| Title | Interpretation of high perchlorate generated during electrochemical disinfection in presence of chloride at BDD anodes |
| Authors | Long, Yujiao Li, Hongna Jin, Hongmei Ni, Jinren |
| Affiliation | Jiangsu Acad Agr Sci, Inst Agr Resources & Environm, Nanjing 210014, Peoples R China Peking Univ, Minist Educ, Key Lab Water & Sediment Sci, Coll Environm Sci & Engn, Beijing 100871, Peoples R China Chinese Acad Agr Sci, Inst Environm & Sustainable Dev Agr, Agr Clean Watershed Res Grp, Beijing 100081, Peoples R China |
| Keywords | BORON-DOPED DIAMOND WASTE-WATER TREATMENT BY-PRODUCT FORMATION ORGANIC POLLUTANTS HYDROXYL RADICALS ESCHERICHIA-COLI DRINKING-WATER OXIDATION ELECTROLYSIS MECHANISM |
| Issue Date | Dec-2021 |
| Publisher | CHEMOSPHERE |
| Abstract | Perchlorate is a disinfection by-product (DBP) of serious health concern. Herein, the long sought mechanism of high perchlorate production during electrochemical disinfection at boron-doped diamond (BDD) anode in the presence of chloride was elucidated. The generated perchlorate at BDD during electrochemical disinfection (in 10 mM NaCl) in 60 min reached 0.125 mM, which was 830 times higher than the EPA standard. In contrast, perchlorate at PbO2 and SnO2 anodes was below the detection limit. Further experiments employing NaClO3 revealed that the conversion ratio from ClO3- to ClO4- in 10 h at BDD (98%) was considerably higher than PbO2 (13%) and SnO2 (12%). Such significant difference among anodes was fully interpreted with a two-step mechanism. The first step is essential to produce center dot ClO3 by oxidizing ClO3- at electrodes. Otherwise, the conversion to perchlorate would be impossible even with excessive center dot OH, which was verified with the photocatalysis process. The second step is the perchlorate generation with radical reaction between center dot ClO3 and center dot OH, where the primary role of center dot OH was substantiated by scavenging test. Interestingly, the capability of perchlorate production was correlated with free center dot OH instead of the total amount of center dot OH. Despite the similar abilities of electron transfer between anodes and ClO3-, much higher free center dot OH exists at BDD anode than at PbO2 and SnO2 anodes through chronoamperometry experiments and work function characterization, which reasonably provides interpretation of high perchlorate production at BDD anode. |
| URI | http://hdl.handle.net/20.500.11897/626433 |
| ISSN | 0045-6535 |
| DOI | 10.1016/j.chemosphere.2021.131418 |
| Indexed | SCI(E) |
| Appears in Collections: | 环境科学与工程学院 水沙科学教育部重点实验室（联合） |
