WANGPeng-ying,SUBing-qin,PENGYa-ya,et al.Reaction Conditions and Mechanism of Peroxymonosulfate for Direct Oxidative Degradation of Pyridine[J].China Water & Wastewater,2022,38(13):64-70.
Reaction Conditions and Mechanism of Peroxymonosulfate for Direct Oxidative Degradation of Pyridine
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第38卷
Number:
第13期
Page:
64-70
Column:
Date of publication:
2022-07-01
- Keywords:
- peroxymonosulfate; direct oxidation; pyridine; nitrogen heterocyclic compound; reaction mechanism
- Abstract:
- Peroxymonosulfate (PMS) was directly applied to oxidize nitrogen heterocyclic compound pyridine in wastewater. The effects of PMS dosage, pH, coexisting anions（Cl-, HCO3-, NO3-）and humic acid (HA) on degradation of pyridine were investigated. The direct oxidation of pyridine by PMS conformed to pseudo first-order reaction kinetics. When the initial concentration of pyridine was 8.0 mg/L, the pH was 7.0, the reaction temperature was 25 ℃, and PMS dosage was 4.0 mmol/L, the removal efficiency of pyridine reached 93.66% after 150 minutes of reaction. The presence of Cl-, HCO3-, NO3- and HA in water had no significant effect on pyridine degradation. Free radical identification showed that no sulfate radical (SO4-·) and hydroxyl radical (·OH) were generated, and a small amount of singlet oxygen (1O2) was formed in the PMS system. The direct oxidation of PMS was the main mechanism of pyridine degradation. GC-MS analysis showed that the intermediate products of pyridine directly oxidized by PMS were N, N-dimethylacrylamide, oxalic acid, acetic acid, and other low?toxic organic compounds.
Last Update:
2022-07-01