LITHOSPHERE, 2002, No. 16, p. 131

The phosphorus compounds are extensively involved in colloidal hypergene processes, migrate and are accumulated in different forms and are radioisotope concentrators. They amount (% P₂O₅): 0.05-0.71 mg/l in peat sediments, 0.02-0.85 in plants, 0.005-0.372 mg/l in subsoil water. The phosphate-ferriginous mineralizations are abundant in river valleys with peat floodplain and are represented by vivianite, kerchenite, bosphorite, beraunite and phosphate ochers, which are often of colloidal and subcolloidal composition. The relation between phosphates and technogene and natural radioisotopes is discussed.

An experiment study of sorption and desorption of Sr-90 and Cs-137 by newly deposited amorphous calcium and iron phosphates and their minerals - vivianite and apatite has been carried out with an aim to ascertain the role of phosphorus compounds in radioisotope migration. At was shown that all the phosphates investigated have the high Sr-90 absorption capacity (90-95 %). Caesium-137 does not create any phases with calcium phosphate and amorphous iron compounds. Its sorption amount is about 30 % of the initial solution with vivianite only, as the latter shows a high desorption capacity (95-98 %). The strontium phosphates are characterized by a low desorption capacity (about 5 %), which is due to the hydroapatite Sr(H₂PO₄)2 formation, which is subsequently turned to hardly soluble Sr₁₀(PO₄)₆(OH)₂.

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