The Utilization of Modified Zeolite for the Removal of Cs Ions in an Aqueous Solution: Adsorption Capacity, Isotherms, Kinetics and Microscopic Studies

Nuclear energy is a double-edged technology, which has a significant role in the chemical industry, but may bring about radioactivity and destruction. The 2011 Fukushima nuclear power plant accident caused by a tsunami, which flooded and led to tens of millions of disaster debris and tsunami deposits, severely disrupted the electricity supply in Japan and induced USD 211 billion worth of direct economic losses. Cs+ was easily dissolved in this accident, had a high chemical activity, and thus required an appropriate adsorption method. Zeolite is an effective removal adsorbent, which is suitable to be investigated. The present study uses natural zeolite and three inorganic modified zeolites. Furthermore, the effects of various factors are investigated. Kinetic models and the isothermal adsorption mechanism are also conducted. For microscale studies for the adsorption mechanism, scanning electron microscope (SEM) and X-ray diffraction (XRD) were involved in the study. The results indicate that the optimal dosage is 1.1 g and the maximum adsorption rate is around 80%. An alkaline environment is more conducive to the occurrence of adsorption. As for the isotherm and kinetic studies, the data fits better with the Redlich-Peterson isothermal model and intragranular diffusion model. In this small-scale experiment, the highest adsorption capacity was for Mg-zeolite at 6.53 mg/g. Finally, Mg-Zeolite presents the best adsorption capacity.

Automated summary

Nuclear energy is a double-edged technology with both significant benefits and potential hazards. The 2011 Fukushima nuclear power plant accident highlighted the importance of appropriate adsorption methods in handling radioactive substances such as Cs+. Zeolite, both natural and modified, was investigated as an effective adsorbent in this study. The optimal dosage and maximum adsorption rate were determined, and the influence of various factors was examined. The results showed that an alkaline environment was more favorable for adsorption, and the Redlich-Peterson isothermal model and intragranular diffusion model provided the best fit for the data. The highest adsorption capacity was found in Mg-zeolite, indicating its superior performance in removing Cs+.