Effect of the Organic and Mineral Constituents of Sapropels from Belarus Republic on the Selective Sorption of Radiocesium

Abstract

The radiocesium interception potential (RIP) characterizing the ability of a sorbent to retain ¹³⁷Cs⁺ cations in the presence of competing K⁺ or NH₄⁺ cations [RIP(K) or RIP(N)] under the conditions controlled by selective sorption was determined for various materials. RIP(K) (mg-equiv kg^–1) is 44–720 and 260–1200, and RIP(N), 21–189 and 96–250 for sapropels of the organic and silica types, respectively. For sapropels of the organic type, the selectivity coefficient K_s(N/K) for the ¹³⁷Cs-selective sorption sites varies from 2.1 to 3.8, and for silica sapropels (Lake Dobeevskoe) it reaches 4.5–4.8, suggesting the presence of illite-type particles, which significantly influence the ¹³⁷Cs uptake by these types of sapropels. The highest RIP(K) values for the sapropels studied are reached at the organic to mineral matter ratios in the interval 0.43–0.61.