Iron-Modified Reed Straw Biochar for Efficient Simultaneous Removal of Cr(III) and Cr(VI): Role of Adsorption and Reduction

Iron-Modified Reed Straw Biochar for Efficient Simultaneous Removal of Cr(III) and Cr(VI): Role of Adsorption and Reduction | 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 Iron-Modified Reed Straw Biochar for Efficient Simultaneous Removal of Cr(III) and Cr(VI): Role of Adsorption and Reduction Yanhao Zhang, Jiyao Zhu, Xizhao Pan, Yanwei Zhong, Lei Zhang, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9438317/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 Chromium pollution in water poses a serious threat to human health and ecosystems. This study systematically investigates the enhanced adsorption performance and mechanisms of iron-modified reed straw biochar (FeBC) for the simultaneous removal of trivalent (Cr(III)) and hexavalent chromium (Cr(VI)) from aqueous solutions. Compared to pristine biochar (BC), FeBC exhibited significantly higher removal efficiencies, achieving 78.78% for Cr(III) and 91.45% for Cr(VI) under optimal conditions (pH 4–6). Adsorption followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating monolayer chemisorption as the dominant mechanism. Thermodynamic analysis confirmed the spontaneous and endothermic nature of the process. Material characterization revealed that Fe modification substantially increased specific surface area (from 51.93 to 134.76 m²/g), pore volume, and introduced Fe₃O₄ crystals, which enhanced adsorption sites and redox activity. The results demonstrate that FeBC is a promising, sustainable adsorbent for efficient remediation of chromium-contaminated water. Iron-modified biochar Chromium Adsorption-reduction removal mechanism Full Text Additional Declarations No competing interests reported. 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-9438317","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":633778551,"identity":"72ba9c00-7095-4791-82eb-68c180019b7b","order_by":0,"name":"Yanhao Zhang","email":"","orcid":"","institution":"Shandong Jianzhu University","correspondingAuthor":false,"prefix":"","firstName":"Yanhao","middleName":"","lastName":"Zhang","suffix":""},{"id":633778552,"identity":"6f1a0611-4b34-4836-86db-a6bb037435a1","order_by":1,"name":"Jiyao Zhu","email":"","orcid":"","institution":"Shandong Jianzhu 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This study systematically investigates the enhanced adsorption performance and mechanisms of iron-modified reed straw biochar (FeBC) for the simultaneous removal of trivalent (Cr(III)) and hexavalent chromium (Cr(VI)) from aqueous solutions. Compared to pristine biochar (BC), FeBC exhibited significantly higher removal efficiencies, achieving 78.78% for Cr(III) and 91.45% for Cr(VI) under optimal conditions (pH 4\u0026ndash;6). Adsorption followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating monolayer chemisorption as the dominant mechanism. Thermodynamic analysis confirmed the spontaneous and endothermic nature of the process. Material characterization revealed that Fe modification substantially increased specific surface area (from 51.93 to 134.76 m\u0026sup2;/g), pore volume, and introduced Fe₃O₄ crystals, which enhanced adsorption sites and redox activity. 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