| Abstract |
| Field applications using the EcoTankTMsystem with hydrophobic expanded polypropylene(EPP) media to remove the heavy metals(Cd, Cr, Cu, Pb and Zn) resulting from road runoff were investigated. The EcoTankTMsystem was designed with a hydraulic retention time(HRT) of 0.55 h and with the capability of treating a maximum road runoff of 9.5 m3/h. The event mean concentrations(EMCs) with standard deviations of the heavy metals, Cd, Cr, Cu, Pb and Zn, derived from road runoff during 18 event periods were 3.6±4.4, 43.2±44.1, 117.8±106.1, 123.6±106, and 795±800 ug/L, respectively. The EMC profile showed a lognormal distribution having an arithmetic mean much greater than the median using the goodness-of-fit test. High levels of motorway-derived heavy metal contamination exist in stormwater runoff from road sections and the levels of heavy metals found in this study were higher than the regulated Korean environmental guideline for lakes and rivers. For Cd, Cr, Cu, Pb and Zn, the influent EMCs during 8 storm periods were 2.75, 37.3, 90.5, 118.5 and 546.5 ug/L, respectively. Main mechanism of the EcoTankTMsystem is filtration and adsorption showed >91%, >93%, >85%, >91% and >80% removal of the heavy metals, Cd, Cr, Cu, Pb and Zn, respectively, and the differences in the medians of the removal efficiencies among the heavy metals determined by the Kruskal-Wallis test for the 8 storm events were not statistically significant (p>0.05). It was found that EPP media is very effective for the removal of the heavy metals. The EcoTankTMsystem is a runoff treatment system designed for road runoff treatment which uses porous EPP media with a large surface area to treat the first-flush of stormwater. |
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| Key Words |
| EcoTankTMsystem, expanded polypropylene (EPP) media, heavy metals, road runoff |
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