Towards a better identification of contaminant retention mechanisms in SUDS soil: Zr deficit as a tracer of sediment accumulation

Abstract : Among the processes governing contaminant retention in soil-based SUDS, the relative contribution of particle settling and filtration is not always properly identified. Since zirconium is a well-documented invariant in pedology, the present work aimed to assess whether its use might be extended to sediment identification in SUDS. Extensive sampling and analysis were carried out in 11 infiltration systems. Zr contents were found to be significantly lower in road-deposited sediment than in soil. A deficit of this element could also be observed in the most contaminated area of most devices, indicating a "dilution-like" mixture of soil and sediments, the fraction of which could be calculated.