WANG Pan-xin,LI Xin-fei,WANG Yun-peng,et al.Removal Efficiency and Mechanism of As(Ⅲ) by Ferrous Activated Peroxydisulfate[J].China Water & Wastewater,2020,36(23 23):14-20.
Removal Efficiency and Mechanism of As(Ⅲ) by Ferrous Activated Peroxydisulfate
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第36卷
Number:
23 23
Page:
14-20
Column:
Date of publication:
2020-12-01
- Keywords:
- ferrous; peroxydisulfate (PDS); As(Ⅲ); oxidation; adsorption
- Abstract:
- Peroxydisulfate (PDS) alone has almost no oxidation on As(Ⅲ). Herein, PDS activated by ferrous, namely Fe(Ⅱ)/PDS system, was applied to remove As(Ⅲ), and the effects of Fe(Ⅱ) and PDS dosages and pH value on oxidizing efficiency of As(Ⅲ) and the adsorption of arsenic by iron hydroxide generated in the system were investigated. When pH value was 5, the optimal dosages of Fe(Ⅱ) and PDS for 10 μmol/L As(Ⅲ) removal were both 30 μmol/L, and the generation rate of As(Ⅴ) was 87.2% and the total removal efficiency of arsenic was 98.9%. It was revealed that the pH value of the solution played a critical role on the removal efficiency of arsenic in the Fe(Ⅱ)/PDS system. Acidic condition was profitable for the oxidation of As(Ⅲ), but it was not beneficial for the adsorption of As(Ⅴ). Thus, the optimal pH value for As(Ⅲ) removal was 5. Free radical quenching experiment proved that SO4·- was the main oxygen species in the system. XPS characterization confirmed that the iron generated in situ in the system was iron oxyhydroxide, and the valence of iron was +3. Arsenic was basically adsorbed and removed in the form of As(Ⅴ).
Last Update:
2020-12-01