Urban pathways of biocides towards surface waters during dry and wet weathers: Assessment at the Paris conurbation scale

Eighteen biocides used in building materials and domestic products were monitored wastewater treatment plants (WWTPs) during dry weather combined sewer overflows (CSOs) wet the Paris conurbation. The aims of this study to (i) acquire data on urban waters, which are very scarce up now, (ii) identify their origins CSOs with perspective reducing these contaminants at source, (iii) compare rank biocide pathways river (dry vs. weather) annual conurbation scales. results showed ubiquity 18-targeted WWTP waters CSOs. High concentrations methylisothiazolinone, benzisothiazolinone (0.2?0.9 ?g/L) benzalkonium C12 (0.5?6 measured wastewater. Poor removals (< 50 %) observed for most biocides. Both (mainly uses) stormwater (leaching from materials) contributed CSO contamination. However, mainly came whereas diuron, isoproturon, terbutryn, carbendazim, tebuconazole, mecoprop stormwater. Annual mass loads discharged by WWTPs into Seine River estimated using a stochastic approach (Monte Carlo simulations) scale that discharges major entry pathway.