Capability and Mechanism of Ammonium Adsorption from Aqueous Solution onto Various Biochars (wood, rice husk, bamboo)

Capability and Mechanism of Ammonium Adsorption from Aqueous Solution onto Various Biochars (wood, rice husk, bamboo) | 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 Capability and Mechanism of Ammonium Adsorption from Aqueous Solution onto Various Biochars (wood, rice husk, bamboo) Nguyen Van Hien, Eugenia Valsami-Jones, Nguyen Thi Thanh Tam, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8235895/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 16 You are reading this latest preprint version Abstract In this study, adsorption of ammonium nitrogen (NH 4 + -N) ions onto various biochars produced from biomass residues in Vietnam were studied as a function of their physicochemical properties. Three biochars, including wood biochar (WBC), rice husk biochar (RBC), and bamboo biochar (BBC), were produced under limited oxygen conditions using Top-Lid Updraft Drum technology at around 550 o C for 2.5 hours. Physicochemical characterization by BET surface area, Cation exchange capacity (CEC), Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy (FTIR) of the three biochars were performed in order to link their porosity and surface functional groups with their NH 4 + -N capture capacities. The adsorption capacity was evaluated using various parameters such as adsorbent dosage, contact time, and initial adsorbate concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and Temkin adsorption isotherm models. The Freundlich model best described the adsorption of NH 4 + -N onto the three biochars. The capacities of the biochar for NH 4 + -N adsorption were in the order RBC > BBC > WBC, which correlates with their overall CEC. The Lagergren-first order and pseudo-second order models were also used to evaluate the kinetics of adsorption, and the adsorption data of NH 4 + -N showed a good fit with the latter model. Thus, the experimental data indicates that all three boimass residue-derived biochar are suitable for maximising NH 4 + -N adsorption from aqueous solutions, with rice husk BC being especially effective. The increased adsorption capacity of rice husk BC correlated with it having the highest CEC despite having the lowest surface area, suggesting that surface chemistry plays the greatest role in the NH 4 + -N adsorption of all the physico-chemical parameters investigated. Physical sciences/Chemistry Earth and environmental sciences/Environmental sciences Physical sciences/Materials science biochar ammonium adsorption equilibrium and kinetics Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementaldatapaper2.docx Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 20 Apr, 2026 Reviews received at journal 19 Apr, 2026 Reviewers agreed at journal 08 Apr, 2026 Reviewers agreed at journal 06 Apr, 2026 Reviewers agreed at journal 06 Apr, 2026 Reviewers agreed at journal 03 Apr, 2026 Reviewers agreed at journal 03 Apr, 2026 Reviewers agreed at journal 01 Apr, 2026 Reviews received at journal 26 Feb, 2026 Reviewers agreed at journal 17 Feb, 2026 Reviewers agreed at journal 16 Feb, 2026 Reviewers invited by journal 11 Feb, 2026 Editor invited by journal 11 Feb, 2026 Editor assigned by journal 01 Dec, 2025 Submission checks completed at journal 01 Dec, 2025 First submitted to journal 29 Nov, 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. 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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-8235895","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":592212569,"identity":"fe0f2a65-cbff-4db8-9a7f-ca073144ff3c","order_by":0,"name":"Nguyen Van Hien","email":"","orcid":"","institution":"Soils and Fertilizers Research Institute","correspondingAuthor":false,"prefix":"","firstName":"Nguyen","middleName":"Van","lastName":"Hien","suffix":""},{"id":592212570,"identity":"b8daf5ec-31d5-4699-a45f-5e0ad6669c85","order_by":1,"name":"Eugenia Valsami-Jones","email":"","orcid":"","institution":"University of 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