State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.
Environ Int. 2022 Sep;167:107396. doi: 10.1016/j.envint.2022.107396. Epub 2022 Jul 7.
In China, the sewerage system plays an essential role in antibiotic removal; however, the fate profiles of antibiotics in sewers are not well understood, and risk identification throughout the sewerage system is inadequate. Based on the extensive detection results for typical groups of antibiotics in the discharge sources, influent and effluent from wastewater treatment plants (WWTPs), and excess sludge, a comprehensive evaluation was conducted to reveal the elimination profiles of the antibiotics, identify the fate characteristics in both sewers and WWTPs, assess the exposure risk levels, and propose a control strategy. The total concentration (based on the median concentrations of the target antibiotics) in aqueous waters was estimated to decrease from 7383.4 ng/L at the discharge source to 886.6 ng/L in the WWTP effluent, among which 69.6% was reduced by sewers and 18.4% was reduced by WWTPs. Antibiotic reduction in sewers was a combined effect of dilution, physiochemical reactions, sorption, biodegradation, and retransformation, and the A2O-MBR + ozonation process in the WWTPs exhibited superior performance in diminishing antibiotics. Notably, accumulated antibiotics in the excess sludge posed a high risk to natural environments (with a risk quotient of approximately 13.0), and the potential risk during combined sewer overflows (CSOs) was undetermined. Thus, enhanced sludge treatment techniques, accurate risk prediction, and proper precautions at CSOs are required to mitigate potential risk. A novel scheme involving an accurate estimation of discharge loads, preliminary treatment of highly concentrated discharge sources, and synergic control in sewers was proposed to eliminate antibiotics at the front end of pipes.
在中国，污水系统在去除抗生素方面发挥着重要作用；然而，污水中抗生素的命运特征尚未得到很好的理解，污水系统中的风险识别也不足。基于对污水排放源、污水处理厂（WWTP）进、出水和剩余污泥中典型抗生素类药物的广泛检测结果，对其进行了综合评价，以揭示抗生素的消除特征，识别污水和 WWTP 中的命运特征，评估暴露风险水平，并提出控制策略。在水样中，基于目标抗生素的中值浓度，总浓度（total concentration）估计从排放源的 7383.4ng/L 降低到 WWTP 出水中的 886.6ng/L，其中 69.6%通过污水去除，18.4%通过 WWTP 去除。污水中抗生素的减少是稀释、物理化学反应、吸附、生物降解和再转化的综合作用，WWTP 中的 A2O-MBR+臭氧工艺在减少抗生素方面表现出优异的性能。值得注意的是，剩余污泥中积累的抗生素对自然环境构成了高风险（风险商数约为 13.0），而合流制污水溢流（CSO）中的潜在风险尚未确定。因此，需要增强污泥处理技术、准确的风险预测以及 CSO 中的适当预防措施，以减轻潜在风险。提出了一种新的方案，涉及准确估计排放负荷、对高浓度排放源进行预处理以及在管道前端协同控制，以消除抗生素。
