International audienceThe concentrations of heavy metals in water, sediments, soil, roots, and shoots of five aquatic macrophytes species (Oenanthe sp., Juncus sp., Typha sp., Callitriche sp.1, and Callitriche sp.2) collected from a detention pond receiving stormwater runoff coming from a highway were measured to ascertain whether plants organs are characterized by differential accumulations and to evaluate the potential of the plant species as bioindicators of heavy metal pollution in urban stormwater runoff. Heavy metals considered for water and sediment analysis were Cd, Cr, Cu, Ni, Pb, Zn, and As. Heavy metals considered for plant and soil analysis were Cd, Ni, and Zn. The metal concentrations in water, sediments, plants, and corresponding soil showed that the studied site is contaminated by heavy metals, probably due to the road traffic. Results also showed that plant roots had higher metal content than aboveground tissues. The floating plants displayed higher metal accumulation than the three other rooted plants. Heavy metal concentrations measured in the organs of the rooted plants increased when metal concentrations measured in the soil increased. The highest metal bioconcentration factors (BCF) were obtained for cadmium and nickel accumulation by Typha sp. (BCF = 1.3 and 0.8, respectively) and zinc accumulation by Juncus sp. (BCF = 4.8). Our results underline the potential use of such plant species for heavy metal biomonitoring in water, sediments, and soil

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International audienceConventional stormwater detention ponds frequently show limitations for dissolved heavy metal removal. Floating treatment wetlands (FTWs), a variant of constructed wetlands, are considered as a promising technology to improve the quality of urban stormwater runoff. Our study aimed at evaluating the treatment performances of FTWs for cadmium, nickel, and zinc removal through a pot experiment. Two macrophytes species, Juncus effusus and Carex riparia, were grown during 4 months under three metal concentrations (in micrograms per liter): high (Cd, 200; Ni, 500; Zn, 2,000), low (Cd, 10; Ni, 10; Zn, 40), and control (Cd-Ni-Zn, 0). Results showed that both macrophytes species significantly removed dissolved heavy metals. Cadmium and nickel accumulations were greater in roots than in shoots for both species. Under low metal concentration, maximum accumulation of 0.4 mu g g(-1) dry weight (DW) for Cd was observed in the roots of J. effusus. Under high metal concentration, accumulations of up to 5 mu g Cdg(-1) DW and 62 mu g Nig(-1) DW were observed in the roots of J. effusus and up to 73 mu g Zng(-1) DW in the roots of C. riparia. Although J. effusus and C. riparia are not recognized as metal hyperaccumulators, our study demonstrated that they can achieve high metal uptake when both roots and shoots are harvested