| Abstrakt: |
Regulation of the equilibrium of ion exchange processes on inorganic sorbents refers to the control of the sorption capacity and selectivity of the sorbent by regulating equilibrium conditions such as temperature, pH, concentration of sorbate, and other competing ions. By controlling these factors, it is possible to control the sorption of ions on inorganic ion exchangers for various applications, such as water purification, chemical separation, and the separation of individual ions from natural or process solutions. The ion exchange isotherm is the equation that describes the equilibrium of the ion exchange process during the absorption (sorption) or release (desorption) of specific ions from an aqueous solution. It determines the equilibrium of the ion exchange process, both sorption and desorption, connecting the amount of transfer of a substance from the aqueous medium to the solid phase at constant pressure, temperature, pH, and other external and internal conditions. This article discusses three methods for reversing ion exchange processes on inorganic sorbents. The first of them is based on a change in the charge of the sorbent matrix, the second on the use of complexing agents, and the third on displacement and equilibrium through the use of salts of weak acids or weak bases. The influence of the buffer properties of a solution on the equilibrium of ion exchange on inorganic sorbents was studied. Based on these ideas, methods have been developed to regulate the equilibrium of sorption processes on inorganic sorbents based on the binding of one of the ions participating in the sorption process into a weakly dissociating compound and changing the charge of the sorbent matrix. An essential factor in the operation of inorganic ion exchange sorbents is the potential for chemical destruction of inorganic sorbents under the influence of external and internal factors. The most radical measures to reduce these losses can be taken when selecting the starting compound for the sorbent manufacture and at the chemical synthesis stage. These factors are considered using the example of lithium-selective sorbents based on manganese oxide, which exhibits structural and external aspects of chemical instability. Their example shows the possibility of controlling the properties of such sorbents from the point of view of their chemical stability. The influence of the Jahn-Teller effect on the chemical stability of inorganic ion-exchange sorbents based on manganese oxide compounds selective for lithium ions was determined. Based on these studies, methods were proposed and tested to ensure the multi-cycle operation of highly selective inorganic ion exchange materials. [ABSTRACT FROM AUTHOR] |
