Occurrence, fate, and risk assessment of vancomycin in two typical pharmaceutical wastewater treatment plants in Eastern China.

Vancomycin (VCM) is an antibiotic, known medically as the deadline for defending against bacteria. In this study, the removal and fate of VCM were investigated in each treatment unit at two pharmaceutical wastewater treatment plants (PWWTPs) in eastern China. VCM was present in all wastewater and sludge samples of both PWWTPs. After the treatment procedure (the moving bed biofilm reactor technology for PWWTP1 and the modified anaerobic-anoxic-oxic technology for PWWTP2), total removal efficiencies were up to 99 %, corresponding to a reduction of two orders of magnitude of the influent concentrations in both PWWTPs. The aerobic tank dominated VCM removal. Mass balance flow analyses indicated that biodegradation (99.15 % for PWWTP1 and 99.51 % for PWWTP2) was the principle mechanism for removing VCM, while the contribution of sorption by sludge for both PWWTPs was negligible. However, the results of the environmental risk assessment of VCM in the effluents showed that the maximum trigger quotient values were much higher than 1 in both PWWTPs, indicating the non-negligible environmental and health risks. This is the first report of the fate and risks of VCM in pharmaceutical wastewater, and underscores the importance of PWWTPs as antibiotic pollution sources, even though wastewater management appeared efficient.