Distribution, removal, and risk assessment of pharmaceuticals and their metabolites in five sewage plants

Abstract

The extensive use of pharmaceuticals and personal care products (PPCPs) leads to a continuous increase of their presence in urban wastewater. These pollutants are discharged into natural waters and pose a threat to human health and the ecological environment. This study focused on five sewage treatment plants in three cities of China’s Yangtze River Delta as research sites to study the distribution and degradation of drugs and their conversion products in wastewater. The concentration of target compounds in the water ranged from 0 to 510.8 ng/L, and both positive and negative removal rates occurred during the treatment. Acetaminophen (ACE) and ibuprofen (IPF) can be completely removed in the biological treatment stage. The addition of flocculants and sand filtration has a positive effect on the removal of naproxen (NPX) and bezafibrate (BZB). Ultraviolet disinfection is beneficial for the removal of antipyrine (ATP) and diclofenac (DCF). A small amount of PPCPs were found in the sludge and particulate matter, which had little effect on removal. Finally, the risk quotients were used to evaluate the harmfulness of the PPCPs detected in the effuent to the ecological environment, and the results showed that there was little hazard.