Adsorption kinetics of [formula omitted] and [formula omitted] over macroreticular and gel type adsorbents by a generalized ZLC method

Abstract

In this paper, we propose an alternative approach to the zero length column (ZLC) method by exploiting the practical advantages of the ZLC method in combination with the advantages of a more generalized dynamic model over the adsorbent layer and its adsorbent particles. The adsorption kinetics are modeled by a mathematical model for both mono- and bidispersed particles. In contrast with the usual ZLC methods, where adsorption in the macropores is neglected, our model allows for possible adsorption in macro- and/or micropores. Also, our model allows for non-linear adsorption isotherms. By this approach, we were able to determine the diffusivity of CoCl 2 into bidisperse macroreticular Amberlyst A21 and monodisperse gel type polymerbound PPh 3 and of PPh 3 in bidisperse macroreticular Ag + functionalized Amberlyst 15 by fitting the theoretical model to experimental data. It was found for CoCl 2 that: (1) adsorption in both macro- and micropores contribute to the uptake in macroreticular Amberlyst A21 and (2) its diffusion into the gel matrix of polymerbound PPh 3 is slower. PPh 3 only adsorbs in the macroporous structure of Ag + functionalized Amberlyst 15, because its microparticles are not accessible to PPh 3 .