Separation Efficiency Of Membrane Research Articles

A capillary effect-inspired sponge-structured carboxymethyl cellulose aerogel layer-modified membrane for efficient separation of dye/salt under ultra-low-pressure

In the field of wastewater treatment, the efficient separation of dyes/salts and the high-pressure drive easily results in concentration polarization and membrane contamination. In this study, inspired by the capillary effect of natural sponge structure, an aerogel layer with a bionic three-dimensional mesh porous sponge structure was designed to construct an ultra-low-pressure membrane. With the assistance of tannic acid, the carboxymethyl cellulose (CMC) aerogel layer were constructed on the surface of polyvinylidene fluoride (PVDF) membrane using the layer-by-layer cross-linking and freeze-drying methods. The unique three-dimensional mesh structure of the aerogel provides a capillary effect that accelerates the rapid transport of water molecules. The introduction of polypyrrole (PPy) to the aerogel improves the mechanical properties of the aerogel, helping avoid the collapse during the separation process. Meanwhile, the formed PPy improves the membrane separation performance. The results showed, that under near-zero pressure conditions, the modified membrane had excellent dye/salt separation performance (dye rejection >99 %, salt rejection <10 %) and high flux of pure water (101.3 L·m−2·h−1). Moreover, the membrane also maintained good long-term stability. The study demonstrated the potential of using membrane for dye/salt separation applications by constructing bionic sponge-structured aerogels having capillary effect and good mechanical strength on membrane.

Novel approaches to improving gas separation: Ionic liquids coated coke/ NH2-UiO-66-based mixed matrix membranes for CO2/N2 separation

Permeability and separation efficiency of mixed matrix membranes (MMMs) are two important aspects. Polymeric membranes offer excellent mechanical and physical properties; however, they have a low permeability. To enhance the permeability and separation performance of polyvinyl chloride (PVC) membranes, Cholinium amino acid-based (IL) were impregnated with activated coke/ NH2-UiO-66 (Zr) (AC/MOF) composite and then IL@AC/MOF filler was incorporated into PVC matrix. FTIR spectroscopy, TGA, SEM, EDX, and Brunauer-Emmett-Teller (BET) surface area measurement were used to characterize the MMMs prepared. The porous structure of MMMs nanocomposites causes AC/MOF composite to effectively accelerate gas the diffusion in the PVC matrix. The permeability measurements for CO2 and N2 were made at 288.15, 298.15, 308.15, and 318.15 K at pressure 3 bar The outcomes indicates that the incorporation of the IL@AC/MOF filler increased the permeability of the PVC/AC/MOF MMMs compared to the pure polymeric membrane. The mixed matrix membranes exhibit superior gas separation performance, surpassing the 2008 Robson's Upper Bound.

Thin film nanocomposite membranes based on renewable polymer Pebax® and zeolitic imidazolate frameworks for CO2/CH4 separation

This study investigates the impact of integrating Pebax® Rnew® 30R51, a sustainable elastomer-type copolymer material, with zeolitic imidazolate frameworks (ZIFs) to develop advanced membranes for CO2/CH4 gas separation. The fabrication process of ZIF/Pebax® Rnew® 30R51 thin films was optimized to achieve uniform and defect-free thin film composite (TFC) membranes. Crucial membrane properties, including permeability, selectivity and separation efficiency, were analyzed with variations in ZIF type, loading levels, film thickness and operating conditions. Additionally, the resulting TFC and ZIF/Pebax® Rnew® 30R51 thin film nanocomposite (TFN) membranes were subjected to characterization via FTIR, XRD, TGA and SEM to evaluate their physicochemical properties. Nanoparticles of ZIF-8, NH2-ZIF-8 and ZIF-94 were individually added (at 5–15 wt% loadings) to the Pebax® Rnew® 30R51 matrix to develop the CO2 separation efficiency. The pristine TFC membrane showed a 66 GPU CO2 permeance and a 37.5 CO2/CH4 separation selectivity, primarily due to improved CO2 mass transport. Upon inclusion of ZIFs, the CO2 permeance with 5 wt% loadings of ZIF-8, NH2-ZIF-8 and ZIF-94 increased to 148, 99 and 125 GPU, respectively, despite this, the CO2/CH4 separation selectivity maintained at 29.4, 37.0 and 27.0, respectively.

