PDA-cross-linked beta-cyclodextrin: a novel adsorbent for the removal of BPA and cationic dyes

In this study, 4,4'-(hexafluoroisopropene) diphthalic acid (PDA)-CD polymers containing β-cyclodextrin (CD) were synthesized for the adsorption of endocrine disrupting chemicals (EDCs) and dyes. It features great adsorption of bisphenol A (BPA), methylene blue (MB) and neutral red (NR). The maximum adsorption capacities of MB, NR and BPA can reach 113.06, 106.8 and 51.74 mg/g, respectively. The tandem adsorption results revealed that adsorptions of dyes and BPA onto PDA-CD polymer were two independent processes: non-polar BPA entrapment by cyclodextrin cavities while dyes were captured by the carboxyl groups and π-π stacking interactions. The adsorption processes performed well in a wide range of pH (4.0-10.0) and were not affected by fulvic acid (FA) and inorganic ions.