Copper extraction and phytotoxicity of organic acid leached mine tailings

Copper extraction and phytotoxicity of organic acid leached mine tailings | 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 Research Article Copper extraction and phytotoxicity of organic acid leached mine tailings Vinicius H. Oliveira, Sarah Duddigan, James Symons, Michael J. Whelan, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7886189/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 14 Apr, 2026 Read the published version in Environmental Geochemistry and Health → Version 1 posted 11 You are reading this latest preprint version Abstract Mine tailings pose environmental hazards but can also contain economically valuable metals like copper (Cu). Organic solvents, particularly low molecular weight organic acids (LMWOAs), are natural and biodegradable acids with great potential for Cu removal and tailings remediation. We evaluated citric, malic, maleic, malonic and DL-lactic acids (1 M) in extracting Cu from legacy Cu-tailings and assessed their potential toxicity to plants. Brassica napus was grown in acid-leached tailings at three dilutions (1/4, 1/16, 1/128) to simulate solvent biodegradation or dilution by rainfall. Plant height, biomass, chlorophyll, shoot green cover and leachate metal concentrations (Al, Ca, Cu, Fe, K, Mg, Mn, V, Zn) were measured; deionised water was used as a control. At 1/4 dilution, citric, malic, and malonic acids generated the highest Cu concentrations in leachate (625–965 mg L⁻¹). This resulted in poor plant growth, likely due to Cu and Al toxicity. At 1/128 dilution, all acids had minimal impact on growth, with plant biomass similar to controls (41 g), though citric acid mobilised more elements at nutritional levels. Increased macronutrient (Ca, K, Mg) availability from diluted acids led to lower root/shoot ratios, suggesting partial alleviation of nutrient deficiencies. Multivariate analyses showed distinct metal leaching profiles among LMWOAs, which converge with dilution, except for citric acid, which retained discrete patterns even at 1/128 dilution. These findings indicate that citric acid has strong potential for Cu-tailings remediation and rehabilitation, initially extracting high Cu and Al concentrations and supplying essential nutrients as concentrations are diluted. citrate ecotoxicity heavy metals LMWOAs remediation Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 14 Apr, 2026 Read the published version in Environmental Geochemistry and Health → Version 1 posted Editorial decision: Revision requested 15 Dec, 2025 Reviews received at journal 08 Dec, 2025 Reviews received at journal 27 Nov, 2025 Reviews received at journal 26 Nov, 2025 Reviewers agreed at journal 01 Nov, 2025 Reviewers agreed at journal 29 Oct, 2025 Reviewers agreed at journal 29 Oct, 2025 Reviewers invited by journal 27 Oct, 2025 Editor assigned by journal 21 Oct, 2025 Submission checks completed at journal 17 Oct, 2025 First submitted to journal 17 Oct, 2025 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-7886189","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":538562736,"identity":"0d05348c-c5af-408e-9791-2f6e560d4526","order_by":0,"name":"Vinicius H. 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tailings","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"environmental-geochemistry-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"egah","sideBox":"Learn more about [Environmental Geochemistry and Health](https://www.springer.com/journal/10653)","snPcode":"10653","submissionUrl":"https://submission.nature.com/new-submission/10653/3","title":"Environmental Geochemistry and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"citrate, ecotoxicity, heavy metals, LMWOAs, remediation","lastPublishedDoi":"10.21203/rs.3.rs-7886189/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7886189/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMine tailings pose environmental hazards but can also contain economically valuable metals like copper (Cu). Organic solvents, particularly low molecular weight organic acids (LMWOAs), are natural and biodegradable acids with great potential for Cu removal and tailings remediation. We evaluated citric, malic, maleic, malonic and DL-lactic acids (1 M) in extracting Cu from legacy Cu-tailings and assessed their potential toxicity to plants. \u003cem\u003eBrassica napus\u003c/em\u003e was grown in acid-leached tailings at three dilutions (1/4, 1/16, 1/128) to simulate solvent biodegradation or dilution by rainfall. Plant height, biomass, chlorophyll, shoot green cover and leachate metal concentrations (Al, Ca, Cu, Fe, K, Mg, Mn, V, Zn) were measured; deionised water was used as a control. At 1/4 dilution, citric, malic, and malonic acids generated the highest Cu concentrations in leachate (625\u0026ndash;965 mg L⁻\u0026sup1;). This resulted in poor plant growth, likely due to Cu and Al toxicity. At 1/128 dilution, all acids had minimal impact on growth, with plant biomass similar to controls (41 g), though citric acid mobilised more elements at nutritional levels. Increased macronutrient (Ca, K, Mg) availability from diluted acids led to lower root/shoot ratios, suggesting partial alleviation of nutrient deficiencies. Multivariate analyses showed distinct metal leaching profiles among LMWOAs, which converge with dilution, except for citric acid, which retained discrete patterns even at 1/128 dilution. These findings indicate that citric acid has strong potential for Cu-tailings remediation and rehabilitation, initially extracting high Cu and Al concentrations and supplying essential nutrients as concentrations are diluted.\u003c/p\u003e","manuscriptTitle":"Copper extraction and phytotoxicity of organic acid leached mine tailings","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-05 12:50:59","doi":"10.21203/rs.3.rs-7886189/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-16T00:32:47+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-08T20:05:32+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-28T00:25:11+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-26T16:46:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"135531198453453392132883958320931268512","date":"2025-11-01T22:57:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"200170635085734310899586601577553779860","date":"2025-10-29T17:58:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"320650899770370130007374306024377820489","date":"2025-10-29T11:20:10+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-27T08:51:57+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-21T07:36:14+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-17T18:24:17+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Geochemistry and Health","date":"2025-10-17T11:19:56+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-geochemistry-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"egah","sideBox":"Learn more about [Environmental Geochemistry and Health](https://www.springer.com/journal/10653)","snPcode":"10653","submissionUrl":"https://submission.nature.com/new-submission/10653/3","title":"Environmental Geochemistry and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"c6d35561-e0ff-493a-885c-a84fb0a3a677","owner":[],"postedDate":"November 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T16:00:04+00:00","versionOfRecord":{"articleIdentity":"rs-7886189","link":"https://doi.org/10.1007/s10653-026-03188-7","journal":{"identity":"environmental-geochemistry-and-health","isVorOnly":false,"title":"Environmental Geochemistry and Health"},"publishedOn":"2026-04-14 15:56:53","publishedOnDateReadable":"April 14th, 2026"},"versionCreatedAt":"2025-11-05 12:50:59","video":"","vorDoi":"10.1007/s10653-026-03188-7","vorDoiUrl":"https://doi.org/10.1007/s10653-026-03188-7","workflowStages":[]},"version":"v1","identity":"rs-7886189","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7886189","identity":"rs-7886189","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}