Water acts as one of the most important resources in hospitals for operative treatment and disinfection for epidemic prevention. Discharged wastewater contains a variety of viruses and bacteria, pathogenic microorganisms, antiviral and antibiotic agents and other toxic substances, partially metabolized pharmaceutical substances, organic compounds, radioactive elements, and ion pollutants (such as iodinated), which may harm both environmental and human health. It is an additional challenge in the prevention of this epidemic. However, there is a lack of attention on medical wastewater treatment. Membranes, with finely porous and nonporous structures, have rapidly developed for application in separation processes in recent years and show an enormous potential for water treatment. This review analyses and summarizes the advanced membrane technologies that can be applied for medical wastewater treatment with particular attention to the main components of medical wastewater and its effects. Membrane categories, critical factors and main performances in medical wastewater treatment are also highlighted. Following the summary of membrane applications, this review moves beyond material performance to critically examine the systemic engineering risks often overlooked in current research: specifically, the potential for post-treatment biological regrowth, the operational limitations of integrity monitoring, and the complexity of interpreting epidemiological signals from membrane-treated effluents. This tutorial review emphasizes the challenges associated with medical wastewater and its treatment by advanced membrane technologies in epidemic prevention.

Electro-driven membranes with monovalent ion selectivity represent a promising technology for sustainable lithium (Li) recovery from spent lithium-ion battery (LIB) leachate. However, existing membranes suffer from limited Li+ selectivity and low ion permeation rates. In this study, a zeolitic imidazolate framework (ZIF)embedded hydrogel electro-driven membrane was developed for selective Li+ extraction via electrodialysis (ED). A poly(dimethyl diallyl ammonium chloride) (PDDA) network-threaded ZIF (QZIF) layer was in-situ constructed within the hydrogel matrix of Kevlar aramid nanofibers (KANFs), forming a stable composite layer on a sulfonated polysulfone (SPSF) substrate. Benefiting from the synergistic effects of size sieving and electrostatic repulsion, the resulting QZIF@KANF#SPSF membrane exhibited rapid Li+ transport while effectively rejecting larger divalent ions (Ni2+, Co2+, and Mn2+). During ED at 5 mA cm-2, the QZIF@KANF#SPSF membrane achieved a Li+ permeation rate of 0.45 mol m-2 h-1 in a 25 mM Li+, Ni2+, Co2+, and Mn2+ mixed solution, with high permselectivities of 13.8, 12.2, and 10.5 for Li+/Ni2+, Li+/Co2+, and Li+/Mn2+, respectively. This strategy of embedding charged ZIFs within a hydrogel matrix provides a robust and scalable pathway for enhancing Li+ selectivity and transport efficiency in advanced separation processes for spent LIB recycling.

ABSTRACT Efficient phosphate recovery from phosphate‐containing wastewater presents a dual opportunity to mitigate environmental pollution and secure nutrient supply for agriculture. Among many recovery methods, electro‐membrane crystallization (e‐MC) is a promising strategy for sustainable phosphate recovery, yet the low phosphate throughput of conventional electro‐driven membranes constrains its efficacy. Here, we propose an ion carrier‐to‐carrier hopping transport principle and introduce a nanostructured electro‐driven carrier‐conducting membrane (e‐CCM) engineered with monodispersed electro‐ferrihydrite nanoparticles as a built‐in phosphate carrier. This membrane architecture establishes a coordination environment where ≡FeOH acts as transient phosphate binding sites, and the applied electric field promotes directional phosphate migration, thereby accelerating phosphate permeation. Operated at 5 mA cm −2 , the resulting e‐CCM membrane achieves a phosphate permeation rate of 0.92 mol m −2 h −1 and a recovery rate of 98.8%, outperforming state‐of‐the‐art ion exchange membranes. We further demonstrate scalability by integrating the e‐CCM membrane in e‐MC for processing simulated urine, achieving 93.6% phosphate recovery and the precipitation of high‐purity struvite. This work pioneers a hypothesis of carrier‐conducting construction that synergizes membrane electrochemical transport with chemical affinity, establishing a scalable and energy‐efficient pathway to close the phosphorus loop and advance circular resource economies.

