Equilibrium and Kinetic Modeling of Zn (II) Adsorption from aqueous solution using dicalcique dehydrated

Abstract The interactions of Zn (II) ions with the dicalcium phosphate dihydrate (DCPD) in dilute aqueous solutions have been studied in the static mode and in various physico-chemical parameters such as contact time, pH, and the initial concentration of the ion metal. The kinetics shows that the extraction equilibrium is slow; equilibrium is reached in about 75 minutes stirring system where more than 35% of metal is extracted. The amount of adsorbed metal (q) by supporting unit mass increases with increasing pH of the metal solution and decreases by increasing the initial concentration of Cu2+ ions in the supernatant solution. The equilibrium modeling was conducted by applying two isotherms: the Langmuir model and the Freundlich model. The results show that the Langmuir model applies best to the experimental results with maximum adsorption capacity of 333.33 mg/g. The separation factor value RL = 0.93 indicates that the adsorption of zinc on dicalcium phosphate dihydrate is favorable. Kinetic studies show that the adsorption process follows the pseudo-second-order kinetic model.