Motivation of reactive oxidation species in peracetic acid by adding nanoscale zero-valent iron to synergic removal of spiramycin under ultraviolet irradiation: Mechanism and N-nitrosodimethylamine formation potential assessment

Lin Wang; Tingting Yan; Ruijie Tang; Qian Ping; Yongmei Li; Jie Wang

doi:10.1016/j.watres.2021.117684

Motivation of reactive oxidation species in peracetic acid by adding nanoscale zero-valent iron to synergic removal of spiramycin under ultraviolet irradiation: Mechanism and N-nitrosodimethylamine formation potential assessment

Water Res. 2021 Oct 15:205:117684. doi: 10.1016/j.watres.2021.117684. Epub 2021 Sep 23.

Authors

Lin Wang¹, Tingting Yan², Ruijie Tang², Qian Ping³, Yongmei Li³, Jie Wang⁴

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China. Electronic address: wanglin@tongji.edu.cn.
² State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
³ State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
⁴ Fishery Machinery and Instrument Research Institute of Chinese Academy of Fishery Sciences, Shanghai, 200092, China.

PMID: 34610551
DOI: 10.1016/j.watres.2021.117684

Abstract

In this study, nanoscale zero-valent iron (nZVI) was added to motivate the functions of all the reactive oxidation species in peracetic acid (PAA) mixture under ultraviolet (UV) irradiation, and to enhance the removal of spiramycin, which is a typical precursor of N-nitrosodimethylamine (NDMA). Spiramycin (≤ 10 mg/L) could be completely removed within 20 min under the conditions of an initial pH of 4.0, a nZVI dose of 0.02 g/L and a PAA dose of 3.0 mg/L; additionally, 95.8% and 78.8% of PAA and H₂O₂ were consumed during the process. Electron paramagnetic resonance analysis and quenching experiments confirmed that 52.4% and 44.8% of spiramycin removal was contributed by hydroxyl radical (•OH) and carbon-centered radicals (R-C•), respectively; and Fe²⁺ released from nZVI played a critical role in radicals generation. Four degradation pathways of spiramycin were proposed and verified by the density of functional theory analysis. 65.2% of the NDMA formation potential (FP) was reduced after the reaction, and its residual was mainly contributed by the undegraded intermediate of dimethylamine. The results of multiple characterizations and continuous degradation experiments indicated that nZVI was stable in the system as the removal of spiramycin was hardly influenced even if reused three times. The nZVI/UV/PAA process is a promising advanced oxidation technology not only for the removal of refractory NDMA precursors (such as spiramycin) but also for significantly lowering the NDMA FP.

Keywords: N-nitrosodimethylamine; Nanoscale zero-valent iron; Peracetic acid; Spiramycin; Ultraviolet irradiation.

MeSH terms

Dimethylnitrosamine
Hydrogen Peroxide
Iron
Motivation
Peracetic Acid
Spiramycin*
Water Pollutants, Chemical* / analysis

Substances

Water Pollutants, Chemical
Spiramycin
Hydrogen Peroxide
Iron
Peracetic Acid
Dimethylnitrosamine