State Key Laboratory of Eco-Hydraulics in the Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China.
State Key Laboratory of Eco-Hydraulics in the Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China.
Sci Total Environ. 2024 Oct 10;946:174278. doi: 10.1016/j.scitotenv.2024.174278. Epub 2024 Jun 24.
Bioretention systems prove effective in purifying common persistent organic pollutants (POPs) found in urban rainfall runoff. However, the response process of the microecosystem in the media becomes unclear when POPs accumulate in bioretention systems. In this study, we constructed bioretention systems and conducted simulated rainfall tests to elucidate the evolution of micro-ecosystems within the media under typical POPs pollution. The results showed all POPs in runoff were effectively removed by surface adsorption in different media, with load reduction rates of >85 % for PCBs and OCPs and > 80 % for PAHs. Bioretention soil media (BSM) + water treatment residuals (WTR) media exhibited greater stability in response to POPs contamination compared to BSM and pure soil (PS) media. POPs contamination significantly impacted the microecology of the media, reducing the number of microbial species by >52.6 % and reducing diversity by >27.6 % at the peak of their accumulation. Enzyme activities were significantly inhibited, with reductions ranging from 44.42 % to 60.33 %. Meanwhile, in terms of ecological functions, the metabolism of exogenous carbon sources significantly increased (p < 0.05), while nitrogen and sulfur cycling processes were suppressed. Microbial diversity and enzyme activities showed some recovery during the dissipation of POPs but did not reach the level observed before the experiment. Dominant bacterial species and abundance changed significantly during the experiment. Proteobacteria were suppressed, but remained the dominant phylum (all relative abundances >41 %). Bacteroidota, Firmicutes, and Actinobacteria adapted well to the contamination. Pseudomonas, a typical POPs-degrading bacterium, displayed a positive correlation between its relative abundance and POPs levels (mean > 10 %). Additionally, POPs and media properties, including TN and pH, are crucial factors that collectively shape the microbial community. This study provides new insights into the impacts of POPs contamination on the microbial community of the media, which can improve media design and operation efficiency.
生物滞留系统被证明在净化城市降雨径流中常见的持久性有机污染物（POPs）方面非常有效。然而，当 POPs 在生物滞留系统中积累时，介质中的微生态系统的响应过程变得不清楚。在这项研究中，我们构建了生物滞留系统并进行了模拟降雨测试，以阐明在典型的 POPs 污染下介质中微生态系统的演变。结果表明，在不同的介质中，通过表面吸附可以有效地去除径流中的所有 POPs，PCB 和 OCP 的去除率>85%，PAHs 的去除率>80%。与 BSM 和纯土壤（PS）介质相比，生物滞留土壤介质（BSM）+水处理残渣（WTR）介质对 POPs 污染的响应更稳定。POPs 污染显著影响了介质的微生物生态，使微生物种类减少了>52.6%，在积累高峰期降低了多样性>27.6%。酶活性受到显著抑制，降幅范围为 44.42%至 60.33%。同时，在生态功能方面，外源碳源的代谢显著增加（p<0.05），而氮和硫循环过程受到抑制。在 POPs 消散过程中，微生物多样性和酶活性有所恢复，但仍未达到实验前的水平。实验过程中，优势细菌种类和丰度发生了显著变化。变形菌门受到抑制，但仍保持优势门（所有相对丰度>41%）。拟杆菌门、厚壁菌门和放线菌门很好地适应了污染。假单胞菌是一种典型的 POPs 降解菌，其相对丰度与 POPs 水平呈正相关（平均值>10%）。此外，POPs 和介质特性，包括 TN 和 pH，是共同塑造微生物群落的关键因素。本研究为 POPs 污染对介质中微生物群落的影响提供了新的见解，这可以提高介质设计和运行效率。
