Removal of pharmaceuticals by conventional wastewater treatment plants

The chapter details the occurrence of 74 selected pharmaceuticals from 15 therapeutic classes in raw wastewater and in secondary effluent and treated sludge from municipal treatment plants. The ability of the treatment most commonly adopted worldwide, conventional activated sludge system, in removing such compounds from the influent wastewater is discussed. The influence of the main chemical - physical properties of the selected compounds in predicting and explaining their observed removal is analysed, as well as the effect of the main design parameters and operational conditions of the bioreactors. In addition, the risk posed by the pharmaceuticals persisting in the final effluent and sludge is evaluated by calculating their risk quotients. These figures, along with their mass loads, are then used to identify the most critical compounds present in domestic wastewaters. Finally, a brief discussion on the treatment of the effluent from the pharmaceutical industry, generally activated sludge systems, is included, and a critical analysis regarding the ability and reliability of this system in removing pharmaceuticals is made