Photodegradation characteristics of PPCPs in water with UV treatment.
The degradation characteristics of PPCPs commonly found in surface water under UV treatment were examined for 30 kinds of PPCPs using a UV/Lamp1 that emits light at a wavelength of 254 nm and a UV/Lamp2 that emits light at 254 nm and 185 nm in pure water. When a UV dose of some 230 mJ/cm(2) was introduced to the 30 PPCPs, photodegradation rates of about >3% (theophylline) to 100% (diclofenac) and about >15% (clarithromycin) to 100% (diclofenac) were observed for UV/Lamp1 and UV/Lamp2, respectively. This study also showed that UV/Lamp2, which photolyzes water molecules and generates OH radicals, is more effective for PPCP removal than UV/lamp1. It was postulated that the degradation rates of sulfamethoxazole, sulfamonomethoxine, sulfadimethoxine and sulfadimidine, all, including sulfamethoxazole, derived from sulfanilamide, under UV/Lamp1 resulted mainly from the bond-breaking reactions occurring between -SO(2)- and its side atoms, the C-S bond and the N-H bond. Some PPCPs with amide bonds, such as cyclophosphamide and DEET, were highly resistant to photodegradation by UV/Lamp1. AOPs (Advanced oxidation processes) such as the UV/H(2)O(2) or UV/O(3) processes should therefore be considered for their potential to remove these substances effectively.
Kim
Ilho
I
Research Center for Environmental Quality Management, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan. jinker123@gmail.com
Tanaka
Hiroaki
H
D052918:Environmental Restoration and Remediation / Q000379:methods; D006795:Household Products / Q000528:radiation effects*; D004364:Pharmaceutical Preparations / Q000737:chemistry / Q000528:radiation effects*; D010782:Photolysis; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects*; D014877:Water Pollution, Chemical / Q000517:prevention & control
D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical