The Potential of Acacia Raddiana Bark as A Low-Cost Biosorbent for Removing Methylene Blue Dye From Aquous Solution

Abstract

The present study examines the potential of using Acacia raddiana bark as a sustainable, low-cost biosorbent for removing methylene blue (MB) dye from wastewater. Comprehensive characterization of the biosorbent was completed using FTIR, SEM-EDX, BET, XRD, and the pH point of zero charge (pHpzc) was determined. According to experiment, the equilibrium times of was found to be 100 min, with a maximum adsorption capacity of  9.128 mg/g. The optimum pH=10, and MB initial concentration =10 mg/L. The thermodynamic data revealed an endothermic mechanism adsorption (ΔH = 66.72 kJ/mol) and spontaneous process (ΔG = –0.77 kJ/mol), with adsorption efficiency gradually rising with temperature. The Langmuir model showed the strongest correlation (R² = 0.99), indicating monolayer adsorption with a maximum Langmuir adsorption capacity of 10.04 mg/g at 15 °C. The process follows a pseudo-second-order model (R² = 0.99). FTIR analysis confirmed the existence of functional groups (O–H, C=C), which are important binding sites involved in the process of MB biosorption. The material has an irregular, porous structure and a surface area of 5.617 m²/g. On the whole, the findings suggest that Acacia raddiana bark is a promising natural sorbent for treating dye-polluted wastewater.