玉米-土壤和大豆-土壤体系中^(95)Zr的消长动态  

Dynamics of Accumulation and Disappearance of Zirconium-95 in the Maize/Soil and Soybean/Soil Ecosystem

作　　者：史建君[1] 陈晖[2] 

机构地区：[1]浙江大学原子核农业科学研究所(华家池校区)农业部核农学重点开放试验室,杭州310029 [2]浙江工程学院基础部,杭州310033

出　　处：《环境科学》2002年第3期97-101,共5页Environmental Science

基　　金：国家自然科学基金资助项目 (批准号 :39970 14 7)

摘　　要：采用模拟污染物的同位素示踪技术进行了95Zr在 2种作物 土壤体系中的消长动态研究 ,并应用库室模型和非线性回归方法确定了各体系的拟合方程 .结果显示 :①玉米和大豆从土壤中吸收的95Zr主要集中在根部 ,且根部中的95Zr比活度随时间呈缓慢增加 ,并在经历一段时间后逐渐趋于动态平衡 ;其余各部位的比活度较低 ,较大部分接近于本底水平 ,表明95Zr被玉米和大豆根系吸收后不易在其体内迁移、输运 ;②喷施进入土壤中的95Zr主要滞留在表层 (0～ 8cm)土壤中 ,其量占总量的 97 5 %以上 ,表明95Zr被表层土壤吸附 ,不易随水流向下迁移 ;③对实验数据进行回归分析 ,得玉米和大豆植株中95Zr比活度的消长动态拟合方程为Cm(t) =3 2 0 67(1 -e- 0 .1582t)和Cb(t) =3 0 92 5 (1 -e- 0 .136 3t) ,经方差分析 ,表明回归方程较好地反应了95Zr在玉米 土壤和大豆The dynamics of accumulation and disappearance of 95 Zr in two kinds crop soil ecosystem was studied by using isotope tracer techniques for simulated pollutants, and the fitting equation was confirmed by application of the closed tow compartment model and nonlinear regression method. The results showed: ① The Zirconium 95 absorbed from soil main retention in root of the maize and soybean, and the specific activity of 95 Zr in root increased with time slowly, then tended dynamics balance gradually after a period of time. The specific activity of rest parts was lower,and biggish parts were background activity level, which indicated that the 95 Zr absorbed by roots was difficult of transference and transportation in the maize and soybean. ② The 95 Zr in soil main retention in surface layer soil(0～8cm),and the rate of it's activity and total activity>97 5%, which indicated that the 95 Zr absorbed by surface soil could not readily move downwards with percolating water. ③ The regression equation of accumulation and disappearance of 95 Zr in the maize and soybean were C m( t )=3 2067(1-e -0.1582 t ) and C b( t )=3 0925(1-e -0.1363 t ) by analyzing the experiment data with exponential regression method. The results of squared deviations analyzing indicated that each regression equation could describe the dynamics of accumulation and disappearance of 95 Zr in the maize soil and soybean soil ecosystems preferably.

关 键 词：^95ZR 玉米 大豆 消长动态 非线性回归 放射生态学 

分 类 号：X591[环境科学与工程—环境工程]