A novel composite material, magnetic chitosan-clay/benzoin/Fe
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(CS-CY/Benz/Fe
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), was synthesized for effectively removing thionine dye (TH) from water solutions. The structural integrity and suitability of CS- CY/Benz/Fe
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composite for adsorption purposes were validated through extensive characterization techniques including BET, XRD, FTIR, and SEM. The adsorption efficiency was optimized through a Box–Behnken design (BBD) employing response surface methodology (RSM), focusing on variables such as adsorbent dose (A: 0.02–0.08 g), solution pH (B: 4–10), temperature (C: 30–60 °C), and time (D: 5–30 min). Experimental results revealed a maximum TH removal of 99% with significant interactions between temperature (C) and time (D) (p-value = 0.0001). The optimal conditions for TH removal were determined as pH ~ 5.91, adsorbent dosage of 0.08 g, temperature of 54.34 °C, and time of 29.7 min. The investigation of kinetics revealed that the adsorption process conformed to a pseudo-second-order (PSO) model, while the equilibrium data were effectively described by the Freundlich isotherm model. At a temperature of 333.15 K and a TH concentration of 350 mg/L, the adsorption capacity was determined to be 660.86 mg/g. The mechanism of adsorption encompassed various interactions such as electrostatic attractions, n–π interactions, hydrogen bonding, and Yoshida H-bonding. Particularly, the CS-CY/Benz/Fe
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composite demonstrated strong magnetic responsiveness, enabling straightforward separation from water using an external magnetic field after adsorption. Particularly, the CS-CY/Benz/Fe
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composite demonstrated strong magnetic responsiveness, enabling straightforward separation from water using an external magnetic field after adsorption. This research contributes important findings to the advancement of magnetic chitosan-based composites for efficient removal of TH dye pollutants from water environments.
