LAUSR

Abstract Understanding removal mechanisms of emerging organic contaminants in conventional activated sludge systems is of fundamental and engineering importance. In this study, we selected six environmentally relevant pharmaceuticals as target organic contaminants, namely, metronidazole (MTZ), bezafibrate (BZF), ibuprofen (IBP), sulfamethoxazole (SMX), carbamazepine (CBZ), and ciprofloxacin (CIP) for the mechanistic investigation for their removal. We demonstrated that sorption and biodegradation were the dominant pathways for contaminant removal, while volatilization and hydrolysis were negligible. The sorption removal process varied for the selected pharmaceuticals in the batch system. Then, first-order rate model was used to fit the biodegradation kinetics, and their first-order rate constants (kbio) were ranged from 3.67 × 10−3 to 10.2 L g−1 d−1, in order of CBZ