Institute of Environmental Engineering (ISA), RWTH Aachen University, 52056 Aachen, Germany.
IMT Atlantique Bretagne-Pays de Loire, Department of Energy Systems and Environment, 44307 Nantes, France.
Sci Total Environ. 2020 Sep 20;736:139519. doi: 10.1016/j.scitotenv.2020.139519. Epub 2020 May 22.
Combined sewer overflows are contaminated with various micropollutants which pose risk to both environmental and human health. Some micropollutants, such as carbamazepine and sulfamethoxazole, are very persistent and difficult to remove from wastewater. Event loaded vertical-flow constructed wetlands (retention soil filters; RSFs) have proven to be effective in the treatment of combined sewer overflows for a wide range of pollutants. However, little is known about how microbial communities contribute to the treatment efficiency, specifically to the reduction of micropollutants. To the best of our knowledge, this is the first study attempting to close this gap. Microbial communities in pilot-scale RSFs were investigated, which showed explicit grouping of metabolic activity at different filter depths with some differential abundance of identified genera. The highest microbial activity was found in the top layer of 0.75 m deep filters, whereas homogeneous activity dominated in a 0.50 m deep filter, indicating oxygen availability to be a limiting factor of the metabolic activity in RSFs. The removal efficiencies of all investigated organic trace substances were correlated to the utilization of specific carbon sources. Most notable is the correlation between the carbon source glucose-1-phosphate and the removal of metoprolol. The strongest correlations for other substances were the removal of diclofenac to the utilization of the carbohydrate i-erythritole; bisphenol A to carbohydrate α-d-lactose, and 1-H-benzotriazole to carbonic acid D-galacturonic acid. Those results are supported by positive correlations of specific microbial genera with both the utilization of the above mentioned carbon sources and the removal efficiency for the respective micropollutants. Most notable is correlation of Tetrasphaera and the removal of benzotriazole and diclofenac.
合流制污水溢流中含有各种微量污染物，这些污染物对环境和人类健康都构成了风险。一些微量污染物，如卡马西平和磺胺甲恶唑，非常持久，难以从废水中去除。垂直流人工湿地（保留土壤过滤器；RSF）已被证明在处理各种污染物的合流制污水溢流方面非常有效。然而，对于微生物群落如何有助于处理效率，特别是如何减少微量污染物，人们知之甚少。据我们所知，这是首次尝试填补这一空白的研究。研究了中试规模 RSF 中的微生物群落，结果表明，不同过滤深度的代谢活性明显分组，一些鉴定属的丰度存在差异。在 0.75 m 深的过滤器的顶层发现了最高的微生物活性，而在 0.50 m 深的过滤器中则存在均匀的活性，表明氧气供应是 RSF 中代谢活性的限制因素。所有研究的有机痕量物质的去除效率与特定碳源的利用相关。值得注意的是，葡萄糖-1-磷酸与美托洛尔去除之间的相关性。其他物质的最强相关性是双氯芬酸与碳水化合物 i-赤藻糖醇的利用；双酚 A 与碳水化合物α-d-乳糖的利用以及 1-H-苯并三唑与碳酸 D-半乳糖酸的利用。这些结果得到了特定微生物属与上述碳源的利用以及各自微量污染物去除效率之间的正相关的支持。最值得注意的是 Tetrasphaera 与苯并三唑和双氯芬酸的去除之间的相关性。
