Evaluation of Thirteen Haloacetic Acids and Ten Trihalomethanes Formation by Peracetic Acid and Chlorine Drinking Water Disinfection

Abstract

Free chlorine is a commonly used disinfectant in drinking water treatment. However, disinfection by-products (DBPs) are formed during water disinfection. Haloacetic acids (HAAs) and trihalomethanes (THMs) are two major groups of DBPs. Iodo-HAAs and iodo-THMs (I-HAAs and I-THMs) are formed during the disinfection of the water containing high levels of iodide and are much more toxic than their chlorinated and brominated analogs. Peracetic acid (PAA) is a strong antimicrobial disinfectant that is expected to reduce the formation of HAAs and THMs during disinfection. In this study, the formations of thirteen HAAs and ten THMs, including the iodinated forms, have been investigated during PAA disinfection and chlorination as the comparison. The DBP formations under different iodide concentrations, pHs, and contact times were systematically investigated. Two types of commercial PAAs containing different concentrations of PAA and hydrogen peroxide (H2O2) were studied. A solid-phase microextraction gas chromatography-mass spectrometry method was upgraded for THM analysis including I-THMs. HAAs were analyzed by following a recently developed high performance ion chromatography-tandem mass spectrometry method. Results show that the ratio of PAA and H2O2 concentration significantly affect the formation of I-THMs and I-HAAs. During PAA disinfection with lower PAA than H2O2, no detectable levels of THMs and HAAs were observed. During PAA disinfection with higher PAA than H2O2, low levels of monoiodoacetic acid, diiodoacetic acid, and iodoform were formed, and these levels were enhanced with the increase of iodide concentration. No significant quantities of chloro- or bromo-THMs and HAAs were formed during PAA disinfection treatment.

Department(s)

Chemistry

Second Department

Civil, Architectural and Environmental Engineering

Keywords and Phrases

Drinking water disinfection by-products; Iodo-haloacetic acids; Iodo-trihalomethanes; Peracetic acid disinfection; Solid-phase microextraction gas chromatography-mass spectrometry

International Standard Serial Number (ISSN)

0045-6535

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2017 Elsevier Ltd, All rights reserved.

Publication Date

01 Dec 2017

PubMed ID

28942261

Link to Full Text

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