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The adsorption kinetics of Sb(V) ions onto a-Fe203 from a 0.25 mol dm"1 23 LiCl aqueous solution of pH 4.0 ± 0.1 was studied by using no-carrier-added 119Sb as a tracer. The concentration of Sb(V) was (1.1 ± 0.2) X 10"8 mol dm"3. The rate of the adsorption was proportional to the square of both the concentration of Sb(V) in the solution and the surface area of a-Fe203: dx/dt = k(ax)2b2, k = (2.3 ± 0.5) X 107 dm3 mol"1 m~4 56min"1 at 50 °C, where k, a, and b are the rate constant of adsorption, initial concentration of Sb(V), and surface area of a-Fe203, respectively. The activation energy of the adsorption was 37 kJ/mol. Desorption of U9Sb from the a-Fe203 surface at pH 4-10 was very slow. Tin(IV) ions in concentration up to 7 X 10"7 mol dm"3 were found to have no influence on the adsorption of 119Sb(V) ions onto a-Fe203. The adsorption capacity of the a-Fe203 sample for antimony(V) ions was determined to be 7 mg of Sb/g at 30 °C, which is much less than the calculated value (45 mg of Sb/g) from the BET surface area of the sample and by assuming monolayer adsorption.

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Concentration of 11 trace elements (Ca, Sc, Cr, Fe, Co, Zn, Rb, Cs, Ba, La, and Ce) in 96 pteridophytes (fern and fern ally species) was determined by instrumental neutron activation analysis to evaluate a concentration range for each element and also to find species characteristic in the uptake of trace elements. Asplenium trichomanes was found to accumulate Sc, Cr, and Co to the highest concentrations among 96 pteridophytes. The highest concentration of Ca and Zn was observed for Asplenium obscurum. The other Pteridophytes exhibited only one element whose concentration was the highest. A positive correlation was found between the concentrations of Fe and Sc, and also between the concentrations of Cr and Co. The remarkable accumulation of lanthanides (La and Ce) was observed mainly in diversifying genera (Polystichum and Dryopteris in Dryopteridaceae, Diplazium in Woodsiaceae, and Asplenium in Aspleniaceae).