SORPTION OF HEAVY-METALS AND METAL-PRECUR RORS OF LONG-LIVED RADIONUCLIDES ON HUMIC ACIDS .1. SORPTION OF CESIUM(I), STRONTIUM(II), CERIUM(III), AND RUTHENIUM(IV)

Sorption of metal-precurrors of the long-lived radionuclides Cs-137, S r-90, Ce-144, and Ru-206 on ashless samples of humic acids extracted f rom peat of the Moscow district was studies. The procedure for extract ing humic acids was improved, and the ash content of samples was reduc ed nearly by two orders of magnitude. The order of sorption of the ion s proves that complex formation contributes considerably to the sorpti on. The sorption capacities of humic acids (mg-equiv./g HA) were calcu lated from sorption isotherms: Cs(I), 0.22; Sr(II), 0.40; Ce(III), 0.6 6; and Ru(IV), 0.32.