Abstract
The fate of pharmaceuticals, azithromycin (AZI), carbamazepine (CBZ), diclofenac (DCF), mefenamic acid (MFA), ibuprofen (IBP) and one ibuprofen metabolite (1-hydroxy ibuprofen (1-OH IBP)), were investigated in single-stage anaerobic (AN) and sequential anaerobic/aerobic/anoxic (AN/AERO/ANOX) sludge digestion under thermophilic conditions (55 °C). Intermittent aeration was used for the sequential AERO/ANOX vessel. Digesters showed an increase in CBZ, MFA and DCF at a hydraulic retention time (HRT) of 18 days as organic matter is degraded. However, the rate of increase for MFA was 10 times lower in sequential digestion compared to single-stage AN digestion (control). Sequential AN/AERO/ANOX digestion showed a 50% decrease in IBP levels while increasing IBPs aerobic metabolite 1-OH IBP by 12%. The control AN digester showed a 62% increase in IBP and a 34% decrease in 1-OH IBP. Sequential digestion provided other benefits, including reduced ammonia generation (44.5%), improved solids removal (4.1%) and enhanced digestate dewaterability (20%) compared to the control.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
