Abstract
This current research implements statistical physics principles to microscopically elucidate and interpret the retention mechanism of Captopril onto the activated carbon derived from Butia catarinensis (ABc-600) for water decontamination. The empirical points were modeled exploiting four different statistical isotherm frameworks: the single-energy monolayer, dual-energy monolayer, trienergetic monolayer and dual-energy bilayer. Supported by an error quantification approach (R(2), Reduced Chi-Square, RSS and R(adj)(2)) the single-energy monolayer was identified as the most rigorous scenario. Stereographic analysis revealed that the adsorption sites consistently capture a fraction of the adsorbed species with n < 1 across all tested temperatures indicating a multianchorage mechanism without aggregation. The decrease in the monolayer adsorbed amount with incrementing temperature highlights the endothermic nature of the Captopril/ABc-600 retention mechanism. Moreover, the energetic assessment corroborates the predominance of physisorption (<40 kJ/mol) indicating that van der Waals forces primarily govern the docking operation. PSD examination revealed a predominantly macroporous structure (0.7 μm) with a discernible shift toward smaller pore radii at elevated temperatures. The AED curves consistently displayed physisorption within the 22-29 kJ/mol energy range across all temperature conditions.