Changes in the adsorption patterns of radioactive cesium by litter during the litter decomposition in forest floor

Abstract

Changes in the adsorption patterns of the ¹³⁷Cs by litter was investigated in the test site of organic horizon removal in Yamakiya District of Kawamata Town, Fukushima Prefecture, using litterbag method and sequential extraction experiment. ¹³⁷Cs concentration of litterbag was increased from May to October. Unavailable form of ¹³⁷Cs increased from 17% in May to 76% at control site and 89% at organic horizon removal site in October. Immobilization of ¹³⁷Cs is considered to be caused by uptake by fungi and fixation by clay minerals, which was introduced into the litterbag by the work of the removal of organic horizon.