TiO2-assisted photocatalytic degradation of diclofenac, metoprolol, estrone and chloramphenicol as endocrine disruptors in water

The photocatalytic oxidation of diclofenac, metoprolol, estrone and chloramphenicol was tested in the tube reactor using different commercially available TiO2. The photocatalysts were characterized using BET, XRD and SEM. The studied photocatalysts differed in S-BET, pore volume and rutile presence. It was observed that generally anatase TiO2 possessed the highest activity in the photocatalytic oxidation of diclofenac, chloramphenicol and estrone. The presence of rutile enhanced the photooxidation of metoprolol. In case of the other pollutants, however, rutile diminished the photooxidation efficiency. The most effective in the reduction of the COD parameter of treated water was anatase with 21 nm crystals. The photooxidation of all studied pollutants can be described by the pseudo-first order kinetics with the values ranging from 0.46 x 10(-2) min(-1) in case of estrone removal over Tytanpol (Z.A. Police, Poland) to 1.87 x 10(-2) min(-1) for the removal of chloramphenicol over TiO2 21 nm (Sigma-Aldrich). The highest initial reaction rates were obtained for metoprolol removal over TiO2 21 nm (Sigma-Aldrich) 1.9 x 10(-6) mol dm(3) min(-1) being three times higher than that determined for estrone photocatalytic oxidation over TiO2 (Sigma-Aldrich).