Review on physical and chemical characterizations of contaminated sediments from urban stormwater infiltration basins within the framework of the French observatory for urban hydrology (SOERE URBIS)

Abstract

Urban stormwater infiltration basins are designed to hold runoff from impervious surfaces and allow the settling of sediments and associated pollutants. However concerns have been expressed about the environmental impacts that may be exerted by the trapped pollutants on groundwater, soils and ecosystems. In this context, sediment characterization represents a key issue for local authorities in terms of management strategies. During the last two decades, several studies were launched including either physical or chemical characterization of stormwater sediments but without real synthesis of data and methods used. Consequently, there is an important need for reviewing the current experimental techniques devoted to the physico-chemical characterization of sediment. The review is based on the outcomes of two experimental sites for which long term monitoring and data collection have been done: the Cheviré basin (near Nantes) and the Django Reinhardt basin (near Lyon). The authors summarize the studies dealing with bulk properties, pollutant contents, their potential mobility and speciation. This paper aims at promoting the significant progresses that were made through a multidisciplinary approach involving multi-scaled and combined experimental techniques.

Spatial and Temporal Stability of Major and Trace Element Leaching in Urban Stormwater Sediments

“…These studies constitute a database on sediments contamination that points at the high contents of trace element (e.g. up to 2400 ppm of zinc, 500 ppm of lead, 300 ppm of chromium and copper) [2] [4]- [10].…”

“…Within the framework of the French observatory for urban hydrology-SOERE URBIS [10], different studies were dedicated to the geochemical characterization of stormwater sediments and their pollutant-carrier solid phases. A large panel of analytical techniques was employed to characterize the sediments geochemical characteristics at both bulk and micro scales using XRD and SEM analysis [7] [8] [13].…”

“…A large panel of analytical techniques was employed to characterize the sediments geochemical characteristics at both bulk and micro scales using XRD and SEM analysis [7] [8] [13]. These analyses gave information on the main pollutants-bearing solid phases (mineral and organic) and showed that the main mineral phases are related to the local geochemical context of the basin and should remain constant over time.…”

“…These analyses gave information on the main pollutants-bearing solid phases (mineral and organic) and showed that the main mineral phases are related to the local geochemical context of the basin and should remain constant over time. Few SEM observations of anthropogenic and non-crystallized particles underline the presence of slag mineral particles composed of various alloys made of cupro aluminium with Fe, Ni, Mn, Fe-Cr-Ni stainless steels or organic residues spread from tire abrasion, brake pads or road asphalt grains containing traces of Zn or Cu [13]. However, these measures and observations have often been conducted on samples taken at a single time and a single location in the infiltration system.…”

“…This study focuses on the characterization of solid phase alteration and associated major and trace element release for stormwater sediment accumulated at the surface of an infiltration basin (experimental pilot) monitored within the framework of the French survey on urban sediments [13]. For this purpose, we carried out ANC-BNC titrations with the following objectives: i) address the question of space and time stability of phase alteration and trace element release, in relation to the functioning of the infiltration basin and its evolution with time, ii) link the release of trace element with majors and phase alteration to pinpoint the bearing phases.…”