Microbial capacity for trace contaminant biotransformation – from wastewater to natural surface water

Complex mixtures of micropollutants (MPs), originating from anthropogenic activities and entering the environment via various pathways, pose a significant threat to ecosystems and human health. Microbial biotransformation has the potential to remove them from the environment, yet there is limited mechanistic understanding of the key drivers influencing contaminant biotransformation. Activated sludge (AS) treatment in wastewater treatment plants (WWTPs) acts as partial barrier, mitigating the release of MPs from domestic and industrial wastewater (WW) into downstream aquatic ecosystems. However, removal efficiency has been observed to vary considerably between different MPs and WWTP technologies. In this study, we have been exploring the biotransformation capacity of AS from six WWTPs across Switzerland, operated at three different treatment condition.