In-Situ construction of Bulge-like microstructures in sugarcane-based superhydrophobic membranes for efficient separation of water-in-oil emulsions

The separation of oil/water pollution is of great importance to environmental protection. However, the development of superwetting materials for efficient separation of surfactant-stabilized oil/water emulsions still faces challenges. As agricultural waste, sugarcane straw contains many hydrophilic groups and multilayered pore structures, making it suitable for purifying oil/water emulsions by simple chemical modification treatments. Herein, sugarcane-based superhydrophobic membranes (SSMs) were prepared by a facile vacuum impregnation method in hexadecyltrimethoxysilane (HDTMS) solution. The unique bulge-like microstructures were constructed in the intrinsic pores of sugarcane, which significantly increased the roughness and resulted in superhydrophobicity with the water contact angle of 153.5°. More importantly, the bulge-like structure is easy to break the emulsion and thus SSMs offer excellent separation efficiency (> 99 %), suitable fluxes (368 L•m−2•h−1) and strong cycling stability for surfactant-stabilized water-in-oil emulsions. In addition, SSMs can separate oil/water mixtures and directly adsorb oil from water with adsorption rates exceeding 99 %. SSMs have good durability and anti-mold adherence properties, and they do not lose their unique wetting properties even in harsh environments. More importantly, SSMs can be degraded in soil at the end of their life cycle, avoiding secondary pollution for the environment. This simple, in-situ impregnation technique offers a novel way to create green, inexpensive and stable biomass membranes for effective water-in-oil emulsion separation, showing great promise for use in oily wastewater treatment.

Silver nanoparticle-decorated reduced graphene oxide/ nanocrystalline titanium metal-organic frameworks composite membranes with enhanced nanofiltration performance and photocatalytic ability

Nanofiltration (NF) has garnered significant attention for removing persistent dyes from industrial wastewater. However, limited membrane separation efficiency and performance deterioration due to membrane fouling are the primary challenges hindering the broader application of NF technology. Herein, we developed high-performance silver nanoparticle-coated reduced graphene oxide/nanocrystalline MIL125(Ti) composite NF membranes (nAg-rGO/n-MIL), which feature self-cleaning capabilities through photocatalytic activity. This was achieved by intercalating nanocrystalline MIL-125(Ti) (n-MIL) metal-organic frameworks between graphene oxide (GO) nanosheets, followed by reducing the GO nanosheets and decorating them with silver nanoparticles (nAg) via UV exposure. The nAg-rGO/n-MIL demonstrated high water permeability (21.7 LMH/bar) and achieved excellent removal efficiencies for targeting dyes with relatively small molecular weights ranging from 300 to 500 Da. Additionally, when operated in an NF system equipped with a UV side-emitting optical fiber, the nAg-rGO/n-MIL exhibited significantly reduced water flux decline and enhanced removal efficiencies, achieving up to 97.5 % for methylene blue. Moreover, the nAg-rGO/n-MIL demonstrated high durability under the tested operating conditions, indicating its potential for long-term use in industrial applications. The GO composite membrane, with nanosized MOF-intercalated nanochannels and photocatalytic activity via nAg decoration and GO reduction, offers a promising solution to performance limitations and fouling issues in current nanofiltration membranes.

Innovative Trends in Modified Membranes: A Mini Review of Applications and Challenges in the Food Sector.

Membrane technologies play a pivotal role in various industrial sectors, including food processing. Membranes act as barriers, selectively allowing the passage of one or other types of species. The separation processes that involve them offer advantages such as continuity, energy efficiency, compactness of devices, operational simplicity, and minimal consumption of chemical reagents. The efficiency of membrane separation depends on various factors, such as morphology, composition, and process parameters. Fouling, a significant limitation in membrane processes, leads to a decline in performance over time. Anti-fouling strategies involve adjustments to process parameters or direct modifications to the membrane, aiming to enhance efficiency. Recent research has focused on mitigating fouling, particularly in the food industry, where complex organic streams pose challenges. Membrane processes address consumer demands for natural and healthy products, contributing to new formulations with antioxidant properties. These trends align with environmental concerns, emphasizing sustainable practices. Despite numerous works on membrane modification, a research gap exists, especially with regard to the application of modified membranes in the food industry. This review aims to systematize information on modified membranes, providing insights into their practical application. This comprehensive overview covers membrane modification methods, fouling mechanisms, and distinct applications in the food sector. This study highlights the potential of modified membranes for specific tasks in the food industry and encourages further research in this promising field.

