[en] The adsorption-exchange equilibrium time and the adsorption isotherms of UO₂²⁺, ¹³⁷Cs, ¹⁶⁹Yb and HPO₄^2- on modified peat have been investigated by batch experiments. The effect of pH on the adsorption-exchange percentage (E) and the distribution coefficients (K_d) was also examined. It was found that the adsorption-exchange of UO₂²⁺ and ¹⁶⁹Yb on the modified peat was described well by Freundlich isotherm, whereas the adsorption-exchange of ¹³⁷Cs and HPO₄^2- on modified peat corresponded to a Langmuir isotherm and the maximum adsorption capacities of the modified peat for ¹³⁷Cs and HPO₄^2- ions were 4.4 and 4.1 μg/g, respectively. The optimum pH for the adsorption-exchange of UO₂²⁺, ¹³⁷Cs, ¹⁶⁹Yb and HPO₄^2- on the modified peat was 7.0 at 25 deg C. (author)