摘要: |
The removal of paint from bridges and other structures is a significant issue facing transportation agencies because of the presence and potential for release of lead and other contaminants upon disposal. A large percentage of the bridges are reaching a critical level of deterioration, resulting in management issues for paint waste. The New York State Department of Transportation (NYSDOT) applies a conservative approach by assuming all waste generated from bridges previously painted with lead-based paint (LBP) is hazardous. Therefore, an approach that provides accurate in-situ characterization of the waste classification would be beneficial. The goal of this project is to develop a rapid and cost-effective method that can provide an accurate characterization of waste classification. With 11 Regions and 2,385 bridges rehabilitated and subsequently repainted after NYSDOT stopped using LBP on bridges (after 1988), 24 bridges from across the NYS were selected for this study based on Sampling Theory (Deliverable Task 1). The literature review demonstrated that elevated metal concentrations in paint waste have resulted in leaching that exceeds toxicity characteristic (TC) concentrations; however, models to predict leaching behavior have not been developed (Deliverable Task 2). Field portable X-ray fluorescence (FP-XRF) (Deliverable Task 3) was applied to quantify Resource Conservation and Recovery Act (RCRA) metals (i.e., As, Ba, Cr, Cd, Pb, Hg, Se, and Ag) along with iron and zinc in paint waste samples (Deliverable Task 4), while Hach DR 2800 field portable spectrophotometer (Deliverable Task 3) was employed for measuring dissolved and total lead concentrations in bridge wash water (Deliverable Task 5). Leaching behavior of the paint waste was evaluated with the U.S. Environmental Protection Agency (U.S. EPA) toxicity characteristic leaching procedure (TCLP) and multiple extraction procedure (MEP) (Deliverable Task 6). Elevated Pb (5 to 168,090 mg kg-1), Cr (21 to 10,19 |