Removal of pharmaceuticals from wastewater of health care facilities

Health care facilities can represent point sources for pharmaceutical residues in public sewer systems. Compared to general hospitals, more specialized health care facilities might also have a different pattern of medication. Therefore, the on-site treatment of wastewater from such facilities could be an effective strategy to reduce emissions into water bodies and was the aim of this study. Wastewater from three health care facilities (nursing home, clinic with orthopaedic focus, and psychiatric clinic) was treated in lab-scale and semi-industrial trials. Biological treatment was performed via an ultrafiltration membrane bioreactor (UF-MBR), after which adsorption onto granular activated carbon (using rapid-small-scale column tests GAC-RSSCT), ozonation and a UV/H₂O₂ advanced oxidation process (AOP) were tested and compared. The removal of 17 pharmaceutical compounds and drug metabolites from 9 drug classes (e.g. analgesics, antibiotics, anticonvulsants) was evaluated. Most of the measured OMP were detected with concentrations between 1,000 and 30,000 ng L^-1 in the influent of the MBR. The UF-MBR provided an effective mechanical-biological cleaning of the wastewater, with micropollutant removal efficiencies between 0 and > 95%, making further treatment necessary to remove the micropollutants. Each combination of the UF-MBR with one of the three further treatments achieved removal efficiencies above 80% for most of the investigated substances, reducing many to below the quantification limit of 10 ng L^-1. The results show the general suitability of combining the UF-MBR with either GAC-adsorption, ozonation or AOP for eliminating pharmaceutical residues. However, the AOP process has a significantly higher energy demand than the other two processes. Moreover, specific settings and dosages depend on the respective wastewater matrix.