi.org/10.3390/membranes15090253 - 27 Aug 2025
Viewed by 517
Abstract
Hollow-fiber water gap membrane distillation (HF-WGMD) modules are gaining attention for desalination applications due to their compact design and high surface-area-to-volume ratio. This study presents a comprehensive CFD model to analyze and compare the performance of two HF-WGMD module configurations: one with a [...] Read more.
Hollow-fiber water gap membrane distillation (HF-WGMD) modules are gaining attention for desalination applications due to their compact design and high surface-area-to-volume ratio. This study presents a comprehensive CFD model to analyze and compare the performance of two HF-WGMD module configurations: one with a conventional stagnant water gap (WG) and the other incorporating water gap flow circulation. The model was validated against experimental data, showing excellent agreement, and was then used to simulate flow patterns in the feed, water gap, and coolant domains. Results indicate that, at a feed temperature of 80 °C with a stagnant WG, employing a turbulent flow scheme in the feed side increases water flux by 20.7% compared to laminar flow, while increasing coolant flow rate has a minor impact. In contrast, introducing circulation within the water gap significantly enhances performance, boosting water flux by 30.1%. This effect becomes more pronounced with rising feed temperature: increasing from 50 °C to 80 °C leads to a flux increase from 6.74 to 27.89 kg/(m2h) under circulating WG conditions. However, in multistage systems, the energy efficiency trade-off becomes evident. Water gap circulation is more energy-efficient than the stagnant configuration only for systems with fewer than 20 stages. At higher stage counts, the stagnant WG setup proves more efficient. For example, at 80 °C and 50 stages, the stagnant configuration consumes just 793 kWh/m3, representing a 47.3% reduction in energy consumption compared to the circulating WG setup. These findings highlight the performance benefits and energy trade-offs of water gap circulation in HF-WGMD systems, providing valuable guidance for optimization and scalability of high-efficiency desalination module designs. Full article
(This article belongs to the Section Membrane Applications for Water Treatment)
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14 pages, 4424 KB  
Article
Fabrication and Evaluation of pH-Sensitive Chitosan-Coated Membranes for Enhanced Oil Emulsion Filtration
by Eunseo Choi, Siyoung Byun and Sanghyun Jeong
Membranes 2025, 15(9), 252; https://doi.org/10.3390/membranes15090252 - 27 Aug 2025
Viewed by 515
Abstract
Oil-contaminated wastewater presents a significant environmental challenge, necessitating the development of efficient and adaptable treatment technologies. In this study, a pH-responsive chitosan-coated polyethersulfone (Ch/PES) membrane was developed and systematically evaluated for oil/water separation performance under varying pH conditions. PES was chosen as the [...] Read more.
Oil-contaminated wastewater presents a significant environmental challenge, necessitating the development of efficient and adaptable treatment technologies. In this study, a pH-responsive chitosan-coated polyethersulfone (Ch/PES) membrane was developed and systematically evaluated for oil/water separation performance under varying pH conditions. PES was chosen as the base membrane material due to its excellent chemical resistance and mechanical durability, while Ch, a biodegradable and environmentally friendly biopolymer with pH-sensitive properties, was applied as a functional surface coating. The Ch/PES membrane was successfully fabricated and characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy, confirming successful surface modification and structural integrity. Additional analyses—including underwater oil contact angle measurements, porosity assessment, and cross-sectional morphological evaluation—demonstrated the membrane’s dynamic pH-responsive wettability and pore size modulation. Oil emulsion separation experiments, conducted using sodium dodecyl sulfate-stabilized emulsions, revealed that the Ch/PES membrane achieved oil removal efficiencies exceeding 97% under acidic conditions. This enhancement was attributed to increased hydrophilicity and reduced effective pore size resulting from chitosan swelling. In contrast, under alkaline conditions, the membrane exhibited greater oleophilicity and maintained a relatively stable pore structure, leading to a reduced separation efficiency of 83.8%. Compared to the unmodified PES membrane, the Ch/PES membrane demonstrated significantly improved responsiveness and adaptability to changes in pH, underscoring its potential as a versatile platform for treating oil-contaminated wastewater of varying chemistries. These findings suggest that the Ch/PES membrane offers a promising, sustainable, and efficient solution for advanced oil/water separation applications. Full article
(This article belongs to the Section Membrane Fabrication and Characterization)
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19 pages, 2654 KB  
Article
Fabrication and Evaluation of Ceramic-Based Hollow Fiber Membrane Modules for Hemodialysis Applications
by Jae Yeon Hwang, Sung Woo Han, Seung Hee Huh, So Hee Park, Sang Min Park and Jung Hoon Park
Membranes 2025, 15(9), 251; https://doi.org/10.3390/membranes15090251 - 26 Aug 2025
Viewed by 472
Abstract
The application of ceramic membranes in hemodialysis modules remains underexplored, as prior investigations have primarily concentrated on flat-sheet samples or small-scale assessments. This study advances the field by fabricating Al2O3 hollow fiber membranes, integrating them into a lab-scale module, and [...] Read more.
