ABSTRACT
This study was undertaken to evaluate and compare the leachability of Cd, Ni, Cr, and As in ash disposal basins of different ages located at the U.S. Department of Energy (DOE) Savannah River Site. Intact ash cores were removed from the basins and leached in two successive pulses with solutions of varying pH and redox status. The leaching under all of the experimental conditions resulted in the slow release of metals from the ashes. Nickel was the most mobile and Cd was the least mobile. All of the metals examined were released in the highest amounts by leaching under reducing conditions in cores from both the new and old ash disposal sites. The amount of metal released was kinetically controlled under the leaching used. Although the amount of metal released from cores from the new basins was typically greater than those from the old, measurable amounts of metal continued to be released from the old basin-ash cores even after weathering for over 10 years.
