Preparation and Characterization of an Activated Carbon‐Derived from Almond Shell for the Removal of Rhodamine B Dye: Kinetics, Isotherm, and Thermodynamics Analysis

Abstract Since organic pollutants from wastewater have grown more hazardous to the environment in recent years, decontaminating wastewater before disposing of it is crucial. Here, the purpose is to prepare activated carbon (AC) from almond shells (AS) using KOH activation with an impregnation ratio of 1:4 (AS:KOH). ASs and ASAC (almond shell activated carbon) have been characterized using a variety of analytical techniques, including FTIR, XRD, Raman, BET, and SEM with EDS mapping analysis. The prepared ASAC exhibited a specific surface area of 1082 m 2 g −1 . Optimized conditions of the study include an adsorbent dosage of 0.30 g/L, pH of 3, and initial dye concentration of 100–180 mg/L with a contact time of 70 min, wherein batch adsorption study showed high removal efficiency. It demonstrated a remarkable rhodamine B (RhB) removal capacity of 191.331 mgg −1 in aqueous solution. Equilibrium adsorption data were tested using Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) isothermal models by nonlinear regression. The adsorption fit the Langmuir isotherm model well, and pseudo‐second‐order kinetics. The adsorption was exothermic and spontaneous, according to thermodynamic studies. Additionally, the ASAC's reusability showed that it can be used for up to five cycles without its removal efficiency, highlighting its potential for sustainable and cost‐effective water treatment.