Membranes For Water Treatment Research Articles

Waste cellulose acetate-based dynamic membrane for NOM-containing river water filtration

Excessive leaching of natural organic matter (NOM) from swamp forests into water resources poses significant challenges for water treatment plants, primarily due to its high variability. In this study, a waste-based cellulose acetate (W-CA) membrane was explored as a dynamic membrane for the filtration of real river water containing NOM and compared to a commercial-based CA (C-CA) membrane. The membranes were fabricated and thoroughly characterized. The results revealed that the W-CA membrane exhibited greater hydrophilicity, as indicated by a static contact angle of 84°, compared to the hydrophobic nature of the C-CA membrane (104°). The mean pore diameters of the C-CA and W-CA membranes were 4.4 µm and 5.3 µm, respectively, suitable as the base for a dynamic filter. The formation of a dynamic cake filtration layer (identified mainly as humic and fulvic acids) was confirmed from visual observation, SEM image and the decrease in the pore sizes. It was further validated from the cake layer as the dominant fouling mechanism obtained from a curve fitting analysis. Despite the W-CA and C-CA membranes respectively showed a high steady-state river water permeabilities of 348 and 226 L/(m2 h bar) respectively, they were still unable to fully remove NOM (27% removal for W-CA and 39% removal for C-CA membrane), suggesting the necessity for further developments. This study underscores the potential of W-CA membranes for water treatment while promoting a circular economy by converting waste into valuable resources and sustainable products.

Carbon Emission Calculations and Reductions in Membrane Water Treatment: A Review

Carbon Emission Calculations and Reductions in Membrane Water Treatment: A Review

Unveiling the impact of monomer reactivity on the morphology and functionality of thin-film composite membranes

This study delves into the impact of monomer selection and reaction pH on the morphology and performance of thin-film composite (TFC) membranes. The research provides an understanding of how polyamide (PA), polyester amide (PEA), and polyester (PE) membranes can be tailored for specific applications, employing piperazine (PIP) and glucose as monomers in aqueous solution alongside trimesoyl chloride (TMC) as a monomer in an organic solution. PEA-based membranes containing glucose demonstrated several notable improvements, including a reduced contact angle of 60 degrees, a smoother surface, and a more negative zeta potential. These enhancements underscore their increased hydrophilicity, decreased susceptibility to fouling, and heightened surface charge. Controlling pH during fabrication significantly changed the membrane surface charge, hydrophilicity, water flux, and rejection rate. At pH 11, the PA membrane excelled in rejection performance (99.5% Na2SO4, 32% NaCl, and 97.8% methyl orange) with a trade-off in lower water flux (56 LMH). Conversely, the PE membrane achieved the highest water flux (173 LMH) but lower rejection (58% Na2SO4, 10% NaCl, and 97% methyl orange). The PEA membrane offered notable water flux (82.5 LMH) and high rejection for methyl orange (99.3%) and Na2SO4 (99.2%). Increasing the pH reduced permeation rates but enhanced rejection, especially for NaCl. The PE and PEA membranes exhibited remarkable antifouling properties, boasting a flux recovery ratio compared to the PA membrane. This study highlights the pivotal role of monomer selection and pH control in TFC membrane performance, offering prospects for innovative design and optimization in water treatment membrane technology.

Light-Augmented Multi-ion Interaction in MXene Membrane for Simultaneous Water Treatment and Osmotic Power Generation.

The mixing of wastewater and natural water releases abundant osmotic energy. Harvesting this energy could significantly reduce the energy and economic cost of water treatment, leading to sustainable wastewater treatment technology. Yet, such energy harvesting is highly challenging because it requires a material that is highly permeable to nontoxic ions while rejecting toxic ions in wastewater to reach high power density and prevent environmental pollution. In this work, we demonstrate that a light-augmented biomimetic multi-ion interaction in an MXene membrane can simultaneously realize high permeability of Na+ ions for enhanced osmotic power generation and high selectivity to heavy metal ions up to a ratio of 2050 for wastewater treatment. The Na+ permeability is enhanced by the photothermal effect of the MXene membrane. The transport of heavy metal ions, however, is suppressed because, under angstrom-confinement, heavy metal ions are strongly electrostatically repelled by the increased number of permeating Na+ ions. As a result, the membrane can stably generate osmotic power from simulated industrial wastewater, and the power density can be enhanced by 4 times under light illumination of approximate 1 sun intensity. This work highlights the importance of multi-ion interaction for the transport properties of ionic materials, which remains rarely investigated and poorly understood in previous studies.

