The K+ adsorption kinetics of fluvo-aquic soil and cinnamon soil under different temperatures were studied. The results showed: 1) The first order equations were the most suitable for fitting the adsorption under various temperature levels with constant K+ concentration in displacing fluid. With temperature increasing, the fitness of Elovich equation increased,while those of power equation and parabolic diffusion equation decreased; 2)the apparent adsorption rate constant ka and the product of ka multiplied by the apparent equilibrium adsorption q∞ increased when temperature increased, while the apparent equilibrium adsorption q∞reduced; 3)temperature influenced hardly the reaction order, the order of concentration and adsorpton site were always 1 under various temperatures, if they were taken into account simultaneously, the adsorption should be a two-order reaction process; 4)the Gibbs free energy change A G of potassium adsorption were negative, ranged from -4 444.56to -2 450.63 Jmol-1,and increased with temperature increasing, while enthalpy change A H,entropy change A S, apparent adsorption activation Ea, adsorption activation energy E2 and desorption activation energy E2 were temperature-independent; 5)the adsorption was spontaneous process with heat releasing and entropy dropping, fluvo-aquic soil released more heat than cinnamon soil.
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