Comparison of Electrochemical Degradation of Sulfonamides with BDD and Pt Electrodes
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2019-05-01 |
| Journal | ECS Meeting Abstracts |
| Authors | Hongna Li, Jing Ye, Changxiong Zhu |
Abstract
Section titled āAbstractāElectrochemical degradation of a series of sulfonamides (SNs) was investigated using both BDD and Pt anodes. SNs were destroyed faster in Na 2 SO 4 than in NaH 2 PO 4 electrolytes at the BDD anode, while the opposite occurred with Pt anode. In the BDD anode system, the degradation rates of SNs with a singly-substituted pyrimidine ring rose with the Hammettās constants for both electrolytes. The structure of SNs had no significant effect on the degradation rates with the Pt anode. Accordingly, the mineralization rate of SNs with the BDD anode reached 28-45% in Na 2 SO 4 electrolytes, and it decreased to 17-35% when using NaH 2 PO 4 electrolytes in 6-h electrolysis. Further analysis indicated no difference for the intermediates in the electrochemical oxidation of sulfamethazine regardless of the anode used. Anyhow, the relative amount of these intermediates formed varied from BDD to Pt. The compound corresponding to an attack on the pyrimidine ring occupied a relatively higher ratio (M1, 0.3%) in the Pt system, while that associated with cleavage of the sulfonamide bond (M4, 16.7%) as well as M1 (6.7%) covered a large proportion with BDD in the first 1 hour of electrolysis. Due to the efficient oxidative ability of BDD anodes, larger amounts of intermediates with relatively high toxicity were generated initially and then declined. The formation of these intermediates continuously increased in the Pt system. The electrolysis conducted with BDD and Pt anodes were actually at different oxidation stages. For this reason, the electrochemical oxidation process with the BDD anode is advantageous because it accomplishes relatively more complete mineralization of organic pollutants.