Constructing quaternized graphene oxide filtration layer on PVDF membrane by a facile strategy via dopamine crosslinking and its performance

The increasing utilization of polyvinylidene fluoride (PVDF) ultrafiltration membranes in water treatment has necessitated the development of membranes with superior separation, antifouling performance and high pure water permeability. As a hydrophilic and antibacterial modifier, quaternized graphene oxide (QGO) has been successfully applied to improve the antifouling and antibacterial properties of the membranes simultaneously. Herein, we proposed a simple and effective strategy to fabricate a nanocomposite ultrafiltration membrane by coating the PVDF membrane surface with QGO and using polydopamine (PDA) as a “bio-glue”. The filtration followed by cross-linking method was utilized to construct a “brick-mud” structure on the membrane surface. The prepared QGO/PDA-PVDF membrane exhibited favorable separation and antifouling properties (79.5% of BSA rejection rate, 15.7% of irreversible fouling rate when filtering 0.5 g/L BSA solution, 97.2% of E. coli and 96.3% of S. aureus antibacterial rate), while maintaining a high pure water permeability of 1105.4 L.m−2.h−1.bar−1. QGO nanosheets were stably coated on the membrane surface, and the QGO/PDA-PVDF membrane prepared by this novel strategy also demonstrated application potential in the field of seawater desalination pretreatment. Besides, the possible mechanisms during modifications were also discussed. This research could serve as a reference for improving the comprehensive performance of PVDF ultrafiltration membrane through surface coating.

Preparation of super hydrophilic-underwater super oleophobic photoinduced self-cleaning Al2O3 @TiO2 ceramic membrane and separation performance of oil-in-water emulsion

Membrane hydrodynamic irreversible oil fouling is a pressing issue. Here, an antifouling Al2O3 @TiO2 membrane with excellent wettability was created using the sol-gel method to create an anatase nano-TiO2 coating on the surface of an Al2O3 ceramic membrane. Analyzing the separation performance of an Al2O3 @TiO2 membrane on simulated oily emulsions determined the amount of TiO2 covered on the membrane surface (0.8 mol·L−1). Under the synergy of hydrophilic nano-TiO2 and ultraviolet (UV) light, the Al2O3 @TiO2 membrane demonstrated improved wettability and self-cleaning ability and maintained favorable separation performance (769.23 L·m−2·h−1, 97.75%, 1.23 mg·L−1) after 6 h of continuous separation of the actual oilfield produced water. After 30 min of UV illumination, the membrane flux recovered completely. This is due to the fact that the active substances (eg.,·OH,·O2, and 1O2) generated in situ on TiO2 on the membrane surface after UV illumination weakened the interaction of membrane surface fouling, resulting in less oil fouling. In addition, the Al2O3 @TiO2 membrane maintained extremely outstanding oil resistance stability and recoverability during high-intensity hydraulic flushing and 25 cycles of testing. This study provides a theoretical basis for the engineering application of ceramic membranes in oilfield-produced water treatment.

Effect of temperature on organic fouling and cleaning efficiency of nanofiltration membranes for loch water treatment

We investigated the effect of solution temperature on organic fouling and cleaning of polypiperazine nanofiltration (NF) membranes. Fouling experiments were conducted in the temperature range 5 °C ≤ T ≤ 15 °C, characteristic of surface waters in northern latitudes, such as Scottish lochs. Results of laboratory-scale fouling experiments using alginate, a polysaccharide constituent of extracellular polymeric substances, showed a moderate increase in flux loss at 15 °C (41 %) compared to 5 °C (36 %). Analysis of the fouling experiments using a series-resistance model showed that the greater extent of fouling with rising temperature stems from a monotonic increase in water permeance with T. Interfacial property characterisation provided further insight into the effect of temperature on fouling determinants such as membrane hydrophobicity, nanoscale roughness, surface charge, and surface forces. No T-dependence of surface roughness was found. Similarly, we found that water contact angle is invariant within the temperature range investigated, suggesting that the observed fouling behaviour is not due to modulation of hydrophobic interactions. Conversely, colloidal-probe force spectroscopy (CPFS) measurements showed that adhesion forces become stronger with rising temperature. Further analysis showed that repulsive forces – which oppose colloidal particle deposition – become weaker with rising temperature, consistent with fouling trends. Determination of the membrane zeta potential showed that surface charge is invariant over the range of temperatures investigated, suggesting that repulsive forces have a non-electrostatic (likely steric) origin. Additionally, we assessed the effect of temperature on physical and chemical cleaning efficiency, comparing cleaning at the same temperature as the fouling experiments (5 °C ≤ T ≤ 15 °C) with cleaning at 30 °C. We observed that physical cleaning, consisting of water circulation over the fouled membrane surface, is insufficient to remove the foulant layers. On the other hand, chemical cleaning is able to restore 95 % of the original membrane permeance at 10 °C, but only 74 % at 5 °C.

