An anionic Covalent Organic Framework for the removal of Al 3+ from contaminated water

An anionic Covalent Organic Framework for the removal of Al 3+ from contaminated water | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article An anionic Covalent Organic Framework for the removal of Al 3+ from contaminated water Cristina Arqueros, Lorena Welte, Enrique García Michel, Carmen Montoro, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6852533/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Aluminum contamination in water is a critical environmental concern due to its widespread industrial usage and potential toxicity to both humans and ecosystems. Traditional aluminum removal methods such as chemical precipitation, ion exchange, and membrane filtration often present significant limitations, including high operational costs, secondary pollution, or membrane fouling. In this study, we explore the application of ionic covalent organic frameworks (iCOFs), specifically TpPa-SO₃H and TpPa-SO₃Na, as promising materials for the efficient and selective removal of Al³⁺ from aqueous solutions. These β-ketoenamine-linked COFs exhibit high chemical stability, large surface areas, and tunable porosity, making them particularly suitable for harsh water treatment environments. We report the first use of these anionic COFs for aluminum adsorption, achieving rapid uptake kinetics and high removal efficiencies under both static and dynamic conditions. Batch experiments demonstrated adsorption efficiencies exceeding 95% within minutes, while column experiments under continuous flow achieved over 99% removal for more than three hours. Recyclability tests confirmed the robustness of the material, with minimal loss of performance over five cycles. Additionally, the TpPa-SO₃Na was tested on real water samples, yielding removal efficiencies of up to 85%. The adsorption mechanism was investigated in-depth, revealing strong electrostatic interactions and selective binding with Al³⁺ ions. These findings highlight the potential of iCOFs as a sustainable and effective alternative to conventional aluminum removal technologies, advancing current water purification strategies and contributing to the development of next-generation materials for clean water applications. Earth and environmental sciences/Environmental sciences Physical sciences/Materials science Full Text Additional Declarations No competing interests reported. Supplementary Files COFforAlcaptureSICM.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6852533","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":469681901,"identity":"5c805ca3-9c86-42af-adca-cc82c2cc8444","order_by":0,"name":"Cristina Arqueros","email":"","orcid":"","institution":"Kleinscale","correspondingAuthor":false,"prefix":"","firstName":"Cristina","middleName":"","lastName":"Arqueros","suffix":""},{"id":469681902,"identity":"898556df-870f-4e5e-830a-83941721e02c","order_by":1,"name":"Lorena Welte","email":"","orcid":"","institution":"Kleinscale","correspondingAuthor":false,"prefix":"","firstName":"Lorena","middleName":"","lastName":"Welte","suffix":""},{"id":469681903,"identity":"110b182f-c771-4902-b12c-b7db89dcac12","order_by":2,"name":"Enrique García Michel","email":"","orcid":"","institution":"Department of Condensed Matter Physics","correspondingAuthor":false,"prefix":"","firstName":"Enrique","middleName":"García","lastName":"Michel","suffix":""},{"id":469681904,"identity":"84501d8b-45a1-42be-a6a2-d9b3a4a7bfb2","order_by":3,"name":"Carmen Montoro","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA10lEQVRIiWNgGAWjYAgAG5JUM4OINNK1HCasjr/97NMNH3cwRPNL9x98XFFxPrF/2gHGhz/waJE4k252c+YZhtyZcw4zG545cztxxu0EZmMePFoMGNLYbvO2MeRuuJHMJtnYdjux4XYCmzQ+hxnwP2O7/Reh5Vzi/NsJ7D/xOcxAAmgLI0LLgcQNQFsY8DlM4sYztpu9bRK5M2ckGxs2nEk23ng7sVkanxb+/jS2Gz/bbHL7JRIfPmyosJOddzv54Ed8DoNZhsxhbCCsYRSMglEwCkYBXgAApO1PQ0oStQAAAAAASUVORK5CYII=","orcid":"","institution":"Departament of Inorganic Chemistry","correspondingAuthor":true,"prefix":"","firstName":"Carmen","middleName":"","lastName":"Montoro","suffix":""},{"id":469681905,"identity":"375d9602-dc2f-47f5-8d5d-061f515d39cd","order_by":4,"name":"Félix Zamora","email":"","orcid":"","institution":"Departament of Inorganic Chemistry","correspondingAuthor":false,"prefix":"","firstName":"Félix","middleName":"","lastName":"Zamora","suffix":""}],"badges":[],"createdAt":"2025-06-09 08:53:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6852533/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6852533/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":84679277,"identity":"e55548ad-94ec-46f0-afe0-796004a13f8a","added_by":"auto","created_at":"2025-06-16 08:08:29","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":899513,"visible":true,"origin":"","legend":"","description":"","filename":"COFforAlcaptureCM.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6852533/v1_covered_4c7585d6-b084-4002-bf62-c197a1589dba.pdf"},{"id":84475980,"identity":"5029e562-e9f3-49a9-be98-c28e18b4f79b","added_by":"auto","created_at":"2025-06-12 11:26:28","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":2296173,"visible":true,"origin":"","legend":"","description":"","filename":"COFforAlcaptureSICM.docx","url":"https://assets-eu.researchsquare.com/files/rs-6852533/v1/4941d3e8b8940cdcb066d53e.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"An anionic Covalent Organic Framework for the removal of Al 3+ from contaminated water","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6852533/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6852533/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Aluminum contamination in water is a critical environmental concern due to its widespread industrial usage and potential toxicity to both humans and ecosystems. 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