Kinetics and Equilibrium of the Ion Exchange of Cd2+at Na-montmorillonite: Analysis of Heterogeneity by Means of the Regularization Technique CONTIN

Effect of Pore Clogging on Kinetics of Lead Uptake by Clinoptilolite

“…Ion exchange kinetics on zeolites have been investigated experimentally and several models have been proposed. Evidence in the literature about the rate-controlling step is given by Boyd et al (10), and particle diffusion, film diffusion, or chemical reaction are proposed to control the overall kinetics (11)(12)(13)(14). These attempts, however, as well as numerous later investigations on ion exchange kinetics, refer to synthetic ion exchange media, mainly chelating resins.…”

Reaction rates of heavy metal ions at goethite: relaxation experiments and modeling

“…Eqs. (8). For simplicity we have left these terms out, since their contributions turned out to be negligible in all cases.…”

“…The calculation of the reaction rate coefficients is performed by solving Eqs. (4)- (8) and Eqs. (C4)-(C6) from [2].…”

“…The first one is the nonnegativity of S(µ), and the second one is the smoothness of S(µ). The analysis is then performed by the regularization method described in detail in [8][9][10][11]. The result is a kinetic spectrum S(µ) plotted vs log µ, consisting of one or several modes, which contribute to the overall observed relaxation behavior.…”

“…If in an experiment more than one relaxation effect is to be expected, or if distributions of relaxation effects occur, it is convenient to analyze the kinetic modes by means of the kinetic spectrum method [8]. The basic idea is to set up the integral rate equation:…”