Synthesis, characterization and performance evaluation of activated carbon-encapsulating alginate beads from...

This article reports the new sodium alginate/AC composite bead synthesized from activated carbon obtained by pyrolysis of argan shells and blended with an alginate polymer functionalized to remove sofosbuvir residues from aqueous solution. The composite beads do not pose a health risk to humans and are composed of natural, environmentally friendly, and biocompatible materials. Alg/AC does so by algal clarification and absorption, which means water clarification without the addition of photonics and the removal of drug residues. The performance of Alg/AC beads was optimized by FTIR, SEM, and XRD characterizations. We also optimized the different adsorption parameters including drug residual levels, amount of absorbent, pH, and initial Sofosbuvir concentration via BBD. Data on sofosbuvir adsorption to beads was better fitted by the Freundlich isotherm model (R² = 0.9985) and pseudo-second-order kinetic model (R² = 0.9984). The calculated adsorption thermodynamic parameters, ΔH° (enthalpy), ΔS°(entropy) and ΔG° (free energy) were discussed to reveal that the surface of beads showed heterogeneity in their chemisorption process which was governed by numerous mechanisms. The three-dimensional molecular structure of sofosbuvir was modified by wB97XDB with 6-311 + g (d,2p) basis set in solution. From these, the energies of HOMO and LUMO were employed in evaluating some Global chemical reactivity descriptors. Furthermore, Monte Carlo (MC) and molecular dynamics (MD) simulations were carried out to investigate the higher dimensional interplay of a sofosbuvir molecule with simulated alginate beads coating on an activated carbon surface. Thirdly, the beads exhibited good removal performance even after three adsorption-regeneration cycles indicating their possible use in decontaminating drugs from wastewater.