Pressure retarded osmosis (PRO) is a green technology for harvesting Gibbs free energy from mixing solutions with different salinity gradients. Although lab-synthesized membranes showed high PRO performance, there is no available flat-sheet industrial-scale PRO membrane production. Most of the previous studies have focused on enhancing the power density of the PRO process by using a hypersaline draw solution that potentially causes severe internal and external concentration polarization (ICP and ECP) and limits achievable performance. Using the most accessible resources – seawater and commercially available membranes – can be a more practical way to develop a large-scale PRO plant. However, only a limited number of studies have evaluated the PRO performance under such realistic conditions. In our study, we compared the PRO performance of some commercial FO and RO membranes. We observed that, at an elevated feed velocity and temperature, the RO membrane had a significant enhanced water flux and power density. Due to turbulent flow at a high feed velocity and low viscosity at a high feed temperature (30 °C), the RO membrane was able to perform at low concertration polarization, hence maximum power density (5.3 W/m 2 ) could be obtained at half the osmotic pressure (15 bar). • Seawater and commercial RO and FO membranes were used for PRO • An elevated feed velocity and temperature resulted in high power density • Commercial RO membranes outperformed FO membranes in the PRO tests • 5.3 W/m 2 was achieved at 15 bar using a commercial RO membrane

This data article presents a structured dataset from the transfer of a proven PVDF hollow-fiber formulation to macro-porous PVDF flat sheet membranes via a vapor-assisted non-solvent induced phase separation (VNIPS) process designed for membrane distillation (MD). The study uses N-methyl-2-pyrrolidone (NMP) as a solvent and water as a non-solvent. A face-centered composite design (33 membranes) was implemented to efficiently sample six controllable factors at three levels each: polymer content (16-20 wt %), solvation temperature (30-60 °C), wet casting thickness (300-500 µm), vapor-induced phase separation (VIPS) conditioning time (60-360 s at fixed 90 % RH), coagulation bath temperature (25-50 °C), and bath solvent content (0-50 wt %). For each treatment, one 100 × 200 mm membrane was cast on a lab-scale line (dope dispense + doctor blade → VIPS tunnel with controlled humidity/airflow → NIPS bath), then transferred to polyester fleece and dried at 40 °C for 24 h. Materials comprised PVDF (Mw ≈ 534 kDa), N-methyl-2-pyrrolidone (NMP, 99.5 %), and RO water. The dataset includes: (i) full experimental design with factor settings for all 33 runs; (ii) raw and processed characterization results-mean thickness, water contact angle, liquid entry pressure, porosity, and permeate flux-for each membrane; (iii) linear regression models linking process factors to responses, constructed by retaining only coefficients with p < 0.05 and summarized by goodness-of-fit (R²: 67-94 % across endpoints); and (iv) scanning electron microscopy (SEM) micrographs of the top surface, bottom surface, and cross-section of each membrane, capturing morphological changes across the design space. The accompanying tables also report the materials list and an optimization scenario (target-value approach) that returns factor settings maximizing wetting resistance and flux within the explored design bounds. These data enable reuse for multiple purposes: reproducing and extending VNIPS DoE studies; meta-analysis of factor-response relationships in phase inversion casting; benchmarking inverse design, response-surface, or machine-learning models; informing scale-up constraints and uncertainty analyses; and guiding MD membrane pre-screening under alternative objective functions or constraints.

This work focuses on the systematic optimization of PVDF/PTFE blended dope formulations for the fabrication of flat-sheet membranes using the NIPS technique. The influence of PVDF (15–17 wt%), PTFE (0–7 wt%), and PEG (0–2 wt%) was examined using a Box–Behnken experimental design, and model accuracy was assessed by comparing RSM-predicted values with experimental porosity and contact angle measurements through an error function. Based on the optimization outcomes, four dope formulations were selected for membrane casting and subjected to comprehensive physicochemical characterization. Surface and cross-sectional morphologies were analyzed using FE-SEM, while FTIR and XRD confirmed chemical signatures and crystalline structure. Hydrophilicity was quantified through static contact angle measurements. Pure water permeation and BSA filtration were conducted under transmembrane pressures of 1–4 bar for four operational cycles. Among the optimized membranes, M2 demonstrated superior protein retention (∼30 mg/mL at 3 bar), whereas M4 exhibited performance variability attributable to concentration polarization, underscoring the critical role of compositional tuning in biomolecule separation applications.

