EFFECT OF INDUCED AGGREGATION OF SOIL MATERIALS ON THE CHEMICAL EXTRACTABILITY OF Sr90 AND Pm147 CONTAMINANTS

Laboratory experiments were conducted to determine the effect of induced aggregation of soil materials on the chemical extractability of Sr90 and Pm147 contaminants in the soil. Four different binding agents (Portland cement, ferrous sulfate, sodium silicate, and polyester coating resin) were used to induce soil aggregation. In general, each binding agent increased the water-extractable fraction of Sr90, while it decreased the NH4OAc-extractable fraction. The increase of the water-extractable fraction was due to exchange displacement during the interaction of the soil particulates and the binding agent. The decrease of the NH4OAc-extractable fraction was considered to be due to the blocking action resulting from the interaction of soil particulates and the binding agent. The extractability of Pm147 differed from Sr90 in that the NH4OAc-extractable fraction was increased by FeSO4and the water-extractable fraction was decreased by the resin treatment. Several reasons for these effects are given.