This study explores the adsorption potential of hydrothermally treated waste derived algal biomass for removing methylene blue (MB) dye. Synthesizing a modified hydrochar through hydrothermal carbonization (150°C, 35 bar) followed by NaOH modification, we observed enhanced thermal stability and distinctive chemical changes. Optimal conditions were determined at pH 6 and 1 h contact time. Soluble salts with cations were identified as impacting adsorption efficiency, with increased interference for higher cation charges. Thermodynamic parameters (ΔG, ΔH, and ΔS) indicated a spontaneous and exothermic process, the calculated values (−5.417 to −6.907 kJ mol−1, −29.0 kJ mol−1, −73.8 J K−1 mol−1) aligned with this behavior. Adsorption isotherms favored the Freundlich model, revealing heterogeneous multilayer adsorption, with a maximum capacity of 97%. Kinetic studies supported the pseudo-first-order model. This detailed exploration provides insights into thermodynamics, kinetics, and the impact of adsorption parameters on MB removal, emphasizing the practicality of alkaline-modified hydrochar as an effective, sustainable adsorbent.
Removal of methylene blue by hydrochar modified from hydrothermal carbonization technique
Barzagli, Francesco;
2024
Abstract
This study explores the adsorption potential of hydrothermally treated waste derived algal biomass for removing methylene blue (MB) dye. Synthesizing a modified hydrochar through hydrothermal carbonization (150°C, 35 bar) followed by NaOH modification, we observed enhanced thermal stability and distinctive chemical changes. Optimal conditions were determined at pH 6 and 1 h contact time. Soluble salts with cations were identified as impacting adsorption efficiency, with increased interference for higher cation charges. Thermodynamic parameters (ΔG, ΔH, and ΔS) indicated a spontaneous and exothermic process, the calculated values (−5.417 to −6.907 kJ mol−1, −29.0 kJ mol−1, −73.8 J K−1 mol−1) aligned with this behavior. Adsorption isotherms favored the Freundlich model, revealing heterogeneous multilayer adsorption, with a maximum capacity of 97%. Kinetic studies supported the pseudo-first-order model. This detailed exploration provides insights into thermodynamics, kinetics, and the impact of adsorption parameters on MB removal, emphasizing the practicality of alkaline-modified hydrochar as an effective, sustainable adsorbent.| File | Dimensione | Formato | |
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Envir Progr Sust Energy 2024 43 e14469.pdf
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Descrizione: "This is the peer reviewed version of the following articleAmer MW, Khdeir EM, Barzagli F, et al. Removal of methylene blue by hydrochar modified from hydrothermal carbonization technique. Environ Prog Sustainable Energy. 2024; 43(6):e14469, which has been published in final form at https://doi.org/10.1002/ep.14469. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited."
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