Natural Organic Matter Innovative Characterization and transformation by-product prediction – NOMIC

Analytical developments are proposed to characterize halogen incorporation (using liquid chromatography coupled to an elemental detector) and to better understand the reactivity of nitrogen species (using derivatization and chromatographic analysis).
A more realistic methodology for assessing the toxicity of the products formed is also proposed. Finally, on-line monitoring of the evolution of organic matter will be carried out on a key water resource in the Lille metropolitan area.

A method for characterizing unknown halogenated by-products is currently being developed, and has already been used to characterize the incorporation of iodine and bromine atoms into an extract of organic matter (Suwanee River), showing similar behavior for iodinated and brominated oxidants.
Toxicity data for individual disinfection by-products obtained on human cells show that cellular mechanisms linked to inflammation are probably altered in the presence of certain by-products, sometimes at very low concentrations.

The halogenation characterization method will be applied to real waters in the coming months.
Organic matter monitoring has been carried out since April 2023 on a drinking water treatment plant and will continue until the end of 2024. Monthly samples of the resource and of the water at various stages of treatment are characterized in the laboratory. The samples are also pre-treated for analysis using chromatography coupled with high-resolution mass spectrometry.

Dejaeger, K., Criquet, J., Vanoppen, M., Vignal, C., Billon, G., Cornelissen, E.R., 2022. Identification of disinfection by-product precursors by natural organic matter fractionation and dedicated removal techniques: A critical review. Environmental Chemistry Letters 20, 3861-3882. doi.org/0.1007/s10311-022-01478-x
hal.archives-ouvertes.fr/hal-03800868

NOMIC proposes a new methodology to characterize natural organic matter (NOM) and its behavior during treatment processes. NOM is ubiquitous in aquatic environment. While nontoxic, NOM largely outweighs the reactivity of micropollutants and consumes the majority of the oxidants used during drinking water treatment. The transformation of NOM produces potentially toxic compounds in treated waters. Most of those by-products are still unknown. Innovative tools will be applied to characterize halogen incorporation and nitrogenous reactive species in real waters. Key precursors and transformation products will be identified and a predictive modelling will be developed. An alternative methodology to evaluate the toxicity towards intestinal cells will be developed. Finally, an on-line monitoring campaign in which a smart sampling tool will be developed will be performed on a key water resource of Lille metropolis.