High-Flow Structural Media for Removing Stormwater-Dissolved Phosphorous in Permeable Paving: Fid-Bau Portal

High-Flow Structural Media for Removing Stormwater-Dissolved Phosphorous in Permeable Paving

Ostrom, Travis K. / Aydilek, Ahmet H. / Davis, Allen P.

Phosphorus (P) loadings from urban runoff is a persistent contributor to waterbody impairment. Dissolved phosphorus (DP), however, is not well retained by many stormwater control measures (SCMs), including permeable pavements. This study seeks to evaluate a novel base material developed to enhance P removal in permeable paving. The media has high hydraulic conductivity, $9.0 \times 10^{- 4} \pm 1.9 \times 10^{- 5} m / s$ ( $324 \pm 6.8 cm / h$ ), and is structurally suitable as a permeable pavement base. It demonstrated long-term DP adsorption capacity and achieved treatment above 90% total DP removal for the first 50 m of applied water, beyond the typical pavement design lifetime, with no contributing area. This indicates potential application of permeable pavement to treat run-on at loading rates of $5 ∶ 1$ or possibly higher. Adsorption to aluminum (hydr)oxides is thought to be the primary mechanism for DP retention. DP uptake is described by a first-order steady-state plug flow model developed and fit to experimental data. This novel media has the potential to improve P retention in permeable pavement and enable run-on treatment.