Estimation of Pharmaceutical Removal in a Sewage Treatment Plant -Model Simulation Based on Laboratory Test Data-

Abstract

A model was developed to estimate the removal of pharmaceutical compounds in a sewage treatment plant. The model was based on the material balances of activated sludge and pharmaceuticals in liquid and solid phases in the aeration tank and the settler. Non-ideal mixing characteristics for the aeration tank were described using a tanks-in-series model. The model took into account the biological degradation of pharmaceuticals by microorganisms in the activated sludge in addition to sorption and desorption onto the microorganisms. The concentration profiles of activated sludge and pharmaceuticals in liquid and solid phases in the aeration tank could be predicted by the model using input data from laboratory tests, such as kinetic constants for degradation by the activated sludge, and adsorption-desorption onto the microorganisms. The model predictions were compared with the observed removal efficiencies for atenolol, carbamazepine, diclofenac, ibuprofen, sulfamethoxazole, and trimethoprim. The model could reasonably predict the removal trends for several pharmaceuticals.