Photocatalytic degradation of 17-β-oestradiol on immobilised TiO2

Micro-molar concentrations of aqueous 17-β-oestradiol were 98% destroyed in 3.5h by photocatalysis over the titanium dioxide powder immobilised on Ti-6Al-4V alloy. The concentration of oestradiol was determined by HPLC with fluorescence detection. The degradation kinetics were fitted to a Langmuir–Hinshelwood model with k(S)=4.4×10−2μmoldm−3min−1 and K(S)=0.347dm3μmol−1. The pseudo-first-order rate constant (1.57×10−2min−1) was in line with the 50% degradation time of 40min. The apparent quantum yield per electron was φe′ =0.41%. The effect of pH on the initial rate of degradation was similar to that reported for phenol.