University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Department of Aquatic Ecology and Ecotoxicology, Science Park 904, 1098 XH Amsterdam, The Netherlands; Stichting Waternet, Korte Ouderkerkerdijk 7, 1096 AC Amsterdam, The Netherlands.
Sci Total Environ. 2014 Jan 1;466-467:881-7. doi: 10.1016/j.scitotenv.2013.07.103. Epub 2013 Aug 25.
Suspended particles are a major constituent of municipal wastewater and generally contain high levels of bacteria, including human pathogens. Discharge of these particles of anthropogenic nature can have profound effects on receiving aquatic ecosystems and mitigation of these effects requires additional polishing of treated municipal wastewater. Previously it was shown that surface flow constructed wetlands are effective in improving water quality by reducing the numbers of fecal indicator organisms. However, fecal indicator organisms represent only a minor fraction of the total planktonic bacterial community and knowledge on the effects of these constructed wetlands on the composition and functioning of the entire planktonic bacterial community is limited. The aim of this descriptive study was therefore to identify changes in the planktonic bacterial community during residence of secondary treated municipal wastewater in a full-scale surface flow constructed wetland. To this purpose water samples were taken in which the bacterial community composition and functioning were analyzed using FISH, DGGE and BIOLOG. Surprisingly, the bacterial abundance at the inflow of the constructed wetland was relatively low compared with more natural surface waters. However, the inflowing bacterial community showed high metabolic activity and functional diversity. During residence in the surface flow constructed wetland the bacterial abundance doubled, but decreased in metabolic activity and functional diversity. Shifts in the community composition indicate that these changes are related to turn-over of the bacterial community. The planktonic bacterial community in the effluent of the constructed wetland closely resembled natural bacterial communities in urban and agricultural ditches. Based on these observations we conclude that constructed wetlands are capable to mitigate possible impacts of the particle load in treated wastewaters by transforming the anthropological bacterial community to a bacterial community resembling more "natural" surface waters.
悬浮颗粒是城市污水的主要成分，通常含有高水平的细菌，包括人类病原体。这些人为来源的颗粒排放会对受纳水生生态系统产生深远影响，需要对处理后的城市污水进行进一步的深度处理。此前已经表明，表面流人工湿地通过减少粪便指示生物的数量来有效改善水质。然而，粪便指示生物仅占浮游细菌群落的一小部分，关于这些人工湿地对整个浮游细菌群落的组成和功能的影响的知识有限。因此，本描述性研究的目的是确定二级处理后的城市污水在全尺寸表面流人工湿地中停留时浮游细菌群落的变化。为此，采集水样，使用 FISH、DGGE 和 BIOLOG 分析水样中的细菌群落组成和功能。令人惊讶的是，与更自然的地表水相比，人工湿地入口处的细菌丰度相对较低。然而，流入的细菌群落表现出高代谢活性和功能多样性。在表面流人工湿地中停留期间，细菌丰度增加了一倍，但代谢活性和功能多样性降低了。群落组成的变化表明这些变化与细菌群落的更替有关。人工湿地出水的浮游细菌群落与城市和农业沟渠中的天然细菌群落非常相似。基于这些观察结果，我们得出结论，人工湿地能够通过将人为细菌群落转化为更类似于“自然”地表水的细菌群落，减轻处理废水中颗粒负荷可能产生的影响。
