FASTLÄGGNING AV TUNGMETALLER I TVÅ ÖVERSILNINGSYTOR FÖR TRAFIKDAGVATTEN I MALMÖ / Accumulation of heavy metals in two Vegetative Filter Strips treating road runoff in the city of Malmö, Sweden
This paper evaluates the accumulation of the heavy metals cadmium, chromium, copper, nickel, lead, zinc and the effect of deicing salt in two Vegetative Filter Strips in an eight years old facility in southern Malmö. The two Vegetative Filter Strips were the road shoulder and the last step in the treatment facility after a swale, pond and filter mound. Samples were taken at the surface and at 20 cm depth, along the two Vegetative Filter Strips. Cadmium, Chromium, Copper, Nickel, Lead, Zinc and the exchangeable sodium percentage were analyzed.
The results show that the road shoulder has accumulated Cadmium, Chromium, Copper, Lead and Zinc. No metal concentrations in the surfaces have reached the Swedish guideline values for sensitive land-use. In the surface of the road shoulder Zinc shows the highest levels compared to the Swedish guideline values for sensitive land-use. The exchangeable sodium percentage in the soil indicates that the first Vegetative Filter Strip is most affected by de-icing salts, but also the last Vegetative Filter Strip indicate increased levels. There is therefore an increased risk of colloidal transport of pollutants in the road shoulder because of deteriorated soil physical properties.