Grantee Research Project Results
A Scientific Rational for Assessing Mobility of Sorbed Contaminants in Subsurface Systems
EPA Grant Number: U915168Title: A Scientific Rational for Assessing Mobility of Sorbed Contaminants in Subsurface Systems
Investigators: Johnson, Martin D.
Institution: University of Michigan
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 1997 through January 1, 2000
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1997) RFA Text | Recipients Lists
Research Category: Fellowship - Civil Engineering , Academic Fellowships , Safer Chemicals
Objective:
The objective of this research project is to contribute to the fundamental understanding of the mechanisms that cause slow and often irreversible desorption of contaminants from sediment materials. A rapid screening tool also will be developed to utilize subcritical water extraction to reveal a sediment's specific potential for releasing sorbed compounds.
Approach:
Phenanthrene has been selected as the probe hydrophobic organic contaminant for this research project. Canadian peat, Michigan peat, Chelsea soil, Lachine shale, and Norwood shale will constitute the natural sorbents representative of a broad range of soil organic matter characteristics. Sorption/desorption experiments will be performed to determine Freundlich isotherm coefficients for the sorbents, and correlations will be developed between soil organic matter macromolecular properties and isotherm parameters. The subcritical water extractability of sorbed phenanthrene from preloaded sorbents will form the basis for using the technique as a rapid screening tool. The rates and efficiencies of phenanthrene extraction will be interpreted from the desorption versus time data, and this information will be correlated to the soil organic matter characteristics. In addition, the subcritical water extraction system will be used to selectively remove the humic type organic matter from soil, and sorption/desorption studies will be conducted with the extracted soils. Extracted soil organic matter will be characterized by gas chromatography/mass spectrometry, and remaining organic matter will be characterized by solid-state 13C nuclear magnetic resonance spectroscopy. Phenanthrene isotherm experiments, with both the extracted and nonextracted soils, should reveal the specific contributions of the humic type organic matter to the sorption process.
Supplemental Keywords:
fellowship, phenanthrene, sorbed contaminants, subsurface systems, desorption, sediments, sediment materials, rapid screening tool, sorbed compounds, organic contaminant, soil organic matter., Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Waste, Water, Ecological Risk Assessment, Fate & Transport, Environmental Chemistry, Contaminated Sediments, Ecology and Ecosystems, Phenanthrene, contaminated sediment, desorption kinetics, fate and transport, supercritical water extraction, contaminant transport modelsProgress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.