Stationary Redox Sorption of Oxygen Dissolved in Water on Granular Layers of Copper-Ion-Exchange Nanocomposites

Abstract—The process of redox sorption of oxygen dissolved in water on cathodically polarized granular layers of copper-ion-exchange nanocomposites was studied depending on the water flow rate and the value of the polarizing current. It is noted that initially the amount of absorbed oxygen exceeds the amount of electricity that passed. Over time, the chemical activity of the nanocomposite decreased, and oxygen continued to be sorbed and further restored mainly due to the current component of the process. It was concluded that the simultaneous increase in the water flow rate and the maximum permissible current strength has a beneficial effect on the rate of oxygen absorption. Maintaining a constant water supply mode and corresponding current strength provides a steady flow of diffusion and chemical and electrochemical stages. It has been established that the successive stages of external diffusion transfer of oxygen to the surface of nanocomposite grains, internal diffusion transfer of oxygen through grain pores, and chemical oxidation of copper nanoparticles to oxides, which is characteristic of final sources, are compensated by the stages of electroreduction of oxygen from surface adsorbed complexes and regeneration of oxidation products into metallic copper nanoparticles. The nanocomposite is a continuous source of freshly reduced metal particles and promotes the process of oxygen redox sorption to reach a steady state. Unlike the unpolarizable granular layer, the oxygen concentration remains at a low constant level under conditions of the maximum permissible imposed electric current.