Kontchou Julios Armand, Baetz Nicolai, Grabner Daniel, Nachev Milen, Tuerk Jochen, Sures Bernd
Department of Aquatic Ecology, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany; Centre of Water and Environmental Research (ZWU), University Duisburg-Essen, Universitätsstr. 2, 45141 Essen, Germany.
Centre of Water and Environmental Research (ZWU), University Duisburg-Essen, Universitätsstr. 2, 45141 Essen, Germany; Institut für Energie- und Umwelttechnik e. V. (IUTA, Institute of Energy and Environmental Technology), Bliersheimer Str. 58-60, 47229 Duisburg, Germany.
Sci Total Environ. 2023 Feb 10;859(Pt 2):160185. doi: 10.1016/j.scitotenv.2022.160185. Epub 2022 Nov 14.
The overflow of stormwater retention basins during intense and prolonged precipitation events may result in the direct input of particulate pollutants and remobilization of already sedimented particle-bound pollutants to receiving freshwater bodies. Particle-bound pollutants may cause adverse effects on aquatic biota, particularly sediment dwellers. Therefore, we investigated the sediment pollution load of a stream connected to the outfalls of two stormwater basins to determine the impact of the basins' discharges on the metal and organic pollutant content of the sediment. Also, the possible adverse effects of the pollutant load on benthic dwellers were evaluated in sediment toxicity tests with Lumbriculus variegatus and the effects on its growth, reproduction and the biomarkers catalase, acetylcholinesterase and metallothionein were analyzed. The results showed that the retention basins contained the highest load of pollutants. The pollutant load in the stream did not show a clear pollution pattern from the inlets. However, metal enrichment ratios revealed contamination with Cu, Pb and Zn with Pb and Zn above threshold effect concentrations in all sites. Ecotoxicity results showed that the retention basin samples were the most toxic compared to sediment from the stream. Exposure experiments with the stream sediment did not show considerable effects on reproduction, catalase activity and metallothionein concentration. However, modest inhibitions of growth and activity of acetylcholinesterase were detected. Based on the observed results, it cannot be concluded that overflows of the retention basin are responsible for the pollutant contents downstream of their inlet. Other sources that were not considered in this study, such as diffuse input, historic pollution and point sources further upstream as well as along the stream, are likely the major contributors of pollutant load in the sediment of the studied transects of the stream. Additionally, the observed results in the stormwater basin sediment further highlight their importance in retaining particle-bound pollutants and preventing ecotoxicological effects from receiving surface water bodies.
在强烈且持续的降水事件中,雨水滞留池溢流可能导致颗粒污染物直接输入,并使已沉淀的颗粒结合污染物重新进入接受水体。颗粒结合污染物可能对水生生物群落,尤其是底栖生物造成不利影响。因此,我们调查了一条与两个雨水池排水口相连的溪流的沉积物污染负荷,以确定这些水池排放对沉积物中金属和有机污染物含量的影响。此外,还通过用颤蚓进行沉积物毒性试验评估了污染物负荷对底栖生物的可能不利影响,并分析了其对颤蚓生长、繁殖以及生物标志物过氧化氢酶、乙酰胆碱酯酶和金属硫蛋白的影响。结果表明,滞留池中污染物负荷最高。溪流中的污染物负荷从进水口未呈现出明显的污染模式。然而,金属富集率显示所有采样点均受到铜、铅和锌的污染,铅和锌超过了阈值效应浓度。生态毒性结果表明,与溪流沉积物相比,滞留池样品毒性最大。用溪流沉积物进行的暴露实验未显示对繁殖、过氧化氢酶活性和金属硫蛋白浓度有显著影响。然而,检测到对生长和乙酰胆碱酯酶活性有适度抑制。基于观察结果,不能得出滞留池溢流是其进水口下游污染物含量的原因。本研究未考虑的其他来源,如扩散输入、历史污染、上游及沿溪流的点源,可能是所研究溪流断面沉积物中污染物负荷的主要贡献者。此外,在雨水池沉积物中观察到的结果进一步凸显了它们在截留颗粒结合污染物以及防止接受水体产生生态毒理学效应方面的重要性。