High-performance 19-channel monolithic chabazite membranes for efficient separation of water/ethanol and water/isopropanol mixtures by pervaporation and vapor permeation

Pervaporation (PV) and vapor permeation (VP) using selective zeolite membranes are more energy-saving in dealing with azeotropic mixtures compared with conventional distillation for organic solvent dehydration. Herein, we developed a monolithic supported chabazite membrane and exploited its dehydration performance. The membrane was fabricated by secondary growth method on the 19-channel alumina monolithic without organic template. By finely controlling the homogeneity of nuclei growth and minimizing the intracrystalline defects through the epitaxial growth of uniformly nanosized SSZ-13 seed layer using cesium hydroxide and sodium hydroxide as cooperative hydration-mismatched inorganic structure directing agents (ISDA). The resulting monolithic chabazite membrane exhibits excellent water-perm-selectivity. The effects of feed water composition and operating temperature on the dehydration performance of the monolithic chabazite membrane were investigated through PV and VP processes. The typical membrane displayed excellent selectivities of more than 10,000 and 30,000 in 10/90 wt% water/ethanol and water/isopropanol mixtures at 393 K. The membrane exhibited excellent hydrothermal stability in a VP with a 10/90 wt% water/ethanol at 393 K for 72 h. The robust monolithic chabazite membrane with high packing density, strong mechanical strength, large membrane area and excellent water-selective performance significantly outperforms state-of-the-art membranes for dehydration in practical applications.

Thermodynamic efficiency of membrane separation of dilute gas: Estimation for CO2 direct air capture application

Gas separation technology is crucial for addressing environmental issues like CO2 capture to mitigate climate change. While membrane separation is often cited for its efficiency, accurate estimations are scarce. We present estimations based on classical thermodynamics for very lean CO2 composition (400 ppm), revealing rich details in simple systems and deriving guiding principles. Our main conclusion emphasizes the critical necessity of a high membrane separation ratio, and we discuss candidates for achieving this goal.

Bio-inspired MXene membranes for enhanced separation and anti-fouling in oil-in-water emulsions: SHAP explainability ML

Optimizing membrane performance for efficient water treatment is crucial for sustainable development and environmental protection, aligning with UN SDGs. This study involves experimental design, statistical reliability of small data, and explainable machine learning (ML) using SHAP (Shapley Additive Explanations). The research uses ML models and statistical tests to ensure data reliability and stationarity and investigate various membranes’ fouling and separation efficiency (MX-CM, PDMX-CM, and SPDMX-CM). Stationarity tests, including the Augmented Dickey–Fuller (ADF) and Phillips–Perron (PP) tests, revealed that MX-CM is stationary at level (I(0)), while PDMX-CM and SPDMX-CM required first differencing (I(1)) to achieve stationarity. SHAP analysis showed that in the fouling study, higher values of PDMX-CM and MX-CM positively influenced model predictions, with SHAP values of +0.09 for Cycle, −0.06 for PDMX-CM, and −0.06 for MX-CM. In the separation efficiency study, Cycle had a neutral impact (0.00), PDMX-CM had a slight positive effect, and MX-CM had a slight negative impact. These findings highlight the importance of ensuring data stationarity and utilizing SHAP for model explainability in predicting membrane performance. Accurate preprocessing and model interpretation enhance decision-making and optimization in membrane fouling and separation efficiency studies, ensuring robust and reliable ML models.

Porous organic cage induced high CO2/CH4 separation efficiency of carbon molecular sieve membranes

Porous fillers have been incorporated into precursor membranes to fabricate carbon molecular sieve (CMS) membranes, where the interfacial compatibility between fillers and matrix significantly influences the separation performance of converted CMS membranes. To address this issue, we introduce molecular fillers of porous organic cages (POCs) into precursor membranes, the organic composition and discrete molecular characteristics of which can enhance the compatibility with the polymer matrix (PIM-1), bringing enhanced porosity and narrowed pore size distribution, especially in the ultra-micropore region, to the CMS membranes. The obtained CMS membrane shows simultaneously improved gas permeability and selectivity wherein the optimized CMS membrane pyrolyzed at 600 °C with 10 wt% POCs loading (CMS-10%-600) exhibits a CO2 permeability of 2002 Barrer and a CO2/CH4 selectivity of 221.6, surpassing the 2019 CO2/CH4 upper bound and superior to most of reported CMS membranes. Due to the incorporation of POC, the CMS-10%-600 membrane demonstrates a 147.5 % increase in CO2 permeability and a 297.1 % increase in CO2/CH4 selectivity compared to pristine PIM-1-based CMS membrane, along with the excellent aging resistance for over 30 days. This study provides new insights into the design of high-performance CMS membranes for gas separation.

Polyamidoamine dendrimer-modified polyvinylidene fluoride microporous membranes for protein separation

The separation efficiency of pressure-driven filtration membranes is primarily dictated by the membrane pore size. Membranes with larger pores typically demonstrate high flux but low or zero rejection when it comes to separating small molecules. In protein separation, ultrafiltration (UF) membranes with pore sizes smaller than the molecular dimensions of target proteins are commonly used for size rejection. Taking inspiration from the separation mechanism of nanofiltration (NF) membranes, we hypothesize that introducing charged groups into membranes of appropriate pore sizes could significantly enhance the electrical interaction between membrane charges and protein charges. This enhancement, occurring at the nanoscale distance when protein molecules approach or pass through charged nanoscale membrane channels, may enable the rejection of proteins substantially smaller than the pore size. Using membranes with relatively large pore sizes could lead to an increase in flux. To test this hypothesis, we conducted experiments involving the modification of polyvinylidene fluoride (PVDF) membranes with suitable pore sizes, using polyamidoamine (PAMAM) dendrimers to introduce negative charges to the membranes. The performance of the PVDF membranes and the modified membranes were investigated in the separation of whey proteins. To evaluate the contribution of steric and electrical hindrance to the solute separation, filtration experiments were performed using polyethylene oxide (PEO) and polyacrylic acid (PAA). The membranes were characterized using techniques such as attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The results indicate that the modification enhances the rejection efficiency of whey proteins. The whey protein rejection and permeate flux for PVDF membranes were 58.9% and 15.3 LMH, respectively. Following alkaline treatment or PAMAM-G3.5 dendrimer modification, the whey protein rejection increased to 97.3% and 98.8%, respectively. However, alkaline treatment and PAMAM-G3.5 dendrimer modification resulted in a reduction of permeate flux to 5.6 LMH and 2.3 LMH, respectively. This suggests that increasing membrane charge effectively enhances the separation ability of filtration membranes in charged macromolecule separation.

Correction to “A Rapid and Facile Preparation of PVDF–PG/KH550 Bioinspired Membrane for Efficient Separation of Oil-in-Water Emulsions”

Correction to “A Rapid and Facile Preparation of PVDF–PG/KH550 Bioinspired Membrane for Efficient Separation of Oil-in-Water Emulsions”

Expanded polystyrene (EPS) waste upcycling and efficient oil/water emulsion separation with advanced EPS-cotton membranes

The current work describe the fabrication of an oleophilic and hydrophobic EPS-cotton membrane through a facile one-step process, involving the immersion of pristine cotton fabric in a freshly prepared solution of EPS in tetrahydrofuran (THF). The characterization of EPS-cotton membrane is carried out using FTIR spectroscopy, scanning electron microscopy (SEM), and contact angle measurements. The EPS-cotton membrane exhibits remarkable absorption capacity for diesel, gasoline, olive oil, and canola oil, i.e., 0.21 gg−1, 0.13 gg−1, 3.7 gg−1 and 0.40 gg−1, respectively. Using vacuum filtration, the membrane effectively segregates diesel oil, gasoline, olive oil, and canola oil emulsions from water. The flux of membrane for diesel oil, gasoline, olive oil, and canola oil emulsions with water is found to be 133 LMH, 207 LMH, 59 LMH and 89 LMH, respectively. Moreover, the water rejection (%) remains above 95 % in all cases. The separated samples are monitored through FTIR and UV/Vis, which suggests high separation efficiency of EPS-cotton membrane. Furthermore, FTIR and SEM analyses of EPS-cotton membrane before and after separations demonstrate suitable membrane stability, allowing for at least six cycles of effective use. EPS-cotton membrane fabrication not only facilitates the eco-friendly recycling of waste plastics but also promises versatile applications in environmental remediation.

