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  • Author or Editor: M. Yanokura x
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Abstract  

Environmental effects on plants caused by geothermal resource development were studied. Neutron activation method was found most suitable for this kind of multi-element analysis, and 24 elements could be identified and determined without any chemical separation. When the amounts of chemical elements detected in plants were plotted against the distance from the source well, clear correlations sould be observed for Na, Cl, Rb, Cs, As and Sb. Those turned out to be the elements especially concentrated in the geothermal hot water. From the present studies it was concluded that plants growing within the radius of 300 to 400 meters from the source well were affected by chemical pollutants carried over by mist particles.

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Abstract  

Environmental effects of geothermal waste water discharged into the neighbouring streams were investigated by ordinary chemical analyses and by the neutron activation method. Results show that serious effects of a large amount of discharge in the past are still retained in the sediments of the near-by water system. It was also found that As and Cs are the best chemical species for tracing the long-standing effects of past discharge.

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Abstract  

Transport and distribution of metal ions in rice and soybean plants were studied using multitracers produced by irradiating an Au target by 135 MeV/nucleon12C,14N, or16O ions accelerated by RIKEN Ring Cyclotron. The multitracer consisted of radioisotopes of the following elements: Be, Na, Sc, Mn, Fe, Co, Zn, Se, Rb, Sr, Y, Zr, Nb, Ag, Te, Ba, Ce, Pm, Eu, Gd, Tb, Tm, Yb, Lu, Hf, Ir, and Pt. Rice and soybean plants were grown in a nutrient solution and also on soil containing a multitracer. -ray spectroscopy of different parts of the plants showed that all the elements were more or less taken up by roots, while appreciable transport to leaves and seeds was observed only for Mn, Zn, Se, Rb, Sr, and Ba.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Ambe
,
S. Chen
,
Y. Ohkubo
,
Y. Kobayashi
,
H. Maeda
,
M. Iwamoto
,
M. Yanokura
,
N. Takematsu
, and
F. Ambe

Abstract  

We established Multitracer, a new versatile radiotracer technique, for simultaneous tracing of a number of elements in various chemical, environmental, and biological systems. Metal foil targets (typically Au, Ag, Ge, Cu and Fe) are irradiated with C, N, or O ions accelerated up to 135 MeV/nucleon by RIKEN Ring Cyclotron. Radiochemical procedures have been developed to remove the target material leaving the nuclides as Multitracer solutions containing various radionuclides of Be, Na, Mg, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Te, I, Ba, Ce, Pm, Eu, Gd, Tb, Tm, Yb, Lu, Hf, W, Re, Os, Ir, Pt, and Hg. Multitracers enable efficient tracing of a number of elements, and comparison of their behavior under strictly identical experimental conditions. Such features will be demonstrated by means of an example of application to a model experiment for the study of removal mechanism of various elements from the ocean.

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