Covalent Organic Framework Membranes Research Articles

Understanding the effect of layer spacing on water desalination through two-dimensional covalent organic framework membranes via molecular dynamics simulation

The desalination performance of covalent organic framework (COF) membrane can be tuned through adjusting its layer spacing, which can improve the water permeance while maintaining high ion rejection rate. However, the mechanism of the influence of COF membrane spacing on its seawater desalination performance is still unclear. In this work, the molecular dynamics (MD) simulation were performed to systematically investigate the influence of the layer spacing on desalination performance of AB-stacked MPCOF, including 0.34 nm, 0.44 nm, 0.54 nm and 0.64 nm. The findings indicated a decrease in the resistance of water molecules passing through the AB stacked MPCOF membrane, leading to a significant increase in water permeance as the layer spacing increases. The interlayer spacing of the COF membrane also significantly influenced its interactions with ions. When the layer spacing exceeded 0.44 nm, the ion rejection rate began to decrease. As a result, the AB-stacked MPCOF membranes with 0.44 nm possessed the superior desalination performance, which was much better than other conventional membranes. Our work explored the mechanisms of the effects of COF layer spacing on desalination performance, which might provide valuable suggestions for the optimization of subsequent COF desalination membranes.

Ultrathin PEI-functionalized carboxyl covalent organic framework membranes for efficient CO2/N2 separation

Covalent organic frameworks (COF) are deemed as disruptive membrane materials owing to their versatile functionalities, high stability and ordered nanochannels. However, the size mismatch between the COF intrinsic pore and gas molecules becomes a grand challenge when using COF membrane for carbon capture. Herein, we propose a new type of polymer-functionalized COF laminar membranes through grafting CO2-phlic polyethyleneimine (PEI) polymer onto carboxylic acid COF (cCOF) laminar membranes. The cCOF nanosheets with high density of carboxyl groups are prepared via modified single phase solution method and then assembled to fabricate membranes. Further, the cCOF membranes are functionalized with PEI using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-Hydroxysuccinimide (EDC/NHS) coupling chemistry. The introduction of abundant amino groups from PEI afford the affinity of membranes toward CO2. Meanwhile, the graft of the PEI polymers reduces the defects or pinholes on the membrane surface. As a result, the PEI functionalized cCOF membranes exhibit a high CO2 permeance of 1004 GPU and a CO2/N2 selectivity of 33.7, which reach the carbon capture target performance and show great prospect for treating real flue gas. Our approach of functionalizing cCOF membranes with tailored functionalities may inspire the design of molecule-selective COF membranes.

Effect of Tautomerization on Water Desalination by Covalent Organic Frameworks

Covalent organic frameworks (COFs) have gained increasing interest as promising building blocks for desalination membranes due to their inherent porosity. Efforts have been made to prepare COF membranes and explore their transport mechanisms, however the effect of tautomerization has not been reported. Using non-equilibrium molecular dynamics, we discover here that a mere 0.5-Å atomic displacement between two tautomers of an imine-based COF (TpHZ) can surprisingly lead to dramatic changes in the desalination behavior of their multilayers. The tautomeric transformation (from TpHZ-NH to TpHZ-OH) improves the water permeability by about 1.6–3 times. The interior resistance rather than the entrance resistance is found to dominate the water transport. The weaker adhesion and the smoother channel path of TpHZ-OH result in a much lower interior resistance. Furthermore, NaCl rejection increases from ∼ 89 % to 100 % due to the stronger sieving effect resulting from the reduced compensatory effect of TpHZ-OH for ion hydrations.

Construction of covalent organic frameworks membranes in situ through nonsolvent-induce phase separation for fast and accurate nanofiltration

