1. Graduate Student, Dept. of Civil Engineering, 500 Pillsbury Dr. SE, University of Minnesota, Minneapolis, MN 55455.
2. Graduate Student, Dept. of Chemistry, 207 Pleasant St. SE, University of Minnesota, Minneapolis, MN 55455.
3. Laboratory Fellow, Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O, Box 999, Richland, WA 99352.
4. Joseph T. and Rose S. Ling Professor, Dept. of Civil Engineering, 500 Pillsbury Dr. SE, Univ. of Minnesota, Minneapolis, MN 55455 (corresponding author).
5. Associate Professor, Dept. of Chemistry, 207 Pleasant St. SE, Univ. of Minnesota, Minneapolis, MN 55455.