[Mechanisms and Efficiencies of Removal of PPCPs by Pilot River Water Bypass Treatment Process]

The pharmaceuticals and personal care products (PPCPs) released into urban rivers are triggering certain ecological risks. The current study investigated the removal efficiencies of 30 frequently detected PPCPs by two river water bypass treatment processes (CS-BAF-UF-Ozone and CS-MBR-Ozone), and investigated the removal mechanism and eco-toxicological risk variation of target compounds via section-removal investigation and risk quotient model, respectively. Results indicated that both processes could efficiently remove the target PPCPs; the removal rates of tetracyclines and caffeine were>90% in the biological sections, while sulfonamides, fluoroquinolones, and other pharmaceuticals could only be efficiently removed when the COD of the influent and the water temperature were comparatively higher; the ozone process had particular effect on removing these compounds. The cumulative removal rate of all PPCPs during the whole process was higher than 92.5%. The total risk quotient (RQ_tot) of target PPCPs could be efficiently reduced by the bypass treatment processes; the RQ_tot decreased from 12.6 in the influent river water to 0.2 in the ozone effluent, with a removal rate of 98.4%.