Here, ultraviolet light-emitting diodes (UV-LED) combined with TiO2 was used to investigate the feasibility of carbamazepine (CBZ) degradation. The effects of various factors, like crystal form of the catalyst (anatase, rutile, and mixed phase), mass concentration of TiO2, wavelength and irradiation intensity of the UV-LED light source, pH of the reaction system, and coexisting anions and cations, on the photocatalytic degradation of CBZ were studied. The mixed-phase (2.8 g/L) showed the best degradation efficiency at 365 nm among three kinds of TiO2, wherein CBZ (21.1 µM) was completely oxidized within 1 h. The results of batch experiments showed that: (i) CBZ degradation efficiency under UV-LED light at 365 nm was higher than 275 nm, due to stronger penetrability of 365 nm light in solution. (ii) The degradation efficiency increased with increase in irradiation intensity and pH, whereas it decreased with increase in initial CBZ concentration. (iii) The optimal amount of mixed-phase TiO2 catalyst was 2.8 g/L and excessive catalyst decreased the rate. (iv) The co-existence of CO32−, HCO3−, and Fe3+ ions in water significantly accelerated the degradation rate of photocatalytic CBZ, whereas Cu2+ ions strongly inhibited the degradation process of CBZ. ·OH was found to be the main active species in the UV-LED photocatalytic degradation of CBZ. UV-LED is more environmentally friendly, energy efficient, and safer, whereas commercial TiO2 is economical and readily available. Therefore, this study provides a practically viable reference method for the degradation of pharmaceuticals and personal care products (PPCPs).

Batch experiments were performed to investigate the effect of several environmental factors on atenolol (ATL) degradation efficiency, including catalyst crystal phase (anatase TiO 2 , rutile TiO 2 , and mixed phase), catalyst dosage, UV-LED wavelength and intensity, co-existing anions, cations, and pH. The mixed phase (2 g/L) exhibited the best photocatalytic activity at 365 nm, with ATL (18.77 µM) completely oxidized within 1 h. These results suggest that: (i) The mixed phase exhibits the highest activity due to its large specific surface area and excellent charge separation efficiency.(ii) ATL can be effectively degraded using mixed phase TiO 2 combined with UV-LED technology and the ATL degradation efficiency could reach 100% for 60 min; (iii) ATL photodegradation was more effective under 365 nm UV-LED than 254 nm, which was caused by the effect of light-induced charge separation; (iv) the ATL Degradation efficiency(De) decreased with an increase in initial ATL concentrations; and (v) co-existing anions and cations had different effects on the ATL De, mainly by changing the concentration of hydroxyl radicals. Considering that UV-LED is more energy-saving and environmentally friendly, and commercial TiO 2 is cheap and easy to obtain, our research provides feasibility for practical application.