The absorption of atmospheric radionuclides by soybean plants was experimentally studied using a radioactive multitracer consisting of radionuclides of Sc, Mn, Co, As, Se, Rb, Sr, Y, Eu, Gd, Yb, Hf, Re, and Ir. The soybean plants were cultivated in soil under no-rain conditions in a box containing air in which multitracer-absorbed cellulose particles were dispersed. The soil was covered with plastic film. After about one-month cultivation, the plants were harvested and washed with dilute HCl solution. The leaves, stems, and beans were subjected to γ-ray measurement. The radionuclides of As, Se, and Re were accumulated in the leaves, and those of Co, Se, and Rb were accumulated in the beans. Among them Se was accumulated to a large extent in the leaves and in the beans. Small amounts of the radionuclides of Co, Se, Rb and Re were found in the roots. Little absorption of these radionuclides into the soil occurred. These results indicate that various radionuclides in the atmosphere were absorbed through the soybean leaves and then transported to the seeds. These findings must be taken into consideration for a complete understanding of the system of uptake of radionuclides by the soybean plant.

A great deal of research has been directed towards the problem of reduction and control of volatile organic compounds (VOCs). The aim of this research is to find a process that is both efficient and inexpensive in comparison with traditional air treatment technologies.Our biofilter (one stage system, 2 m in height) is an aerobic system for waste gases containing VOCs using the degradation properties of microbial flora (assorted cultures of Bacillus, Micrococcus, Acinetobacter and yeast). In this process, polluted gas diffuses across a filter bed into which a microbial culture has previously been introduced. Peat is the medium of choice for inoculation with microorganisms because of its adsorption and absorption properties, ability to retain moisture, and buffering capacity. Furthermore, the peat utilized is spherical in shape; thus, it is possible to avoid problems related to compacting.The objective of this study was to eliminate VOCs emitted from a rotogravure process. We were able to achieve promising results from biofiltration of two types of VOCs (a mixed solvent containing isopropyl acetate and 1-nitropropane, and the solvent: 1-nitropropane). The results obtained indicate that the elimination of nitropropane and the mixed solvent in the biofilter are considered to follow zero-order kinetics with reaction rate limitation and diffusion rate limitation, respectively.