A stochastic method for evaluating the in situ mass balance of micropollutants in a stormwater biofilter, accounting for inlet and outlet loads and the evolution of pollutant mass in the filter media (ΔMsoil) at an annual scale, is proposed. In the field context, this type of calculation presents a number of methodological challenges, associated with estimating water quality for unsampled rain events, reconstituting missing or invalidated flow data and accounting for significant uncertainties associated with these estimations and experimental measurements. The method is applied to a biofiltration swale treating road runoff for two trace metals, Cu and Zn and six organic micropollutants: pyrene (Pyr), phenanthrene (Phen), bisphenol-A (BPA), octylphenol (OP), nonylphenol (NP) and bis(2-ethylhexyl) phthalate (DEHP). Pollutant loads were reduced by 27–72%. While organic micropollutants are likely to be lost to degradation or volatilization processes in such systems, dissipation could not be demonstrated for any of the organic micropollutants studied due to emissions from construction materials (case of BPA, OP, NP and DEHP) or high uncertainties in ΔMsoil (case of Pyr and Phen). The necessary conditions for establishing an in situ mass balance demonstrating dissipation, which include acquisition of data associated with all terms over a period long enough that uncertainty propagation is limited and the absence of additional sources of pollutants in the field, are discussed.

No abstract

No abstract

No abstract

No abstract

<p>Abstract</p><p>Water pollution has long been considered a major problem causing environmental and public health issues. A range of contaminants are encountered in wastewater, industrial effluents and also road runoff, they include total suspended solids, nutrients, hydrocarbons and heavy metals. These latter have been found very toxic and hazardous, either for human health, or fauna and flora. In recent decades, studies have demonstrated a good removal efficiency of heavy metals by adsorption technique, and especially biosorption. Numerous biosorbents have been investigated, mainly lignocellulosic materials which have shown high adsorption capacity. Within this context, this study aims to investigate flax fibers capacity of zinc, copper and lead ions removal from aqueous solutions, in order to examine the best conditions to test a full-scale device designed to treat stormwater runoff. The choice of flax is related to its high availability, low cost and local economy reasons. The device consists of sand and layers of flax fibers geotextiles. It will be placed on a parking at the entrance of a retention basin in Le Havre. For this purpose, batch experiments were carried out with ternary and mono-metal solutions of zinc, copper and lead ions at room temperature with molar concentrations of 0.04 mmol.l<sup>-1</sup>, at pH around 6.4. Biosorption kinetics and biosorption equilibrium were performed and analyzed. The results showed a favorable adsorption for the three metals in the order Pb > Cu > Zn for both types of solutions, with adsorption rates of 94%, 75% and 62% respectively in the ternary metal solution and 94%, 81% and 82% in the mono-metal solutions. The effect of competition was important for zinc, barely visible for copper, and non-existent for lead.</p><p>Keywords: Biosorption, heavy metals, pollutants, stormwater management systems.</p><p> </p>