Transport and Partitioning of Metals from Urban Port Facilities in Liguria, Italy

Stormwater runoff from the paved surface of commercial ports has been investigated at the plot scale within the port industries of the Liguria Region (Italy). In particular the paper focuses on the characterization of the storm runoff quality in the container terminal and the tourism terminal sites. Both experimental catchment has been monitored for hydrology, chemistry and particulate loads. General water quality parameters (TSS, COD, pH, HC_tot, conductivity) as well as dissolved and particulate metals have been examined. Stormwater quality data collected confirm that pollutants EMC values are significantly higher than those observed in other urban land use sites. At both sites a mass-limited first flush phenomenon is generally observed for TSS while dissolved metals reveal a tendency to a linear response with respect to runoff volume. Particular attention is given to the partitioning of metals, which has direct implications on stormwater treatment BMPs for particle separation or treatment of the soluble fraction. The trend in non-equilibrium heavy metal partitioning has been analysed using the dissolved metal fraction f_d and the partition coefficient K_d.