The application of ceramic membranes in hemodialysis modules remains underexplored, as prior investigations have primarily concentrated on flat-sheet samples or small-scale assessments. This study advances the field by fabricating Al2O3 hollow fiber membranes, integrating them into a lab-scale module, and systematically evaluating the influence of sintering temperature on their structural characteristics, hemocompatibility, and dialysis performance. Al2O3 hollow fiber membranes were prepared using a phase inversion method and then sintered at three different temperatures. All membranes exhibited superior protein adsorption behavior compared to conventional polymer-based membranes, which indicates higher biocompatibility. Furthermore, the amount of adsorbed protein decreased with increasing sintering temperature. This suggests that the amount of protein adsorption can be controlled by adjusting the heat treatment conditions. The lab-scale hemodialyzer integrated with a membrane sintered at 1200 °C achieved the fastest urea removal rate of approximately 90% in 2 h and reached a Kt/V value of 1.1 after 60 min, which is comparable to the performance of commercial polymer-based hemodialyzers. Full article
(This article belongs to the Special Issue Preparation, Characterization, and Application of Advanced Separation Membrane Materials)
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23 pages, 2786 KB  
Article
Membrane-Assisted Electrochemical Removal of Mg2+ and Ca2+ from Lithium Brines: Effects of Temperature and Current Density Through a Zeta Potential Approach
by Alonso González, Geovanna Choque, Mario Grágeda and Svetlana Ushak
Membranes 2025, 15(9), 250; https://doi.org/10.3390/membranes15090250 - 25 Aug 2025
Viewed by 722
Abstract
Understanding surface charge behavior is essential for improving ion separation during lithium brine treatment. This paper investigates the performance of a three-compartment electrodialysis system designed for the selective removal of divalent cations (Mg2+ and Ca2+). The relationship between zeta potential [...] Read more.
Understanding surface charge behavior is essential for improving ion separation during lithium brine treatment. This paper investigates the performance of a three-compartment electrodialysis system designed for the selective removal of divalent cations (Mg2+ and Ca2+). The relationship between zeta potential and the recovery of Li+, Na+, and K+ is analyzed. Zeta potential measurements at various pH values showed that Mg(OH)2 particles maintained a positive charge. The system facilitated the precipitation of Mg(OH)2 and Ca(OH)2 via electrochemically generated OH− ions. The specific electrical energy consumption was evaluated for each operating condition. The results showed that the zeta potential of the precipitates was affected by both the current density and temperature. This influenced lithium losses due to brine entrapment within the precipitated solids. At 600 A/m2 and 50 °C, more than 99% of Mg2+ and Ca2+ were removed, and more than 90% of lithium was recovered, with a specific electric energy consumption of 2.58 kWh per kilogram of Li recovered. The system also generates HCl as a valuable by-product, which improves the sustainability of the process. This study provides a new framework for improving the energy efficiency of lithium purification from brines and lithium recovery. Full article
(This article belongs to the Special Issue Electrochemical Membranes for Micropollutant Removal)
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