Water pollution caused by organic substances such as dyes necessitates the implementation of advanced treatment processes. Among the proposed solutions, using adsorption techniques with cost-effective adsorbent materials derived from plant waste has been suggested. The aim of this study is to assess the effectiveness of activated carbon in adsorbing Rhodamine B. The research investigates the adsorption mechanism of Rhodamine B, focusing on parameters including pH, adsorbent mass, and initial dye concentration. The obtained results were analyzed using kinetic models such as pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion equations. The findings demonstrate that the adsorption kinetics of Rhodamine B on the chemically and physically activated biomaterial conform well to the pseudo-second order model, with correlation coefficients (R2) ≥ 1 at all tested temperatures. Intraparticle diffusion is identified as the controlling step in the adsorption process after 50 minutes of contact time. Moreover, thermodynamic analysis and adsorption isotherms indicate that the adsorption process is favorable, spontaneous, and exothermic.