Amphoteric polyelectrolyte ultrafiltration membranes with high permeability property via in-situ modified by PES-N and PES-COOH

Ultrafiltration membrane is one of the most commonly used separation materials for wastewater treatment, due to its low operating pressure, high flux and large specific surface area. In this work, we utilized PES polymer as a polymer precursor to prepare a series of amphoteric polyelectrolyte membrane with different content of amphoteric polyelectrolyte group via simple polymer blending processes. The amphoteric polyelectrolyte groups in amphoteric polyelectrolyte membrane could effectively regulate the retention ability and significantly improve the water flux of membrane. The amphoteric polyelectrolyte membrane with the content ratio of 4:6 (PES-N/PES-COOH) exhibited the highest water flux of 467 Lm−2 h−1 and BSA retention factor of 94.2% than that of other ultrafiltration membranes owning to the abundant porosity and suitable thickness of the top layer. Moreover, the results of static BSA adsorption and flux recovery ratio also proved that the amphoteric polyelectrolyte membrane have a good BSA rejection and antifouling performance. Therefore, these results reveal a simple synthesis and design strategy for constructing the high-performance amphoteric polyelectrolyte membrane for water treatment and provide theoretical and technical guidance for water treatment process based on membrane technology.

Biofouling metallic membranes in algae-laden water treatment: Performance, mechanism, and the role of the pre-coated layer

Biofouling is the primary factor limiting the performance of ultrafiltration membrane systems in drinking water treatment. This study systematically investigated the application effect and biofouling behavior of metallic membranes in the treatment of algae-laden water and evaluated the mitigation effect and mechanism of the pre-coated layer on biofouling. The findings demonstrate that the metallic membrane can almost completely remove algal cells (>99.99 %) and macromolecular organics in EOM (Extracellular Organic Matter) but has limited effects on micromolecules, such as humic acid and fulvic acid, in EOM (47.29 % and 17.72 % for TOC (Total Organic Carbon) and UV254, respectively). During direct filtration, algal cells can form a cake layer in front of the metallic membrane to reduce the membrane flux, whereas the presence of EOM makes the cake layer denser and hastens the decline in flux. In addition, irreversible membrane fouling is exasperated in acidic or Ca2+-rich solutions, whereas an increase in algal cell particles exacerbates reversible membrane fouling, causing a faster decline in flux. According to the membrane mechanism analysis, the fouling mechanism ranges from complete pore blocking to standard and intermediate blocking throughout the direct filtration process. In contrast, the application of a pre-coated kaolin layer significantly decreases membrane fouling compared with direct filtration. The pre-coated layer can prevent direct contact between the foulants and the membrane surface during the early stages of filtration, resulting in a delayed complete pore blockage stage. On the other hand, XDLVO (Derjaguin-Landau-Verwey-Overbeek) data reveals that the force between kaolinite and algae (−102.323 mJ/m2) is greater than that between kaolinite and metallic membranes (−61.424 mJ/m2), resulting in better backwashing efficacy. These findings support the use of metallic membranes in drinking water treatment.

