Marazuela Miguel Angel, Formentin Giovanni, Erlmeier Klaus, Hofmann Thilo
Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Josef-Holaubek-Platz 2 UZAII, Vienna 1090, Austria.
Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Josef-Holaubek-Platz 2 UZAII, Vienna 1090, Austria; HPC Italia Srl, via Francesco Ferrucci 17/A, Milano 20145, Italy.
Water Res. 2023 Apr 1;232:119670. doi: 10.1016/j.watres.2023.119670. Epub 2023 Jan 27.
The persistence of the artificial sweetener acesulfame potassium (ACE) during wastewater treatment and subsequently in the aquatic environment has made it a widely used tracer of wastewater inputs to both surface water and groundwater. However, the recently observed biodegradation of ACE during wastewater treatment has questioned the validity of this application. In this study, we assessed the use of ACE not only as a marker of wastewater, but also as a transient wastewater tracer that allows both the calculation of mixing ratios and travel times through the aquifer as well as the calibration of transient groundwater flow and mass transport models. Our analysis was based on data obtained in a nearly 8-year river water and groundwater sampling campaign along a confirmed wastewater-receiving riverbank filtration site located close to a drinking water supply system. We provide evidence that temperature controls ACE concentration and thus its seasonal oscillation. River water data showed that ACE loads decreased from 1.5-4 mg·s in the cold season (December to June; T<10 °C) to 0-0.5 mg·s in the warm season (July to November; T>10 °C). This seasonal variability of >600% was detectable in the aquifer and preserved >3 km, with ACE concentrations oscillating between <LOQ in the warm season up to 1 μg·L in the cold season. The large seasonal variation in ACE concentrations during wastewater treatment, compared to the other sweeteners (sucralose, cyclamate, and saccharin) and chloride enables its use as a transient tracer of wastewater inflows and riverbank filtration. In addition, the arrival time of the ACE concentration peak can be used to estimate groundwater flow velocity and mixing ratios, thereby demonstrating its potential in the calibration of groundwater numerical models.
人工甜味剂乙酰磺胺酸钾（ACE）在废水处理过程中以及随后在水生环境中的持久性，使其成为地表水和地下水废水输入的广泛使用的示踪剂。然而，最近在废水处理过程中观察到的ACE生物降解对这种应用的有效性提出了质疑。在本研究中，我们评估了ACE不仅作为废水标志物的用途，还作为一种瞬态废水示踪剂的用途，它既可以计算混合比和通过含水层的运移时间，也可以用于校准瞬态地下水流和质量传输模型。我们的分析基于在一个靠近饮用水供应系统的已确认的受纳废水河岸过滤场地，进行的近8年河水和地下水采样活动中获得的数据。我们提供的证据表明，温度控制着ACE浓度，进而控制其季节性振荡。河水数据显示，ACE负荷从寒冷季节（12月至6月；T<10°C）的1.5 - 4 mg·s降至温暖季节（7月至11月；T>10°C）的0 - 0.5 mg·s。这种>600%的季节性变化在含水层中可检测到，并在>3 km的范围内保持，ACE浓度在温暖季节低于检测限，在寒冷季节高达1μg·L之间振荡。与其他甜味剂（三氯蔗糖、甜蜜素和糖精）以及氯化物相比，废水处理过程中ACE浓度的大幅季节性变化使其能够用作废水流入和河岸过滤的瞬态示踪剂。此外，ACE浓度峰值的到达时间可用于估计地下水流速和混合比，从而证明其在校准地下水数值模型方面的潜力。
