Department of Civil and Environmental Engineering, Henry Samulei School of Engineering, University of California Irvine, Irvine, CA 92697, USA.
Integrative Oceanography Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA.
Water Res. 2018 Jun 15;137:310-323. doi: 10.1016/j.watres.2018.03.020. Epub 2018 Mar 12.
Constructed stormwater wetlands provide a host of ecosystem services, including potentially pathogen removal. We present results from a multi-wetland study that integrates across weather, chemical, microbiological and engineering design variables in order to identify patterns of microbial contaminant removal from inlet to outlet within wetlands and key drivers of those patterns. One or more microbial contaminants were detected at the inlet of each stormwater wetland (Escherichia coli and Enterococcus > Bacteroides HF183 > adenovirus). Bacteroides HF183 and adenovirus concentrations declined from inlet to outlet at all wetlands. However, co-removal of pathogens and fecal indicator bacteria only occurred at wetlands where microbial assemblages at the inlet (dominated by Proteobacteria and Bacteriodetes) were largely displaced by indigenous autotrophic microbial communities at the outlet (dominated by Cyanobacteria). Microbial community transitions (characterized using pyrosequencing) were well approximated by a combination of two rapid indicators: (1) fluorescent dissolved organic matter, and (2) chlorophyll a or phaeophytin a fluorescence. Within-wetland treatment of fecal markers and indicators was not strongly correlated with the catchment-to-wetland area ratio, but was diminished in older wetlands, which may point to a need for more frequent maintenance.
人工构建的雨水湿地提供了多种生态系统服务，包括潜在的病原体去除功能。本研究通过多湿地综合分析，整合了天气、化学、微生物学和工程设计等变量，以确定湿地内部从入口到出口处微生物污染物去除的模式，以及这些模式的关键驱动因素。每个雨水湿地的入口处都检测到一种或多种微生物污染物（大肠杆菌和肠球菌>拟杆菌 HF183>腺病毒）。在所有湿地中，从入口到出口，拟杆菌 HF183 和腺病毒的浓度均呈下降趋势。然而，只有在那些入口处微生物群落（以变形菌门和拟杆菌门为主）很大程度上被出口处土著自养微生物群落（以蓝藻门为主）取代的湿地中，病原体和粪便指示菌才会同时被去除。微生物群落的演替（通过焦磷酸测序进行表征）与两种快速指标很好地吻合：（1）荧光溶解有机物，（2）叶绿素 a 或脱镁叶绿素 a 荧光。在湿地内部对粪便标志物和指示物的处理与集水区到湿地面积的比值没有很强的相关性，但在较老的湿地中则减弱，这可能表明需要更频繁的维护。
