Analyse en ligne de pesticides et de leurs métabolites dans la Seine et étude de leur dégradation au cours du traitement

On line sampling and analyses of pesticides and their metabolites in the Seine river. Study of their evolution and behaviour in a surface water treatment plant

SAGEP, 9, rue Schoelcher - 74014 Paris

Résumé

La SAGEP a pour mission principale l'approvisionnement en eau potable de Paris. L'usine d'Ivry traite à cette fin l'eau de Seine. Il est donc indispensable de connaître la qualité de l'eau de la rivière pour agir sur le processus de traitement. Les pesticides et métabolites ont été suivis à l'aide d'une chaîne HPLC en ligne, équipée d'une barrette de diode. Un lien très net a été établi entre les précipitations et les concentrations. De plus, les eaux de la filière de traitement ont été analysées aux étapes essentielles du traitement d'élimination des micropolluants organiques.

Abstract

SAGEP's main mission is the drinking water supply of the city of Paris. The drinking water in Paris is supplied for 50% by spring water and for 50% by surface water (from river Seine and river Marne). Two plants are located on the river Seine and one plant on the river Marne. It is very important for SAGEP to know the water quality of the river to act on the treatment process. The knowledge of the evolution of concentration of pesticides can lead to treatment with crisis reagents (powdered activated carbon...) So pesticides and their metabolites were analysed on line by HPLC equipped with diode array detector. The results show a very clear link between rain falls and pesticides concentration. Atrazine was systematically found in the raw water and was good removed by PAC adsorption and GAC adsorption. Desethylatrazine was not detected in raw water but was detected in the ozonated and GAC filtered waters. Diuron was detected in spring but is good removed by ozonation. Isoproturon was detected from december to february in raw water and in also good removed by ozonation.