Laoufi N., Hout S., Tassalit D., Ounnar A., Djouad A., Chekir N., Bentahar F., 2013, Removal of a Persistent Pharmaceutical Micropollutant by UV/TiO2 Process Using an Immobilized Titanium Dioxide Catalyst: Parametric Study, Chemical Engineering Transactions, 32, 1951-1956.
Antibiotics are considered as emerging environmental microcontaminants because of their potential adverse effects on ecosystems and human health. The photocatalysis process, in presence of TiO2 particles, is one of the most promising techniques for the removal of antibiotics. In the present work, photodegradation of tylosin, a veterinary antibiotic, has been released in a photoreactor containing a catalyst (TiO2 P25 from Degussa) deposited on a glass substrate. The study of tylosin photodegradation was conducted in the presence of a black light UV radiation of 18 watts. Different parameters were investigated and optimized on the removal of tylosin. The results showed that this process with the use of optimized operating parameters can lead to total degradation of tylosin. Thus, photodegradation is favored for low pollutant concentration and a high rate of the reaction mixture recirculation. The antibiotic was completely removed after 7 hours of illumination; the best degradation was obtained at pH 3. More than 98 % of tylosin has been oxidized after an irradiation time of 7 hours at the optimum position of UV light. The photolysis of tylosin has reached an abatement not exceeding 30 %. In addition, the study of the effect of the volume of the reaction mixture showed that a change in the rate of degradation was obtained for differences in volumes of 100 mL, below this value, no change were observed. The kinetic study showed the high activity and efficiency of titanium dioxide Degussa P25 and the degradation of 98 % of tylosin after 7 hours of UV irradiation at the optimal position of 5.5 cm from the catalyst surface. The kinetics was described by the Langmuir-Hinshelwood kinetic model.
