Indirect photodegradation of sulfisoxazole: Effects of environmental factors (CDOM, pH, salinity, HCO3−, metal ions, halogen ions and NO3−)

• Published in: Marine pollution bulletin 2022-01, Vol.174, p.113320-113320, Article 113320
• Main Authors: Duan, Jiaqi, Jian, Huimin, Dou, Qiwei, Shi, Xiaoyong, Su, Rongguo
• Format: Article
• Language: English
• Subjects: Analytical methods; Chromophoric dissolved organic matter; Coastal waters; Components; Copper; Dissolved Organic Matter; Emission analysis; Environmental factors; Excitation spectra; Fluorescence; Halogens; Hydrogen-Ion Concentration; Indirect photodegradation; Intermediates; Iron; Metal ions; Metals; Organic Chemicals; pH effects; Photodegradation; Photolysis; Reactive intermediates; Salinity; Salinity effects; Spectrometry, Fluorescence; Spectroscopy; Sulfisoxazole; Terrestrial environments; Water
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2022.113320

It's a new perspective to explore the influences of chromophoric dissolved organic matter (CDOM) components and environmental factors on the removal of sulfisoxazole (SIX) from the water matrix. Reactive intermediates (RIs) trapping experiments demonstrated that excited triplet-state CDOM (3CDOM⁎) played a dominant promoting role (54.11%) in the CDOM-mediated SIX indirect photodegradation. Additionally, terrestrial humic-like (C1, C3 and C4) and marine humic-like (C2) fluorescent components were identified by parallel factor (PARAFAC) analysis of CDOM excitation-emission matrix spectroscopy (EEMs). C1 and C4 were significantly correlated (R2 > 0.91) with the SIX degradation rate owing to their higher productivity of RIs and a greater contribution to the production of 3CDOM⁎ compared to others. Salinity, pH and HCO3− were conducive to the SIX indirect photodegradation, while metal ions (Fe3+ and Cu2+), halogen ions (Cl− and Br−) and NO3− were opposite. These findings are essential for understanding the environmental fate of SIX in coastal waters. [Display omitted] •The SIX removal was controlled by the CDOM exogenous components (C1 and C4).•OH, 1O2 and 3CDOM⁎ played a key role in the indirect photodegradation of SIX.•The 3CDOM⁎contribution rate to the SIX indirect photodegradation was up to 54.11%.•Salinity, pH and HCO3− were favorable to the indirect photodegradation of SIX.