Investigations of nanomaterial-based membranes for efficient removal of contaminants from wastewater via membrane distillation: a critical review

The requirement for wastewater treatment is paramount in ensuring environmental sustainability and safeguarding public health. As industrialization and urbanization accelerate, the volume of wastewater generated continues to increase, containing a diverse range of pollutants and contaminants. Untreated wastewater poses serious threats to ecosystems, water bodies, and human communities, leading to pollution, waterborne diseases, and ecological imbalances. Effective wastewater treatment becomes essential to mitigate these adverse effects by removing or reducing pollutants before discharge into natural water sources. This process helps to preserve water quality, protect aquatic life, and maintain the overall health of ecosystems. Membrane distillation (MD) has emerged as a promising technology for wastewater treatment, offering an innovative approach to address the challenges associated with conventional treatment methods. In MD, a hydrophobic membrane serves as a selective barrier, allowing water vapor to pass through while preventing the passage of contaminants. This paper offers an extensive overview of the latest advancements in nanotechnology and membrane distillation applied in wastewater treatment. We will delve into different types of nanomaterials that have been used to enhance the properties of MD membranes, such as nanocomposites, nanoparticles, and nanofiber membranes. We also explore the mechanisms by which these nanomaterials improve the separation efficiency, anti-fouling properties, and durability of MD membranes. Additionally, we highlight the potential of hybrid membranes that combine different types of nanomaterials for further improving the performance of MD in wastewater treatment. We provide examples of recent studies that have investigated the use of hybrid membranes, including carbon nanotube-graphene oxide hybrid membranes, nanocomposite nanofiber membranes, and silver nanoparticle-embedded membranes. We also identify some areas for future research and development, such as the scale-up and commercialization of nanotechnology-based MD systems. In summary, this review paper highlights the potential of nanotechnology to enhance the performance of MD in wastewater treatment, leading to improved water quality and a cleaner environment.

Thin polyamide layer cross-linked graphene-oxide based ceramic membranes for efficient separation of the surfactant stabilized oil-in-water emulsions

Two-dimensional (2D) graphene oxide (GO) membranes (GOM) have great potential in separation applications. However, GOMs face two distinct challenges: low flux arising from their tight stacking and instability arising from re-exfoliation of GO sheets in solution. To address these challenges, herein, we report the functionalization of basal planes of GO layers with 2-[2-(3-Trimethoxysilylpropylamino)ethylamino]ethylamine (TSE), followed by transforming them into membranes through a two-step process. In the first step, the functionalized GO sheets were assembled onto the porous ceramic support. At this stage, the interlayer distance between GO sheets was modulated via TSE’s long hydrocarbon chain. Afterward, the free amines of TSE on functionalized GO membranes (fGOM) surface were cross-linked with trimesoyl chloride (TMC) to prepare a hydrophilic thin-layer on top of fGOM (TL-fGOM), further enhancing their stability. Further, TL-fGOMs were tested for oil-in-water-emulsion separation. The increased interlayer distance and the increased surface hydrophilic nature of TL-fGOM offered ultra-high water permeance, 4860 % higher compared to the non-functionalized GOM. Moreover, the separation efficiency of TL-fGOM improved from 37 % of that of ceramic membranes to 99.5 %. Additionally, they showed excellent anti-fouling properties. After exposing the membranes to 500 ppm emulsion for 10 hours in batches, the flux recovery ratio exceeded 90 %. The TL-fGOM in our work demonstrated outstanding performance in purifying oily emulsions containing diesel/toluene/heptane-in-water. All these results revealed that the appropriate functionalization of graphene oxide could assist in forming a thin layer of graphene oxide on the support membranes, offering high separation efficiency and fouling resistance. This approach can be extended further to utilize the graphene oxide membranes for practical applications.

Design and fabrication of PPTA-braid-reinforced PFA/GE hollow fiber composite membranes

Due to the effects of the rapid development of modern society and fresh water resource pollution, water shortage has further accelerated, which is becoming a very urgent problem. Herein, the poly (p-phenylene terephthalamide)-(PPTA-) braid-reinforced (PBR) poly(tetrafluoroethylene-co-perfluoropropylvinylether)/graphene (PFA/GE) hollow fiber composite membranes (HFCMs) were prepared by dipping coating-thermal sintering coupling technique with a green process. GE is an emerging type of two-dimensional functional nanoparticle with a tunable passageway for oil molecules. The influences of the GE concentration in the casting solution on the structure and performance of the PBR−PFA/GE HFCMs were investigated. The results showed that the addition of GE produced a finger-like pore structure suitable for oil channels. Meanwhile, the roughness and contact angle of the composite membrane increased accordingly, and the water contact angle increased from 115° to 120°. The permeation fluxes of kerosene also increased obviously with the increase of GE contents, and the maximum flux of M-3 reached as high as 217.66 L·m−2·h−1. The application of the lubricating oil flux test under working conditions of 60–150 °C has demonstrated the high-temperature oil permeability resistance of the composite membrane. Even after long-term use, its separation efficiency for water-in-oil emulsions still remains above 99.5 %. In addition, the membrane separation-efficiency both up to 99.9 % for activated carbon and silica dioxide (SiO2) in kerosene. Overall, the PBR-PFA/GE HFCMs with excellent lipophilicity presented great potential for oily wastewater treatment at high temperatures.

