Kinetics of humic acid (HA) adsorption onto soil minerals (kaolinite and hematite) has been investigated under various conditions. The influence of ionic strength, pH, and solution cations on the rate of adsorption has been studied. The rate and the amount of adsorbed humic acid onto soil minerals increased with increasing ionic strength, decreasing pH, and in the presence of Ca(2+) as background electrolyte. The adsorption equilibrium data showed that adsorption behavior of humic acid could be described more reasonably by Freundlich adsorption isotherm than Langmiur adsorption isotherm. Pseudo first order and pseudo second order kinetic models were used to evaluate the kinetic data and the rate constants. The results explained that humic acid adsorption on hematite and kaolinite was more conforming with pseudo second order kinetics.

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Kinetics of the decay of methyl cellulosemanganate(VI) intermediate polysaccharide 22 ] have been followed spectrophotometrically in different strong basic solutions at different temperatures, as well as, in the presence of different concentrations of perchlorate salt. The reaction is base-catalyzed. Salt never affects the reactivity. The activation parameters have been evaluated and discussed in connection with the proposal mechanism.

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