Assessing the impact of global change on micropollutants in aquatic ecosystems: Modelling the fate of nonylphenolic compounds in the Seine River

Mathieu Cladière (1) , Céline Bonhomme (1) , Lauriane Vilmin (2) , Johnny Gasperi (1) , Nicolas Flipo (2) , Florence Habets (2, 3) , Bruno Tassin (1)

1 LEESU - Laboratoire Eau, Environnement et Systèmes Urbains
2 GEOSCIENCES - Centre de Géosciences
3 SISYPHE - Structure et fonctionnement des systèmes hydriques continentaux

This study aims at modelling the annual variability in concentrations of nonylphenolic compounds such as 4 nonylphenol (4-NP), nonylphenol monoethoxylate (NP1EO) and nonylphenoxy acetic acid (NP1EC) within the Seine River in the Paris metropolitan area. These compounds are of prime interest because the 4-NP is a well known endocrine disrupting chemical, while NP1EO and NP1EC are expected to be biodegraded into 4-NP in the environment (Giger et al. 2009). Thus the potential consequence of climatic change and urban evolution on the fate of these micropollutants is an actual issue for aquatic ecosystems. So far as we know, no study deals with the modelling of annual concentrations of 4-NP, NP1EO and NP1EC in surface water and especially in a heavily urbanized area such as Paris. Firstly, concentrations were simulated for 2010 and compared to monthly measured values downstream the Paris metropolitan area. To achieve this goal, the hydrodynamic and biogeochemical "ProSe" model (Even et al. 1998) was updated to simulate the fate of 4-NP, NP1EO and NP1EC. Boundary conditions such as the upstream concentrations as well as the lateral inflows - wastewater treatment plant (WWTP) and the Oise River (tributary of the Seine River) - were estimated by using monthly sampling campaigns performed in 2010. The biodegradation kinetics of 4-NP, NP1EO and NP1EC in the Seine River were deduced from a sampling campaign carried out on the same transect of the Seine River in September 2011. The Nash-Sutcliffe coefficient indicates, for year 2010, a good efficiency of the ProSe model to simulate the concentrations of 4-NP, NP1EC and NP1EO at the annual scale. Secondly, 8 scenarios were built to forecast the impacts of global warming (Seine River flow), population growth (WWTP effluents flow) and optimization of wastewater treatments (quality of effluents) on annual concentrations of 4-NP, NP1EO and NP1EC at Meulan in 2050 and 2100. A major assumption is to consider that the use of alkylphenols will remain constant during the 21st century. Based on these scenarios, the forecasts highlight that global warming and population growth may increase the concentrations of 4-NP, NP1EC and NP1EO especially during low-flow conditions, while the optimization of WWTP may balance the global changes by reducing inputs from WWTP. Finally, this study is of prime interest to understand the long term behaviour of 4-NP, NP1EO and NP1EC in surface water and may feed the decision making process to find what action should be taken to reach or maintain the good ecological state of water bodies in the future.

Domaines: Sciences de l'environnement

Mathieu Cladière, Céline Bonhomme, Lauriane Vilmin, Johnny Gasperi, Nicolas Flipo, et al.. Assessing the impact of global change on micropollutants in aquatic ecosystems: Modelling the fate of nonylphenolic compounds in the Seine River. 14th EuCheMS International Conference on Chemistry and the Environment, Jun 2013, Barcelone, Spain. ⟨hal-00862208⟩