With the development of covalent organic frameworks (COFs), their superior separation performance in membrane separation has gradually becoming apparent. The method of combining COFs with membrane materials is crucial for their applications prospect. In this study, inspired by the traditional Chinese mortise and tenon structure, we selected 1,3,5-triacetaldehyde mesityl phenol (TFP) and 1,3,5-tris(4-aminophenyl)benzene (TAPB) as the reactive building monomers. P-Phenylenediamine (PDA) was introduced into the casting solution to construct Polyether-sulfone (PES) bottom membranes with amino ligand sites, utilizing the phase transition effect generated by the non-invasive solvent-induced method (NIPS). Subsequently, COFs composite nanofiltration membranes with two-dimensional layered structures were prepared through mild interfacial polymerization (IP) under optimized reaction conditions. The synthesis of COFs composite nanofiltration membranes was demonstrated through a series of characterizations, including scanning transmission electron microscopy and infrared spectroscopy. The COFs composite nanofiltration membranes synthesized by this method exhibited better alignment, greater chemical stability, and higher separation efficiency compared to traditional interracially polymerized COFs composite nanofiltration membranes. As the method involves the addition of additives, it can be more widely applied to a broad range of organic polymer membranes. Furthermore, we demonstrated the effectiveness of the COF composite nanofiltration membranes produced using this method in the separation of molecular dyes. They exhibited rejection exceeding 99% for 0.1 g L−1 methyl blue (MB), Congo red (CR) and chrome black-T (EBT). Additionally, they achieved separation fluxes of up to 300 L m−2 h−1 bar−1 for mixed solutions (dyes/salts) and proved to be effective under extreme conditions, such as 1 M HCl/NaOH. Moreover, COFs-NH2PES composite nanofiltration membranes exhibited the ability to efficiently separate dye molecules of different sizes. This work introduces new ideas for constructing stable and durable COF functional composite membrane materials for practical applications.

Decoupling synthesis and crystallization of covalent organic frameworks (COFs) for more crystalline layer targeting high efficiency dye separation

Covalent organic frameworks (COFs) are crystalline porous materials composed of organic building blocks linked by covalent bonds, which have attracted great attention for membrane–based separation applications. However, fabrication of COF membranes with high quality and performance remains a challenge, especially for the β–ketoenamine linked COFs. In the conventional IP methods, the synthesis process (the Schiff–base reaction of the monomers and the tautomerism of the oligomers) and the crystallization process (the self–assembly of the oligomers) of the COFs materials occur simultaneously on the surface of the support membrane, which can result in low crystallinity, high defect density, and poor separation performance of the COF layer. In this study, a novel strategy for fabricating large-area, defect–free COFs composite membranes by interfacial polymerization (IP) was presented to overcome this problem. By incorporating both the amine and aldehyde monomers in one organic phase, and dissolving organic acid catalyst in another phase (the water), the synthesis process mostly take place in the bulk of the organic phase, while the crystallization occurs on the surface of the support membrane under the influence of the organic acid catalyst. This strategy effectively decoupled the synthesis process with the crystallization, providing a stable growth region for crystalline layer, ultimately leading to the formation of a thin, defect–free and highly ordered COF layer on the support membrane. The strategy was demonstrate by synthesis of triformylphloroglucinol phenylenediamine (TpPa)–Ⅱ/Poly(m–phenylene isophthalaminde) (PMIA) composite membrane. We characterize the structure and morphology of the TpPa–Ⅱ/PMIA composite membrane by various analytical techniques to verify our hypothesis, and evaluate its separation performance using pure water permeance and dyes retention rate as indicators. The results show that the TpPa–Ⅱ/PMIA composite membrane has an 80 nm thick top-layer with regular COF structure and orderly pores. It exhibits an excellent dye separation performance, with a (pure water permeance) PWP of 105.6 L·m−2·h−1·bar−1 and CR rejection of 99.2 %, which surpasses most of the TpPa–type COFs composite membranes reported in literature, as well as the reference (TpPa–I/PMIA membrane) in this work. Moreover, the TpPa–Ⅱ/PMIA composite membrane maintains both its performance and structural stability during a 240–hour cross–flow filtration of the dye solution, demonstrating its excellent potential in the dye wastewater treatment.

Self-standing perylene diimide covalent organic framework membranes for trace TMA sensing at room temperature

