Effect of pH on the surface charges of permanently charged soils and clay minerals

Effect of pH on the surface charges of permanently charged soils and clay minerals | 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 Effect of pH on the surface charges of permanently charged soils and clay minerals Hua Cao, Xinmin Liu, Bo Feng, Jiaqi Sun, Deyuan Ma, Xijing Chen, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4684462/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Oct, 2024 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Traditionally, the surface charge number (SCN) of permanently charged soils/clay minerals is believed to be unaffected by environmental pH. However, recent studies have revealed the occurrence of polarization-induced covalent bonding between H + and the surface O atoms of permanently charged clay minerals. This discovery challenges the traditional notions of “permanently charged soils” and “permanently charged clay minerals”. The purpose of this study is to confirm that there is no true “permanently charged clay” or “permanently charged soil”. In this study, the SCNs of two permanently charged clay minerals, two variably charged clay minerals, five permanently charged soils, and four variably charged soils were measured at different pH values using the universal determination method of surface charge number. The results showed that: ( 1 ) The SCNs of both the permanently and variably charged soil/clay minerals decreased significantly with decreasing pH; ( 2 ) the SCN of montmorillonite decreased less with decreasing pH than the SCNs of the variably charged minerals, whereas the SCN of illite decreased to nearly the same extent, indicating strong polarization-induced covalent bonding between H + and the surface O atoms of illite; ( 3 ) the SCNs of the permanently charged soils decreased to a similar extent as those of the variably charged soils with decreasing pH. This study demonstrated that there is no true “permanently charged clay mineral” or “permanently charged soil” because of the polarization-induced covalent interactions between H + and the surface O atoms of clay minerals. Earth and environmental sciences/Environmental sciences/Environmental chemistry/Geochemistry Earth and environmental sciences/Solid earth sciences/Mineralogy Asymmetric hybridization orbitals Surface charge number Permanently charged clay Permanently charged soil Polarization-induced covalent bonding Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 05 Oct, 2024 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 10 Sep, 2024 Reviews received at journal 07 Sep, 2024 Reviewers agreed at journal 17 Aug, 2024 Reviews received at journal 08 Aug, 2024 Reviewers agreed at journal 04 Aug, 2024 Reviewers invited by journal 17 Jul, 2024 Editor assigned by journal 17 Jul, 2024 Editor invited by journal 11 Jul, 2024 Submission checks completed at journal 08 Jul, 2024 First submitted to journal 04 Jul, 2024 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-4684462","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":333111697,"identity":"e77aee60-e52d-4c05-a995-cf7e06f8a669","order_by":0,"name":"Hua Cao","email":"","orcid":"","institution":"College of Resources and Environment, Southwest University","correspondingAuthor":false,"prefix":"","firstName":"Hua","middleName":"","lastName":"Cao","suffix":""},{"id":333111702,"identity":"baa42c8c-6738-4857-a548-6335cdfc6acf","order_by":1,"name":"Xinmin Liu","email":"","orcid":"","institution":"College of Resources and Environment, Southwest 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Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Asymmetric hybridization orbitals, Surface charge number, Permanently charged clay, Permanently charged soil, Polarization-induced covalent bonding","lastPublishedDoi":"10.21203/rs.3.rs-4684462/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4684462/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTraditionally, the surface charge number (SCN) of permanently charged soils/clay minerals is believed to be unaffected by environmental pH. However, recent studies have revealed the occurrence of polarization-induced covalent bonding between H\u003csup\u003e+\u003c/sup\u003e and the surface O atoms of permanently charged clay minerals. This discovery challenges the traditional notions of \u0026ldquo;permanently charged soils\u0026rdquo; and \u0026ldquo;permanently charged clay minerals\u0026rdquo;. The purpose of this study is to confirm that there is no true \u0026ldquo;permanently charged clay\u0026rdquo; or \u0026ldquo;permanently charged soil\u0026rdquo;. In this study, the SCNs of two permanently charged clay minerals, two variably charged clay minerals, five permanently charged soils, and four variably charged soils were measured at different pH values using the universal determination method of surface charge number. The results showed that: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) The SCNs of both the permanently and variably charged soil/clay minerals decreased significantly with decreasing pH; (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) the SCN of montmorillonite decreased less with decreasing pH than the SCNs of the variably charged minerals, whereas the SCN of illite decreased to nearly the same extent, indicating strong polarization-induced covalent bonding between H\u003csup\u003e+\u003c/sup\u003e and the surface O atoms of illite; (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) the SCNs of the permanently charged soils decreased to a similar extent as those of the variably charged soils with decreasing pH. This study demonstrated that there is no true \u0026ldquo;permanently charged clay mineral\u0026rdquo; or \u0026ldquo;permanently charged soil\u0026rdquo; because of the polarization-induced covalent interactions between H\u003csup\u003e+\u003c/sup\u003e and the surface O atoms of clay minerals.\u003c/p\u003e","manuscriptTitle":"Effect of pH on the surface charges of permanently charged soils and clay minerals","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-31 06:01:06","doi":"10.21203/rs.3.rs-4684462/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-09-10T06:46:31+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-07T08:37:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"10031897533521480178907178944269893878","date":"2024-08-18T02:17:29+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-08-09T03:26:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"281491377830009309470190076205499295308","date":"2024-08-04T06:41:53+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-07-17T07:55:13+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-17T07:53:03+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-07-11T14:03:57+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-08T05:36:47+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-07-04T07:12:36+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":"46fe263c-2f7e-482c-94c4-9e4baccf2fe4","owner":[],"postedDate":"July 31st, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":35267952,"name":"Earth and environmental sciences/Environmental sciences/Environmental chemistry/Geochemistry"},{"id":35267953,"name":"Earth and environmental sciences/Solid earth sciences/Mineralogy"}],"tags":[],"updatedAt":"2024-10-07T16:10:21+00:00","versionOfRecord":{"articleIdentity":"rs-4684462","link":"https://doi.org/10.1038/s41598-024-74563-6","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2024-10-05 15:57:22","publishedOnDateReadable":"October 5th, 2024"},"versionCreatedAt":"2024-07-31 06:01:06","video":"","vorDoi":"10.1038/s41598-024-74563-6","vorDoiUrl":"https://doi.org/10.1038/s41598-024-74563-6","workflowStages":[]},"version":"v1","identity":"rs-4684462","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4684462","identity":"rs-4684462","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}