Overlooked role of secondary radicals in the degradation of beta-blockers and toxicity change in UV/chlorine process
| Autor: | Jun Shi, Yishuai Pan, Xuchun Li, Huiping Deng, Kun Fu, Zhengyang Gu |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
General Chemical Engineering
Bicarbonate Radical Advanced oxidation process chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Chloride Industrial and Manufacturing Engineering 0104 chemical sciences chemistry.chemical_compound chemistry Bromide Chlorine medicine Environmental Chemistry Degradation (geology) Hydroxyl radical 0210 nano-technology medicine.drug |
| Zdroj: | Chemical Engineering Journal. 391:123606 |
| ISSN: | 1385-8947 |
| DOI: | 10.1016/j.cej.2019.123606 |
| Popis: | UV/chlorine is regarded as a promising advanced oxidation process (AOPs) for the abatement of micro organic pollutants, but there is still much uncertainty about the involved radical chemistry. In this study, degradation of three beta-blockers, i.e. propranolol (PRO), metoprolol (MTP) and atenolol (ATE) were investigated in UV/chlorine process. The roles of primary and secondary radicals were differentiated by various radical scavengers and kinetic modeling. Chlorine radical (Cl ) played major role in beta-blocker degradation while hydroxyl radical (HO ) dichloride radical anion (Cl2 −) and carbonate radical (CO3 −) also made nonnegligible contributions. Bromide and chloride ions significantly facilitated the degradation of PRO but not for MTP and ATE. Ammonium and natural organic matter (NOM) inhibited the degradation of three beta-blockers, while bicarbonate showed only slight impacts. The degradation products of PRO by UV/chlorine were determined by UPLC-Q-TOF MS analysis with three new oxidation products (OPs, P290, P324 and P326-Cl) firstly reported, and thus the specific radical-based transformation pathway of PRO was proposed. Furthermore, the cytotoxicity evolution was studied by ECOSAR program, and the increased toxicity during PRO degradation was attributed to the accumulation of some toxic OPs. This study provides an insight into the important role of secondary radicals in the oxidation efficiency and toxicity evolution in the UV/chlorine process, and helps with optimization and risk control when applying the process. |
| Databáze: | OpenAIRE |
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