The formation of haloacetamides and other disinfection by-products from non-nitrogenous low-molecular weight organic acids during chloramination
File(s)
Accepted version
Author(s)
Chu, W
Li, X
Bond, T
Gao, N
Yin, D
Type
Journal Article
Abstract
Low-molecular weight organic acids (LMWOAs) are widespread in nature, and many are recalcitrant during conventional drinking water treatment, due to their LMW and hydrophilic character. This study assessed the formation of a range of disinfection by-products (DBPs) from the chloramination of seven non-nitrogenous LMWOA precursors, with an emphasis on the contribution of N-chloramine incorporation to haloacetamide (HAcAm) formation. The other DBPs comprised chlorinated halomethanes, haloacetonitriles and haloacetic acids. Citric acid generated higher yields of trichloromethane and two chloroacetic acids than the other LMWOAs. Further, the unsaturated acids (fumaric acid and itaconic acid) formed more chloroacetic acids than saturated acids (oxalic acid, succinic acid, adipic acid). Importantly, non-nitrogenous LMWOAs formed three nitrogenous DBPs (dichloroacetamide, trichloroacetamide, and small amounts of dichloroacetonitrile) during chloramination, firstly indicating the monochloramine can supply the nitrogen in nitrogenous DBPs, and the formation of haloacetamides at least in part is independent of the hydrolysis of haloacetonitriles. To the authors’ knowledge, this is the first time formation of halogenated nitrogenous DBPs (N-DBPs) has been reported from chloramination of non-nitrogenous LMWOA precursors. This indicates that concentrations of dissolved organic nitrogen compounds in drinking water are not a reliable surrogate for formation of N-DBPs during chloramination. Bromine incorporation factor increased with increasing bromide during chloramination of citric acid, and bromine was easier to incorporate into di-HAcAms than mono- and tri-HAcAms during chloramination.
Date Issued
2015-10-03
Date Acceptance
2015-10-01
Citation
Chemical Engineering Journal, 2015, 285, pp.164-171
ISSN
1873-3212
Publisher
Elsevier
Start Page
164
End Page
171
Journal / Book Title
Chemical Engineering Journal
Volume
285
Copyright Statement
© 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects
Low-molecular mass organic acids (LMWOAs)
Nitrogenous disinfection by-products (N-DBPs)
Haloacetamides (HAcAms)
Chloraminatio
Bromine substitution
Drinking water
Publication Status
Published