Ultrafiltration (UF) faces the dual challenges of membrane fouling and low small-sized virus removal. This study found that Fe(II)/peracetic acid (F/P) pretreatment significantly reduced irreversible resistance while achieving high virus removal (similar to 5.71 log, with the pretreatment inactivation approximately 3.67 log), thereby breaking the traditional trade-off between high virus removal and high irreversible fouling. From the perspective of floc regulation to interface optimization, and comparing with the conventional Fe(II)/H2O2 (F/H) system, we elucidated the synergistic mechanism of F/P pretreatment through integrated water quality analysis, floc characterization, interfacial thermodynamics, fouling modeling, and Spearman correlation analysis: (i) efficient degradation of hydrophobic organic matter, reducing irreversible fouling; (ii) enhanced membrane hydrophilicity, weakening hydrophobic adhesion and delaying dense fouling layer formation; (iii) formation of a loose, particle-stacked cake layer by iron flocs, trapping viruses within its deep pores, with irreversible retention being the primary contributor to virus removal during UF. Spearman correlation analysis further confirmed that virus removal rate was significantly positively correlated with DOC removal (r = 0.838), polysaccharide removal (r = 0.672), and standard blocking R-2 (r = 0.790), while negatively correlated with irreversible resistance (r = -0.779), reflecting the high oxidation-coagulation intensity of F/P pretreatment simultaneously promoted water purification, fouling mitigation, and virus removal. The extremely low concentration of free viruses in backwash water reduced the biosafety risks of backwash water reuse. This study provides a theoretical basis for developing low-energy, high-safety UF pretreatment technologies.

Control of waterborne pathogens by chemical- and energy-intensive disinfection methods poses significant challenges in underdeveloped regions. Here, plant-derived photosensitive carbon composites with a photo-allosteric strategy are proposed as a novel approach for designing green and responsive systems for controllable capture and inactivation of viruses. A composite comprising porous carbon, gallic acid, ε-polylysine and curcumin was synthesized and exhibited dual functions. In the dark, electrostatic attractions from ε-polylysine chains and electron shuttle through the graphene-like carbon matrix enable rapid viral adsorption (> 6-log removal within 30 min). Under illumination, curcumin-triggered singlet oxygen (1O2) achieves effective virus inactivation (> 6-log removal within 10 min; > 7-log within 30 min) while simultaneously restoring active sites. Importantly, this in situ1O2 further induces the conformational transitions of ε-polylysine into compact, oxidation-resistant structures, ensuring a sustained antiviral performance under the light-dark cycles and repeated viral challenges. By activating the intrinsic properties of plant-derived porous carbon, herbal extracts, and poly(amino acid)s, this work establishes a green, locally sourced water treatment strategy to ensure water biosafety. This photo-responsive interfacial engineering strategy also holds promise to develop materials for personal protective equipment and medical environments.

Mineral scaling, driven by concentration polarization, is an inevitable challenge in electro-membrane technologies for recovering valuable metals from lithium-ion battery (LIB) leachates. Here, we elucidate the synergistic scaling mechanism and propose an electric field-assisted organic acid control (eF-OAC) principle to prevent membrane mineral scaling while enabling metal recovery. The eF-OAC utilizes an electric field to direct organic acids into the membrane matrix, where ligand-metal coordination dissolves hydroxide-rich scale and mobilizes metal species for selective transport and crystallization. Dynamic experimental analysis reveals that concentration polarization enriches metal hydroxides at the membrane interfaces and pores. Static density functional theory calculations further demonstrate that organic ligands are thermodynamically favored over sulfonate groups for coordinating metal hydroxides, enabling targeted dissolution from the membrane. Leveraging this molecular-level selectivity, the eF-OAC converts scale into recoverable crystalline products. In optimized electro-membrane crystallization, this eF-OAC achieves high recovery rates of 97.6% for Li+, 95.3% for Ni2+, 94.2% for Co2+, and 97.8% for Mn2+. It further yields high-purity Li2SO4 (99.4%), Ni(OH)2 (99.2%), Co(OH)2 (99.0%), and Mn3O4 (99.3%). This study clarifies the mechanisms of mineral scaling and demonstrates a scaling-free approach that transforms fouling liabilities into valuable resource recovery for spent LIBs.

