The occurrence and removal of selected pharmaceutical compounds in a sewage treatment works utilising activated sludge treatment

Pharmaceutical substances have been detected in sewage effluents as well as receiving waters in many parts of the world. In this study, the occurrence and removal of a number of drug compounds were studied within a large sewage treatment plant in the south of England. Samples were processed using solid phase extraction and analysed using gas chromatography–mass spectrometry (GC–MS). The results demonstrate that ibuprofen, paracetamol, salbutamol and mefenamic acid were present in both the influent and effluent of the works while propranolol–HCl was not found above the limit of quantification in any sample. Elimination rates were circa 90% for each compound but several hundred nanograms per litre were still present in the final effluent.