Degradation of Di-(2-ethylhexyl) Phthalate (DEHP) by TiO2 Photocatalysis

The photocatalytic degradation of di-(2-ethylhexyl) phthalate (DEHP) in solution using titanium dioxide (TiO₂) was analyzed in this study. It was found that DEHP was completely removed in the solution after 150 min irradiation. The effect of different factors, such as photocatalyst amount, DEHP concentration, light intensity, pH, and temperature on photocatalytic degradation was investigated. The degradation mechanism of DEHP with proton and hydroxyl radicals oxidation were also studied. It is suggested that either ethylhexyl or ester chain scissions of the aliphatic part of DEHP was the dominant degradation mechanism of the process. The photocatalytic degradation process was well described by first-order reaction. The final mineralization product was carbon dioxide and the intermediate products were identified by GC-MS. Thus, the photocatalytic degradation treatment of DEHP in wastewater is a relative simple and fast method.