Recent advances in TiO2-based materials for photocatalytic degradation of antibiotics in aqueous systems

The present review contains information on classification, sources and environmental risks of antibiotics entering the environment. A critical review of the main modern wastewater treatment methods of antibiotics removal is presented; their advantages and disadvantages are shown. The prospects and advantages of the photocatalytic method as the most efficient and economical useful are demonstrated. The antibiotics photocatalytic degradation mechanisms on the titanium dioxide surface and the influence of various factors on it are described. The efficiency of TiO2 co-doping in small concentrations, ratio of which is established experimentally for a real object, is shown. Structuring the photocatalyst allows to achieve a combination of high surface area and high density of available active centers. The optimal ratio of photocatalyst concentrations is recommended in the range of 0.5–1.0​ g/L. It is shown that it is necessary to take into account the acid–base properties of the antibiotic and maintain the optimal pH to achieve a synergistic effect of dissociation, hydrolysis, and sorption properties of the photocatalyst during the antibiotics degradation. It is found that antibiotics with a stronger structure (sulfonamides and macrolides) will take longer to decompose than less chemically resistant (β-lactam). This review allows selecting the optimal conditions for wastewater treatment from antibiotics using TiO2 based materials under UV or visible light irradiation with maximum efficiency.