Pilot-Scale Quaternary Treatment of Municipal Wastewater for Agricultural Reuse: Removal of Pharmaceuticals and Compliance with EU Regulation 2020/741

This study evaluates the performance of a pilot-scale quaternary post-treatment unit installed at the municipal wastewater treatment plant in Slovakia. The unit integrates coarse filtration, coagulation, ultrafiltration, granular activated carbon (GAC) adsorption, and UV disinfection. The regenerated effluent consistently met EU Regulation 2020/741 standards for Class A water quality, making it suitable for unrestricted agricultural irrigation. Microbiological analysis showed nearly complete elimination of Escherichia coli and coliform bacteria, except for occasional regrowth linked to accumulation tank contamination. Field tests with irrigated crops (parsley, potatoes, carrots, onions) indicated minor accumulation of some pharmaceuticals, illicit drugs, and their metabolites (12 out of 118 monitored compounds), particularly telmisartan and carbamazepine, in both soil and plant tissues. Health risk assessment based on TTC values of selected PPCPs in crops indicates no health risks to adults or children. Findings confirm the feasibility of wastewater reuse for food crop irrigation in compliance with EU regulations.