Nakamaru Yasuo, Tagami Keiko, Uchida Shigeo
Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba-shi 263-8555, Japan.
Chemosphere. 2005 Mar;58(10):1347-54. doi: 10.1016/j.chemosphere.2004.09.086.
In order to evaluate the selenium (Se) sorption level in Japanese soils, soil/soil solution distribution coefficients (K(d)s) were obtained for 58 agricultural soil samples (seven soil classification groups) using 75Se as a tracer. Although several chemical forms of Se are present in agricultural fields, selenite was used, because it is the major inorganic Se form in acid soils such as found in Japan. The Kd values obtained covered a wide range, from 12 to 1060l/kg, and their arithmetic mean was 315l/kg. Among the soil groups, Andosols had higher Kd values. The Kd values for all samples were highly correlated with soil active-aluminum (Al) and active-iron (Fe) contents. Thus, active-Al and active-Fe were considered to be the major adsorbents of Se. Then, a new sequential extraction procedure was applied to 12 soil samples in order to quantify the effect of soil components on Se adsorption. The sequential extraction results showed that 80-100% of the adsorbed Se was recovered as Al-bound Se and Fe-bound Se. The amount of Al-bound Se was the highest in the soils that showed high Kd values, though the relative contribution of Fe-bound Se tended to increase with decreasing Kd values. The high values of Kd seemed to be caused mainly by the adsorption of Se onto active-Al in Japanese soils.
为了评估日本土壤中硒（Se）的吸附水平，以75Se为示踪剂，对58个农业土壤样品（七个土壤分类组）测定了土壤/土壤溶液分配系数（K(d)s）。尽管农田中存在多种化学形态的硒，但使用亚硒酸盐，因为它是日本酸性土壤中主要的无机硒形态。得到的Kd值范围很广，从12到1060l/kg，算术平均值为315l/kg。在土壤组中，火山灰土壤的Kd值较高。所有样品的Kd值与土壤活性铝（Al）和活性铁（Fe）含量高度相关。因此，活性铝和活性铁被认为是硒的主要吸附剂。然后，对12个土壤样品采用了一种新的连续提取程序，以量化土壤成分对硒吸附的影响。连续提取结果表明，80%-100%的吸附硒以铝结合硒和铁结合硒的形式回收。在Kd值高的土壤中，铝结合硒的含量最高，尽管铁结合硒的相对贡献倾向于随着Kd值的降低而增加。Kd值高似乎主要是由于日本土壤中硒吸附到活性铝上所致。
