Vitamin C promoted refractory organic contaminant elimination in the zero-valent iron/peracetic acid system: Efficiency, mechanism and effects of various parameters

Peng Xu; Lei Wang; Xin Liu; Shiqi Xie; Baolin Hou

doi:10.1016/j.chemosphere.2023.138481

Vitamin C promoted refractory organic contaminant elimination in the zero-valent iron/peracetic acid system: Efficiency, mechanism and effects of various parameters

Chemosphere. 2023 Jun:326:138481. doi: 10.1016/j.chemosphere.2023.138481. Epub 2023 Mar 21.

Authors

Peng Xu¹, Lei Wang², Xin Liu², Shiqi Xie², Baolin Hou³

Affiliations

¹ Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Hunan University, Changsha, 410082, PR China. Electronic address: xp12904@hnu.edu.cn.
² Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Hunan University, Changsha, 410082, PR China.
³ School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.

PMID: 36958501
DOI: 10.1016/j.chemosphere.2023.138481

Abstract

The conventional zero-valent iron/peracetic acid (ZVI/PAA) system is severely limited owing to the passivation of ZVI and the low recovery of Fe²⁺. In this study, a reducing agent, vitamin C (H₂A), was used for the first time to enhance the ZVI/PAA system as a way to improve its degradation performance. Under optimal conditions, the removal efficiency of the H₂A/ZVI/PAA system was 82.9%, while that of the H₂A/PAA and ZVI/PAA systems were only 19.0% and 25.6%. Free radical quenching and electron paramagnetic experiments (EPR) confirmed that CH₃C(O)O•, •OH and CH₃C(O)OO• were the major active species for acid orange 7 (AO7) degradation with contributions of 9.7%, 75% and 14.4%, respectively. The degradation mechanism was proposed through UV-vis full-wavelength scanning and chemical oxygen demand (COD) experiments. The removal of AO7 was not affected in the presence of Cl^-, SO₄^2- and HCO₃^-, while inhibition occurred with humic acid. ZVI exhibited excellent catalytic properties and stability, and the removal efficiency of AO7 exceeded 70% after three cycles. Additionally, the H₂A/ZVI/PAA system showed good ability to remove AO7 in well water, lake water, river water and reservoir water, and the elimination efficiency of MO, DCF and ACE also exceeded 70%. Overall, this study contributes new cognition for enhancing the ZVI/PAA system to degrade contaminants, which is expected to achieve a cleaner water environment.

Keywords: Fenton-like; Peracetic acid; R–O•; Vitamin C; Zero-valent iron.

MeSH terms

Ascorbic Acid
Iron* / chemistry
Oxidation-Reduction
Peracetic Acid
Vitamins
Water Pollutants, Chemical* / chemistry

Substances

Iron
Ascorbic Acid
Peracetic Acid
Water Pollutants, Chemical
Vitamins
2-naphthol orange