Adsorptive removal of crystal violet using chemically activated biowaste: Molecular insights from DFT and molecular dynamics simulations and experimental assessment

Abstract

In this study, we explore the removal of crystal violet (CV), a cationic organic dye, by adsorption utilizing a biomass-derived material made from date pits, which provides a novel class of cost-effective and efficient adsorbents for CV removal. The synthesized material's structural and surface characteristics were analyzed using XRD, SEM, and FTIR methods to identify its crystalline phases, morphological traits, and distribution of functional groups. This lignocellulosic biowaste, notably abundant in cellulose, was utilized as a natural support to improve dye adsorption from water solutions. To enhance the adsorption process, the Response Surface Methodology (RSM) in conjunction with a Box-Behnken Design (BBD) was utilized to assess how adsorbent dosage, initial concentration of crystal violet, and solution pH interactively affect dye removal efficiency. The model forecasted optimal conditions as 0.5 g/L of adsorbent dosage, an initial dye concentration of 100 mg. L −1 , and a pH of 10, which resulted in the highest removal efficiency. Under these ideal conditions, a crystal violet removal efficiency of 91.12% was achieved, highlighting the significant potential of using date pits as a sustainable biomass-derived adsorbent for treating dye-polluted wastewater. According to simulation results, the favorable interactions between crystal violet and the DP-AC (111) adsorbent surface enhances adsorption. Molecular modeling and quantum descriptors reveal that the dye's adsorption follows a spontaneous mechanism, influenced by heteroatoms and π bonds within the conjugated system, as evidenced by the analysis of adsorption energies.