95Zr在土壤中的淋溶与垂直迁移

采用土柱法研究了⁹⁵Zr在浙江省有代表性的3种土壤(小粉土、红黄壤和海泥)中的淋溶和垂直迁移及盐度对其行为的影响.结果显示:①淋溶后收集到的全部淋溶水中95Zr的含量较少,250ml、500ml和750ml 3种不同淋溶水量下,小粉土约占原始引入量的5.33%～7.68%,海泥为0.77%～1.32%,红黄壤几乎为0;且随着总的淋溶水量的增加,被淋溶下的⁹⁵Zr的总量变化不明显,表明⁹⁵Zr一旦被土壤吸附,则不易被解吸;②滞留于土壤中的⁹⁵Zr绝大部分分布在土壤表层,小粉土约有45.99%～50.02%的⁹⁵Zr滞留于0～0.4cm土层范围内,红黄壤和海泥则分别为96.02%～97.16%和95.94%～98.01%;③随淋溶水盐度的增加,表层土(0～0.2cm)中⁹⁵Zr的量明显提高,表明水体盐度增加有助于提高土壤对⁹⁵Zr的吸附率

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.