Batch Kinetic Studies of Pharmaceutical Compounds Removal Using Activated Sludge Obtained from a Membrane Bioreactor

Pharmaceutical compounds are emerging pollutants found in the wastewater, which have recently drawn general concerns due to their potential to affect the quality of water bodies, ecosystems, and human health. The purpose of this paper was to assess the removal mechanisms sorption and biodegradation of two lipid regulator pharmaceutical compounds, clofibric acid (CLA) and gemfibrozil (GFZ), through batch experiments using activated sludge obtained from a membrane bioreactor (MBR). As a result, biodegradation was the main removal mechanism in activated sludge for both pharmaceutical compounds, followed by sorption and desorption. The highest removals of CLA and GFZ were 72 and 97%, respectively. According to results from the adsorption test, the CLA and GFZ have a strong adsorption capacity on inactivated biomass. The solid-water distribution coefficient (K-d) for CLA was 8.5 L.g(-1) and for GFZ was 0.75 L.g(-1). The value for Monod constants q was 0.6 h(-1) for both pharmaceutical compounds. The affinity constant K-s value of CLA (4.37 mu g L-1) was higher than the K-s value of GFZ (0.35 mu g.L-1). COD and NH4-N removals were 99 and 97%, respectively, during the kinetic test.

Automated summary

Pharmaceutical compounds are emerging pollutants that can potentially affect the quality of water bodies, ecosystems, and human health. This study assessed the removal mechanisms of two lipid regulator pharmaceutical compounds, clofibric acid (CLA) and gemfibrozil (GFZ), through batch experiments using activated sludge obtained from a membrane bioreactor (MBR). The results showed that biodegradation was the main removal mechanism for both pharmaceutical compounds, followed by sorption and desorption.