Quorum quenching (QQ) is a promising biological approach that has the potential to control membrane biofouling. However, the implementation of the QQ membrane bioreactor still requires a more systematic and comprehensive understanding, including the selection of membrane materials, the determination of the optimal QQ bacterial dosage, and the use of appropriate media for the immobilization of QQ bacteria, all of which are important to ensure long-term operation. The present study investigated the impact of QQ bacteria on biofilm formation across different polymeric membranes. These include flat sheet membranes, Polytetrafluoroethylene (PTFE), Polysulfones (PSs), and hollow-fibre polyvinylidene difluoride (PVDF) membranes. It also evaluated biofilm development, membrane filtration performance, extracellular polymeric substance (EPS) production, and sludge floc properties, which were characterized using fluorescence microscopy. The results revealed that QQ intervention markedly suppressed quorum sensing (QS), leading to a pronounced, dose-dependent reduction in biofilm thickness, membrane fouling, EPS production and sludge floc size. Biofilm thickness was reduced by 63.5% on PTFE and 55.4% on PS membranes, accompanied by a notable reduction in EPS protein and polysaccharides, thereby weakening the biofilm formation and enhancing membrane filterability. Therefore, the permeability performance of the PVDF membrane improved by 338.2%. Furthermore, sludge settleability was enhanced, and floc size was reduced, resulting in the mitigation of biofilm formation without impacting pollutant degradation. These findings elucidate the material-dependent and dose-responsive mechanism by which QQ regulates EPS synthesis and biofilm formation in MBR.

Maintaining functional integrity during ultrafiltration-based concentration of milk protein concentrate (MPC) is as critical as achieving high solids in the retentate. Previous studies demonstrated that ultrafiltration in plate-and-frame filtration (PF) modules can effectively concentrate MPC derived from spiral-wound ultrafiltration (UF) of skim milk, particularly at elevated temperatures. This study compares the functionality of powdered MPCs produced via UF and PF systems. Skim milk retentate from UF containing 20% total solids and approximately 80% protein on dry basis (feed) was processed using PF modules equipped with flat-sheet membranes across 3 replicates. Three PF treatments were applied: PF22 at 22°C, PF50MS at 50°C targeting medium solids, and PF50HS at 50°C targeting high solids. Filtration for PF22 and PF50HS continued until transmembrane pressure reached 900 kPa, while PF50MS was terminated upon achieving ∼30% solids. Retentates from UF, PF22, PF50MS, and PF50HS were spray-dried and evaluated for rheological and functional properties. All reconstituted MPC powders exhibited pseudoplastic behavior, best described by the Herschel-Bulkley model. Functional assessments revealed that rennet coagulation time increased with PF temperature, necessitating the addition of ∼0.25% CaCl2 to achieve timely coagulation. Elevated PF temperatures negatively affected other functional attributes, including increased wetting time, reduced solubility, and shortened heat coagulation time-most notably in PF50HS compared with PF22 and UF. Conversely, high-temperature PF enhanced emulsion stability without altering emulsion formation. All PF treatments improved foaming capacity while maintaining comparable foaming stability to UF. A slight reduction in whey protein content and increased protein denaturation was observed at higher PF temperatures. These findings underscore the importance of temperature optimization in preserving the functional properties of MPC during PF concentration.

Viruses pose risks to human health and might be of special concern in filter backwash water recycling, yet there are no published studies on the subject. The fate of the bacteriophages MS2 and ΦX174 during biological filtration was studied at pilot scale. Furthermore, the efficacy of phage removal in ultrafiltration of filter backwash water was investigated for four different ultrafiltration (UF) membranes at laboratory scale. During biotic iron and manganese removal from groundwater (2.1–2.7 mg/L Fe dis and 0.4–0.7 mg/L Mn dis ), both phages were removed by less than one log 10 unit at filtration velocities of 7.5 m/h and 15.0 m/h. Treatment of filter backwash water (3.9–7.9 mg/L Fe total ) with a polyether sulfone flat-sheet UF membrane (pore size 26 nm) yielded a removal of MS2 phages of 4 log 10 units and of ΦX174 of approx. 3 log 10 units. Using different UF membranes revealed no clear relation between pore size and phage retention, with phage retention reaching up to 7 log 10 units with pore sizes larger than phage diameters. • First study on phage removal from filter backwash water. • Comparison of one ceramic and two polymeric UF membranes in dead-end. • Comparison of pore size, membrane material, and water matrix on phage removal. • Phage removal from filter backwash was high for all studied membranes. • Interactions between phages and membrane surfaces influence phage removal.

