Novel Efficient and Eco‐Friendly Biosorbent Derived from Ditax (Detarium senegalense) Fruit Hulls for Removal of Cationic Dyes: Adsorption Modeling and Statistical Optimization

Abstract

Remediation of wastewater laden with dyes using optimized and less expensive techniques remains a challenge for environmental protection. In the current research work, alkaline activation approach was employed to derive a biosorbent from ditax fruit hulls (DS‐FHB), and its sorption performance was tested on Methylene blue (MB) dye biosorption with optimizing adsorption parameters. Structural and chemical properties of DS‐FHB including crystallinity, morphology, and surface functionality were analysed using XRD, SEM, FTIR technics, and pHPZC determination. Optimization of adsorption parameters using a centered composite design (CCD) from response surface methodology led to achieving a peak dye removal rate of 98.97 %. The optimal conditions were determined as DS‐FHB mass of 0.23 g, pH 7.12, contact time 39.00 min, and initial MB concentration of 69.35 mg/L. The findings demonstrated a strong alignment with both the Langmuir isotherm and pseudo‐second order kinetic model, suggesting their appropriateness in describing the adsorption process of MB onto DS‐FHB. According to the Langmuir isotherm model, the sorption of MB dye onto DS‐FHB occurred by monolayer formation with a maximum dye sorption capacity of 96.453 mg/g. Based on the structural and physico‐chemical properties of DS‐FHB biosorbent, and its adsoption applicability evaluated in the experimental conditions, detax derived‐biosorbent can be proposed as a successful and effective low‐cost biosorbent for removing cationic dyestuffs from aqueous solutions.