Hierarchically porous activated carbon derived from Lansium domesticum peel via hydrothermal-H 3 PO 4 activation for enhanced methylene blue removal: adsorption behavior, advanced modeling and mechanistic insights

= 0.9975, ΔAIC = 0), suggesting the relevance of surface heterogeneity in describing adsorption behavior. Kinetic analysis further indicated that no single model adequately captured the adsorption process, supporting a multi-step mechanism involving intraparticle diffusion and heterogeneous surface interactions. Mechanistic interpretation, supported by physicochemical characterization and adsorption behavior, suggests that electrostatic attraction, π-π interactions, hydrogen bonding, and pore diffusion collectively contribute to adsorption in a coupled and condition-dependent manner. These findings highlight that rational pore structure design and surface functionality can partially compensate for relatively low surface area, offering a viable strategy for converting agricultural residues into efficient carbon-based adsorbents. This study also provides a statistically supported framework for interpreting adsorption behavior, contributing to the development of sustainable materials aligned with circular economy principles.