ENHANCED PHOTOCATALYTIC DEGRADATION OF BISPHE- NOL F BY β-CYCLODEXTRIN IN AQUEOUS TIO_2 DISPERSION

摘要

Enhancement of β-cyclodextrin (β-CD) on TiO_2 photo-catalytic degradation of bisphenol F (BPF, bis(4-hydroxy-phenyl)methane) was investigated under a 250W metal hal-ide lamp (λ ≥ 365 nm). In the system of photocatalytic BPF degradation, the photodegradation rate of BPF in aqueous solutions containing β-CD and TiO_2 was obviously faster than that in those containing only TiO_2. After 40 min of irradiation, β-CD could increase the photodegradation efficiency by about 21% for 10 mg l~(-1) BPF in the UV-VIS/TiO_2 system, and for 2.5-20.0 mg l~(-1) BPF in aqueous solutions efficiency was found to follow pseudo-first order law, and the adsorption constant and the reaction rate constant of BPF in the system containing β-CD and TiO_2 are obviously higher than those in the system without β-CD. The factors influencing BPF photodegradation, such as β-CD concentration, pH and BPF initial concentration, were studied and described in detail. The formation of CO_2 as a result of BPF mineralization was observed during the photodegradation process. After 120 min of irradiation, the mineralization efficiency of BPF reached 48% in the presence of β-CD, whereas it was only 18% in the absence of β-CD. The enhancement of BPF photodegradation could be dependent on the enhancement of adsorption of BPF on TiO_2 surface, and moderate inclusion-depth of BPF in the β-CD cavity.