无机离子SO_4^(2-)对小麦幼苗积累稀土的影响

Influence of SO_4^(2-) on the Bioaccumulation of Rare Earth Elements in Wheat Seedling

采用ＭＩＮＴＥＱＡ 程序计算出在无机离子ＳＯ２－４ 存在下，轻（Ｌａ）、中（Ｇｄ）、重（Ｙ）３ 种稀土元素在溶液中的形态分布．研究了在水培条件下ＳＯ２－４ 对３种稀土元素在小麦幼苗根、茎和叶部的积累规律．热力学实验表明，小麦幼苗在加ＳＯ２－４ 的稀土元素溶液中培养３０ｄ 后，小麦根部对Ｌａ、Ｇｄ 的积累受抑制，而对Ｙ的积累却明显提高；加入ＳＯ２－４ 后茎叶部对Ｌａ、Ｙ积累值改变不明显，但对Ｇｄ的积累有所增加．生长动态实验表明，在ＳＯ２－４ 存在下，小麦幼苗根部对稀土的积累随时间增加而增加，其积累值符合线性递增函数方程，相关系数ｒ＞ ０．９４；而茎叶部最初积累能力较强，ＳＯ２－４ 的加入对小麦植株动态吸收稀土规律无明显影响．

The species of light (La)、medium(Gd)and heavy(Y)rare earth elements(REEs)with SO 2- 4 were calculated by MINTEQA procedure. The effects of SO 2- 4 on the bioaccumulation of three REEs in wheat seedling were investigated. The results showed that bioaccumulation values of La and Gd in roots became lower after adding SO 2- 4 in culture solution containing 2.0 mg/L REE, but the contrary law was obtained for Y. Bioaccumulation values of three REEs in tops(steam & leave)were only increased of Gd after adding SO 2- 4 respectively. Kinetic experimental results indicated that bioaccumulation values of REEs in roots in 30 days were correlated with the linear growth equation(correlation factors are higher than 0.94) in the culture solution containing 2.0 mg/L REE+0.01 mol/L SO 2- 4 , and those in tops were higher in initial culture time. The influence of the adding SO 2- 4 on the law of wheat seedling absorbing REEs is not obvious.