Iodide sources in the aquatic environment and its fate during oxidative water treatment – A critical review

Autor: Henry MacKeown, Urs von Gunten, Justine Criquet
Přispěvatelé: Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2022
Předmět:
Environmental Engineering
nonmetal redox kinetics
Halogenation
oxidation
[SDE.MCG]Environmental Sciences/Global Changes
drinking-water
Iodates
Water Purification
[CHIM.ANAL]Chemical Sciences/Analytical chemistry
ray contrast-media
Organic Chemicals
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces
environment
natural organic-matter
Waste Management and Disposal
hypoiodous acid
Water Science and Technology
Civil and Structural Engineering
i-thm
chlorination
chloramination
[SDE.IE]Environmental Sciences/Environmental Engineering
disinfection by-products
Drinking Water
Ecological Modeling
iodo-trihalomethanes
chlorine dioxide
Iodides
bromide-containing waters
Pollution
Disinfection
Oxidative Stress
iodinated trihalomethane formation
Water Pollutants
Chemical
Disinfectants
Iodine
Zdroj: Water Research
Water Research, 2022, 217, pp.118417. ⟨10.1016/j.watres.2022.118417⟩
ISSN: 0043-1354
Popis: Iodine is a naturally-occurring halogen in natural waters generally present in concentrations between 0.5 and 100 mu g L-1. During oxidative drinking water treatment, iodine-containing disinfection by-products (I-DBPs) can be formed. The formation of I-DBPs was mostly associated to taste and odor issues in the produced tap water but has become a potential health problem more recently due to the generally more toxic character of I-DBPs compared to their chlorinated and brominated analogues.
This paper is a systematic and critical review on the reactivity of iodide and on the most common intermediate reactive iodine species HOI. The first step of oxidation of I- to HOI is rapid for most oxidants (apparent second-order rate constant, k(app) > 10(3) M(-1)s(-1) at pH 7). The reactivity of hypoiodous acid with inorganic and organic compounds appears to be intermediate between chlorine and bromine. The life times of HOI during oxidative treatment determines the extent of the formation of I-DBPs. Based on this assessment, chloramine, chlorine dioxide and permanganate are of the highest concern when treating iodide-containing waters. The conditions for the formation of iodo-organic compounds are also critically reviewed.
From an evaluation of I-DBPs in more than 650 drinking waters, it can be concluded that one third show low levels of I-THMs ( 10 mu g L-1. The most frequently detected I-THM is CHCl2I followed by CHBrClI. More polar I-DBPs, iodoacetic acid in particular, have been reviewed as well.
Finally, the transformation of iodide to iodate, a safe iodine-derived end-product, has been proposed to mitigate the formation of I-DBPs in drinking water processes. For this purpose a pre-oxidation step with either ozone or ferrate(VI) to completely oxidize iodide to iodate is an efficient process. Activated carbon has also been shown to be efficient in reducing I-DBPs during drinking water oxidation.
Databáze: OpenAIRE
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