Performance study of flat-sheet water membrane evaporators for vacuum evaporative cooling

CXL-DETR: a lightweight Transformer framework for ceramic flat sheet membrane X-CT data defect detection

Direct nanofiltration treatment using flat-sheet membrane modules reconfigured from spiral-wound elements

It is promising to in situ retrofit the activated sludge process with a membrane bioreactor (MBR) to increase treatment capacity and improve effluent quality in a textile dyeing wastewater treatment plant (WWTP). Membrane selection among commercial products for real engineering applications is critical for this specific wastewater, and little information is available in the literature. This study systematically evaluated the application potential of two flat-sheet microfiltration membranes made of polyvinylidene fluoride (PVDF) and polyether sulfone (PES) in pilot-scale MBRs for in situ retrofitting textile dyeing WWTP. During the four stages with different loads, both membranes achieved nearly the same effluent quality and rejection performance. Both membranes showed little trans-membrane pressure (TMP) increase at an average flux of 15 L/(m2·h) with sub-critical flux characteristics, and showed a sharp TMP increase with super-critical flux characteristics observed at an average flux of 18/22.5 L/(m2·h). After 74 d of filtration, at an average sludge concentration of 12,000 g/L, the PVDF membrane showed less variation in pore size distribution and bubble point pressure, while the PES membrane showed less change in permeability and contact angle. Both membranes met general MBR requirements due to the minimizing pristine effects of both membranes by this specific wastewater matrix. The PVDF membrane showed better anti-fouling capability, especially during high-/over-load stages, and thus was suggested for MBR retrofit, with a sustainable membrane flux below 18 L/(m2·h).

Sour cherry juice is a popular fruit juice known for its high phenolic content and associated health benefits. However, effective clarification and processing remain challenging due to the complexity of conventional multi-step methods. Membrane-based processing offers advantages but is hindered by membrane fouling, which involves complex mechanisms. This study investigates the effect of enzymatic pretreatment on membrane fouling during sour cherry juice clarification at different permeate fluxes. Juice with and without pectinase pretreatment was filtered through a flat-sheet polyethersulfone microfiltration membrane at fluxes ranging from 8 to 52 L m−2 h−1. Microfiltration was performed using a submerged 0.4 μm PES flat-sheet membrane at a transmembrane pressure of 0.03–0.35 bar. Total hydraulic resistance was analyzed using Darcy’s law and divided into cake (R C), pore blocking (R P), and fluid (R F) resistances. A multi-scale model incorporating pore blocking and cake parameters was optimized with experimental data to characterize fouling. R C dominated at high fluxes regardless of pretreatment, while enzymatic pretreatment significantly reduced R F and increased R P. Flux was the primary driver of all resistances (p < 0.05), with pretreatment affecting only R P and R F. The model effectively captured the contrasting trends of cake formation and pore blockage, with R 2 values of 0.99 (without enzyme) and 0.82 (with enzyme). Optimized parameters support more efficient, sustainable clarification of sour cherry juice.

ABSTRACT The present work investigates two methods for preparing defect‐free, symmetric membranes of the thermochemically robust polymer, poly(2,5‐benzimidazole) (commonly known as ABPBI) for forward osmosis (FO), a growing technology for niche separations. The obtained polymer and membranes were analyzed for physical properties of significance. The FO analysis was performed using three salt solutions, viz., sodium chloride (NaCl), magnesium chloride (MgCl 2 ), and sodium sulfate (Na 2 SO 4 ). The effects of casting methodology (solvents present in the dope), membrane heat treatment, draw solution concentration, long‐duration analysis, and FO‐assisted enrichment of organic acids were evaluated. Some of the membranes exhibited extremely low reverse salt flux (RSF), which conveys the novelty of these membranes. Some of these membranes were analyzed using a high draw solution (DS) concentration (4 mol L −1 ) to enhance water flux and further employed to enrich organic acids. The aqueous acetic and methacrylic acid concentrations were enriched from 4.89 and 2.93 mol L −1 to 11.88 and 10.01 mol L −1 , respectively. These results demonstrate an unmet need of concentrating methacrylic acid (a temperature‐sensitive compound possessing a double bond). The present work demonstrates the potentials of ABPBI‐based symmetric, thin membranes for FO and their industrial applicability for the first time.

