Removal of Methylparaben from an Aqueous Medium Using Biochars Derived from Fique Bagasse. Experimental and...

Emerging pollutants, such as parabens, pose challenges to removal through conventional wastewater treatment and require innovative approaches to remove these contaminants from water. This research evaluated the adsorption of methylparaben onto six biochars derived from fique bagasse. Batch experiments were carried out to investigate adsorption kinetics, equilibrium adsorption, and the influence of solution pH. Results showed that the adsorption capacity decreased at pH values above 6.0 for all evaluated biochars. Kinetic studies revealed that approximately 90% of methylparaben was removed within 10 h, with the pseudo-first-order (PFO) model providing the best fit to the experimental data compared to other tested models. The adsorption process was governed by both internal and external diffusion mechanisms. Equilibrium adsorption data were best described by the Langmuir isotherm, with the adsorption capacity strongly correlated to the specific surface area of the biochars. Maximum adsorption capacities (Q _max) were 134.285 mg g^-1 (FB-3Na), 87.461 mg g^-1 (FB-3C), and 64.349 mg g^-1 (FB-3). Molecular dynamics simulations provided insights into the physisorption of methylparaben onto fique bagasse biochar, confirming that the interactions were exclusively of the π-π and π-alkyl types.