β-Cyclodextrin carbon-based nanoparticles with a core-shell-shell structure for efficient adsorption of crystal violet and bisphenol A

Textile wastewater contains highly toxic, nondegradable, carcinogenic organic pollutants, causing severe damage to the ecological environment. In this work, beta-cyclodextrin carbon-sphere-based nanocomposite (CS/SiO2@beta-CD) with a core-shell-shell configuration was prepared by hydrothermal synthesis and subsequent sedimentation-azeotropic distillation with SiO2 as intermediate layer for the removal of crystal violet (CV) and bisphenol A (BPA). The chemical structure and morphology of the CS/SiO2@pCD were characterized by FT-IR, SEM and TEM. The effects of contact time, pH, temperature and initial concentration of the absorbates on the adsorption property were explored. The CS/SiO2@p-CD showed excellent adsorption capacity on CV and BPA, and the maximum adsorption capacity was 87.873 mg g(-1) and 165.095 mg g(-1), respectively. Their adsorption process was in line with the pseudo-second-order and pseudo-first-order kinetic models, respectively. The adsorption thermodynamics could be better fitted by Langmuir model than by Freundlich model. The calculated thermodynamic parameters (-Delta G(0), Delta S-0 and Delta H-0) illustrated the adsorption of CV was endothermic, in contrast, the adsorption of BPA was exothermic process. Furthermore, the CS/SiO2@p-CD showed excellent recovery performance, making it a potential adsorbent for the practical treatment of textile wastewater. (C) 2021 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.