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Title: INFLUENCE OF HIGHWAY RUNOFF CHEMISTRY, HYDROLOGY, AND RESIDENCE TIME ON NONEQUILIBRIUM PARTITIONING OF HEAVY METALS: IMPLICATIONS FOR TREATMENT AT THE HIGHWAY SHOULDER
Accession Number: 00819975
Record Type: Component
Record URL: Availability: Transportation Research Board Business Office 500 Fifth Street, NW Find a library where document is available Abstract: The control and treatment of highway-pavement storm water at the edge of the highway shoulder pose unique challenges due to the unsteady nature of processes, including rainfall runoff, mobilization and partitioning of heavy metals, variations in storm-water chemistry, residence time on the pavement, and delivery of particulate mass. Presented are heavy-metal partitioning results as influenced by pavement-runoff chemistry and hydrologic parameters from a series of eight rainfall-runoff events over a 2-year period. Water-quality characteristics such as low alkalinity, low hardness, and short pavement residence times cause a majority of the heavy-metal mass to remain in solution at the edge of the pavement, with partitioning coefficients approaching equilibrium conditions only toward the end of the event, as heavy metals partition to entrained solids. There are two primary implications when considering the application of typical best management practices (BMPs) for highway runoff within the right-of-way. The first implication is to use a BMP such as a detention basin or roadside swale to detain runoff and produce sufficient residence time so that partitioning to the entrained solids occurs. The second implication is to use a BMP such as an engineered infiltration trench to provide surface complexation for dissolved metals and filtration mechanisms for the particulate-bound metals. Although no simple solutions exist for the removal of a heavy metal or particle once it is released in the highway environment, knowledge of the dynamic processes in highway runoff can provide insights for the proper selection of BMPs, depending on the conditions at the highway site. A design should be based on the concept that BMPs, to be effective, are essentially garbage cans for heavy metals and solids and as such must be emptied and maintained.
Supplemental Notes: This paper appears in Transportation Research Record No. 1755, Geology and Properties of Earth Materials 2001.
Language: English
Corporate Authors: Transportation Research Board 500 Fifth Street, NW Authors: Glenn III, D WLiu, DanSansalone, J JPagination: p. 129-140
Publication Date: 2001
Serial: ISBN: 0309072166
Features: Figures
(8)
; References
(15)
; Tables
(2)
TRT Terms: Uncontrolled Terms: Subject Areas: Design; Environment; Highways; Hydraulics and Hydrology; I26: Water Run-off - Freeze-thaw
Files: TRIS, TRB, ATRI
Created Date: Nov 8 2001 12:00AM
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