Due to a lack of knowledge regarding the organic contamination of surface waters and to mitigate the harmful effects of pollution sources on aquatic ecosystems, this thesis aims to develop an approach for sampling, detecting, and identifying micropollutants to establish a map of organic contamination in the surface waters of Aïn Taoujdate, Morocco (Fès-Meknès region). The area is home to a wastewater treatment plant and other industrial units that are active year-round. These sites have been accused by the local population of contaminating surface waters, particularly in the loss of livestock drinking from these waters. This situation results in significant health and environmental issues.

The evaluation of aquatic environment contamination, the identification of pollution sources, the assessment of wastewater treatment efficiency at treatment plants, and the traceability of contaminant families are emerging research themes in the field of environmental analysis. Furthermore, due to the wide range of compartments and contaminant families and the large number of samples to analyze, developing rapid and reliable analytical techniques and approaches is a major challenge for the scientific community.
Morocco is ranked among countries experiencing high water stress, with increasing water scarcity. In line with national, European, and international water quality regulations, the National Sanitation Program (PNA) was developed to improve water quality in aquatic environments and assess the ecological and health impacts associated with the presence of potentially harmful organic pollutants to aquatic ecosystems. My doctoral work fully aligns with this research theme.

As part of this project, we aim to enhance knowledge about the different anthropogenic pollution sources in the river by deploying passive integrative samplers (Polar Silicone Rod - TSP, Margoum et al. 2021) to explore contamination by organic micropollutants through chromatographic analysis coupled with mass spectrometry, and by characterizing dissolved organic matter (DOM) through 3D fluorescence coupled with PARAFAC (Huibin Yu et al. 2021). Due to their nature, analytical capabilities (both qualitative and quantitative), sensitivity, and ease of use, these two techniques are rapidly growing in the environmental water quality assessment (natural, wastewater, or treated). Our work aims to better characterize this organic pollution by evaluating wastewater treatment efficiency at the treatment plant (WWTP), analyzing effluents from an oil mill located within the municipality, and establishing a map of contamination from these sources in the river (Figure 1) by quantifying a targeted list of organic micropollutants, such as pesticides, pharmaceuticals, and hormones.

An initial field survey was conducted in 2021, and the results confirm that TSPs are simple and relevant tools for sampling and monitoring the chemical quality of aquatic environments, both at low and high concentrations. Chromatography coupled with mass spectrometry and 3D fluorescence/PARAFAC are complementary and reliable analytical approaches for characterizing environmental water quality.
Two additional field campaigns are planned for 2022, as well as further laboratory work to test the sampling and preservation efficiency of TSPs under temporary desiccation conditions and in the presence of dissolved organic matter. We will continue exploring DOM through 3D fluorescence/PARAFAC in the solid phase (direct analysis on passive integrative samplers) to study the effect of this DOM on the adsorption of micropollutants in TSPs.

References

• Margoum C., Martin A., Le Dréau M., Guillemain C., Gouy V., Coquery M. (2021). Un échantillonneur intégratif passif simple et flexible pour étudier le transfert des pesticides dans des petits bassins versants. Revue Science Eaux & Territoires, Directive cadre européenne sur l’eau, numéro 37, p.100-105. Doi:10.14758/SET-REVUE.2021.4.18.
• Yu, H., Song, Y., Tu, X., Du, E., Liu, R., & Peng, J. (2013). Assessing removal efficiency of dissolved organic matter in wastewater treatment using fluorescence excitation emission matrices with parallel factor analysis and second derivative synchronous fluorescence. Bioresource Technology, 144, 595–601. https://doi.org/10.1016/j.biortech.2013.07.025.

Cite the thesis

Hassan Ba-Haddou. Exploration et distribution des polluants anthropiques dans les eaux de surface : investigation par fluorescence d’excitation/émission et chromatographie. Ingénierie de l'environnement. Université Claude Bernard - Lyon I; Université Moulay Ismaïl (Meknès, Maroc), 2024. Français. ⟨NNT : 2024LYO10372⟩. ⟨tel-05057726⟩

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