Study of the regularities of cesium electrosorption by the activated carbon DAK

Abstract

The need of various fields of technology for salts of rare alkali metals actualizes the problem of the development of new ways for the recovery of these elements from various raw sources. In this work, the equilibrium and kinetics of cesium sorption on active carbon and its polarized derivative was studied using the batch mode. The regularities of sorption of cesium ions on the activated carbon DAK and the electrosorption at its cathode polarization have been investigated. It has been found that cesium adsorption on cathode-polarized carbon is satisfactorily described by the Langmuir isotherm. The comparison of experimental data on kinetics with different diffusion models allows to assume that the electrosorption process takes place in the mixed-diffusion mode. The electrosorption of some part of target component is irreversible, and the influence of chemical interaction of cesium with the carbon surface, which gives a contribution into the total rate of process, can be proposed. This is approved by good agreement between experimental results and the kinetic model for pseudo-second order.
Additional study is required for elucidation of the nature of comlexing functional groups responsible for chemisorption and the corresponding mechanisms in detail.