Temperature and photo sensitive PVDF-g-PNIPAAm/BN@PDA-Ag nanocomposite membranes with superior wasterwater separation and light-cleaning capabilities

Traditional water treatment membranes always face the problem of membrane contamination in the practical application. Those contaminants deposited on the membrane surface and inside the membrane pores make the filtration process more difficult. Herein, the temperature and photo sensitive nanocomposite membranes with superior wasterwater separation and light-cleaning capabilities were prepared by a non-solvent induced phase separation method, which combined the thermo-responsive property of poly(N-isopropylacrylamide) (PNIPAAm) grafted polyvinylidene fluoride (PVDF) and the high photothermal conversion character of core–shell structured BN@PDA-Ag nanosheets. The membranes can be heated to high temperature within a short period of light exposure due to the fast photothermal conversion capability of Ag and the excellent thermal conductivity of boron nitride (BN). The increase in temperature led to the contraction of PNIPAAm chains and bigger pore size. The microstructure, filtration, and cleaning performance of the nanocomposite membranes can be controlled by illumination, which allowed PVDF-g-PNIPAAm/BN@PDA-Ag membranes to achieve the effect of first interception and then cleaning. The membranes showed retention rates of 82, 99 and 95 % for BSA, oil–water emulsions and various dyes with flux recovery rates of > 90 % after light cleaning. This work provides a simpler, more efficient membrane cleaning strategy with superior potential for dealing with membrane contamination.

MXene-based membranes in water treatment: Current status and future prospects

Emerging highly selective MXene-based membranes have drawn a greater scientific interest in the field of water treatment due to their ion-selective and controlled molecular transport characteristics. However, MXene-based membranes have limitations in water treatment due to the difficulties including permeability-selectivity trade-off, swelling, fouling, oxidation, etc. Thus, a better understanding of the rational structural design principles of the membranes and their separation mechanisms are essential to further their development in water treatment. This review provides a concise overview of the key timeline in the fabrication of MXene-based membranes, the membrane characterization approaches used to understand their structure-property correlations, and the present difficulties in synthesizing high-performance MXene-based membranes. To overcome these challenges, new designing approaches are comprehensively reviewed to enhance the permeability, selectivity, stability, and antifouling properties of MXene-based membranes. These approaches include physical intercalation, chemical cross-linking, membrane surface modification, etc. Then, the separation mechanisms involved in the membranes in water treatment are presented, followed by the related applications. Looking forward, the perspective is provided on the future research directions for further advancing the membranes. This timely review may help to bridge the gap between academic research and industrial needs of MXene-based membranes for water treatment.

Flexible membranes fabricated by initiated chemical vapor deposition for water treatment, battery, and drug delivery

With the development of advanced yet structurally complex systems, flexible membranes have attracted increasing attention. Initiated chemical vapor deposition (iCVD), an emerging, facile, scalable technique to deposit high-quality polymer thin films on arbitrary substrates, holds great promise in the fabrication of flexible membranes. iCVD features solvent-free, gentle deposition conditions that enable the processing of various solvent-susceptible, fragile, or delicate substrates. The mechanical flexibility, precisely controlled morphology, and abundant physiochemical property of iCVD polymer films enable the design and optimization of membrane characteristics for diverse applications. Herein, we provide a comprehensive review of the fabrication and applications of iCVD flexible membranes. First, we introduce the deposition mechanism and parameters of iCVD. We then critically discuss the applications of iCVD membranes in water treatment, battery, and drug delivery, elaborating their processing–property–performance interrelationships. Finally, we discuss the scale-up and commercialization of iCVD, followed by the limitations and future directions in the field.

Polycation-Intercalated MXene Membrane with Enhanced Permselective and Anti-Microbial Properties.

Two-dimensional (2D) nanomaterial-based membranes feature attractive properties for molecular separation and transport, which exhibit huge potential in various chemical processes. However, the low permeability and bio-fouling of the MXene membrane in water treatment become huge obstacles to its practical application. Herein, a highly permselective and anti-bacterial 2D nanofiltration membrane is fabricated by intercalating a polycation of polydiallyldimethylammonium chloride (PDDA) into the Ti3C2Tx MXene laminar architecture through a facile and patternable electrostatic assembly strategy. As a result, the as-fabricated Ti3C2Tx/PDDA composite membrane exhibits higher water permeance up to 73.4 L m-2 h-1 with a rejection above 94.6% for MgCl2. The resultant membrane simultaneously possesses good resistance to swelling and long-term stability in water environments, even after 8 h. Additionally, the Ti3C2Tx/PDDA membrane also demonstrates a high flux recovery ratio of nearly 96.1% to bovine serum albumin proteins after being cleaned. More importantly, the current membrane shows excellent anti-adhesive and anti-microbial activity against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), with inhibition rates of 90% and 95% against E. coli and S. aureus, respectively. This holds great potential for the application of the polyelectrolyte-intercalated MXene membrane in serving as a promising platform to separate molecules and/or ions in an aquatic environment.

Synchronously improved permeability, selectivity and fouling resistance of Fe-N-C functionalized ceramic catalytic membrane for effective water treatment: The critical role of Fe

Constructing catalytic membrane simultaneously displaying high permeability, selectivity and antifouling performance in water treatment remains challenging. Herein, the surface and pore channels of the ceramic membrane were co-functionalized with nitrogen doped carbon supported Fe catalyst (CN-F), and the Fe content was varied to investigate its effect on performance of CN-F coupled with peroxymonosulfate (PMS) activation (CN-F/PMS) for water treatment. Results confirmed the introduced Fe (in Fe-N coordination form) greatly enhanced the permeability, selectivity and fouling resistance of CN-F. Optimal CN-F3/PMS achieved 96.5% removal and 52.1% mineralization of sulfamethoxazole in short retention duration (2.7 min), whose performance was 5.4 and 6.7 times higher than that of nitrogen doped carbon functionalized ceramic catalytic membrane (CN/PMS) and CN-F3 filtration alone, respectively. CN-F3/PMS also efficiently inhibited fouling on both surface and pores with 2.8 and 2.4 times lower flux loss than that of CN/PMS and CN-F3 filtration alone, respectively. Moreover, CN-F3/PMS displayed superior performance in long-term treatment of real coking wastewater. The outstanding performance of CN-F was mainly attributed to the dual role of supported Fe, which served as hydrophilic site for enhanced water permeation and major active site for PMS adsorption and reduction into reactive species (mainly high-valent Fe(IV)=O species) towards pollutant elimination.

Modification of microfiltration membranes by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/n-hydroxy sulfosuccinimide coupling mediated antimicrobial peptides grafting for biofouling mitigation

Microfiltration membrane separation is widely applied for water and wastewater but biofouling is a challenging task in real applications. In this work, we fabricated a novel antibiofouling polyvinylidene fluoride (PVDF) membrane by grafting non-drug-resistant antimicrobial peptides (AMPs) on the membranes via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxy sulfosuccinimide (EDC/Sulfo-NHS) chemistry. Effects of AMPs concentration on the membrane basic properties, antibacterial and antibiofouling behaviors of the modified membranes were systematically investigated. Membrane surface characterization demonstrated that the AMPs were successfully grafted onto the base PVDF membranes. The AMPs modified membrane showed enhanced hydrophilicity, consistent permeability and prominent antimicrobial ability (i.e., >90% of antibacterial efficiency against both Escherichia coli and Staphylococcus aureus). Batch filtration tests exhibited that the modified membranes with the concentration of AMPs less than or equal to 0.7 mg/mL had lower flux decline rate compared to the pristine membrane (M0). According to the images from confocal laser scanning microscopy analysis, less total cells as well as more dead cells were observed on the AMPs modified membrane compared to M0. Furthermore, the grafted AMPs on the membranes also displayed favorable stability suffered from a cycle involving biofouling and chemical cleaning. This grafting protocol for AMPs highlights a robust way to fabricate antibiofouling membranes for water and wastewater treatment.

Leveraging ChatGPT and Bard: What does it convey for water treatment/desalination and harvesting sectors?

Artificial intelligence (AI) has emerged as a prominent tool in the modern day. The utilization of AI and advanced language models such as chat generative pre-trained transformer (ChatGPT) and Bard is not only innovative but also crucial for handling challenges related to water research. ChatGPT is an AI chatbot that uses natural language processing to create humanlike conversations. ChatGPT has recently gained considerable public interest, owing to its unique ability to simplify tasks from various backgrounds. Similarly, Google introduced Bard, an AI-powered chatbot to simulate human conversations. Herein, we investigated how ChatGPT and Bard (AI powdered chatbots) tools can impact water research through interactive sessions. Typically, ChatGPT and Bard offer significant benefits to various fields, including research, education, scientific publications, and outreach. ChatGPT and Bard simplify complex and challenging tasks. For instance, 50 important questions about water treatment/desalination techniques and 50 questions about water harvesting techniques were provided to both chatbots. Time analytics was performed by ChatGPT 3.5, and Bard was used to generate full responses. In particular, the effectiveness of this emerging tool for research purposes in the field of conventional water treatment techniques, advanced water treatment techniques, membrane technology and seawater desalination has been thoroughly demonstrated. Moreover, potential pitfalls and challenges were also highlighted. Thus, sharing these experiences may encourage the effective and responsible use of Bard and ChatGPT in research purposes. Finally, the responses were compared from the perspective of an expert. Although ChatGPT and Bard possess huge benefits, there are several issues, which are discussed in this study. Based on this study, we can compare the abilities of artificial intelligence and human intelligence in water sector research.

