The Ph.D. thesis that won of the 2019 Water and Health Prize focuses on monitoring and modelling variations of pharmaceuticals in wastewater.
Pharmaceutical residues are substances resulting from the consumption of pharmaceutical products that may be present in wastewater in very low concentrations. Some of these substances are not completely eliminated by wastewater treatment plants, and reach the natural environment in minute quantities.
The study of these substances and their potential impact on the environment is an important field of research in environmental sciences. However, there has been little study of the temporal variability of their concentration in wastewater. In addition, the models used to predict their presence are based on drug sales volumes on large spatial and temporal scales, which does not allow the concentrations observed to be reliably reproduced.
Tanguy Pouzol's thesis focused on the study of two sites, one that treats domestic wastewater and the other hospital wastewater, with three main objectives:
- To analyse, for both sites, the quantities of pharmaceuticals entering the wastewater treatment plant, compare them and establish their seasonal, daily and hourly fluctuations;
- To collect and analyse precise drug sales data for the hospital and pharmacies in the region;
- To design, using these different data, a reliable predictive model of hourly variations in pharmaceuticals concentrations in wastewater, based on drug sales volumes and daily hospital consumption.
This innovative research has made it possible to better understand the correlations between drug consumption and the presence of drug residues in wastewater, and to anticipate their fluctuations.
Supervised by Yves Lévi (Pharmacy Faculty of Paris Sud) and Jean-Luc Bertrand-Krajewski (INSA Lyon), the paper was written as part of the linked projects SIPIBEL, IRMISE Arve Aval and SIPIBEL-RILACT. These projects, which deal more generally with the problem of micropollutants in water, are managed and coordinated by the non-profit organisation GRAIE (Group of Research, Technical Coordination and Water Information, graie.org).