Emerging contaminants in drinking water treatment plants: how ozonation affects activated carbon adsorption

Contaminants of Emerging Concern (CECs) in drinking water are a growing concern for potential negative effects on human health. This study combines full-scale monitoring campaigns in a drinking water treatment plant (DWTP) and lab-scale experiments using real water matrices without CECs spike. Monitoring campaigns were performed over one year and over 116 monitored CECs, a maximum of 22 compounds have been detected at the DWTP inlet. The analyses show that ozonation and adsorption on activated carbon (AC) have the main impact in reducing a wide variety of CECs, with performances influenced by their characteristics. At lab-scale adsorption isotherms were performed on 4 different water matrices, before and after ozonation, the evaluate the effect of ozonation on the adsorption process. Ozonation is less effective than AC adsorption in CECs removal, but the combination of the two processes allows to reduce the variability of the removal efficiencies, providing a highest performance for the removal of all the investigated CECs.