Remediation of Barium Contaminated Soil By In-situ Immobilization
Heather D. Harle, Phyllis A. Leber, Kenneth R. Hess, and Claude H. Yoder
Journal of Chemical Education
A laboratory project, designed for the first-year chemistry course, is described that uses environmental chemistry to teach concepts and techniques such as solubility determination, precipitation reactions, and the use of qualitative and quantitative analysis for product characterization. The student determines the relative insolubilites of a series of barium salts and uses a suction-extraction technique to quantitatively determine their solubilties. The student then learns about a very insoluble double salt of barium, prepares the double salt, and quantitatively determines its solubility and percent composition. The reagents used to prepare the double salt are used in situ to tie-up barium in a sample of barium-contamined soil. Finally, the student determines the efficiency of the process by determining how much barium is retained in the soil after treatment. This laboratory experiment provides students with a firm basis in qualitative and quantitative analysis in the context of dealing with an environmental problem.