Biogenic Hydroxyapatite Obtained from Bone Wastes Using CO2‑Assisted Pyrolysis and Its Interaction with Glyphosate: A Computational and Experimental Study

In this work, biogenic hydroxyapatite (BHap) obtained from cattle bone waste is proposed as an adsorbent of this dangerous pollutant. Density functional theory (DFT) and calorimetric studies were developed to study the interaction between BHap and glyphosate (GLY). A strong interaction was found in the experiments through the measurement of immersion enthalpy, confirmed by the exothermic chemisorption obtained with DFT calculations. These results suggest that hydroxyapatite is a promising adsorbent material for GLY adsorption in aqueous solutions. In addition, it was determined that the GLY–hydroxyapatite interaction is greater than the water–hydroxyapatite interaction, which favors the GLY adsorption into this material.