Optimizing Soil Cover Systems for Coal Gangue Reclamation: Balancing Leachate Control, Environmental Risk, and Cost

Optimizing Soil Cover Systems for Coal Gangue Reclamation: Balancing Leachate Control, Environmental Risk, and Cost | 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 Optimizing Soil Cover Systems for Coal Gangue Reclamation: Balancing Leachate Control, Environmental Risk, and Cost Xihui Liu, Zhenqi Hu, Jingwei Gao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7691521/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Jan, 2026 Read the published version in Scientific Reports → Version 1 posted 11 You are reading this latest preprint version Abstract The large-scale accumulation of coal gangue not only occupies land resources but also generates serious environmental risks, while offering potential for resource recovery through mine land reclamation. This study examines how varying soil cover thickness regulates rainfall infiltration in coal gangue backfill systems, using a combination of laboratory column experiments, field-scale infiltration monitoring, and HYDRUS simulations calibrated with measured hydraulic properties. Under extreme short-term rainfall, a 50-centimeter intermediate soil layer delayed infiltration and reduced moisture at the soil–gangue interface by about 40 percent, substantially limiting leachate generation. Increasing the thickness to 70–100 centimeters further delayed infiltration but yielded diminishing benefits. For prolonged rainfall, a layered structure of five meters of coal gangue alternated with half-meter soil layers and topped with a one-meter surface layer moderated moisture transfer and reduced deep percolation. Even under extreme rainfall of 50 centimeters per day, the system maintained stable hydrological behavior. Multi-objective optimization with the NSGA-II algorithm indicated that a total soil cover thickness of 50 to 60 centimeters achieves an effective balance between leachate control, environmental risk reduction, and cost, and can be applied in both arid and humid regions. These results provide a practical basis for designing sustainable cover systems that integrate solid waste utilization with environmental protection. Physical sciences/Engineering Earth and environmental sciences/Environmental sciences Earth and environmental sciences/Hydrology Coal gangue reclamation Soil cover design Water infiltration control Leachate management Multi-objective optimization Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 05 Jan, 2026 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 21 Oct, 2025 Reviews received at journal 09 Oct, 2025 Reviews received at journal 05 Oct, 2025 Reviewers agreed at journal 26 Sep, 2025 Reviewers agreed at journal 26 Sep, 2025 Reviewers agreed at journal 26 Sep, 2025 Reviewers invited by journal 26 Sep, 2025 Editor assigned by journal 26 Sep, 2025 Editor invited by journal 26 Sep, 2025 Submission checks completed at journal 25 Sep, 2025 First submitted to journal 25 Sep, 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. 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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-7691521","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":525165844,"identity":"c23b8183-d1f3-4660-ad72-438ee8aaa560","order_by":0,"name":"Xihui 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Cost","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":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Coal gangue reclamation, Soil cover design, Water infiltration control, Leachate management, Multi-objective optimization","lastPublishedDoi":"10.21203/rs.3.rs-7691521/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7691521/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cdiv class=\"SectionHeadings\"\u003e\u003cdiv class=\"SectionHeading\"\u003e\u003cdiv class=\"Paragraphs\"\u003e\u003cp\u003eThe large-scale accumulation of coal gangue not only occupies land resources but also generates serious environmental risks, while offering potential for resource recovery through mine land reclamation. This study examines how varying soil cover thickness regulates rainfall infiltration in coal gangue backfill systems, using a combination of laboratory column experiments, field-scale infiltration monitoring, and HYDRUS simulations calibrated with measured hydraulic properties. Under extreme short-term rainfall, a 50-centimeter intermediate soil layer delayed infiltration and reduced moisture at the soil\u0026ndash;gangue interface by about 40 percent, substantially limiting leachate generation. Increasing the thickness to 70\u0026ndash;100 centimeters further delayed infiltration but yielded diminishing benefits. For prolonged rainfall, a layered structure of five meters of coal gangue alternated with half-meter soil layers and topped with a one-meter surface layer moderated moisture transfer and reduced deep percolation. Even under extreme rainfall of 50 centimeters per day, the system maintained stable hydrological behavior. Multi-objective optimization with the NSGA-II algorithm indicated that a total soil cover thickness of 50 to 60 centimeters achieves an effective balance between leachate control, environmental risk reduction, and cost, and can be applied in both arid and humid regions. These results provide a practical basis for designing sustainable cover systems that integrate solid waste utilization with environmental protection.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","manuscriptTitle":"Optimizing Soil Cover Systems for Coal Gangue Reclamation: Balancing Leachate Control, Environmental Risk, and Cost","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-08 03:11:21","doi":"10.21203/rs.3.rs-7691521/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-21T10:12:57+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-09T06:50:25+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-05T15:15:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"99529738647814387677013631114627277222","date":"2025-09-26T15:29:53+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"190245009076269883899299678300235833271","date":"2025-09-26T13:27:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"131516604386301656004362405788426087498","date":"2025-09-26T13:11:33+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-26T06:44:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-26T06:36:14+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-26T04:42:33+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-25T11:33:58+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-09-25T11:27:09+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0d4cbb66-7b7f-48a3-9adb-2f4bbb4b8c04","owner":[],"postedDate":"October 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":55806998,"name":"Physical sciences/Engineering"},{"id":55806999,"name":"Earth and environmental sciences/Environmental sciences"},{"id":55807000,"name":"Earth and environmental sciences/Hydrology"}],"tags":[],"updatedAt":"2026-01-12T16:15:51+00:00","versionOfRecord":{"articleIdentity":"rs-7691521","link":"https://doi.org/10.1038/s41598-025-32202-8","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2026-01-05 15:58:45","publishedOnDateReadable":"January 5th, 2026"},"versionCreatedAt":"2025-10-08 03:11:21","video":"","vorDoi":"10.1038/s41598-025-32202-8","vorDoiUrl":"https://doi.org/10.1038/s41598-025-32202-8","workflowStages":[]},"version":"v1","identity":"rs-7691521","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7691521","identity":"rs-7691521","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}