Polysulfone (PSF) hollow fiber membranes incorporating a asymmetric microstructures suitable for ultrafiltration, were fabricated using dry–wet phase inversion method. The optimized dope solution contained PSF (25 wt%), polyethylene glycol (PEG-400; 22 wt%), and polyvinylpyrrolidone (PVP-K90, Mw ≈ 1,300 kDa; 0.3 wt%) dissolved in N,N-dimethylacetamide (52.7 wt%). The extruded nascent fibers coagulated in deionized water to form membranes with a dense selective skin layer supported by a porous substructure. Fourier Transform Infrared Spectroscopy (FT-IR) analysis confirmed the presence of the characteristic sulfone functional groups, indicating the chemical stability of the PSF matrix. Scanning Electron Microscopy (SEM) revealed a well-defined lumen structure with a diameter of 1.09 ± 0.05 mm and a wall thickness of 0.20 ± 0.01 mm. The membrane cross-section showed distinct finger-like macrovoids. These extended throughout the structure, indicating effective phase inversion and stable morphology. The membrane exhibited a porosity of 48.8 ± 2.1% and a pure water permeance of 70 ± 5 L m⁻² h⁻¹ bar⁻¹. The evaluation of ultrafiltration performance was done using bovine serum albumin (BSA, Mw ≈ 66 kDa). The membrane showed a rejection rate of 95 ± 1% at 2 bar pressure. This confirms its effective size-exclusion capability. Compared with reported PSF flat-sheet membranes, the present hollow fiber configuration demonstrated a more favourable balance between permeability and selectivity, attributed to PEG-400-driven rapid demixing and PVP induced pore interconnectivity. These findings showcase the potential of this minimalist dual additive formulation for scalable, high-performance PSF hollow fiber membranes in aqueous separation applications.

Finite element analysis of the mechanical performance of TiO2/PVDF composite membranes versus traditional PVDF flat sheet membranes for gas separation applications

Ammonia recovery from synthetic thermophilic anaerobic digestate was achieved through Direct Contact Membrane Distillation (DCMD) using hydrophobic flat-sheet membranes under different operating conditions. The influence of temperature gradients (0 °C, 20 °C, 35 °C, and 45 °C) and pH levels of the thermophilic anaerobic sludge (7.8, 8.2, 9, and 12) was investigated. The process utilized a DCMD setup with hydrophobic PTFE membranes of 0.22 µm nominal pore radius, and receiving solutions consisting of deionized water and 1 M H2SO4. The best results were obtained with isothermal distillation and high pH levels in the feed. Isothermal distillation at 65 °C (a temperature gradient of 0 °C), with 1 M H2SO4 as the receiving solution, and at pH levels 8.2 and 12, yielded NH3 recoveries of 36.4 ± 1.6% and 100.0 ± 0.1%, respectively. Under the same conditions, the molar fluxes were 0.63 ± 0.01 mol TAN m−2 h−1 and 1.84 ± 0.01 mol TAN m−2 h−1, respectively. It is worth noting that some very low depositions on the membrane were detected, leading to changes in the surface morphology, as confirmed by atomic force microscopy.

Abstract Olefins including ethylene (C 2 H 4 ) and propylene (C 3 H 6 ) are pivotal raw materials in the chemical industry, and methanol‐to‐olefin (MTO) process provides a sustainable strategy to replace conventional petroleum‐based methods for the olefin production. The purification of olefin mixture is an essential part in the MTO process where membrane technology has emerged as a high‐efficiency and energy‐saving approach. However, it remains a critical challenge to achieve precise sieving of C 2 H 4 and C 3 H 6 due to their similar molecular size. Herein, we report an interfacial coordination induced sub‐angstrom channel regulation strategy and achieve unprecedented cut‐off shift of ZIF‐8 from C 3 H 6 /C 3 H 8 to C 2 H 4 /C 3 H 6 . Ionic covalent organic framework with crystalline structure and high‐density sulfonate groups was used as growth template for ZIF‐8 membrane. The coordination between sulfonate groups and Zn 2+ ions induced lattice contraction of ZIF‐8 framework, which is confirmed by XRD patterns and molecular dynamic simulations. The resulting membranes demonstrate a distinct cut‐off between C 2 H 4 and C 3 H 6 , achieving a C 2 H 4 permeance of 405 GPU and an exceptional C 2 H 4 /C 3 H 6 selectivity of 45, surpassing the separation performance of all reported membranes. Finally, we demonstrate the excellent scalability of this strategy by fabricating large area flat sheet membrane (&gt;500 cm 2 ) on polymer substrates.