The unprecedented demand for highly selective, real-time monitoring and low-power gas sensors used in food quality control has been driven by the increasing popularity of the Internet of Things (IoT). Herein, the self-standing perylene diimide based covalent organic framework membranes (COFMPDI-THSTZ) were prepared via liquid–liquid interfacial synthesis method. By incorporating the perylene diimide monomer into the COFM through molecular engineering, COFMPDI-THSTZ based sensor demonstrated an outstanding trimethylamine (TMA)-sensing performance at room temperature. Benefited from the TMA-accessible self-standing membrane morphology, π-electron delocalization effect, and extensive surface area with continuous nanochannels, the specific and highly sensitive TMA measurement has been achieved within the range of 0.03–400 ppm, with an exceptional theoretical detection limit as low as 10 ppb. Moreover, the primary internal mechanism of COFMPDI-THSTZ for this efficient TMA detection was investigated through in-situ FT-IR spectra, thereby directly elucidating that the chemisorption interaction of oxygen modulated the depletion layers on sensing material surface, resulting in alterations in sensor resistance upon exposure to the target gas. For practical usage, COFMPDI-THSTZ based sensor exhibited exceptional real-time in-situ sensing capabilities, further confirmed their potential for application in dynamic prediction evaluation of marine fish products and quality monitoring in IoT.

Enhancing ion selectivity by tuning solvation abilities of covalent-organic-framework membranes

Understanding the molecular-level mechanisms involved in transmembrane ion selectivity is essential for optimizing membrane separation performance. In this study, we reveal our observations regarding the transmembrane behavior of Li+ and Mg2+ ions as a response to the changing pore solvation abilities of the covalent-organic-framework (COF) membranes. These abilities were manipulated by adjusting the lengths of the oligoether segments attached to the pore channels. Through comparative experiments, we were able to unravel the relationships between pore solvation ability and various ion transport properties, such as partitioning, conduction, and selectivity. We also emphasize the significance of the competition between Li+ and Mg2+ with the solvating segments in modulating selectivity. We found that increasing the length of the oligoether chain facilitated ion transport; however, it was the COF membrane with oligoether chains containing two ethylene oxide units that exhibited the most pronounced discrepancy in transmembrane energy barrier between Li+ and Mg2+, resulting in the highest separation factor among all the evaluated membranes. Remarkably, under electro-driven binary-salt conditions, this specific COF membrane achieved an exceptional Li+/Mg2+ selectivity of up to 1352, making it one of the most effective membranes available for Li+/Mg2+ separation. The insights gained from this study significantly contribute to advancing our understanding of selective ion transport within confined nanospaces and provide valuable design principles for developing highly selective COF membranes.

Covalent Organic Framework Membranes and Water Treatment.

Covalent organic frameworks (COFs) are an emerging class of highly porous crystalline organic polymers comprised entirely of organic linkers connected by strong covalent bonds. Due to their excellent physicochemical properties (e.g., ordered structure, porosity, and stability), COFs are considered ideal materials for developing state-of-the-art separation membranes. In fact, significant advances have been made in the last six years regarding the fabrication and functionalization of COF membranes. In particular, COFs have been utilized to obtain thin-film, composite, and mixed matrix membranes that could achieve effective rejection (mostly above 80%) of organic dyes and model organic foulants (e.g., humic acid). COF-based membranes, especially those prepared by embedding into polyamide thin-films, obtained adequate rejection of salts in desalination applications. However, the claims of ordered structure and separation mechanisms remain unclear and debatable. In this perspective, we analyze critically the design and exploitation of COFs for membrane fabrication and their performance in water treatment applications. In addition, technological challenges associated with COF properties, fabrication methods, and treatment efficacy are highlighted to redirect future research efforts in realizing highly selective separation membranes for scale-up and industrial applications.

Bioinspired Gradient Covalent Organic Framework Membranes for Ultrafast and Asymmetric Solvent Transport.

Gradients play a pivotal role in membrane technologies, e.g., osmotic energy conversion, desalination, biomimetic actuation, selective separation, and more. In these applications, the compositional gradients are of great relevance for successful function implementation, ranging from solvent separation to smart devices; However, the construction of functional gradient in membranes is still challenging both in scale and directions. Inspired by the specific function-related, graded porous structures in glomerular filtration membranes, a general approach for constructing gradient covalent organic framework membranes (GCOMx) applying poly (ionic liquid)s (PILs)as template is reported here. With graded distribution of highly porous covalent organic framework (COF) crystals along the membrane, GCOMx exhibts an unprecedented asymmetric solvent transport when applying different membrane sides as the solvent feed surface during filtration, leading to a much-enhanced flux (10-18 times) of the "large-to-small" pore flow comparing to the reverse direction, verified by hydromechanical theoretical calculations. Upon systematic experiments, GCOMx achieves superior permeance in nonpolar (hexane≈260.45 LMH bar-1) and polar (methanol≈175.93 LMH bar-1) solvents, together with narrow molecular weight cut-off (MWCO, 472g mol-1) and molecular weight retention onset (MWRO, <182g mol-1). Interestingly, GCOMx shows significant filtration performance in simulated kidney dialysis, revealing great potential of GCOMx in bionic applications.

