[Leaching and vertical transport of Zirconium-95 in soils]

The leaching and vertical transport of Zirconium-95 in three representational soils (paddy soil, red-yellow earth and sea mud) in Zhejiang province and the influence of salinity on the activities of Zirconium-95 in sea mud were studied with soil-pole installation. The results show that: 1. The content of Zirconium-95 in collected leachate was low after passing through soil column with 250 ml, 500 ml, 750 ml leaching amount. The amount of Zirconium-95 in collected leachate of paddy soil, sea mud and red-yellow earth was about 5.33%-7.68%, 0.77%-1.32% and almost 0 of labelled amount respectively. And with increasing the total amount of leaching water, the content of Zirconium-95 in collected leachate varied indistinctively, which indicated that once Zirconium-95 was absorbed by soils, it was very difficult to desorb. 2. In paddy soil, red-yellow earth and sea mud, 45.99%-50.02%, 96.02%-97.16% and 95.94%-98.01% radioactivity of Zirconium-95 was concentrated in the 0.4 cm upper layer soils respectively, which illustrated that most of Zirconium-95 remained in the surface soils. 3. With the increase of salinity in leaching water, the amount of Zirconium-95 in surface soils (0-0.2 cm) presented obviously increased, which demonstrated that increasing salinity could raise the adsorption rate of Zirconium-95 in soils.