Preparation, characterization and dye adsorption properties of activated olive residue and their novel bio-composite beads: New computational interpretation

Preparation, characterization, and application of activated olive residue (ROA) and their novel biocompatible bio-composite beads (ROA/AS) are investigated. The adsorbents are characterized by FTIR, XRD, and SEM and subsequently tested to remove methylene blue (MB) taken as a probe-pollutant. Experimental results show a marked enhancement in the adsorptive removal of MB by ROA/AS bio-composite beads as compared to ROA. When statistical physics theory is used to describe the dye removal process, the best match for experimental adsorption isotherms is a monolayer isotherm model coupled with real gas law (MMRG model). Quantum chemical descriptors including frontier orbital energies (EHOMO and ELUMO), gap energy (ΔE), dipole moment (μ), and Fukui index have also been computed and discussed. All the examined systems' adsorption and interaction energies are estimated using Monte Carlo and molecular dynamics simulations. To summarize, integrated experimental and computational calculations have shown to be unique and robust techniques for in-depth investigations of physical processes such as adsorption, providing crucial insights at the molecular level to elucidate the adsorption mechanism.