Valorization of acid‐treated date palm leaves composited with chitosan‐oxalate for safranin T dye removal: A step toward sustainability and adsorption modeling studies

Abstract The sustainable valorization of agricultural waste into high‐performance adsorbents offers a promising pathway for eco‐friendly wastewater treatment. In this study, a biomaterial was formulated using acid‐treated date palm leaves and chitosan‐oxalate to boost the adsorption of safranin T (SFT) dye. A variety of analytical techniques were employed to investigate the physicochemical properties of the biomaterial that was developed, namely chitosan‐oxalate/acid‐treated date palm leaves (CH‐OA/ADPL), including pH pzc , XRD, CHN‐O, FTIR, BET, and FESEM. Box–Behnken design (BBD) was employed to optimize the adsorption efficacy of CH‐OA/ADPL, with consideration given to the following variables: A: dosage of CH‐OA/ADPL (0.02–0.08 g), B: pH range (4–10), and C: duration (10–40 min). The experimental findings of SFT adsorption by CH‐OA/ADPL are consistent with the pseudo‐first‐order, Langmuir model. The adsorption capacity of CH‐OA/ADPL was found to be high, reaching 364.3 mg/g. The outstanding uptake of SFT onto CH‐OA/ADPL is mostly attributed to the electrostatic interactions between the positive group of SFT and the acidic groups of CH‐OA/ADPL. This study introduces a sustainable and environmentally conscious methodology for producing efficient bioadsorbents, thereby paving the way for the potential development of bioadsorbents entirely composed of bioresources (biopolymers and agricultural residues) that could serve as an alternative for cationic dye removal. This study also demonstrates the eco‐friendly management and valorisation of biomass, including the well‐known biomass waste (date palm leaves).