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Implementation of Solid Phase Microextraction (SPME) Polydimethylsiloxane (PDMS) Fibers for In-situ Performance Evaluation of Remediation Efforts at Contaminated Sediment Sites
Oral Presentation
Prepared by C. Thomas1, D. Lampert2, D. Reible3
1 - The University of Texas at Austin, 1 University Station , C1786, Austin, TX, 78712, United States
2 - Oak Ridge Institute for Science and Education, 9700 S Cass Ave, B109, Lemont, IL, 60439, United States
3 - Texas Tech University, 911 Boston Avenue, Lubbock, TX, 79409, United States
Contact Information: courtneyt713@gmail.com; 713-408-6885
ABSTRACT
PAH contaminated sediment sites pose a unique challenge in terms of remediation and monitoring for a variety of reasons including: the large number of past and ongoing sources, sediment stability, and the extent of contamination. Capping, an accepted remediation approach, with a clean sediment layer can reduce the risk posed by the fate and transport of contaminants by stabilizing the underlying sediments, isolating the water column, and reducing contaminant flux. Evaluating performance of a cap is challenging due to the long time frames associated with migration of PAHs. In addition, the non-sorbing nature of most caps limits the usefulness of bulk solid phase measurements. Here, the freely-dissolved contaminant concentrations can be measured using solid phase microextraction (SPME) profilers with polydimethylsiloxane (PDMS) as the receiving phase sorbent. Using SPME profilers, one obtains vertical concentration profiles that assist in the determination of the mechanisms and rates of transport within a cap. This approach has been used by Dr. Danny D. Reible’s University of Texas research group at a variety of contaminated sites across the continental United States. This presentation will summarize the implementation of the approach and results at several contaminated sediment sites to illustrate its utility and usefulness at evaluating sediment remedial performance, including protectiveness in terms of flux and bioavaliability. Additional topics covered in the presentation will include the most appropriate methods to evaluate the kinetics of uptake onto the SPME-PDMS fiber and demonstrations of those techniques under field conditions, and experiment quantifying the effects of key interferences in the technique including evaporation from the PDMS sorbent layer and the influence of dissolved organic matter (DOM) on the uptake of analytes.
Oral Presentation
Prepared by C. Thomas1, D. Lampert2, D. Reible3
1 - The University of Texas at Austin, 1 University Station , C1786, Austin, TX, 78712, United States
2 - Oak Ridge Institute for Science and Education, 9700 S Cass Ave, B109, Lemont, IL, 60439, United States
3 - Texas Tech University, 911 Boston Avenue, Lubbock, TX, 79409, United States
Contact Information: courtneyt713@gmail.com; 713-408-6885
ABSTRACT
PAH contaminated sediment sites pose a unique challenge in terms of remediation and monitoring for a variety of reasons including: the large number of past and ongoing sources, sediment stability, and the extent of contamination. Capping, an accepted remediation approach, with a clean sediment layer can reduce the risk posed by the fate and transport of contaminants by stabilizing the underlying sediments, isolating the water column, and reducing contaminant flux. Evaluating performance of a cap is challenging due to the long time frames associated with migration of PAHs. In addition, the non-sorbing nature of most caps limits the usefulness of bulk solid phase measurements. Here, the freely-dissolved contaminant concentrations can be measured using solid phase microextraction (SPME) profilers with polydimethylsiloxane (PDMS) as the receiving phase sorbent. Using SPME profilers, one obtains vertical concentration profiles that assist in the determination of the mechanisms and rates of transport within a cap. This approach has been used by Dr. Danny D. Reible’s University of Texas research group at a variety of contaminated sites across the continental United States. This presentation will summarize the implementation of the approach and results at several contaminated sediment sites to illustrate its utility and usefulness at evaluating sediment remedial performance, including protectiveness in terms of flux and bioavaliability. Additional topics covered in the presentation will include the most appropriate methods to evaluate the kinetics of uptake onto the SPME-PDMS fiber and demonstrations of those techniques under field conditions, and experiment quantifying the effects of key interferences in the technique including evaporation from the PDMS sorbent layer and the influence of dissolved organic matter (DOM) on the uptake of analytes.