Gravity-driven catalytic membrane filtration offers a promising low-energy strategy for removing pharmaceutically active compounds (PhACs). Nevertheless, achieving high degradation efficiency remains challenging, especially when coupling enhanced intrinsic catalytic activity with improved hydraulic properties. In this study, a series of CoxFey-LDH/PVA nanofibrous catalytic membranes with varying Co/Fe molar ratios were fabricated via a facile hydrothermal method. The LDH-mediated peroxymonosulfate (PMS) activation and the degradation of a model PhACs (tetracycline (TC)) were evaluated under a flow-through operation. Among them, the optimized Co3Fe1-LDH/PVA exhibits the best overall performance, achieving 97.23% TC removal rate and an ultra-high water permeance of 397 L m⁻2 h⁻1 with an apparent rate constant of 567.44 min⁻1. Its superior performance is associated with the optimized Co/Fe ratio of 3, which favors stronger TC–membrane interaction, faster interfacial electron transfer, and more efficient PMS activation. Dynamic filtration experiments reveal that TC degradation is jointly governed by external and internal mass transfer together with intrinsic catalytic activity, which are collectively determined by the molar flux and hydraulic residence time. Mechanistic investigation indicates that 1O2 is the dominant reactive species, while SO4·- also contributes to TC degradation. In addition, Co3Fe1-LDH/PVA exhibits effective removal of alternative representative PhACs, considerable operational stability, and acceptable tolerance toward complex water matrices. This work provides a feasible strategy for developing highly permeable catalytic nanofibrous membranes for decentralized, low-energy water purification.

Membrane techniques have garnered much attention for the selective separation and purification of lithium from salt lakes due to their environmental friendliness, based on a physical separation mechanism without the addition of chemicals. The urgent need to recover lithium from salt lakes is hampered by the intrinsic permeance-selectivity trade-off in membrane technologies. Despite its importance, reviews specifically focusing on this trade-off in the context of lithium harvesting remain scarce. Accordingly, this review analyzes the permeance-selectivity trade-offs of various membrane technologies in lithium recovery from salt lakes. A systematic framework is established on the basis of lithium permeance and Li+/Mg2+ selectivity, resulting in a permeance-ion/ion selectivity trade-off fundamentally distinct from the conventional permeance-water/ion trade-off. The key mechanisms, advanced theories, and modeling and simulation results for ion transport through membranes are highlighted. Furthermore, challenges and potential solutions for these membrane technologies are summarized. Future research needs to bridge the gap between the laboratory conditions and the real-world environments for lithium separation and recovery from salt lakes are suggested accordingly. This review will provide a solid basis to guide the future development of membrane technologies for selective resource separation and recovery.

