Enhanced Photodegradation Behavior of Bisphenol F in the Presence of β-Cyclodextrin under UV Light

In the presence of β-cyclodextrin (β-CD), the photodegradation behavior of bisphenol F has been studied under UV irradiation (λ_max = 254 nm) in this work. The results show that the photodegradation rate of bisphenol F (BPF) in aqueous solution with β-CD was clearly faster than that without β-CD. After 60 min of UV irradiation, the addition of β-CD increased the photodegradation efficiency by about 40.0% for 10.0 mg L⁻¹ bisphenol F, and the first-order rate constant increased by 3.40-fold in the presence of β-CD. The following factors were investigated as to their influence on the photodegradation rates of bisphenol F: concentration of β-CD, pH, bisphenol F initial concentration, and organic solvent. Also, the variation of the electrical conductivity of the solution during the photodegradation was examined. It was found that the photodegradation of 2.50–15.0 mg L⁻¹ bisphenol F in aqueous solution followed pseudofirst-order kinetics. This work indicates that β-CD enhanced photodegradation under UV light has high potential of removal of bisphenols from water, and the enhancement of photodegradation of BPF mainly results from moderate inclusion depth of BPF molecule in the β-CD cavity. This kind of inclusion structure allows BPF molecule sufficient proximity to secondary hydroxyl groups of the β-CD cavity, and these hydroxyl groups could be activated and converted to hydroxyl radicals under UV irradiation, which can enhance the photooxidation of BPF.