Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5758723 | Water Research | 2017 | 31 Pages |
Abstract
The degradation of natural organic matters (NOMs) by the combination of UV and chlorine (UV/chlorine) was investigated in this study. UV/chlorine oxidation can effectively degrade NOMs, with the degradation of chromophores (â¼80%) and fluorophores (76.4-80.8%) being more efficient than that of DOC (15.1-18.6%). This effect was attributed to the chromophores and fluorophores (double bonds, aromatic groups and phenolic groups) being preferentially degraded by UV/chlorine oxidation, particularly reactive groups with high electron donating capacity. Radical species
- OH and
- Cl were generated during UV/chlorine oxidation, with the contribution of
- OH 1.4 times as high as that of
- Cl. The degradation kinetics of different molecular weight (MW) fractions suggests that UV/chlorine oxidation degrades high MW fractions into low MW fractions, with the degradation rates of high MW fractions (>3000Â Da) 4.5 times of those of medium MW fractions (1000-3000Â Da). In comparison with chlorination alone, UV/chlorine oxidation did not increase the formation (30Â min) and formation potential (24Â h) of trihalomethanes, but instead promoted the formation and formation potential of haloacetic acids and chloral hydrate. Adsorbable organic halogen (AOX) formed from UV/chlorine oxidation of NOM were 0.8 times higher than those formed from chlorination. Cytotoxicity studies indicated that the cytotoxicity of NOM increased after both chlorination and UV/chlorine oxidation, which may be due to the formation of AOX.
- OH and
- Cl were generated during UV/chlorine oxidation, with the contribution of
- OH 1.4 times as high as that of
- Cl. The degradation kinetics of different molecular weight (MW) fractions suggests that UV/chlorine oxidation degrades high MW fractions into low MW fractions, with the degradation rates of high MW fractions (>3000Â Da) 4.5 times of those of medium MW fractions (1000-3000Â Da). In comparison with chlorination alone, UV/chlorine oxidation did not increase the formation (30Â min) and formation potential (24Â h) of trihalomethanes, but instead promoted the formation and formation potential of haloacetic acids and chloral hydrate. Adsorbable organic halogen (AOX) formed from UV/chlorine oxidation of NOM were 0.8 times higher than those formed from chlorination. Cytotoxicity studies indicated that the cytotoxicity of NOM increased after both chlorination and UV/chlorine oxidation, which may be due to the formation of AOX.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Earth-Surface Processes
Authors
Wen-Long Wang, Xue Zhang, Qian-Yuan Wu, Ye Du, Hong-Ying Hu,