The increasing water pollution calls for more effective and sustainable treatment technologies. Conventional technologies face critical challenges such as fouling, struggling with emerging micropollutants, and limited mass transfer. Electrocatalytic membranes (ECMs) couple convective transport through a porous membrane-electrode with interfacial electrochemical reactions, enabling simultaneous separation and contaminant transformation in compact process trains. High removal efficiencies are governed by permeation-enhanced mass transfer and current distribution rather than intrinsic catalytic activity. The dominant removal pathway shifts among electrosorption, direct electron transfer, and indirect oxidation. ECMs also reduce fouling via electrostatic repulsion and in-situ redox reactions, suitable for various organic pollutants, including pharmaceuticals and micropollutants, while also enabling resource recovery from wastewater. However, they are limited by durability and secondary burdens, including catalyst deactivation or leaching, pore blockage, catalytic instability, sludge management, and energy-intensive fabrication routes for ceramic ECMs. This review provides a comprehensive overview of ECM fabrication strategies, system configurations, and their multifunctional roles in water treatment. Emerging frontiers include single-atom ECMs that maximize atom utilization and enable tunable reactive-species selectivity, and machine-learning-assisted design frameworks that accelerate multi-objective optimization of catalyst-architecture-operation for durability and by-product control. Standardized metrics linking energy use, current efficiency, by-products, and long-term ageing and life-cycle analyses are essential for scalable deployment of ECM technology.

Ultrafiltration is critical for water reclamation, yet membrane fouling, biostability, and biosafety remain coupled hurdles. This study identified the bio-cake as an ecological interface linking the three challenges and introduced a Ca2+-enabled backwash to reshape its function. The optimal Ca2+ level (0.05 mM) reduced pore fouling, promoted a thinner and more porous bio-cake formation, thereby improving hydraulic performance. Source tracking revealed that permeate microorganisms originated mainly from biofilm detachment on the membrane permeate-side and pipe surface, rather than incomplete membrane retention. The engineered bio-cake enhanced assimilable organic carbon (AOC) removal, with permeate AOC dropping by 42% on day 22 compared to the control group. This AOC reduction restricted the in-situ niche of the relevant microbial sources, leading to a lower initial total cell count (TCC) in permeate, and, critically, attenuated microbial regrowth during storage, thereby improving biostability. From a biosafety perspective, the bio-cake microorganisms accelerated pathogen inactivation through carbon competition, thereby preventing the pathogen leakage into the permeate. Mechanistically, the optimal Ca2+ level stimulated microbial activity and selected heterotrophic taxa with broad substrate utilization. Enrichment of carbohydrate-active enzymes and diverse metabolic pathways enhanced AOC biodegradation, while improved quorum sensing, cofactor supply, and stress resistance supported stable community function. This work recasts the bio-cake from a risk carrier to a functional barrier and provides an ecological engineering strategy that couples fouling control with simultaneous gains in reclaimed water biostability and biosafety.

Formaldehyde (HCHO) is class 1 carcinogen. In the food supply chain, some vendors illegally use formalin (HCHO aqueous solution) to soak food products in order to extend their shelf life. Eating this food can increase the risk of developing malignant diseases such as leukemia and breast cancer. Therefore, it is crucial to develop portable sensors with high sensitivity, selectivity, and stability for HCHO detection. In this study, Fe/Ni-BTC derived Fe2O3/NiO nanoparticles are grown in situ on g-C3N4 nanosheets, forming a unique g-C3N4/Fe2O3/NiO ternary composite. Gas-sensing test results indicate that the g-C3N4/Fe2O3/NiO sensor exhibits excellent gas-sensing performance at 240 °C to 50 ppm HCHO, including superior selectivity, high response (44.95), low theoretical detection limit (50.1 ppb) and long-term stability (60 days). We have further developed a portable HCHO detection system that has been successfully applied to detect residual HCHO in simulated aquatic products (fresh shrimp). This provides an effective monitoring approach to counteract the illegal use of HCHO for preventing food spoilage. It holds broad application prospects in the fields of environmental monitoring and food safety.

