Biodegradation of trace pharmaceutical substances in wastewater by a membrane bioreactor

The biodegradation of selected pharmaceutical micropollutants, including two pharmaceuticals with argued biodegradation, was studied by a lab-scale membrane bioreactor. The reaction kinetics and affecting factors were also investigated in this paper. Clofibric acid (CA) with contradictive biodegradation reported was degraded almost completely at different hydraulic retention times (HRTs) after adaptation to microorganisms. The biodegradation of CA was disturbed at low pH operation, while the activity of microorganisms recovered again after pH adjustment to neutral condition. Ibuprofen (IBP) degraded under neutral and acidic conditions. Removals of IBP and CA were zero-order and first-order reactions under high and low initial concentrations, respectively. Carbamazepine and diclofenac were not degraded regardless of HRTs and pH.