Fate and Removal of Pharmaceuticals in CAS for Water and Sewage Sludge Reuse

Among organic micropollutants, pharmaceutical active compounds (PhACs) have been extensively investigated in the last decades due to their potential adverse ecological and/or human health effects. Wastewater treatment plants are one of the first barriers in preventing them from reaching sensible ecosystems. In particular, conventional activated sludge (CAS) systems may be only partially effective in PhAC removal or degradation. The present work presents an overview of the fate of PhACs in CAS. Several parameters and constraints affecting PhAC removal are given and discussed including the physicochemical properties of the compounds and the operating parameters like the influent concentration, its seasonal variation, CAS hydraulic retention time and sludge retention time. A detailed data analysis is dedicated to selected representative compounds (i.e. carbamazepine, ibuprofen and sulfamethoxazole) in the water line of CAS systems, while for the sludge line, different treatment options are discussed, with special focus on the sequential anaerobic-aerobic digestion, a promising alternative to improve the removal of organic micropollutants, including PhACs, in the sludge matrix. Finally, the criteria for safe reuse of treated effluent and agricultural application of the produced sludge, related to PhACs, are discussed and analysed in the frame of EU and other regulations.