Preferential removal of phthalic esters by photocatalysis on selective TiO2

Abstract

Endowing traditional photocatalysis with selectivity for a class of characteristic pollutants is important in environmental science. Using PAEs-TiO2 as a selective photocatalyst, 302.5 μg L−1 of 11 phthalic esters (PAEs) were preferentially removed to 4.94 μg L−1 in the presence of 10 mg L−1 of natural organic matter via specific hydrogen bonds or cation-π interactions. Further, degradation of PAEs is a lower risk pathway for PAEs-TiO2. The in-situ photocatalytic electron paramagnetic resonance initially revealed that PAEs-TiO2 facilitated the ring opening and mineralization of PAEs, resulting in nearly 100 % detoxification. In actual wastewater, PAEs were not detected after treatment with PAEs-TiO2. Further, the energy cost was reduced by 48.1 %, reaching discharge standard. This study offers new sights into selective photocatalysis of a class of pollutants with similar molecular structure.