Variations of dissolved and suspended solid heavy metals through an urban hydrograph

Zn, Cd and Cu in stormwater runoff from an urban catchment are found to be present mainly in the dissolved phase, whereas Pb is most strongly associated with the suspended solid phase. High levels of metals, particularly Cu, are found in stormwater solids which may be due to the high percentage of particulate organic material in the runoff. The metal loadings over the storm event for the dissolved and suspended solid associated metals show similar distributions to the flow and suspended solids respectively. However, in some cases secondary peaks and deviations due to dissolved metal scavenging are observed.