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

Abstract

The photocatalytic oxidation of diclofenac, metoprolol, estrone and chloramphenicol was tested in the tube reactor using different commercially available TiO 2 . 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 TiO 2 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 9 10 -2 min -1 in case of estrone removal over Tytanpol (Z.A. Police, Poland) to 1.87 9 10 -2 min -1 for the removal of chloramphenicol over TiO 2 21 nm (Sigma-Aldrich). The highest initial reaction rates were obtained for metoprolol removal over TiO 2 21 nm (Sigma-Aldrich) 1.9 9 10 -6 mol dm 3 min -1 being three times higher than that determined for estrone photocatalytic oxidation over TiO 2 (Sigma-Aldrich).

The role of pH in the decomposition of organic micropollutants during the heterogeneous photocatalysis process

“…It should be highlighted that for pH values above pH zpc (the value at which the total charge of the catalyst surface shall be zero), the surface of the semiconductor assumes a negative charge and repel anionic compounds. Whereas for pH below pH zpc , the surface assumes a positive charge, resulting in repulsion of cationic donors and electron acceptors [13].…”

Photocatalytic Activity of SnO2-Doped SiO2@TiO2 Nanocomposites

“…The other constants such as the apparent rate constants of the catalyst per mass units k w and per surface area k s were calculated from Eqs. 25.7 and 25.8 [33]:…”

Kinetics of the Photocatalytic Degradation of Selected Organic Micropollutants in the Water Enviroment

“…W takich warunkach powierzchnia cząsteczek fotokatalizatora będą-cego mieszaniną dwóch odmian TiO 2 tj. anatazu i rutylu posiada ładunek ujemny, co sprzyja sorpcji związków posiadających dodatni lub obojętny ładunek elektrostatyczny [Czech, Rubinowska 2013].…”