Nanofiltration for circularity: Fit-for-purpose design and evaluation

Nanofiltration—a technology that selectively extracts critical materials from streams—can help secure resources while minimizing wasteful and unsustainable extraction practices. However, next-generation nanofiltration membranes must be designed with a fit-for-purpose framework in mind to fully harness its capabilities resource conservation minimize trade-offs. Rapid population economic growth require an unprecedented level of material supply. This presents major challenge can only effectively addressed through sustainable practices, particularly by implementing enhanced circularity. The high consumption rate not jeopardizes their supply chains but is also detrimental the environment.1Watari T. Nansai K. Nakajima Review metal dynamics 2050 for 48 elements.Resour. Conserv. Recycl. 2020; 155104669https://doi.org/10.1016/j.resconrec.2019.104669Crossref Scopus (132) Google Scholar For instance, rising demand batteries has created instability lithium, essential element low-carbon energy technologies. To meet long-term demand, it crucial shift away linear systems rely on extraction, single-use consumption, disposal, which result pollution worsen climate change. Embracing circular prioritize recycling reuse reduce strain chains, enhance security, mitigate change lowering greenhouse gas emissions. Notably, United Nations recognized production as one key development goals, guiding societies toward embracing realization economy necessitates technological advancements facilitate precise separations. Efficient diverse sources—for example, ores, minerals, electronic waste, wastewater, produced water, brines—is achieving economy.2DuChanois R.M. Cooper N.J. Lee B. Patel S.K. Mazurowski L. Graedel T.E. Elimelech M. Prospects recovery wastewater brine.Nat. Water. 2023; 1: 37-46https://doi.org/10.1038/s44221-022-00006-zCrossref variable complex nature these sources, plethora include metals, rare earth elements, nutrients, pharmaceuticals, requires adaptable versatile separation One such candidate (NF), achieve energy-efficient, modular, chemical-free, customized separation, provided suitably engineered.3Zhao Y. Tong Wang X. Lin S. Reid E.M. Chen Differentiating Solutes Precise Nanofiltration Next Generation Environmental Separations: A Review.Environ. Sci. Technol. 2021; 55: 1359-1376https://doi.org/10.1021/acs.est.0c04593Crossref PubMed (98) NF employs nanoporous membrane serves molecular filter, distinguishing between various species present mixture. In contrast reverse osmosis reject most ions uncharged molecules, allow some solutes pass nanopores, offering opportunity differentiate them recover those are critical. holds significant potential catalyst promoting circularity within industries.3Zhao Scholar,4Wang Januszewski Liu Li D. Fu R. Huang Tailored design water treatment based synthesis–property–performance relationships.Chem. Soc. Rev. 2022; 51: 672-719https://doi.org/10.1039/D0CS01599GCrossref Currently, utilized softening, removal organic compounds surface groundwater, textile, leather, paper sectors, well biopharmaceuticals (e.g., purifying antibiotics) food processing concentrating demineralizing lactose, maple syrup, dealcoholizing beer). unleash manufacturing, necessary optimize properties differentiation similar increase stability, especially under harsh operational conditions existing streams containing materials. Given wide array streams, relying solely single type feasible solution. Even target application lithium recovery), there variability terms competing species, mineral scalants, foulants, pH present, depending source brines waters different locations). Designing unlock versatility (Figure 1). successful desalination antibiotics demands open-structure engineered pore size distribution allows salt molecules at retain valuable antibiotics. Recovering unconventional other hand, control over membrane-ion interactions confinement ions. Although both applications fall category, required features differ significantly. enable membranes, advance our understanding fundamental principles underlying fabrication single-species selective follow strategy informed specific requirements targeted stream. upcoming vary significantly, hand. Therefore, optimal tailored each purpose, have comprehensive transport mechanisms encompassing species. Particularly, acquiring detailed how ions, neutral traverse utmost significance aiming like mining brines, nutrient purification Similar where been recently shown governed pore-flow mechanism pressure gradient driving force,5Wang He J. Heiranian Fan H. Song Water flow, solution-diffusion mechanism.Sci. Adv. 9eadf8488https://doi.org/10.1126/sciadv.adf8488Crossref (2) likely mechanism, since looser more porous active layer structure. On ion solute combined contribution diffusion, advection, electromigration, following partitioning into membrane.6Wang Du Biesheuvel P.M. Salt Transport Reverse Osmosis Membranes : Beyond Solution-Diffusion Model.Environ. 1-25https://doi.org/10.1021/acs.est.1c05649Crossref (49) unraveling when dealing designs trivial. ultra-permeable advection play important role transport, coupling govern transport. Overall, improved mechanisms, presence conditions, needed effective optimization strategies. After selecting robust imperative conduct optimization. During process, identify significantly influence performance particular Key properties, charge, average size, cross-linking density, solution ionic composition, pH, temperature. These vital determining application. charge passage Li+ impeding Mg2+ context metals hydrometallurgical battery utilization exceptional stability highly acidic environments importance. Additionally, should possess accurate Most studies focus limited number without providing justification selection, potentially overlooking influential factors. address this limitation, we propose machine learning techniques guide experimental investigations assessing sensitivity feature. By leveraging algorithms, process discovering optimized accelerated made efficient. Further, systematically evaluating impact features, gain insights make decisions regarding feature selection optimization.7Zhong Zhang Bagheri Burken J.G. Gu A. Ma Marrone B.L. Ren Z.J. Schrier et al.Machine Learning: New Ideas Tools Science Engineering.Environ. 