β-Cyclodextrin magnetic graphene oxide (β-CD@MGO) for efficient removal of Ni(II) and phenol: Adsorption performance, reusability and adsorption mechanism studies

Pollutants in the wanton discharge of wastewater have seriously threatened the ecosystem on which human beings depend, so the treatment of wastewater is very necessary. In this work, a novel recyclable high-efficiency treatment material, β-cyclodextrin magnetic graphene oxide (β-CD@MGO), was prepared for the removal of Ni(II) and phenol in wastewater. A variety of research methods were used to explore the micro- and macro-structure of the material, and the removal efficiency of the material for Ni(II) and phenol was explored under various conditions. Under optimal conditions, the maximum adsorption capacities of Ni(II) and phenol were 272 mg/g and 233 mg/g, respectively. In addition, the pseudo-first-order model was found to be most consistent with the kinetic data through the kinetic fitting, the Langmuir isotherm model in the isotherm study, as well as the thermodynamic exploration showed that the adsorption was a spontaneous exothermic and a monolayer physical adsorption process. For the recovery experiment, the maximum adsorption capacity of the adsorbent for pollutants remained above 88% after 6 cycles. Finally, the mechanism of adsorption is also discussed, and it is found that the host-guest interaction can be used to explain the adsorption, and physical adsorption is dominant. In summary, the material has a relatively good adsorption effect on Ni(II) and phenol, and is expected to be used in future adsorption projects.