Ultrasonic Assisted Adsorption of Crystal Violet (CV) Dye by CM-β-CD-Fe3O4NPs Synthesis: Experimental Design Methodology

The applicability of the synthesized CM-β-CD-Fe3O4NPs as a novel adsorbent for eliminating Crystal Violet (CV) dye from aqueous media was investigated. This paper focuses on the development of an effective methodology to obtain the optimum removal conditions assisted by ultrasonic to maximize removal of (CV) dye onto CM-β-CD-Fe3O4NPs in aqueous solution using response surface methodology (RSM). This novel material was characterized by different techniques such as FT-IR, XRD and SEM. The influences of variables such as initial (CV) dye concentration (X1), pH (X2), adsorbent dosage (X3), sonication time (X4) investigated by central composite design (CCD) under response surface methodology. The process was empirically modeled to reveal the significant variables and their possible interactions. The optimization conditions were set as: 10.0 mg L-1, 6.0, 5 min and 0.025 g, for ultrasound time, pH, adsorbent mass, (CV) dye concentration respectively. Finally, it was shown that the adsorption of (CV) dye removal by adsorbent was at pH 6.0. This issue that the sorption of (CV) dye conforms to the pseudo-second-order rate equation and the Langmuir model explains equilibrium data was clearly proven. The maximum monolayer capacity (qmax) was found to be 100.0 mgg-1 for (CV) dye at optimum conditions. The application of Isotherms in obtaining the thermodynamic parameters like free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) of adsorption were confirmed. The exothermicity of the process was proven by negative value of (ΔGo, ΔHo and ΔSo) which showed the affinity of CM-β-CD-Fe3O4NPs synthesis for Crystal Violet (CV) dye deletion.