Biomimetic construction of smart nanochannels in covalent organic framework membranes for efficient ion separation

Smart nanochannels can regulate ion transport behavior by external stimulus and display precise ion selectivity in biological membrane systems, but constructing artificial membranes with responsive and tunable channel remains a severe challenge. Herein, smart covalent organic framework (COF) membranes decorated with photo-responsive azobenzene derivatives (COF-Azo) were fabricated by a biomimetic nanochannel modulation (BNM) strategy, endowing membranes with charged and switchable sub-nanochannels. Under different wavelength of light, the smart COF-Azo membranes simultaneously exhibited outstanding mono/monovalent and mono/divalent ion selectivity (K+/Li+ ideal selectivity of 17.9 and Li+/Mg2+ ideal selectivity of 24.9) via closing and opening channels. The conversion of effective pore size at angstrom level is realized by photoisomerization of azobenzene. After several photoswitch cycles, the smart membranes still maintained K+/Li+ selectivity of 6.1 and Li+/Mg2+ selectivity of 20.7 in mixed salt solution, exhibiting great potentials in lithium extraction. This work may blaze a trail in constructing photo-responsive nanochannel membranes for energy-efficient ion separation.

Ionic Covalent Organic Framework-Based Membranes for Selective and Highly Permeable Molecular Sieving.

Two-dimensional covalent organic frameworks (COFs) with uniform pores and large surface areas are ideal candidates for constructing advanced molecular sieving membranes. However, a fabrication strategy to synthesize a free-standing COF membrane with a high permselectivity has not been fully explored yet. Herein, we prepared a free-standing TpPa-SO3H COF membrane with vertically aligned one-dimensional nanochannels. The introduction of the sulfonic acid groups on the COF membrane provides abundant negative charge sites in its pore wall, which achieve a high water flux and an excellent sieving performance toward water-soluble drugs and dyes with different charges and sizes. Furthermore, the COF membrane exhibited long-term stability, fouling resistance, and recyclability in rejection performance. We envisage that this work provides new insights into the effect of ionic ligands on the design of a broad range of COF membranes for advanced separation applications.

Highly Flexible and Self‐Standing Covalent Organic Framework–Metal–Organic Framework (COF–MOF) Composite Crystalline Porous Material (CPM) Membrane for Molecular Separation

AbstractCrystalline porous materials (CPMs), including covalent organic frameworks (COFs) and metal–organic frameworks (MOFs), are promising materials for advanced separation technologies. However, the challenge of transforming nanoscale CPMs into large‐area functional membranes hinders their application in the membrane separation process. Herein, a self‐standing pure COF (TpPa‐1) nanofiber membrane with high crystallinity, good flexibility, excellent mechanical properties, and scalability is prepared using an electrospinning process and polymer sacrificial template strategy. Subsequently, the COF nanofiber membrane is innovatively used to replace traditional inorganic discs, metal meshes, and polymer membranes as porous supports, and the COF–MOF composite CPM membrane is prepared through the tailorable and confined growth of zeolite imidazolium salt frame‐8 (ZIF‐8) on the surface of the COF membrane and in the gaps of the COF nanofibers. The COF–MOF composite membrane exhibits excellent permeability and significantly enhances separation selectivity for organic dyes. Moreover, MOF and COF form an interpenetrating network structure, and their similar chemical properties improve the interfacial stability between the two phases, giving the COF–MOF composite membrane good long‐term separation performance. This is the first self‐standing composite CPM membrane with excellent molecular sieving performance, which provides new insights into the design of high‐performance and robust composite membranes.

