Comparison of the removal efficiencies of selected pharmaceuticals in wastewater treatment plants in the region of Murcia, Spain

The presence of certain pharmaceutical compounds in ground- and surface waters may constitute a serious environmental problem, even at low concentrations. The occurrence of pharmaceuticals in the environment indicates incomplete removal of these pharmaceuticals from municipal wastewater treatment plants (WWTPs). In this study four representative pharmaceutical compounds were identified and quantified in influent and effluent of WWTPs around the Region of Murcia. In addition, the removal efficiencies of the five different treatment systems employed by these WWTPs were evaluated for the four pharmaceutical compounds. Influent and effluent wastewaters were sampled on a weekly basis during four consecutive weeks and compound concentrations were quantitatively determined by HPLC-DAD. Pharmaceuticals were detected at μg/L levels (0.34–26.52μg/L) in influent and effluent samples from all five different systems of the twelve WWTPs sampled in this work. The two most abundant pharmaceutical compounds were carbamazepine and naproxen. WWTPs that worked with extended aeration activated sludge processes, coagulation-flocculation, sand filtration and as tertiary treatment processes are used ultraviolet and chlorination systems (EAAS+C-F+SF+UV+Cl) removed better carbamazepine and ketoprofen than conventional activated sludge system with a double aeration tank, sand filtration, lamination, coagulation-flocculation and as tertiary treatment processes are used ultraviolet systems (CAS-DS+L+C-F+SF+UV) that removed better naproxen and diclofenac.