Abstract
A small system was developed for volume reduction of radiocesium-contaminated soils. Included in this system was a 100-L air-lift washing chamber, a coagulation tank, and a dewatering apparatus. Soil samples (137Cs 6.2×103 - 1.9×104 Bq/㎏) collected from a parking area in Iitate village, Fukushima Prefecture were put through this soil washing chamber. Results showed that 14-17% (dry weight) of the soil particles were ideally recovered with 75-86% of 137Cs (3.0×104 - 7.4×104 Bq/㎏)．Soil samples collected from an area with bamboo bushes, showed that 53-55% of the soil particle's weight were recovered with 87-89% of 137Cs (3.0×104 - 7.4×104 Bq/㎏)．Soil samples collected from a farm load and ditch in Kawauchi village (1.0×103 - 7.3×103 Bq/㎏) were treated by soil washing, coagulation, and dewatering in series. Results showed that 10-14% weight of the soil particles were recovered as dewatered cake (4.4×103 - 3.1×104 Bq/㎏) with only 43-46% of 137Cs. These results confirm soil-characteristic-dependency from the volume reduction efficiency of radiocesium-contaminated soils.