Surfactant-assisted interfacial polymerization towards high-crystallinity COF membranes for organic solvent nanofiltration

Preparing high-crystallinity covalent organic framework (COF) membranes by interfacial polymerization remains a grand challenge. Herein, a monomer pre-assembly process is proposed to prepare high-crystallinity COF membranes by surfactant-assisted interfacial polymerization (SAIP) strategy. The self-assembled chains of amphiphilic surfactants across interface can gather and pre-assemble monomers and improve their interphase transport for complete topological growth. Apart from the reduction in polymerization time from over 72 h–48 h, the crystallinity and pore uniformity of COF membranes are highly enhanced. This strategy is universal and four kinds of amine monomers are utilized to tune COF pore size. The 1.8 nm-sized COF membrane shows highly enhanced rejection from 65.5% to 95.7% for reactive black with a size of 2.0 nm, when compared to that without surfactants. Importantly, the orderly stacked pores permit fast molecule transport with a 76% increase in acetonitrile permeance (366.9 L m−2 h−1 bar−1). Meanwhile, the robust crystal properties endow this COF membrane with excellent solvent resistance, compressive strength, and hence operational stability for over 100 h. The amphiphilic molecule-assisted interface engineering may represent a technology for scalable fabrication of high-crystallinity framework materials for molecule separation.

Efficient removal of phenanthrene by covalent organic frameworks: An experimental combined with theoretical analysis

It is essential to find a green, efficient, and economical way to deal with polycyclic aromatic hydrocarbons (PAHs) that have a significant impact on human health and the ecosystem. In this study, two covalent organic frameworks (COFs) were prepared by using the Schiff base reaction for the effective removal of phenanthrene (PHE). The COFs were characterized by XRD, FT-IR, SEM, TEM, BET, and XPS. Meanwhile, the effects of pH, contact time, and different ionic strengths on the adsorption process were investigated. The results showed that the COFs had good adsorption performance on PHE. The most favorable bonding modes between the two COFs and PHE molecules were calculated and analyzed by Density Functional Theory, and the mechanism was explored in combination with XPS and FT-IR. This work reveals the potential of COFs as efficient adsorbents for the removal of organic pollutants from polluted water and provides further insight into the interactions present in the adsorption process. In addition, with the help of vacuum self-assembly, a simple and scalable strategy to construct assembled COFs membranes (PES@COFs), it was shown that PES@COFs membranes have good retention of PHE present in water and show the advantages of easy handling, better stability, reduced risk of secondary contamination of samples and good reusability. This work highlights the great application potential of COFs for the removal of PHE and demonstrates that the preparation of COFs monolithic materials by vacuum self-assembly is a simple and easy strategy to promote COFs in practical applications.

Terahertz Conductivity of Free-Standing 3D Covalent Organic Framework Membranes Fabricated via Triple-Layer-Dual Interfacial Approach.

Processable covalent organic framework membranes (COFM) are emerging as potential semiconducting materials for device applications. Nevertheless, the fabrication of crystalline and free-standing 3D COFMs is challenging. In this work, a unique time and solvent-efficient triple-layer-dual interfacial (TLDI) approach for the simultaneous synthesis of two 3D COFMs from a single system is developed. Besides, for the first time, the optical conductivity of these free-standing 3D COFMs is analyzed using terahertz (THz) spectroscopy in transmission mode. Interestingly, these membranes show excellent transmittance at THz frequencies with very high intrinsic THz conductivities. The evaluated scattering time and plasma frequency of the free carriers of the COFMs are highly promising for future applications in optoelectronic devices in THz frequencies.

Recent advances of pure/independent covalent organic framework membrane materials: preparation, properties and separation applications.

Covalent organic frameworks (COF) are porous crystalline polymers connected by covalent bonds. Due to their inherent high specific surface area, tunable pore size, and good stability, they have attracted extensive attention from researchers. In recent years, COF membrane materials developed rapidly, and a large amount of research work has been presented on the preparation methods, properties, and applications of COF membranes. This review focuses on the research on independent/pure continuous COF membranes. First, based on the membrane formation mechanism, COF membrane preparation methods are categorized into two main groups: bottom-up and top-down. Four methods are presented, namely, solvothermal, interfacial polymerization, steam-assisted conversion, and layer by layer. Then, the aperture, hydrophilicity/hydrophobicity and surface charge properties of COF membranes are summarized and outlined. According to the application directions of gas separation, water treatment, organic solvent nanofiltration, pervaporation and energy, the latest research results of COF membranes are presented. Finally, the challenges and future directions of COF membranes are summarized and an outlook provided. It is hoped that this work will inspire and motivate researchers in related fields.

A continuous covalent organic framework membrane as an artificial solid electrolyte interphase for lithium metal anodes.

