Here, we suggest a theoretical approach to investigations of sorption kinetics based on determination of intrinsic characteristics of heterogeneous sorbents (affinity, quantity, and distribution of the sorption sites in the space of constants of sorption and desorption rates, distribution of the adsorbate on sorption sites at any arbitrary time, and the theoretical sorption isotherm) via calculation of the rate constant distribution (RCD) functions using experimental data obtained by the batch method. The effect of random errors in the experimental data on the stability of the calculated parameters was evaluated using simulation modeling that enables one to reduce time- and labor-consuming experimental procedures without loss in the reliability of sorbent characteristics. The applicability of the suggested approach to real experimental data was demonstrated on the sorption of transition metal ions on supermacroporous polyethylenimine cryogels. We have also shown how experimental conditions in the kinetics batch test affect determination of the sorption and desorption rates and calculation of the theoretical isotherm and how they can be optimized to yield reliable parameters to predict performance of supermacroporous monolith under dynamic conditions.