Durable hydrogel-based lubricated composite coating with remarkable underwater performances

HypothesisHydrogel coatings have received great attention in the field of such as medical devices, water treatment membranes, flexible electronics, and marine antifouling. However, when it comes to lubrication of hydrogel materials, though it has great potential applications in the field of industrial and medical drag reduction, some restrained properties are urgently needed to overcome for releasing the practical potential. ExperimentsDurability of high lubrication was revealed from the sliding test during the long-term storage, as well as the long-distance sliding. Some variables which possibly affect the lubrication performance were examined to demonstrate that excellent lubricity of the coating would not be easily influenced by load, frequency, friction pair and temperature. The microstructure and mechanical characterization of the lubricative coating indicate that the resistance to harsh running conditions is premised on enough hydration extent and robustness. The formulae of Possion ratio and ball-on-disk contact stress which apply to soft matter were used for calculating contact stress values in tribology tests. Anti-swelling and bio-compatibility are also verified. FindingsThis work found a route of achieving superior lubrication and coexisting with stability in lubrication, which can be used for drag reduction in medical devices and shipbuilding industry.

A Novel Method to Quantify Real-Time Compaction of Water Treatment Membranes

A Novel Method to Quantify Real-Time Compaction of Water Treatment Membranes

In situ modification of ultrafiltration membranes with eco-friendly pyrogallol/taurine to enhance antifouling performance

Fouling is a long-standing problem in water treatment membranes because it substantially deteriorates process efficiency. Here, we present a facile strategy for the in situ modification of polyethersulfone (PES) ultrafiltration (UF) membranes with eco-friendly antifouling materials (i.e., pyrogallol and taurine) to enhance their fouling resistance. When the PES dope solution was immersed into the nonsolvent containing pyrogallol and taurine, the phase separation and surface modification of the PES phase occurred simultaneously. Surface modification with taurine was mediated by pyrogallol, which reacted with taurine to form pyrogallol–taurine complexes. Amphiphilic pyrogallol–taurine complexes were effectively bound to the phase-transitioning PES, resulting in their uniform, dense, and robust deposition throughout the external and internal pore surfaces of the membrane without changing its pore structure. Consequently, the in situ-modified PES membrane exhibited remarkably higher surface hydrophilicity and a more negative charge than pristine PES. Importantly, the proposed in situ modification strategy significantly improved the protein anti-adhesive and antifouling properties of the pristine membrane and enhanced its permeance performance, which cannot be achieved by ex situ modification. Our study provides a facile antifouling strategy that can be applied to various membranes for water purification and desalination and extensively describes the underlying modification mechanism.

Selective filtration of dye by tannic acid‐molybdenum disulfide composite nanofiltration membrane

AbstractDye‐selective nanofiltration membranes have great potential for chemical dye separation and purification as well as dye wastewater treatment. Two‐dimensional materials such as molybdenum disulfide (MoS2) with excellent physical and chemical properties are ideal nanofiltration membrane materials. MoS2 with few layers is used in combination with polyphenols to prepare highly selective filtration nanofiltration membranes for cationic dyes. The tannic acid (TA)‐MoS2 composite material is constructed on the surface of a micro‐porous Mixed Cellulose Ester membrane by a vacuum filtration method, and the nanofiltration membrane exhibits good flexibility and excellent film‐forming properties. The maximum filtration efficiency of TAMoS2 nanocomposite film for R6G can reach 80%, while for EY and MO, it is only 9.6% and 6.1% respectively. Filtration studies on mixtures of two different types of dyes show that the composite nanofiltration membrane has excellent separation performance. The separation characteristics and mechanism of the composite nanofilm on dyes are carefully studied, showing good selectivity for cationic dyes, which can be ascribed to the synergistic effect of non‐covalent interactions and steric hindrance. This work paves the way for the use of eco‐friendly membranes for water and wastewater treatment and provides an environmentally friendly solution for various applications.