Modeling and prediction of adsorption kinetics of natural and modified zeolite

Strontium (۹۰Sr) and cesium (۱۳۷Cs), radioactive byproducts of uranium fission in nuclear power plants, have long half-lives and high radiotoxicity, posing significant risks to human health if released into the environment[۱]. Following the previous study, which determined the best modification method for natural clinoptilolite zeolite and achieved a ۲۶% increase in strontium adsorption[۲], this research aims to model the adsorption kinetics to offer the most reliable predictions.Studying the kinetics of adsorption provides information about the rate-controlling step or steps[۳]. The pseudo-first-order and pseudo-second-order equations are the most commonly used models for Adsorption process of the adsorbate from liquid solutions. By comparing the R² values in Tables ۱ and ۲, it is observed that the pseudo-second-order model provides a better prediction of strontium (II) and cesium (I) ion adsorption on natural and modified zeolite compared to the pseudo-first-order model. According to the assumptions of this model, the adsorption of these ions occurs via an ion exchange mechanism(Chemical adsorption). Another important point is that the time to reach equilibrium concentration is shorter for modified zeolite compared to natural zeolite.

کلیدواژه ها:

Kinetics ، Clinoptilolite ، Modified zeolite ، Cesium ، Strontium