1. Highly selective and reusable nanoadsorbent based on Fe 3 O 4 -embedded sodium alginate-based hydrogel for cationic dye adsorption: Adsorption interpretation using multiscale modeling.
- Author
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Umar M, Khan H, Akbal F, Usama M, Tariq R, Hussain S, Zaman SU, Eroğlu HA, and Kadıoğlu EN
- Abstract
This study aims to develop a stable and efficient magnetic nanocomposite hydrogel (MNCH) for selective removal of methylene blue (MB) and crystal violet (CV). MNCHs with different Fe
3 O4 contents (0-9 wt%) were synthesized following graft co-polymerization method using sodium alginate, acrylamide, itaconic acid, ammonium persulfate and N,N-methylene bisacrylamide. Among them, MNCH5 , with 5 wt% Fe3 O4 , showed highest removal efficiency (>95 %). Optimal dye removal occurred at pH 10, with 40 min for CV and 60 min for MB using 30 mg dose. MNCH was characterized using various techniques, with X-ray diffraction (XRD) revealing crystallite size of 30.5 nm, and Brunauer-Emmett-Teller (BET) indicating surface area of 59.80 m2 g-1 . Adsorption kinetics followed fractal pseudo-first-order and fractal Vermeulen diffusion models, reflecting MNCH's heterogeneous nature as suggested by fractal exponent (h) ranging 0.38-0.44, significantly deviating from zero. Langmuir-Freundlich isotherm accurately described the process, demonstrating MNCH's superior affinity for MB (4216.69 mg g-1 ) over CV (3730.17 mg g-1 ). Thermodynamics of MB adsorption was exothermic as suggested by negative ΔH value, while CV adsorption was endothermic. Density functional theory confirmed stronger interaction between MNCH and MB (Eads = -49.29 kcal mol-1 ) compared to CV (Eads = -41.30 kcal mol-1 ). These findings underscore MNCH's excellent adsorption capacity, making it promising for removing dyes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2024
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