Authors:H. Wang, S. Ambe, N. Takematsu, and F. Ambe
Using a radioactive multitracer and model acid rain (HCl or H2SO4 solution), batch experiments were performed to examine the pH effect on the adsorption-desorption equilibrium of 16 elements
on soils as a model study of an acid rain effect. Kaolin, black soil (original and with organic matter almost removed) and
Kureha soil (original and with organic matter almost removed) were used as adsorbents. Characteristic dependence on the pH
value of the suspension was observed for the adsorption of the elements on kaolin and the soils. The results of this model
study indicate that acid rain decreases the retention of cations, while it increases or does not change the adsorption of
anions on soils. Organic matter in soils has a positive effect on the extent of adsorption of most elements investigated.
Authors:S. Ambe, S. Chen, Y. Ohkubo, Y. Kobayashi, H. Maeda, M. Iwamoto, M. Yanokura, N. Takematsu, and F. Ambe
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.