Modeling of Ni2+ exchange on the strong acid ion-exchange resin and the organic-inorganic ion exchanger

Abstract

Currently, for calculations of processes in the ion-exchange columns is used the model which require the use of parameters such as diffusion coefficients of the ions in solution and the ion exchanger, exchange capacity, selectivity coefficients, and particle size of the ion exchanger and bed height, velocity of the solution. The greatest difficulty is the definition of the diffusion coefficient of exchanging ions in the ion exchanger, as this parameter varies with the degree of substitution of the resin and is very dependent on the presence of other ions in solution. In this regard, the actual task is creating a formalized process model in a dynamic mode, which allows minimizing the number of parameters, eliminating the diffusion coefficients and selectivity. The aim of research is creation of a formalized model of ion exchange, taking into account only empirical parameters.It is investigated the strongly acidic gel ion exchanger modified by aggregates of nanoparticles of zirconium hydrogen phosphate. In dynamic mode it was performed deionization of combined solution prepared in tap water, which contains ions of calcium, magnesium and nickel.Under dynamic conditions it is investigated extract of nickel ions from the combined solution by using a strongly acidic gel cation exchange resin and the composite ion exchanger on its base, containing aggregates of nanoparticles of zirconium hydrogen phosphate. A model is proposed, which allows determining the time at which the capacity is reached before breakthrough for nickel ions. This model involves the use of only empirical parameters obtained in the investigation of ion exchange in a dynamic mode, reflecting the concentration of ions in the solid phase and does not require prior identification and selectivity coefficient of diffusion of sorbed ions, and the communication mode (external and internal diffusion or mixed).