TREATABILITY TESTING TO EVALUATE WHAT CAN WORK

A soil sample from the Idaho National Engineering Laboratory was physically and chemically characterized, then sequentially extracted to determine if soil washing could be effectively used to remove cesium, cobalt, and chromium. The contaminant distribution did not correlate with surface area or any particular crystalline phase. However, the transition metals did appear to be coincident with the matrix transition metals, iron and manganese. This finding was verified by sequential-extraction data, which showed that most of the cobalt and chromium was extracted by destroying the soil hydrated metal-oxide phases. Unfortunately, <20% of the cesium was extractable even after dissolving >20% of the soil mass. The low recovery of cesium, the primary risk-driver, eliminated extractive soil washing from further consideration for this site.