Impact of wastewater antibiotics on river water quality in Belgrade area

Abstract

Municipal wastewater in the Belgrade area is discharged into the Danube and the Sava Rivers without any treatment. This affects the quality of river water since wastewater is one of the most important sources of environmental pollutants, including pharmaceuticals. To assess the impact of this effect, the presence of three commonly used antibiotics in wastewater and receiving river water was determined. A previously developed liquid chromatography-tandem mass spectrometry method for the analysis of antibiotics in natural water matrices was validated for wastewater and applied in analysis of samples from the Belgrade area. All investigated antibiotics were detected in both wastewater and river water samples. The highest concentration of antibiotics in wastewater was found for sulfamethoxazole, while trimethoprim was detected at the highest level in surface water. The most frequently detected antibiotic in surface water was azithromycin. The environmental risk assessment was performed for surface water biota. Azithromycin was found to pose a high risk to aquatic organisms, while the risk level of sulfamethoxazole was medium or low. In conclusion, the obtained results show the detrimental impact of untreated wastewater discharge on the river water quality in the Belgrade area, emphasizing the need for urban wastewater treatment.