@inproceedings{oai:repo.qst.go.jp:00053657,
 author = {Nakamaru, Yasuo and Tagami, Keiko and Uchida, Shigeo and 中丸 康夫 and 田上 恵子 and 内田 滋夫},
 book = {Waste Management Symposium Proceedings},
 month = {Jun},
 note = {Desorption levels of soil-sorbed Se by adding phosphate (P) ion were studied for 10 typical Japanese agricultural soils. Soil-solution distribution coefficients of Se (Kd-Se) were measured using the batch technique as an index of Se sorption level in the batch process, Se-75 was added to the soils as a tracer. After the Kd measurement, added Se-75 was extracted by a 0.1 M or 1 M Na2HPO4 solution to determine the amount of Se-75 desorbed by the P. When the 0.1 M Na2HPO4 solution was used, 18-57% of sorbed-Se was extracted into the solution (average: 41%). The percentage of Se extracted with the 1 M Na2HPO4 solution was 1.1-1.5 times higher than the percentage extracted with 0.1 M Na2HPO4 for which 27-71% of sorbed-Se was extracted (average: 50%). The observed desorption rates of Se indicated the existence of an upper limit to the Se desorption by P addition. The desorption percentage of Se increased with increasing Kd values, suggesting that the soil with higher Kd-Se contains more reactive components for phosphate-sorption than the soil with lower Kd-Se. To evaluate the effect of phosphate concentration on the Se sorption, the Kd-Se was measured for two typical soils under different levels of P (0.1-20 mM PO4). The Kd value decreased by P addition for both soils. The Kd decrease was observed even for just 0.1 mM P. The P addition with 0.1 mM P corresponded to 0.3 g P per kg dry soil, which is the same level as in phosphate fertilizer applied to paddy fields in Japan. Therefore, it was suggested that Se desorption should occur in Japanese soils due to the phosphate input.},
 title = {Effect of phosphate addition on the desorption of Se from soils},
 volume = {31},
 year = {2005}
}