Heavy metal concentrations and toxicity in water and sediment from stormwater ponds and sedimentation tanks

• Published in: Journal of hazardous materials 2010-06, Vol.178 (1), p.612-618
• Main Authors: Karlsson, Kristin, Viklander, Maria, Scholes, Lian, Revitt, Mike
• Format: Article
• Language: English
• Subjects: Aliivibrio fischeri - drug effects; Applied sciences; Atmospheric pollution; Bacteria; Biological Assay; Chemical engineering; Chromium; Exact sciences and technology; General purification processes; Geologic Sediments - analysis; Heavy metals; Hydrogen-Ion Concentration; Liquid-liquid and fluid-solid mechanical separations; Metals, Heavy - analysis; Metals, Heavy - toxicity; Particle Size; Particulate Matter - analysis; Pollution; Ponds; Sedimentation tanks; Sediments; Settling; Stormwater; Toxicity; Treatment facilities; Urban Water Engineering; VA-teknik; Vibrio fischeri; Wastewaters; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity; Water treatment and pollution; Zinc
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2010.01.129

Sedimentation is a widely used technique in structural best management practices to remove pollutants from stormwater. However, concerns have been expressed about the environmental impacts that may be exerted by the trapped pollutants. This study has concentrated on stormwater ponds and sedimentation tanks and reports on the accumulated metal concentrations (Cd, Cr, Ni, Pb, and Zn) and the associated toxicity to the bacteria Vibrio fischeri. The metal concentrations are compared with guidelines and the toxicity results are assessed in relation to samples for which metal concentrations either exceed or conform to these values. The water phase metal concentrations were highest in the ponds whereas the sedimentation tanks exhibited a distinct decrease towards the outlet. However, none of the water samples demonstrated toxicity even though the concentrations of Cu, Pb, and Zn exceeded the threshold values for the compared guidelines. The facilities with higher traffic intensities had elevated sediment concentrations of Cr, Cu, Ni, and Zn which increased towards the outlet for the sedimentation tanks in agreement with the highest percentage of fine particles. The sediments in both treatment facilities exhibited the expected toxic responses in line with their affinity for heavy metals but the role of organic carbon content is highlighted.