Theses and Dissertations from UMD

Permanent URI for this communityhttp://hdl.handle.net/1903/2

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

Browse

Filters

20171

Settings

Author: search.filters.author.Seybou Insa, OusmaneSubject: search.filters.subject.leaching

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Leaching of Contaminants from Recycled Asphalt Pavement used in Highway Construction
    (2017) Seybou Insa, Ousmane; Aydilek, Ahmet H; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Recycled asphalt pavement (RAP) is a material resulting the removal and reprocessing of the existing asphalt pavement. Annually, more than 80 million tons of RAP is produced in the United States. Most of the RAP is landfilled, which constitutes a significant economic burden and a waste of landfill space. RAP has great potential in highway construction due to its good physical properties. However, concerns have been raised due to potential surface water and groundwater contamination by metals including some heavy metals and Polycyclic Aromatic Hydrocarbons (PAHs) present in RAP. A series of batch-level pH-dependent leaching tests and Toxicity Characteristics Leaching Procedure (TCLP) tests were conducted to investigate the leaching of metals from seven RAPs collected across the state of Maryland. The results of the pH-dependent leaching tests indicated As to be slightly above the U.S EPA Water Quality Limit (WQL). The results of a series of TCLP tests showed that two PAHs, chrysene and Indeno[1,2,3-cd]pyrene, may be present in the leachates, albeit, at concentrations very comparable to those leach from a new asphalt material. The results of the geochemical modeling indicated that the leached metals were solubility-controlled. Oxide and hydroxide minerals control the leaching of Al and Fe; whereas, leaching of Ba, Ca and Mg were controlled by carbonate and/or sulfate minerals.