US EPA

1315311 

Journal Article 

Sonophotolytic diethyl phthalate (DEP) degradation with UVC or VUV irradiation 

National Academy of Sciences :: NAS 

2012 

1 

Ultrasonics Sonochemistry
ISSN: 1350-4177
EISSN: 1873-2828 

Elsevier B.V. 

19 

5 

1094-1098 

English 

22464797 

10.1016/j.ultsonch.2011.10.004 

WOS:000304076900018 

This study investigated the degradation of diethyl phthalate (DEP) by sonolytic, photolytic and sonophotolytic processes. Two types of UV lamps, UVC (254 nm) and VUV (185 nm+254 nm), were combined with ultrasound (283 kHz). The pseudo-first order degradation rate constants were in the order of 10(-1)-10(-3) min(-1) depending on the processes. The sonolytic DEP degradation rate increased with increasing applied power. Photolytic or sonophotolytic degradation of DEP when using a VUV lamp appeared to be effective because the photo ІІ (UVC/VUV) resulted in a significantly faster degradation than the photo І (UVC) processes due to the higher photon energy and higher hydroxyl radical generation by homolysis of water by VUV. Significant degradation and mineralization (TOC) of DEP were observed with the combined sonophotolytic processes. Moreover, synergistic effects of 1.68 and 1.23 were exhibited at DEP degradation of the sonophoto I and sonophoto II processes, respectively. This was attributed to the UV-induced dissociation of hydrogen peroxide (H(2)O(2)) generated by the application of US to hydroxyl radicals. Therefore, US in sonophotolytic processes can play an important role in enhancing DEP degradation. Moreover, the sonophoto ІІ process is more effective on the mineralization and biodegradability of DEP. 

Diethyl phthalate (DEP); Ultrasound; UVC; VUV; Sonophotolysis; Synergistic effect