Polymer based on beta-cyclodextrin for the removal of bisphenol A, methylene blue and lead(II): Preparation, characterization, and investigation of adsorption capacity

•β-CD-CA-PEG polymer was synthesized using an optimized green route.•PEG is present in the polymer’s structure and contributes to the adsorption mechanism.•β-CD-CA-PEG can efficiently adsorb BPA, MB and Pb (II).•MB is entrapped by β-CD cavities & oxygen containing groups, BPA by β-CD cavities, Pb by oxygen containing groups.•The β-CD-CA-PEG polymer has very good regeneration ability and can be reused several times.