Abstract
We conducted this study to reduce radioactive cesium in tea plants that had been contaminated eleven or thirteen months earlier. The results obtained were as follows:
1) High-pressure washing was applied to tea leaves, twigs and branches contaminated with radioactive cesium at 7.5MPa of 1,200L/10a. However, no reduction of the amount of radioactive cesium was observed.
2) Tea branches contaminated with radioactive cesium were soaked in 1% acetic acid solution(pH=3.52), 1% sodium chloride solution(pH=6.84),1% sodium hypochlorite solution(pH=8.67) and 1% sodium carbonate solution(pH=10.77) for 5 minutes respectively and they were then washed in water after they had dried. However, no reduction in the amount of radioactive cesium was observed.
These results suggested that the radioactive cesium would exist not only on the surface of old tea leaves and branches but also in the innner part of them.
