Improved biodegradation of pharmaceuticals after mild photocatalytic pretreatment

Abstract

The combination of photocatalysis and biodegradation was investigated for the removal of nine selected pharmaceuticals as a means to reduce loadings into the environment. The combined process, consisting of a resource-efficient mild photocatalysis and a subsequent biological treatment, was compared to single processes of intensive photocatalysis and biological treatment. The UV-TiO 2 based photocatalysis effectively removed atorvastatin, atenolol and fluoxetine (>80%). Biological treatment after mild photocatalytic pretreatment removed diclofenac effectively (>99%), while it persisted during the single biological treatment (<50%). Moreover, the biodegradation of atorvastatin, caffeine, gemfibrozil and ibuprofen was enhanced after mild photocatalytic pretreatment compared to biological treatment alone. The enhanced biodegradation of these pharmaceuticals appeared to be triggered by the biodegradation of photocatalytic products. Mild photocatalysis followed by biological treatment is an effective and resource-efficient combination for pharmaceutical removal that could substantially reduce the loading of pharmaceuticals into the environment. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Improved biodegradation of pharmaceuticals A. de Wilt et al.

Continuous degradation of micropollutants in real world treated wastewaters by photooxidation in dynamic conditions

“…Yurdakal et al (2007) found the same results for gemfibrozil, with no adsorption for initial concentrations of 5-50 mg/L at pH 10 and the use of Degussa TiO2 and Merck TiO2. De Wilt et al (2020) showed that adsorption to TiO2 contributed little (< 25%) to gemfibrozil removal but also atorvastatin removal, with initial concentrations of 500 µg/L and P25 powdered TiO2. Arlos et al (2016) also found that atorvastatin showed adsorptive removal but only at 15% and with very different conditions to here, as they used TiO2 immobilized on porous titanium sheets, at initial concentration of 2 µg/L, and pH conditions of approximately 4.5-5.…”