A Rapid and Facile Preparation of PVDF–PG/KH550 Bioinspired Membrane for Efficient Separation of Oil-in-Water Emulsions

A Rapid and Facile Preparation of PVDF–PG/KH550 Bioinspired Membrane for Efficient Separation of Oil-in-Water Emulsions

Double-drying 3D lamellar-structured aerogel membrane for efficient oil-water separation and long-lasting antibacterial activity

Conventional oil-water separation membranes are difficult to establish a trade-off between membrane flux and separation efficiency, and often result in serious secondary contamination due to their fouling issue and non-degradability. Herein, a double drying strategy was introduced through a combination of oven-drying and freeze-drying to create a super-wettable and eco-friendly oil-water separating aerogel membrane (TMAdf). Due to the regular nacre-like structures developed in the drying process and the pores formed by freeze-drying, TMAdf aerogel membrane finally develops regularly arranged porous structures. In addition, the aerogel membrane possesses excellent underwater superoleophobicity with a contact angle above 168° and antifouling properties. TMAdf aerogel membrane can effectively separate different kinds of oil-water mixtures and highly emulsified oil-water dispersions under gravity alone, achieving exceptionally high flux (3693 L·m−2·h−1) and efficiency (99 %), while being recyclable. The aerogel membrane also displays stability and universality, making it effective in removing oil droplets from water in corrosive environments such as acids, salts and alkalis. Furthermore, TMAdf aerogel membrane shows long-lasting antibacterial properties (photothermal sterilization up to 6 times) and biodegradability (completely degraded after 50 days in soil). This study presents new ideas and insights for the fabrication of multifunctional membranes for oil-water separation.

Surface modified ceramic membrane for natural volatile oil enrichment with high flux and high component retention

The natural volatile oil has high medicinal value, but the extraction and separation technology were limited by low composition, complex composition, and strong volatility. This study validated the feasibility of membrane separation technology for enriching volatile oil from the aspects of membrane separation efficiency, volatile oil components, and drug efficacy. A shellac coated alumina ceramic (lac@AC) membrane with irregular nanoneedle-like surface structure was prepared to enrich the volatile oil from vinegar-processed Cyperi Rhizoma (vpCR). Compared to the alumina ceramic (AC) membrane, the lac@AC membrane exhibited 29.77 % and 98.05 % increase in water and emulsion flux, respectively. Meanwhile, the oil rejection of lac@AC membrane increased 26.29 %. According to the gas chromatography-mass spectrometry analysis, the similarity between the volatile oils obtained by membrane separation and the traditional steam distillation method was higher than 99.5 %. In addition, antibacterial experiments showed that the volatile oil obtained by membrane separation has similar antibacterial effects to the volatile oil obtained by steam distillation. Component analysis and pharmacodynamic analysis both demonstrated the feasibility of using membrane separation to obtain vpCR volatile oil. This study offers a technical reference for the efficient, high-quality, and environmentally friendly extraction of natural plant oils with complex ingredients.

One-step facile fabrication of Mg(OH)2/PVA/ZnO membrane with superior stability and oil-water separation

The release of oily wastewater is a significant threat to both the environment and the sustainable development of society. The challenge of oil–water separation, which includes immiscible oil/water mixtures and emulsions, is exacerbated by the substantial volume of oily wastewater generated in industrial processes and daily activities. In this study, a one-step electrodeposition method was employed to fabricate a composite membrane composed of Mg(OH)2/PVA/ZnO. A uniform electric field was applied between the cathode and anode to facilitate the deposition of PVA and ZnO nanoparticles onto various metallic mesh of the cathode in the presence of Mg2+. The generation of hydrogen at the mesh surface facilitated the development of a superhydrophilic/underwater superoleophobic composite structure featuring micropores and nanosheets. The membrane durability, water flux, and separation efficiency were significantly enhanced, achieving a separation efficiency of 99.8 % and a water flux of 3.2 × 105 L·m−2·h−1. The membrane demonstrated excellent performance in separating a wide range of oil–water mixtures and emulsions, along with outstanding chemical stability and resistance to oil fouling.