Estimation of haloacetonitriles formation in water: Uniform formation conditions versus formation potential tests
Date
2020-07-13
Authors
Kanan, Amer
Karanfil, Tanju
Journal Title
Journal ISSN
Volume Title
Publisher
Science of the Total Environment
Abstract
To date, several studies have used formation potential (FP) tests to examine the presence of HAN precursors in
water and wastewater. However, given the decomposition of HANs with time at elevated free chlorine levels,
FP test results do not provide meaningful results.Weconducted side-by-side FP and uniform formation condition
(UFC) experiments to demonstrate that, in order to obtain practical, meaningful, and representative information
about HANs formation and their precursors during chlorination, it is important to conduct experiments and report
results under UFC [or simulated distribution system (SDS)] conditions.
The results confirmed higher HAN formation under UFC than FP tests during chlorination of the tested two surface
water and three wastewater effluent samples, indicating HAN decomposition at high chlorine conditions of
FP tests. In addition, thewell reported ratio (~10%) of HAN/THMfrom previous studies was more consistentwith
the UFC results but was lower than 10% in the FP results. On the other hand, HAN formation during
chloramination of the same samples were lower under the UFC than FP conditions. Furthermore, FP tests
under both chlorination and chloramination resulted in lower bromine substitution factor.
We concluded that reporting results of HANs FP tests are not representative, and future studies should focus on
UFC or distribution system specific (SDS) experiments for chlorination. However, chloramination FP tests may
still provide some information about the HAN precursors in waters.
Description
HANs formation from five different
chlorinated water sources were higher
under UFC than FP tests.
• Chlorination FP tests do not provide
meaningful information for HAN precursors
in water samples.
• UFC (or SDS) chlorination test should be
used for a better estimation of HAN precursors
in water.
• Higher HANs formed under FP test compared
to UFC test during chloramination.
• Chloramination FP tests may be used for
determining HAN precursors in water reactive
to chloramine.
Keywords
Disinfection by-products , Haloacetonitriles , Formation potential test , Uniform formation conditions test , Chlorination Chloramination
Citation
Kanan A, Karan T (2020) Estimation of haloacetonitriles formation in water : Uniform formation conditions versus formation potential tests. 744:1–6. https://doi.org/10.1016/j.scitotenv.2020.140987