Utilization of carbon-coated ZrO2/Mn-Mg-Zn ferrites nanostructures for the adsorption of Cs (I) and Sr (II) from the binary system: kinetic and equilibrium studies.

Carbon-coated ZrO2/Mn-Mg-Zn ferrites nanostructures (CZ-FN) have been prepared as a new inorganic sorbent to remove Cs (I) and Sr (II) from a waste stream. Adsorption of Cs (I) and Sr (II) has been implemented considering different noteworthy parameters, for example, shaking time and the optimum time achieved high adsorption capacity of both ions [103 and 41 mg/g for Sr (II) and Cs (I)] was found 30 min. Also, the impact of pH values was studied; the best pH value for the adsorption process is pH 6. The adsorption saturation capacity of CZ-FN is 420.22 and 250.45 mg/g for strontium and cesium, respectively. The solubility percentage of CZ-FN was calculated utilizing diverse molarities from HNO3, HCl, and NaOH as eluents, the obtained data reveals an increase in the solubility percentage with more increase in the molarity of the eluents. The elevation in the solubility percentage follows the following order; HNO3 < HCl < NaOH. The kinetic studies were applied using the nanolinear form of different kinetic models; it was found that the adsorption process obeys the nonlinear pseudo-second-order. According to equilibrium studies, the Langmuir model has been more accurate than the Freundlich model for adsorption in the case of binary systems. The values of Di for the strontium and cesium are 10-10 m2/s, which displays the chemisorption nature of this process. The greatest values of the desorption process for the strontium and cesium are 96.87% and 94.43 by 0.3 M of HNO3. This indicated that the carbon-coated ZrO2/Mn-Mg-Zn ferrites could be regenerated and recycled to remove strontium and cesium ions from waste streams.