Characterization optimization of synthesis Chitosanclay/benzoin/Fe3O4 composite for adsorption of Thionine dye by design expert study

A novel composite material, magnetic chitosan-clay/benzoin/Fe3O4 (CS-CY/Benz/Fe3O4), was synthesized for effectively removing thionine dye (TH) from water solutions. The structural integrity and suitability of CS- CY/Benz/Fe3O4 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 degrees 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 similar to 5.91, adsorbent dosage of 0.08 g, temperature of 54.34 degrees 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-pi interactions, hydrogen bonding, and Yoshida H-bonding. Particularly, the CS-CY/Benz/Fe3O4 composite demonstrated strong magnetic responsiveness, enabling straightforward separation from water using an external magnetic field after adsorption. Particularly, the CS-CY/Benz/Fe3O4 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.