Kinetic and Thermodynamic Analysis of the Adsorption of Malachite Green Dye by ZnO‐Modified Sugarcane Bagasse Biochar

Abstract The goal of the current study was to synthesize an effective ZnO‐modified sugarcane bagasse biochar nanocomposites through impregnation method which remove the toxic malachite green (MG) dye from waste water. Among the innovative aspects of this article are its affordability, technical suitability, and ease of access to adsorbent raw materials with minimal adverse environmental effects. Using the ultrasonication approach, ZnO‐modified sugarcane bagasse biochar nanocomposites (ZnO‐SBB NCs) were prepared. These nanocomposites were characterized by using various methods, including FTIR, SEM‐EDX, XPS, and BET. Nanocomposites may self‐assemble into spherical nano aggregates with an average hydrodynamic diameter of around 428.7 nm (0.3 ZnO‐SBB) and 544.4 nm (0.5 ZnO‐SBB), demonstrating high solubility in aqueous solutions. The results reflect that the adsorption of MG dye over nanocomposites conforms to Langmuir adsorption isotherm models and the pseudo‐second‐ kinetic order. The maximum adsorption efficiency was between 75.30 and 80.40 mg g −1 for 0.3 ZnO‐SBB and 0.5 ZnO‐SBB nanocomposites, respectively. Thermodynamic analysis suggests that the MG dye adsorption on ZnO‐SBB NCs was endothermic and spontaneous process. After five cycles, reusability tests showed that the nanocomposites still had a high removal effectiveness of about 94%.