Ultrafiltration is central to water reclamation but faces two critical challenges: microbial regrowth that threatens biostability and pathogen invasion that undermines biosafety. Here, we proposed an ecological strategy that transformed backwash from a cleaning procedure into a microbiome engineering tool, thereby simultaneously addressing both challenges. Our findings provided evidence for the major microbial sources in permeate, including membrane breakthrough, detachment from the membrane permeate side, and from downstream pipeline surfaces. High-salinity backwash (100 mM NaCl) suppressed the latter two dominant sources, reducing permeate total cell counts (TCC) by more than 50%. It also enhanced the removal of assimilable organic carbon (AOC), thereby limiting microbial regrowth in the permeate by 32% during 40 day storage. Under pathogen shock loading, the salinity-driven biocake layer accelerated pathogen inactivation, reduced pathogen accumulation by 86.9%, and thereby prevented pathogen leakage into the permeate. The mechanism analysis revealed that NaCl reshaped the biocake microbiome, enhancing deterministic assembly. This functionally specialized consortium showed strengthened cooperation and upregulated key metabolic pathways, enabling synergistic AOC degradation. In addition, it suppressed pathogen invasion through superior carbon competitiveness and secretion of antimicrobial metabolites. This work provided an ecological engineering approach to enhance both biostability and biosafety in ultrafiltration-based water reuse systems.

Partial replacement of the organic linkers of metal-organic frameworks (MOFs) often optimizes their functionalities, however, accurate characterization of their molar ratios in many cases is challenging. This work presents a method of determining such linker ratios via measurements of the magnetic susceptibility of small quantities of powdered samples. The main presumption is taking the diamagnetic and paramagnetic contributions to the molar magnetic susceptibility of the two parent MOFs to be additive. To verify this, four examples are provided with commonly used MOFs to represent the cases when both parent MOFs are either paramagnetic or diamagnetic but with different linkers with the following systems: [MIL-101(Cr)-SO3H]1-δ[MIL-101(Cr)-NO2]δ, [EuMOF](1-δ)[EuPDCA]δ, [UiO-66-COOH](1-δ)[UiO-66]δ, and [MIL-101(Cr)F Free]1-δ[MIL-53(Al)]δ, where 1-δ: δ are the ratios to be determined. Depending on whether the systems were strictly paramagnetic, strictly diamagnetic or mixed, the experimental error of δ ranged between 0.00002 and 0.012, respectively. We expect the presented method to be widely employed since samples only need to be in powdered form and because there is a lack of characterization tools in the area of MOF linker ratios. The presented method is also applicable to resolving the ratios of mixed ordinary paramagnetic systems as well as other types of nonmagnetic composite materials such as tapes, zeolites and thin films.

Innovations in self-assembly and aggregate engineering have led to membranes that better balance water permeability with salt rejection, overcoming traditional trade-offs. Here we demonstrate a strategy that uses multivalent H-bond interactions at the nano-confined space to manipulate controllable and organized crystallization. Specifically, we design amphiphilic oligomers featuring hydrophobic segments with strongly polar end-capped motifs. When spreading on air/water interfaces, the hydrophobic parts repel water, yielding an ordered alignment of supramolecular oligomers under nano-confinement, while the strongly polar sections engage in strong hydrogen bonding and reconfigure to strongly interact with water molecules, enabling the controlled assembly and orientation of nano-confined crystalline domains. This arrangement provides dual benefits: refining the distribution of pore sizes for ultra-selectivity and boosting the free volume for water permeation. Compared to counterpart oligomers with weakly polar motifs, the optimized membrane with a 6-nm thickness demonstrates the water permeability of 14.8 L m−2 h−1 bar−1 and extraordinary water/NaCl selectivity of more than 54 bar−1 under pressure-driven condition. This study sheds light on how nano-confined self-assembly and aggregate engineering affect the architectures, functionality, and performance of polymer membranes, emphasizing the promise of controllable crystallization in ultrathin membranes for optimal desalination. Membranes with a balance between water permeability and salt rejection are desirable, and can be developed through self-assembly and aggregation. Here, the authors report a hydrogen-bonding strategy in a nanoconfined space to give controlled crystallisation, for membranes for reverse osmosis.

