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Peracetic Acid Oxidation of Saline Waters in the Absence and Presence of H2O2: Secondary Oxidant and Disinfection Byproduct Formation

Peracetic acid (PAA) is a disinfectant considered for use in ballast water treatment, but its chemical behavior in such systems (i.e., saline waters) is largely unknown. In this study, the reactivity of PAA with halide ions (chloride and bromide) to form secondary oxidants (HOCl, HOBr) was investiga...

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Bibliographic Details
Published in:Environmental science & technology 2015-02, Vol.49 (3), p.1698-1705
Main Authors: Shah, Amisha D, Liu, Zheng-Qian, Salhi, Elisabeth, Höfer, Thomas, von Gunten, Urs
Format: Article
Language:English
Online Access:Get full text
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Summary:Peracetic acid (PAA) is a disinfectant considered for use in ballast water treatment, but its chemical behavior in such systems (i.e., saline waters) is largely unknown. In this study, the reactivity of PAA with halide ions (chloride and bromide) to form secondary oxidants (HOCl, HOBr) was investigated. For the PAA–chloride and PAA–bromide reactions, second-order rate constants of (1.47 ± 0.58) × 10–5 and 0.24 ± 0.02 M–1 s–1 were determined for the formation of HOCl or HOBr, respectively. Hydrogen peroxide (H2O2), which is always present in PAA solutions, reduced HOCl or HOBr to chloride or bromide, respectively. As a consequence, in PAA-treated solutions with [H2O2] > [PAA], the HOBr (HOCl) steady-state concentrations were low with a limited formation of brominated (chlorinated) disinfection byproducts (DBPs). HOI (formed from the PAA–iodide reaction) affected this process because it can react with H2O2 back to iodide. H2O2 is thus consumed in a catalytic cycle and leads to less efficient HOBr scavenging at even low iodide concentrations (
ISSN:0013-936X
1520-5851
DOI:10.1021/es503920n