School of Sustainable Engineering and the Built Environment, Ira A. Fulton Schools of Engineering, Arizona State University, United States.
Sci Total Environ. 2018 Apr 15;621:1485-1490. doi: 10.1016/j.scitotenv.2017.10.080. Epub 2017 Oct 18.
This study elucidates the potential risk posed by Legionella during aquifer recharge practices. Experiments were conducted using pilot-scale column simulating infiltration of bacterial surrogate and pathogen, E. coli and Legionella pneumophila, under central Arizona recharge basin conditions. A column was packed with a loamy sand media collected from a recharge basin and was fitted with six sampling ports at soil depths of 15, 30, 60, 92, 122cm and acclimated for a month with tertiary treated wastewater. Transport of Legionella appeared to be delayed compared to E. coli. The breakthrough of E. coli and Legionella at 122cm depth occurred at 3 and 24h, respectively. Slow transport of Legionella is consistent with its pleomorphic nature and variation in size and shape under low nutrient conditions. Legionella persisted for a longer time in the column, but at lower concentrations. Given the novel results of this study, the transport of Legionella into groundwater aquifers can occur through engineering recharge basin conditions creating a potential public health risk.
本研究阐明了在含水层补给实践中军团菌可能带来的风险。实验采用中亚利桑那州补给盆地条件下模拟细菌替代物和病原体大肠杆菌和嗜肺军团菌渗透的小规模柱进行。用取自补给盆地的壤土砂介质填充一个柱，并在土壤深度为 15、30、60、92 和 122cm 处安装六个取样口，并适应一个月的三级处理废水。与大肠杆菌相比，军团菌的传输似乎被延迟。大肠杆菌和军团菌在 122cm 深度的突破分别发生在 3 和 24 小时。在低营养条件下，军团菌形态多样，大小和形状变化，导致其缓慢传输。军团菌在柱中持续存在的时间更长，但浓度更低。鉴于本研究的新结果，军团菌通过工程补给盆地条件进入地下水含水层的传输可能会带来潜在的公共健康风险。
