Formation of iodinated aromatic DBPs at different molar ratios of chlorine and nitrogen in iodide-containing water

Heng Song; Zhi-Qiang Sun; Da-Long Li; Jing Zhang; Xiao-Qun Zhou; Xiang-Rui Pan; Lu Wang; Yan-Jun Xin; Yu-Lei Liu; Jun Ma

doi:10.1016/j.scitotenv.2021.150385

Formation of iodinated aromatic DBPs at different molar ratios of chlorine and nitrogen in iodide-containing water

Sci Total Environ. 2022 Feb 1;806(Pt 2):150385. doi: 10.1016/j.scitotenv.2021.150385. Epub 2021 Sep 24.

Authors

Heng Song¹, Zhi-Qiang Sun², Da-Long Li³, Jing Zhang², Xiao-Qun Zhou², Xiang-Rui Pan¹, Lu Wang², Yan-Jun Xin¹, Yu-Lei Liu⁴, Jun Ma⁵

Affiliations

¹ Qingdao Engineering Research Center for Rural Environment, College of Resource and Environment, Qingdao Agricultural University, Qingdao 266109, China.
² State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
³ Key Laboratory of Biology and Genetic Improvement of Horticulture Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Northeast Agricultural University, Harbin 150090, China.
⁴ State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. Electronic address: 0536105liuyulei@163.com.
⁵ Qingdao Engineering Research Center for Rural Environment, College of Resource and Environment, Qingdao Agricultural University, Qingdao 266109, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. Electronic address: majun@hit.edu.cn.

PMID: 34610565
DOI: 10.1016/j.scitotenv.2021.150385

Abstract

Variations in iodinated aromatic disinfection byproducts (DBPs) in the presence of I^- and organic compounds as a function of reaction time in different molar ratios (MRs) of HOCl:NH₃-N were investigated. Up to 17 kinds of iodinated aromatic DBPs were identified in the breakpoint chlorination of iodide (I^-)/organic (phenol, bisphenol S (BPS) and p-nitrophenol (p-NP)) systems, and the possible pathways for the formation of iodinated aromatic DBPs were proposed. The reaction pathways include HOCl/HOI electrophilic substitution and oxidation, while the dominant iodinated DBPs were quantified. In the I^-/phenol system (pH = 7.0), the sum of the concentrations of four iodinated aliphatic DBPs ranged from 0.32 to 1.04 μM (triiodomethane (TIM), dichloroiodomethane (DCIM), diiodochloromethane (DICM) and monoiodoacetic acid (MIAA)), while the concentration of 4-iodophenol ranged from 2.99 to 12.87 μM. The concentration of iodinated aromatic DBPs remained stable with an MR = 1:1. When the MR was 6:1, iodinated aromatic DBPs decreased with increasing reaction time, in which the main disinfectant in the system was active chlorine. This study proposed the formation mechanism of iodinated aromatic DBPs during the breakpoint chlorination of iodide-containing water. These results can be used to control the formation of hazardous iodinated aromatic DBPs in the disinfection of iodine containing water.

Keywords: Breakpoint chlorination; Disinfection byproducts; Iodide; Iodinated aromatic DBPs.

MeSH terms

Chlorine
Disinfectants* / analysis
Disinfection
Halogenation
Iodides
Nitrogen
Water
Water Pollutants, Chemical* / analysis
Water Purification*

Substances

Disinfectants
Iodides
Water Pollutants, Chemical
Water
Chlorine
Nitrogen