Integration of ozone and solar TiO2-photocatalytic oxidation for the degradation of selected pharmaceutical compounds in water and wastewater

[Display omitted] •Ozonation and solar TiO2 photocatalysis allow complete removal of ECs and phenolic intermediates.•Mineralization level and reaction products depend on the ozone dose and/or solar radiation dose.•Treated effluents from single or combined treatments are biodegradable.•The degree of mineralization achieved by TiO2 photocatalysis is influenced by the water matrix.•Pre-ozonation slightly improves the mineralization rate achieved by solar TiO2 photocatalysis. The degradation of a mixture of four pharmaceutical compounds (atenolol, hydrochlorothiazide, ofloxacin and trimethoprim) in distilled water and in a synthetic solution simulating a typical secondary effluent from a municipal wastewater treatment plant by ozonation, solar TiO2-photocatalytic oxidation and a sequence of both methods has been investigated. Degradation by ozone led to the complete removal of the selected emerging compounds (EC) but an accumulation of ozonation by-products (e.g., phenolic intermediates and carboxylic acids) in solution was observed. The presence of ozone-consuming substances in the synthetic effluent had not a negative impact on the removal of the pharmaceuticals but on their mineralization (TOC removal