Y. Fujikawa et M. Fukui, RADIONUCLIDE SORPTION TO ROCKS AND MINERALS - EFFECTS OF PH AND INORGANIC ANIONS .1. SORPTION OF CESIUM, COBALT, STRONTIUM AND MANGANESE, Radiochimica Acta, 76(3), 1997, pp. 153-162
Sorption of Cs-137, Sr-85, Mn-54 and Co-60 to rocks (metamorphosed che
rt and shale, and granodiorite) and minerals (hematite, magnetite and
calcite) was investigated in 0.001 N, 0.01 N and 0.1 N solutions of Na
2SO4, NaCl, Na2CO3 and NaHCO3. The effects of pH and co-existing anion
s on the sorption of these radionuclides are discussed in terms of sur
face complex formation. Increase in the sorption of Cs in the presence
of SO42- ions is explained by preferential formation of a ternary com
plex, such as =M-SO4-Cs. Sorption of Sr increases as the pH increases
irrespective of background-anion type at the same electrolyte normalit
y. On the whole, the sorptions of both Co and Mn increase as the pH in
creases, but sorption in a highly basic Na2CO3 solution sometimes is l
ess than that in a solution of lower pH. Hydrolysis is considered to h
ave occurred in the Na2CO3 solution, thereby generating weakly sorbed
species of Mn and Co.