Adsorption of zinc and copper ions simultaneously on a low-cost natural chitosan/hydroxyapatite/snail shell/nano-magnetite composite

Abstract

The Chitosan/Hydroxyapatite/Snail-Shell/nano-Magnetite composite was used in this experiment to remove Zinc(II) and Cu(II) ions from the aqueous medium concurrently. A Central Composite Design, abbreviated as CCD, was used in order to find the optimal conditions for the independent variables. The first and second most important processes in this procedure were the synthesis of magnetite nanoparticles and the extraction of other components from brummagem materials, respectively. In the process of making the composite, the chitosan was first dissolved in acetic acid, and then the remaining components were added to the solution in the form of powder once the chitosan had been dissolved. An external magnet was used in conjunction with the nanoparticles that were embedded within the composites to remove the adsorbent from the solution. In order to describe the composite, EDX and SEM analyses were performed, and FAAS was employed in order to determine the number of ions that were still remaining throughout the solution after the analysis had been completed. Using CCD Expert Software, Zn(II) and Cu(II) concentration levels, the pH variables, contact time, and amount of adsorbent were modified to have values of 25.0 mg/L, 0.025 g, 5.5, 48.3 min, and 10.0 mg/L, respectively. These values represent the final results of the experiment. Several different models, including the Langmuir, Freundlich, and Tempkin models, were studied in order to analyze the data from the experimental isotherm models. In the cases of Cu(II) and Zn(II), respectively, the Freundlich and Langmuir models both revealed a reasonable level of fit. Four distinct classic kinetic models were applied in order to get an accurate match between the experimental findings at the starting concentration of ions and the predicted values. It was discovered that the pseudo-second-order model gives a suitable fit with the adsorption isotherms for both ions. This conclusion was reached on the basis of the observations.