^(95)Zr在水—土体系中的消长动态研究

DYNAMICS OF ACCUMULATION AND DISAPPEARANCE OF ZIRCONIUM-95 IN WATER-SOIL SYSTEM

采用同位素示踪技术进行了95Zr在六种水—土体系中的消长动态研究 ,并应用非线性回归方法确定了各体系的拟合方程。结果显示 :1 .水体中的95Zr比活度起初随时间呈快速下降 ,而后逐渐趋缓 ,不同水—土体统中的下降速率各不相同 ,表明底泥对95Zr有强烈的吸附作用 ,其吸附强弱顺序为 :泮畈红壤 >海盐红壤 >青紫泥 >小粉土 >海泥 >黄沙 ;2 .底泥中95Zr的比活度随时间呈同步增加 ,并在经历一段时间后达到一平衡值 ,不同底质土壤达到平衡的时间各不相同 ,其平衡时间的大小顺序为 :海盐红壤 (1 3.1 0d) <泮畈红壤 (1 5 .53d)<黄沙 (1 5 .64d) <青紫泥 (1 7.85d) <小粉土 (2 0 .65d) <海泥 (2 1 .46d) ;3 .对各体系的消长动态拟合方程进行方差分析 (测定系数r2 、置信区间 ) ,表明各回归方程较好地反应了95Zr在水体和底质土壤中的行为过程。

The dynamics of accumulation and disappearance of 95 Zr in six kinds of water soil systems was studied by using isotope tracer technology, and the fitting equation was confirmed by application of nonlinear regression method. The results showed. 1.The specific activity of 95 Zr in water was reduced quickly in the beginning and then tended to slow down gradually. The descend velocity differed from one water soil system to another. This indicated that the sludge of riverbed had strong capability of adsorption to 95 Zr which was as follows: panfan red soil>red yellow earth>blue purple clay>paddy soil>sea mud> sand. 2.The specific activity of 95 Zr in sludge of riverbed increased synchronously with time and reached a counterbalance after a period of time. The balancing time of different soils differed in the following order: red yellow earth(13.10d)<panfan red soil(15.53d)<sand(15.64d)<blue purple clay(17.85d) <paddy soil(20.65d)<sea mud(21.46d); 3.The differentiation analysis(the determine coefficient r 2 and confidence interval) of the fitting equation of dynamics of accumulation and disappearance in each system indicated that each regression equation could describe the behavior process of 95 Zr in water and bottom soils more efficiently.