Photolysis of bis(2-ethylhexyl) phthalate in aqueous solutions at the presence of natural water photoreactive constituents under simulated sunlight irradiation

The photolysis of bis(2-ethylhexyl) phthalate (DEHP) under simulated sunlight in the presence of the natural water photoreactive constituents was investigated. The presence of nitrate or ferric ions facilitated the photodegradation of DEHP via oxidation by generation of center dot OH. The fulvic acids (FAs), at low concentrations, promoted the photolysis of DEHP via energy transfer from the photoreaction-generated (3)FA*. However, the DEHP photolysis was inhibited with high concentrations of FAs since the excess FAs at the surface of solution could act as light screening agents to keep FAs in bulk solution from the light irradiation, further reducing the (3)FA* generation. When low concentrations of FAs and chloride ions coexist, the reactive chloride species Cl center dot and Cl-2 center dot(-) could generate via energy transfer from (3)FA* to chloride ions and react with DEHP to enhance its degradation. Furthermore, the direct and center dot OH-initiated DEHP photodegraded intermediates and end products were identified by HPLC-MS2 and its corresponding photolysis pathways were proposed.