Cocoa pod husk (CPH), an abundant agricultural waste, represents a promising lignocellulosic resource for sustainable material development. In this study, solid residues (dregs) obtained after extraction of soluble components from CPH were valorized as a novel bioadsorbent for methylene blue (MB) removal from aqueous solutions. The material was prepared via thermal treatment with and without citric acid modification, followed by physicochemical characterization using FTIR, SEM, and BET analyses. The results revealed that the prepared adsorbents possess a predominantly microporous structure with surface areas ranging from 200 to 624 m²/g, depending on the treatment conditions. Adsorption experiments demonstrated high removal efficiency of MB, exceeding 95% under optimal conditions. The enhanced adsorption performance is attributed to the combined effects of surface functional groups and developed porosity. These findings demonstrate that CPH dregs can serve as an effective, low-cost, and sustainable bioadsorbent for wastewater treatment, enabling the direct valorization of agricultural waste within a circular economy framework.