Evaluation of ageing effect on trace element mobility in sediment of sustainable drainage systems by chemical extractions

The management of urban stormwater runoff has moved from approaches narrowly focused on reducing flooding to approaches more focused on improving water quality. From impervious surfaces, stormwater is often diverted into retention ponds where sedimentation is used to limit the impact on waterbodies by trapping particulate pollutants. Trace elements are of particular interest because of their potential toxicity. The composition of the sediment varies over time, particularly through the development of vegetation. Ageing has an effect on sediment removal ability of pollutants (Nuel et al., 2018). The aim of this study was to compare the mobility of trace elements in sediments of a retention-infiltration pond before and after its total dredging. The mobility of these pollutants is related to their geochemical fractionation between solid phases which is generally investigated by extraction methods. The single extraction method with ammonium acetate and calcium chloride was applied on sediment samples to quantify the highest labile fraction of these elements (Sakan et al., 2020). The ultrasound assisted sequential extraction based on the procedure proposed by Rauret et al., (2000) and certified by Pueyo et al., (2001) was applied to determine the pollutant distribution among the acid-extractable, reducible, oxidizable fractions of sediments. The ageing effect is examined to explain the global removal ability of sediments. Then, the distribution of trace elements in different solid phases is analyzed in function of the sediment ageing, the mineral composition and granulometry of sediments.

Nuel, M., Laurent, J., Bois, P., Heintz, D., Wanko, A., 2018. Seasonal and ageing effect on the behaviour of 86 drugs in a full-scale surface treatment wetland: Removal efficiencies and distribution in plants and sediments. Science of The Total Environment 615, 1099–1109. https://doi.org/10.1016/j.scitotenv.2017.10.061

Pueyo, M., Rauret, G., Lück, D., Yli-Halla, M., Muntau, H., Quevauviller, Ph., López-Sánchez, J.F., 2001. Certification of the extractable contents of Cd, Cr, Cu, Ni, Pb and Zn in a freshwater sediment following a collaboratively tested and optimised three-step sequential extraction procedure. J. Environ. Monitor. 3, 243–250. https://doi.org/10.1039/b010235k

Rauret, G., López-Sánchez, J.-F., Sahuquillo, A., Barahona, E., Lachica, M., Ure, A.M., Davidson, C.M., Gomez, A., Lück, D., Bacon, J., Yli-Halla, M., Muntau, H., Quevauviller, Ph., 2000. Application of a modified BCR sequential extraction (three-step) procedure for the determination of extractable trace metal contents in a sewage sludge amended soil reference material (CRM 483), complemented by a three-year stability study of acetic acid and EDTA extractable metal content. J. Environ. Monitor. 2, 228–233. https://doi.org/10.1039/b001496f

Sakan, S., Frančišković-Bilinski, S., Đorđević, D., Popović, A., Škrivanj, S., Bilinski, H., 2020. Geochemical Fractionation and Risk Assessment of Potentially Toxic Elements in Sediments from Kupa River, Croatia. Water 12, 2024. https://doi.org/10.3390/w12072024