Abstract
The speciation of RC on various mineral clay and Fukushima samples were studied using batch method, modified BCR method and Cs LIII-edge extended X-ray absorption fine structure (EXAFS) technique. Modified BCR results showed that more than 65% of RC remained in the residual phase, whereas the exchangeable fraction took up about 15%. The fraction of carbonate could be negligible, whereas the organic matter fraction was ~8%. Cs sorption in illite+HA+Cs system was inhibited to some extent by HA, which might be contributed by blocking the interlayer by HA. EXAFS confirms that the presence of HA can change the speciation of Cs on mineral clays, especially in the HA-Cs-illite system. These findings provide the evidences on the contribution of organic matter to the increase of mobility of Cs in soil due to its blocking effect of interlayer of clay minerals.
