Modelling mechanism of Ca²⁺ removal from dicyandiamide using dynamic ion exchange method

Abstract

Based on breakthrough theory and fractal porous medium theory (FPM), the paper investigates the modelling mechanism of Ca 2+ removal in dicyandiamide by dynamic ion exchange. In this work, parameters within consideration included the flow rate of dicyandiamide crystallization mother liquor, the height-diameter ratio of the resin layer, and the temperature on Ca 2+ exchange. It was found that the removal efficiency of Ca 2+ reached 97.32%. Meanwhile, the through function of the process was obtained, and the behaviour of the dynamic process was modelled and simulated. In addition, using FPM theory, the calculation equation of the spectral dimension of the fractal surface of the resin in the ion exchange process was observed as linear and a mathematical model was established. This paper analyses the dynamics equation of the ideal surface and the fractal surface. According to the analytic results, it was linear relation on the ideal surface and power function on the fractal surface.

Study on the removal of SO42− and Ca2+ from potassium chloride brine via a method combining calcium chloride and carbon dioxide

“…, The removal methods of Ca 2+ mainly include chemical precipitation, 12 membrane filtration, 13 ion exchange, 14 and adsorption 15 methods. Among these methods, chemical precipitation has been most widely used in practical production due to it involving a simple and effective treatment process.…”

“…The removal of SO 4 2− from brine using the calcium chloride method can increase the concentration of Ca 2+ in the system, so it is necessary to remove the excess Ca 2+ from the solution to ensure the removal effect of SO 4 2− , The removal methods of Ca 2+ mainly include chemical precipitation, 12 membrane filtration, 13 ion exchange, 14 and adsorption 15 methods. Among these methods, chemical precipitation has been most widely used in practical production due to it involving a simple and effective treatment process.…”

Effect of Pollutant Species on the Performance of Chelating Membranes for Wastewater Treatment

“…The arbitrary discharge of heavy metals not only causes great harm to the environment, but also poses a potential hazard to human health. The commonly used treatment methods for heavy metal ions in wastewater mainly include flotation [11], ion exchange [12], coagulation-flocculation [13], adsorption [14], chemical precipitation [15], chelation [16], electrochemical methods [17], and membrane separation [18]. If organic pollutants are massively discharged without treatment, they will cause large-scale environmental pollution and affect the biodiversity of the surrounding environment.…”