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Partitioning Coefficients of BTEX Compounds Between NLF Leachate and Water. Jeremy T. Roop Dr. Mark A. Nanny Crystal K. Stearns. Overview. Background Goal Experimental Designs Results/future research. Background. Norman landfill Older landfill Inadequate liner
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Partitioning Coefficients of BTEX Compounds Between NLF Leachate and Water Jeremy T. Roop Dr. Mark A. Nanny Crystal K. Stearns
Overview • Background • Goal • Experimental Designs • Results/future research
Background • Norman landfill • Older landfill • Inadequate liner • Development of leachate plume • BTEX • Benzene, Toluene, Ethylbenzene and Xylene • Hydrophobic, Toxic and Soluble
Background (cont.) • BTEX compounds • Paints, solvents and gas • Present in NLF and other older municipal landfills
Goal: To quantify the partitioning coefficients of BTEX compounds between organic matter present in NLF leachate and water
How does organic matter in leachate interact with BTEX compounds? • BTEX partitions to organic matter • Def. Partitioning • Why is it important to quantify partitioning coefficients? • Shows partitioning to organic matter vs. partitioning to water • Allows prediction of chemical fate in environment
Solid Phase Microextraction • Technique used to measure free concentrations in solution • How it works • Analytes in solution partition to wick and equilibrium is reached • Once at equilibrium, amount on wick is constant • Wick can be exposed to GC for desorption
Benefits of SPME • Time saving • Accurate • Doesn’t involve solvents • Relatively inexpensive
Experimental Design • Goal: Quantify partitioning coefficients • Concept • Prepare solutions with various different leachate/toluene ratios • Determine amount of toluene partitioning by measuring free concentrations • Plot data • Free concentration vs. toluene/leachate ratio • Take slope of best fit line
Preliminary Results • Good data
Effects of Saturation • Runs with leachate • Saturated salt solutions effect sensitivity of SPME method • Increased conductivity of leachate was increasing sensitivity of method
Experimental Design II • Added NaCl to adjust conductivity of control samples • Preliminary data was good
More complications • Not reproducible • Increasing saturation of solution may effect kinetics of wick
Results and Conclusions • SPME is a good technique • Capable of accuracy • Lots of variables • Saturated salt solutions greatly effect sensitivity and accuracy of SPME
Future Research • Explore effects of conductivity on SPME technique • Fulvic acid experiment • Plenty of time • Automation-eliminate error and save time • Newer equipment, capable of greater degree of consistency
Acknowledgements • Dr. Mark A. Nanny and Crystal K. Stearns • Dr. Kolar, Lisa Hare, Erin Breetzke and OU REU • NSF EEC-9912319