Transformation of acetaminophen in solution containing both peroxymonosulfate and chlorine: Performance, mechanism, and disinfection by-product formation

Jiaqi Ding; Hui Nie; Songlin Wang; Yongsheng Chen; Ying Wan; Jingwen Wang; Haoliang Xiao; Siyang Yue; Jun Ma; Pengchao Xie

doi:10.1016/j.watres.2020.116605

Transformation of acetaminophen in solution containing both peroxymonosulfate and chlorine: Performance, mechanism, and disinfection by-product formation

Water Res. 2021 Feb 1:189:116605. doi: 10.1016/j.watres.2020.116605. Epub 2020 Nov 4.

Authors

Jiaqi Ding¹, Hui Nie², Songlin Wang², Yongsheng Chen³, Ying Wan², Jingwen Wang², Haoliang Xiao², Siyang Yue⁴, Jun Ma⁵, Pengchao Xie⁶

Affiliations

¹ School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
² School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
³ School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
⁴ School of Architecture & Urban Planning, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
⁵ State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
⁶ School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; Center for the Environmental Implications of Nanotechnology (CEINT), Duke University, Durham 27708-0287, USA. Electronic address: pengchao.x@gmail.com.

PMID: 33189970
DOI: 10.1016/j.watres.2020.116605

Abstract

With the fast development of peroxymonosulfate (PMS)-dominating processes in drinking water and wastewater treatment, residual PMS is easy to come across chlorine as these processes are usually followed by secondary chlorine disinfection. The synergistic effect of PMS and chlorine on the degradation of micro-organic pollutants is investigated by selecting acetaminophen (ACT) as a reference compound for the first time in this study. Unlike conventional PMS or chlorine activation which generates reactive species such as hydroxyl radical (HO^•), sulfate radical (SO₄^•-), chlorine radical (Cl^•), and singlet oxygen (¹O₂), the efficient ACT removal is attributed to the direct catalytic chlorination by PMS due to the significantly enhanced consumption of chlorine along with negligible change of PMS concentration at neutral condition, and the same reaction pathways in both PMS/chlorine and chlorine processes. The kinetic study demonstrates that ACT oxidation by PMS/chlorine follows second order reaction, and the degradation efficiency can be promoted at alkaline conditions with peak rate constants at pH 9.0-10.0. The presence of chloride can enhance the removal of ACT, while ammonium and humic acid significantly retard ACT degradation. Higher formation of selected disinfection by-products (DBPs) is observed in the PMS/chlorine process than in the sole chlorination. This study highlights the important role of PMS in organic pollutants degradation and DBPs formation during the chlorination process.

Keywords: Acetaminophen; Chlorine; Disinfection by-products; Peroxymonosulfate.

MeSH terms

Acetaminophen
Chlorides
Chlorine
Disinfection
Oxidation-Reduction
Peroxides
Water Pollutants, Chemical* / analysis
Water Purification*

Substances

Chlorides
Peroxides
Water Pollutants, Chemical
peroxymonosulfate
Acetaminophen
Chlorine