title: Contribution of coarse particles from road surfaces to dissolved and particle-bound heavy metal loads in runoff: A laboratory leaching study with synthetic stormwater.
abstract: Laboratory leaching experiments were performed to study the potential of coarse street sediments (i.e. >250μm) to release dissolved and particulate-bound heavy metals (i.e. Cd, Cr, Cu, Ni, Pb and Zn) during rainfall/runoff. Towards this end, street sediments were sampled by vacuuming at seven sites in five Swedish cities and the collected sediments were characterized with respect to their physical and chemical properties. In the laboratory, the sediments were combined with synthetic rainwater and subject to agitation by a shaker mimicking particle motion during transport by runoff from street surfaces. As a result of such action, coarse street sediments were found to release significant amounts of heavy metals, which were predominantly (up to 99%) in the particulate bound phase. Thus, in dry weather, coarse street sediments functioned as collectors of fine particles with attached heavy metals, but in wet weather, metal burdens were released by rainfall/runoff processes. The magnitude of such releases depended on the site characteristics (i.e. street cleaning and traffic intensity), particle properties (i.e. organic matter content), and runoff characteristics (pH, and the duration of, and energy input into, sediment/water agitation). The study findings suggest that street cleaning, which preferentially removes coarser sediments, may produce additional environmental benefits by also removing fine contaminated particles attached to coarser materials.
authors: Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden. Electronic address: matthias.borris@ltu.se.
authors: Matthias
authors: M
authors: Borris
authors: Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden. Electronic address: helene.osterlund@ltu.se.
authors: Heléne
authors: H
authors: Österlund
authors: Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden. Electronic address: jiri.marsalek@ltu.se.
authors: Jiri
authors: J
authors: Marsalek
authors: Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden. Electronic address: maria.viklander@ltu.se.
authors: Maria
authors: M
authors: Viklander
mesh_terms: D002947:Cities; D004785:Environmental Pollutants / Q000378:metabolism*; D019216:Metals, Heavy / Q000032:analysis*; D008962:Models, Theoretical; D052638:Particulate Matter / Q000032:analysis*; D011891:Rain / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D013548:Sweden; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy; D052638:Particulate Matter; D014874:Water Pollutants, Chemical
keywords: Coarse street sediments; Heavy metals; Leaching tests; Stormwater runoff