Olefins including ethylene (C2H4) and propylene (C3H6) are pivotal raw materials in the chemical industry, and methanol-to-olefin (MTO) process provides a sustainable strategy to replace conventional petroleum-based methods for the olefin production. The purification of olefin mixture is an essential part in the MTO process where membrane technology has emerged as a high-efficiency and energy-saving approach. However, it remains a critical challenge to achieve precise sieving of C2H4 and C3H6 due to their similar molecular size. Herein, we report an interfacial coordination induced sub-angstrom channel regulation strategy and achieve unprecedented cut-off shift of ZIF-8 from C3H6/C3H8 to C2H4/C3H6. Ionic covalent organic framework with crystalline structure and high-density sulfonate groups was used as growth template for ZIF-8 membrane. The coordination between sulfonate groups and Zn2+ ions induced lattice contraction of ZIF-8 framework, which is confirmed by XRD patterns and molecular dynamic simulations. The resulting membranes demonstrate a distinct cut-off between C2H4 and C3H6, achieving a C2H4 permeance of 405 GPU and an exceptional C2H4/C3H6 selectivity of 45, surpassing the separation performance of all reported membranes. Finally, we demonstrate the excellent scalability of this strategy by fabricating large area flat sheet membrane (>500cm2) on polymer substrates.

Extracorporeal blood circuits with 3D-printed flat sheet membrane modules

Sustainable biopharmaceutical manufacturing requires cost-effective, scalable, and efficient processes. To achieve this goal, access to scalable screening platforms providing rapid and high-quality data with low material requirements is required. While cell culture/fermentation and purification technologies meeting these criteria have been developed and deployed, microscale filtration solutions, which enable screening a wide range of filtration products and conditions, are largely absent. Microfluidic filtration devices are uniquely positioned to fill this technology gap since they can provide the necessary throughput for screening applications with low feed volumes and in-line monitoring. However, a lack of standardized approaches limits their industrial adoption. We present a microfluidic tangential flow filtration (μTFF) device that can accommodate any flat sheet-membrane. Membrane exchange is easy, enabling application in single-use or re-use formats. We successfully tested a wide flux range (30 to 1055 litres per meter per hour, LMH), observed recovery yields exceeding 80% in single-pass mode (1 bar transmembrane pressure, TMP), and demonstrated cleaning in place (CIP) procedures for extended membrane use with multiple filtration cycles (recoveries > 80%). Furthermore, we integrated sensors to facilitate automation and generation of scale-relevant data, and provided a criteria to facilitate pump selection. Our μTFF device offers therefore a standardised design, paving the way for off-the-shelf microfluidic solutions for filtration optimisation, thus enhancing efficiency and effectiveness of bioprocess development. • Easy-to-use microfluidic TFF device with tool-free assembly and disassembly • Compatible with any standard flat sheet membranes • Device operating over wide pump type and flux ranges, supporting CIP • Achieves >90% recovery in single-pass mode at 1 bar TMP • Device can be used as single-use or as a reusable device (changing membranes)

Membrane filtration is widely used in water treatment to remove foulants from contaminated water. Foulant buildup on the membrane occludes the area open for fluid flow, which impairs the efficiency of the filtration operation by decreasing the flux through the membrane. Backwashing (BW) is a strategy to restore the membrane, wherein clean water is processed backward through the membrane to dislodge attached foulants. We develop a Monte Carlo model to simulate constant-pressure forward filtration (FF) and BW through dead-end, flat-sheet membranes, with membrane fouling dominated by intermediate blocking. We validate our model against real-world experiments conducted with different foulant types and concentrations and run under different filtration conditions. Relying primarily on measurable physical parameters and employing easy-to-implement parameter fitting techniques as needed, we show good agreement between experimental data and numerical simulations. We extend these results to predict flux behavior in FF and BW when foulant properties or filtration conditions are varied. This model can be used to further investigate the impact of varying BW duration, frequency, and/or pressure on the rate of flux recovery.