Biological-based profiling of wastewaters from sources to the discharge into the environment
Abstract
Aquatic ecosystems are widely contaminated by trace micropollutants that may represent a risk for human health and wildlife. Even if some compounds are well removed by wastewater treatments, the discharge of effluents remains one of the main entry of several micropollutants in the environment. It is particularly worrying for the compounds that are endocrine disruptors and/or that can induce genotoxicity. New approach using quantitative biological activities has to be applied along the water line, especially to monitor the pollution of wastewater. The objective of this study was to apply a panel of in vitro bioassays to determine water contamination profiles from the wastewater network to the outlet of the WWTP. A panel of bioassays were applied on various samples collected in six sites on the network, along the WWTP in order to evaluate the impact of biological treatment and tertiary ozonation. Selected in vitro bioassays, applied on water SPE extract, enabled detection of active chemicals responsible of endocrine disruption (estrogen, androgen, progestogen, mineralocorticoid, glucocorticoid, pregnane X and dioxin receptors) and the genotoxicity was evaluated by using the SOS Chromotest. In all sites along the wastewater network, ER, AR, MR activities and genotoxicity were detected. GR activity was measured at only three points of the network and was particularly important in the WWTP influent. Endocrine disruptor activities as well as genotoxicity were detected in raw wastewater (WWTP influent). Biological treatment highly reduced ED activities and genotoxicity. Nevertheless residual activities were still detected in the tertiary effluent. Results of the 1st sampling campaign allowed the identification of three notable points of interest on the network and at the WWTP influent. Results of two next sampling campaigns will help to confirm these “hot-spot” sites in order to apply effect-directed analysis to perform chemical identification of the compounds responsible of endocrine disruption activities and/or genotoxicity.