Distribution And Attenuation Of Typical Pharmaceuticals In Shenzhen River Watershedand Control Technology

Pharmaceuticals and personal care products(PPCPs) is ubiquitous in the aquatic environment, and has caused attentions worldwide in light of its high ecological risks. This study targeted at the occurrence and distribution of PPCPs in urban rivers in China, especially their distribution and attenuation in the mainstream and tributaries of Shenzhen River watershed. Thirty-six target PPCPs were selected, and the measurement was performed with high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS). The efficiencies of relative control technologies in eliminating PPCPs in typical antibiotic production plant, in municipal wastewater treatment plant(WWTP), and in river water inlet were compared to obtain effective and comprehensive technical strategy to control the PPCPs’ entering the urban aquatic environment.Twenty-seven PPCPs were detected in rivers selected in Shenzhen, 20 PPCPs were found in rivers in Beijing, and 21 compounds were found in Changzhou, the PPCPs concentrations in three cities were in the range of 524.1-723.6 ng/L, 324.2-1123.2 ng/L, and 89.2-511.3 ng/L, respectively. Shenzhen River has more antibiotics, while the river in Beijing has more cardiovascular agent PPCPs.Eleven PPCPs were found in each water sample including AZI, CLA, ROX, LIN, SMX, TIA, ATE, IND, PHE, SUL, and CAR. Eight compounds including IND, SMX, SIN, TRI, AZI, CLA, ROX, and ERY were found to pose low to high potential ecological risks to aquatic environment.The attenuation of most detected PPCPs in Shenzhen River watershed followed the first-order kinetics, and the attenuation rate was higher in summer than in winter.Effluents from WWTPs were the predominant sources to PPCPs’ contamination in rivers in Shenzhen, Beijing, and Changzhou. Conventional wastewater treatment technology was not able to effectively remove the target PPCPs. The average removal efficiencies of CLA, LIN, IND, TRI, CRO, and SMX were above 50%, while for ERY, ROX, ATE, MET, SUL, and PRO, the mean removal efficiencies were <50%, and negative removal efficiencies even presented for AZI, CAR, and PHE. The fiber-filtration/chlorination disinfection process, which is frequently used in Shenzhen for reclaimed water treatment performed badly in PPCPs elimination, and the mean removal efficiencies of most detected PPCPs were <10%.In the treatment of auremycin-containing wastewater in antibiotics factory, conventional biological treatment process can remove over 92% of auremycin, while the integrated processes including membrane bioreactor(MBR)-ozone/membrane filtration can remove over 99%. Synergetic catalysis between ozone and ceramic membrane played critical role in effectively removing the detected PPCPs, free radicals mechanism was identified. For domestic wastewater, MBR significantly improved the removal efficiencies of most PPCPs compared with the conventional biological treatment processes. It can be concluded that upgrading the conventional treatment processes with MBR technology, combined with the use of ozone/ceramic-membrane process as advanced technology in the treatment of reclaimed water, would be fully able to control the PPCPs concentrations in urban rivers to be less than 10 ng/L. This has significance in technically controlling PPCPs contamination in urban rivers in China.