Study on the Adsorption Performance of Methylene Blue by FeCl₃-Modified Hydrothermal Rice Straw Biochar and Activated Clay Composite

Study on the Adsorption Performance of Methylene Blue by FeCl₃-Modified Hydrothermal Rice Straw Biochar and Activated Clay Composite | 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 Study on the Adsorption Performance of Methylene Blue by FeCl₃-Modified Hydrothermal Rice Straw Biochar and Activated Clay Composite Liang Zhengxue, Yiming Zhang, Yihua Wu, Lixiao Wu, Lijun Wang, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7640266/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 12 Feb, 2026 Read the published version in Water, Air, & Soil Pollution → Version 1 posted You are reading this latest preprint version Abstract In this study, rice straw biochar (RCHC) and activated clay (AC) were innovatively combined and modified with FeCl₃ to prepare an adsorbent (RCHC-ACFC). The adsorption performance of RCHC-ACFC toward methylene blue (MB) was investigated. The effects of varying RCHC-to-AC mass ratios, FeCl₃ solution concentrations, pH conditions, and loading amounts on the adsorbent's performance were investigated. The adsorption capacity, isotherms, kinetics, and thermodynamics of MB on RCHC-ACFC were explored. Surface morphology, functional groups, and phase composition of RCHC-ACFC were characterized using SEM, FT-IR, and XRD to elucidate the adsorption mechanism. Experimental data indicate that RCHC-ACFC exhibits superior adsorption performance for MB compared to RCHC and AC alone. Isotherm studies reveal that MB adsorption on RCHC-ACFC follows the Langmuir adsorption model. MB adsorption adheres to pseudo-second-order kinetics. The theoretical maximum adsorption capacity of RCHC-ACFC for methylene blue in aqueous solution reaches 539.35 mg/g. Thermodynamic studies confirmed that MB adsorption onto the adsorbent is endothermic and spontaneous. Mechanism pathway analysis indicated the presence of electrostatic forces, ion exchange, chemical bonding, and physical adsorption during the adsorption process. The results demonstrate that this RCHC-ACFC exhibits excellent adsorption performance for methylene blue in aqueous media. Activated clay Methylene blue FeCl₃ modification Adsorption kinetics study Ion exchange Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 12 Feb, 2026 Read the published version in Water, Air, & Soil Pollution → 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. 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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-7640266","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":535101040,"identity":"7b2168ae-6204-412f-be72-2515c9f35024","order_by":0,"name":"Liang Zhengxue","email":"","orcid":"","institution":"Shanghai Polytechnic University","correspondingAuthor":false,"prefix":"","firstName":"Liang","middleName":"","lastName":"Zhengxue","suffix":""},{"id":535101041,"identity":"ebb71705-2cf5-4bf9-8122-9004b54268d1","order_by":1,"name":"Yiming Zhang","email":"","orcid":"","institution":"Shanghai Polytechnic 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exchange","lastPublishedDoi":"10.21203/rs.3.rs-7640266/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7640266/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn this study, rice straw biochar (RCHC) and activated clay (AC) were innovatively combined and modified with FeCl₃ to prepare an adsorbent (RCHC-ACFC). The adsorption performance of RCHC-ACFC toward methylene blue (MB) was investigated. The effects of varying RCHC-to-AC mass ratios, FeCl₃ solution concentrations, pH conditions, and loading amounts on the adsorbent's performance were investigated. The adsorption capacity, isotherms, kinetics, and thermodynamics of MB on RCHC-ACFC were explored. Surface morphology, functional groups, and phase composition of RCHC-ACFC were characterized using SEM, FT-IR, and XRD to elucidate the adsorption mechanism. Experimental data indicate that RCHC-ACFC exhibits superior adsorption performance for MB compared to RCHC and AC alone. Isotherm studies reveal that MB adsorption on RCHC-ACFC follows the Langmuir adsorption model. MB adsorption adheres to pseudo-second-order kinetics. The theoretical maximum adsorption capacity of RCHC-ACFC for methylene blue in aqueous solution reaches 539.35 mg/g. Thermodynamic studies confirmed that MB adsorption onto the adsorbent is endothermic and spontaneous. Mechanism pathway analysis indicated the presence of electrostatic forces, ion exchange, chemical bonding, and physical adsorption during the adsorption process. The results demonstrate that this RCHC-ACFC exhibits excellent adsorption performance for methylene blue in aqueous media.\u003c/p\u003e","manuscriptTitle":"Study on the Adsorption Performance of Methylene Blue by FeCl₃-Modified Hydrothermal Rice Straw Biochar and Activated Clay Composite","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-29 03:47:00","doi":"10.21203/rs.3.rs-7640266/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","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}}],"origin":"","ownerIdentity":"76963ff1-e3f8-4c80-b9bf-1f5f97704fe8","owner":[],"postedDate":"October 29th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-02-16T16:03:21+00:00","versionOfRecord":{"articleIdentity":"rs-7640266","link":"https://doi.org/10.1007/s11270-026-09199-5","journal":{"identity":"water-air-and-soil-pollution","isVorOnly":false,"title":"Water, Air, \u0026 Soil Pollution"},"publishedOn":"2026-02-12 15:58:51","publishedOnDateReadable":"February 12th, 2026"},"versionCreatedAt":"2025-10-29 03:47:00","video":"","vorDoi":"10.1007/s11270-026-09199-5","vorDoiUrl":"https://doi.org/10.1007/s11270-026-09199-5","workflowStages":[]},"version":"v1","identity":"rs-7640266","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7640266","identity":"rs-7640266","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}