The conventional Fenton system suffers from critical limitations, including significant pH dependence and inefficient iron cycling. This study innovatively developed a Fe(II)/peracetic acid (PAA) hybrid disinfection system, systematically investigating its viral inactivation performance and molecular mechanisms under near-neutral conditions. The results demonstrated that this system achieved above 5 logs viral inactivation (under 50 μM Fe(II)/50 μM PAA, pH 3-7) through a unique three-stage mechanism. This mechanism included radical burst, self-catalytic iron cycling and coordination environment reconstruction, inducing deformation and conformational changes in capsid protein. Notably, non-radical species (Fe(IV) and 1O2) consistently accounted for over 50% of total inactivation efficiency. Steady-state concentration calculations, cumulative reactive species quantification, and 30% Fe(II) regeneration observed within 30 min all jointly confirmed the virus enhanced Fe(II)/Fe(III) cycling. Study on the mechanism revealed that the components of virus capsid performed dual roles: sulfur-containing amino acids (e.g., cysteine) acted as oxidation targets, while aromatic residues (e.g., phenylalanine) served as catalytic sites. Through strong coordination interactions via Fe(III)-π intermediates, an efficient Fe(II)/Fe(III) coupling cycle was achieved. This system reveals a novel mechanism whereby the virus itself catalyzes and enhances iron cycling. In practical applications, it is expected to reduce chemical reagent usage and decrease iron sludge production, offering a new pathway for developing cost-effective green disinfection technologies.

Nanotechnology advancements have significantly contributed to the development of thin-film nanocomposite (TFN) reverse osmosis membranes for addressing global water scarcity through more efficient separation and purification processes. However, the impact of nanomaterials on membrane preparation, structure, and performance remains insufficiently understood. In this study, graphitic carbon nitride/polydopamine (g-C3N4/PDA) incorporated TFN membrane was proposed and systematically investigated through experimental methods and molecular dynamics (MD) simulations. The incorporation of g-C3N4/PDA increased the resistance to MPD diffusion during the interfacial polymerization process, the obtained TFN membrane displayed a thinner, smoother active layer and enhanced hydrophilicity. Therefore, the membrane exhibited a remarkable water flux of 53.43 L center dot m-2 center dot h-1, triple that of the conventional membrane, with a NaCl rejection of 98.9 %. Meanwhile, the TFN membrane displayed excellent antifouling properties against both organic, inorganic and mixed foulants, maintaining a high flux recovery rate during long-term operation. MD simulation further revealed the stable interaction between g-C3N4/PDA nanocomposites and the polyamide matrix, enhancing structural compatibility and improving membrane performance. This study provides insights into the role of nanomaterials in the active layer of the membrane, offering both theoretical and practical guidance for the design of advanced TFN membranes with enhanced water permeance and antifouling performance.

Membranes with precise ion transport behaviors are regarded as an alternative for lithium (Li) extraction from water streams. Current membranes demonstrate limited viability due to the lack of efficient Li + -selective architectures. We propose an electric field–assisted ion control hypothesis in reinforcing ultraefficient Li + -selective membranes, in which an ionized zeolitic imidazolate framework layer (Q-PEI@ZIF) is constructed via polyethylenimine (PEI) in situ confinement conversion and subsequent quaternization of 2,3-epoxypropyl trimethyl ammonium chloride. In electrodialysis at 5 milliampere per square centimeter, the resulting membrane Q(5%)-PEI(1.0)@ZIF#CEM shows that the ion permeation rates follow the order of K + ~ Li + > Na + > Ca 2+ ~ Mg 2+ , corresponding to 0.31, 0.30, 0.25, 0, and 0 mole per square meter per hour in 120 minutes, respectively. With a 25-millimolar Li + /Mg 2+ mixed solution, it exhibits an unprecedented Li + /Mg 2+ permselectivity of 20,000 and 99.99% purity of Li + product in 120 minutes. This study expands the hypothesis of electric field–assisted ion control in enabling an ultraefficient Li + -selective construction.