Evaluation of removal of illicit drugs, pharmaceuticals and caffeine in a wastewater reclamation plant and related health risk for non-potable applications

Abstract

The present study aimed at determining the presence and removal rate achieved through the main treatment stages of a full-scale wastewater reclamation plant for some classes of Organic Micropollutants. Furthermore, the human health risk due to the reuse of the final effluent containing residual concentrations of these pollutants for non-potable applications was assessed.The 8-months monitoring campaign on the influent and effluent of the treatment stages of the plant highlighted that the main removal took place in the bioreactor, reaching median removal of 99 %, 97 %, 60 % 76 %, 71 %, 96 % and 100 %, for benzoylecgonine, cocaine, methamphetamine, trimetoprim, sulfadiazine, ketoprofene and caffeine, respectively. This result was also confirmed by the application of the principal component analysis. A further abatement, although slight, occurred in the tertiary compartment (made up by filtration, UV disinfection and chlorination) for sulfamethoxazole, trimethoprim and ketoprofen, determining a final median removal of 50 %, 94 % and 98 %, respectively. A significant correlation between the removal processes of the investigated organic micropollutants and the traditional water quality parameters was also found out. The human health risk for incidental ingestion and dermal contact resulted to be always below 1 under average and worst scenarios, which indicates that the risk can be considered acceptable.