Chemically Modified Banana Stem Adsorbent for Adsorption of Reactive Orange 16 from Aqueous Solutions

Introduction: Anionic azo dye contamination poses environmental hazards. This study investigated surfactant-modified banana stem (SMBS) as an adsorbent for the removal of Reactive Orange 16 (RO16), with RO16 serving as a model for anionic azo dyes. Methods: SMBS was prepared via NaOH mercerization and CTAB modification for enhanced porosity/ surface charge. FTIR and SEM confirmed functionalization, showing morphological changes and an increase in positive surface charge (pHpzc 5.48 to 6.8). Kinetics, isotherms, desorption, and realworld application studies were evaluated. Results: The adsorption kinetics best fit the pseudo-second-order model. Isotherms fit the Freundlich model, suggesting multilayer adsorption. Maximum RO16 removal (19.83 mg/g, 98%) occurred at pH 3 via electrostatic attraction. Minimal dye leaching (1.25-4.02%) was observed with 95% removal efficiency maintained in lake water. Discussion: SMBS demonstrated high efficacy and viability as an eco-friendly adsorbent from agricultural waste for industrial wastewater treatment. Strong pH dependence and minimal desorption suggest robust electrostatic binding, confirming enhanced adsorption properties. Conclusion: This study highlights SMBS's significant potential as an efficient RO16 adsorbent, offering a promising alternative for treating industrial wastewater using agricultural waste.