55 (1c01339): 12741-12754https://doi.org/10.1021/acs.est.1c01339Crossref (190) Addressing enabling applications, aims materials, collective collaborative efforts. foster collaboration knowledge sharing community, establish open database. model osmosis8Ritt C.L. Stassin Davenport D.M. DuChanois Nulens I. Yang Z. Ben-Zvi Segev-Mark N. Tang C.Y. al.The database: Synthesis–structure–performance relationships membranes.J. Membr. 641119927https://doi.org/10.1016/j.memsci.2021.119927Crossref (45) implemented, researchers report findings contribute centralized repository data. database would serve practitioners, facilitating models supporting advancement technology. engineering synthesis. osmosis, universal does exist. Implementing improve will portfolio More challenging requiring resilience or solute-solute selectivity benefit novel synthesis techniques. Interfacial polymerization, characterized formation film interface two immiscible solvents mutually reactive monomers, platform efficient scalable membranes. inherent self-limiting yields continuous thin films barriers, easily controlled simple parameters additives. Moreover, extensive use technique large-scale four decades led accumulated expertise expedite upscaling interfacial polymerization-based applications. tunability polymerization enables readily scalable, purpose-specific Typically, produces layers reaction either amine hydroxyl groups acyl chloride groups, liquids (Figures 2A 2B ). fine-tuning during appropriate improvements permeance 2C). surfactant generate crumpled structures larger area transport9Shen Q. Mai K.-R. Yoshioka Guan Gonzales R.R. Matsuyama When self-assembly meets polymerization.Sci. 9eadf6122https://doi.org/10.1126/sciadv.adf6122Crossref (0) uniformity sub-nanometer pores polyamide precision separations.10Liang Zhu C. Hung W.-S. Jin Polyamide uniform sub-nanometre sub-1 Å separation.Nat. Commun. 11: 2015https://doi.org/10.1038/s41467-020-15771-2Crossref (284) Alternatively, contorted monomers employed microporosity flux applications.11Ali Ghanem B.S. Pacheco F. Ogieglo W. Vovusha Genduso G. Schwingenschlögl U. Han Pinnau Finely Tuned Submicroporous Thin-Film Molecular Sieve Highly Fluid Separations.Adv. Mater. 322001132https://doi.org/10.1002/adma.202001132Crossref (51) sustainability manufacturing bypass protocols commonly associated bio-derived alternatives explored.12Bai Yao Dong Rao P. Cao Villalobos L.F. al.Microstructure bioderived polyester nanofilms antibiotic via nanofiltration.Sci. 9eadg6134https://doi.org/10.1126/sciadv.adg6134Crossref Lastly, cavitands provides nanopores layer, thereby permeation conducive container-shaped molecule’s cavity, rejecting conducive.13Villalobos Peinemann K.-V. Cyclodextrin Films Fast Solvent Shape-Selective Permeability.Adv. 2017; 291606641https://doi.org/10.1002/adma.201606641Crossref (177) functionalized promote arrangement produce aligned pores, further enhancing performance.14Jiang Evans A.M. Biere Ebrahim M.A. Anselmetti Dichtel W.R. Livingston A.G. Aligned macrocycle ultrathin sieving.Nature. 609: 58-64https://doi.org/10.1038/s41586-022-05032-1Crossref (34) There promising beyond polymerization-derived layers, block copolymers, covalent frameworks, zeolites, 2D may offer advantages compared polymeric research could lead breakthroughs remarkable ability precisely functionalities crystalline metal-organic frameworks discrimination monovalent selectivities comparable exhibited biological channels15Lu Jiang Qian Yan J.Z. Freeman B.D. An artificial sodium-selective subnanochannel.Sci. 9eabq1369https://doi.org/10.1126/sciadv.abq1369Crossref Scholar—an achievement systems. efforts cost processability show they manufactured scale.16Patel Ritt Deshmukh Qin Epsztein relative insignificance advanced efficiency technologies.Energy Environ. 13: 1694-1710https://doi.org/10.1039/D0EE00341GCrossref recent example solution-processable nanosheets cast using doctor blade, solutions, large-area (>200 cm2) homogeneity sufficient flexibility.17Yuan Shi Yu Buenconsejo P.J.S. Zhao Large-Area Fabrication Ultrathin Metal-Organic Framework Membranes.Adv. 352211859https://doi.org/10.1002/adma.202211859Crossref Resource typically involve handling substantial volumes making consider intended scale early discovery process. Hence, demonstrate industrial reasonable cost, determined techno-economic analysis.18Lee Directing agenda technologies analysis.Energy 16: 714-722https://doi.org/10.1039/D2EE03271FCrossref paramount importance adoption While pose uncertainties scaling up value new improving ones, equally undertake parallel feasibility level. Collaborations academia industry take lab-scale demonstrating scale-up emerging next level, achieved. Our need future opened many opportunities become driver circularity, contributing management agricultural, energy, pharmaceutical industries. agricultural industry, expected farming nutrients irrigation harmful substances, pesticides heavy runoff. sector, offers solutions sourcing range technologies, storage. Similarly, wastewaters. additional applied attain customization processes respective ensuring performance. side, deeper inform Interdisciplinary collaborations pave way strategies fulfill separations, evaluation framework, analysis, properly current ones. Techno-economic analysis plays pivotal viability garner greater attention among scientists—particularly designing generation establishing clearly defined pathway NF, marked enabled technology, anticipated. work was financially supported US National Foundation (NSF) US−Israel Binational (BSF) award no. CBET-2110138 part Center Enhanced Nanofluidic (CENT), Energy Frontier Research funded U.S. Department Energy, Office Science, Basic Sciences Award # DE-SC0019112. L.F.V. thanks Swiss Postdoc.Mobility Fellowship (P400P2_199330). authors declare no interests.