The role of reactive phosphate species in the abatement of micropollutants by activated peroxymonosulfate in the treatment of phosphate-rich wastewater

Jiaqi Ren; Ying Huang; Jiani Yao; Shujie Zheng; Yingjie Zhao; Yang Hou; Bin Yang; Lecheng Lei; Zhongjian Li; Dionysios D Dionysiou

doi:10.1016/j.watres.2023.120341

The role of reactive phosphate species in the abatement of micropollutants by activated peroxymonosulfate in the treatment of phosphate-rich wastewater

Water Res. 2023 Sep 1:243:120341. doi: 10.1016/j.watres.2023.120341. Epub 2023 Jul 13.

Authors

Jiaqi Ren¹, Ying Huang², Jiani Yao¹, Shujie Zheng², Yingjie Zhao³, Yang Hou⁴, Bin Yang⁴, Lecheng Lei⁴, Zhongjian Li⁵, Dionysios D Dionysiou⁶

Affiliations

¹ College of Chemical and Biological Engineering, Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310027, China.
² School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.
³ Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, China.
⁴ College of Chemical and Biological Engineering, Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310027, China; Institute of Zhejiang University-Quzhou, Quzhou 324000, China.
⁵ College of Chemical and Biological Engineering, Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310027, China; Institute of Zhejiang University-Quzhou, Quzhou 324000, China; Academy of Ecological Civilization, Zhejiang University, Hangzhou 310058, China. Electronic address: zdlizj@zju.edu.cn.
⁶ Environmental Engineering and Science program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, United States.

PMID: 37625213
DOI: 10.1016/j.watres.2023.120341

Abstract

This study investigated the mechanisms of forming reactive species to degrade micropollutants through the activation of peroxymonosulfate (PMS) by phosphate, a prevalent ion in wastewater. Considering the density functional theory results, the formation of hydrogen bonds between phosphate and PMS molecules might be the crucial step in the overall reactions, which prefers producing ^⋅OH and reactive phosphate species (RPS, namely H₂PO₄^⋅, HPO₄^⋅-, and PO₄^⋅2-) to yielding SO₄^⋅-. Besides, in the phosphate (5 mM)/PMS system at pH = 8, HPO₄^⋅- was modeled to be the dominant radical with a steady-state concentration of 3.6 × 10^-12 M, which was 666 and 773 times higher than those of ^⋅OH and SO₄^⋅-. The contributions of ¹O₂, ^⋅OH, SO₄^⋅-, and RPS to the micropollutant decomposition in phosphate/PMS were studied, and RPS were found to be selective for micropollutants with electron-donating moieties (such as phenolic and aniline groups). Additionally, the degradation pathways of bisphenol A, diclofenac, ibuprofen, and atrazine in phosphate/PMS were proposed according to the detected transformation products. Cytotoxicity analysis was carried out to evaluate the potential environmental impacts resulting from the degradation of micropollutants by phosphate/PMS. This study confirmed the significance of RPS for micropollutant degradation during PMS-based treatment in phosphate-rich scenarios.

Keywords: Hydroxyl radical; Peroxymonosulfate; Reactive phosphate species; Sulfate radicals; Wastewater treatment.

MeSH terms

Atrazine*
Diclofenac
Phosphates*
Wastewater

Substances

Phosphates
peroxymonosulfate
Wastewater
Atrazine
Diclofenac