Lithium (Li) metal is a promising next-generation anode material, but it suffers from dendrite growth and unstable solid electrolyte interphase (SEI). We developed a robust and continuous self-standing covalent organic framework (COF) membrane using a same-phase synthesis method and utilized the membrane as an artificial SEI. The membrane suppressed dendrite growth and enhanced the stability and longevity of Li metal anode cycling.

Microwave-assisted synthesis of triazine covalent organic frameworks via friedel-crafts reaction for use in treating brackish Water

Water scarcity is becoming an ever-growing problem in society. This is all due to the rapid increase in human population, harsh changes in the weather climate. New approaches for treating and recycling brine water into freshwater instead of discharging are needed, significantly large reduction in energy usage and decreasing harmful impact to the environment must be achieved in brine recovery. This study aims to introduced green technology into the reclamation of brine water by use of covalent organic frameworks (COFs) materials which will be used as part of a novel triazine-based COFs material which can be used as a nanomembrane for desalination of brine water from water treatment plants at Umgeni Water. Current technological approaches used are inefficient and unsuitable in 3rd world, developing countries including the republic of South Africa. This work focuses on a microwave-assisted synthesis involving Friedel Crafts reaction between monomers to yield a product of a triazine-based covalent organic frameworks (COFs) membranes. To confirm the products high resolution transmission electron microscopy (HRTEM), carbon NMR (13C NMR) with peaks at chemical shifts of 131, 143 and 172 ppm respectively. Fourier-transform infrared spectroscopy (FTIR) was employed and showed N-H stretches at a region of 3396 to 3050 cm-1. The COFs that were successfully synthesised are going to be incorporated on a polymeric substrate to fabricate a nanofiltration membrane and applied for nanofiltration or ultrafiltration purposes.

Recent advances in the fabrication of organic solvent nanofiltration membranes using covalent/metal organic frameworks.

Organic solvent nanofiltration (OSN) has evolved as a vital technological frontier with paramount significance in the separation and purification of organic solvents. Its implication is particularly prominent in industries such as pharmaceuticals, petrochemicals, and environmental remediation. This comprehensive review, meticulously navigates through the current state of research in OSN membranes, unveiling both the critical challenges and promising opportunities that beckon further exploration. The central focus of this review is on the unique utilization of covalent organic frameworks (COFs) and metal-organic frameworks (MOFs) in OSN membrane design, leveraging their distinctive structural attributes-tunable porosity, robust chemical stability, and molecular sieving capabilities. These qualities position them as exceptional candidates for crafting membranes tailored to the intricacies of organic solvent environments. Our investigation extends into the fundamental principles that render COFs and MOFs adept in OSN applications, dissecting their varied fabrication methods while offering insights into the advantages and limitations of each. Moreover, we address environmental and sustainability considerations in the use of COF and MOF-based OSN membranes. Furthermore, we meticulously present the latest advancements and innovations in this burgeoning field, charting a course toward potential future directions and emerging research areas. By underscoring the challenges awaiting exploration, this review not only provides a panoramic view of the current OSN landscape but also lays the groundwork for the evolution of efficient and sustainable OSN technologies, specifically harnessing the unique attributes of COFs and MOFs.

Effective separation of dyes/salts by sulfonated covalent organic framework membranes based on phenolamine network conditioning.

This study developed a modified polyacrylonitrile (PAN) membrane controlled by a phenol-amine network and enhanced with a sulfonated covalent organic framework (SCOF), aimed at improving the efficiency of textile wastewater treatment. Utilizing a phenol-amine network control strategy allows for precise manipulation of interfacial reactions in the synthesis of SCOF, achieving highly uniform modification on the surface of the PAN membrane. This modified membrane demonstrated high rejection of over 98% for various water-soluble dyes, including Alcian blue 8GX, Coomassie Brilliant Blue G250, methyl blue, congo red, and rose bengal, and also exhibited specific selectivity in processing salt-containing wastewater. By adjusting the deposition time of the phenol-amine and the concentration of SCOF monomers, optimal retention performance and permeate flux were achieved, effectively separating dyes and salts. This research provides a new and effective solution for treating textile wastewater, especially in separating and recovering dyes and salts, offering broad application prospects in environmental management and water resource management, and highlighting its significant practical implications.