Adsorption of cesium from waste desalination brine through Dowex G26 resin and comparison with t-BAMBP/kerosene and t-BAMBP/C₂ mimNTf₂ systems

Cesium can be widely used in many industries now. However, the primary reservoir of cesium is often located in high mountains and deserts, so it is challenging to obtain cesium resources. To solve this problem, cesium was recovered from waste desalination brine through Dowex G26 resin in this study. Due to the lack of water resources, desalination technology was developed since the 20th century. Nevertheless, its by-product, brine, is harmful to the environment. To reduce the threat of waste brine, this experiment aims to provide a simple procedure to recover cesium resources from brine. The study could be divided into three parts. First, the adsorption isotherms and the thermodynamics parameters such as enthalpy, entropy, and Gibbs free energy of cesium adsorption were investigated. In the second part, the batch experiments would explore the optimal adsorptive period, pH value, and liquid-solid ratio (L/S ratio) of cesium adsorption through Dowex G26 resin. The results showed that the adsorption of cesium fit with the Langmuir model, and the reaction was spontaneous. On the other hand, cesium could be recovered efficiently under the conditions of 4 min of contacting time, pH 9, and L/S ratio of 1,000. After adsorbing, the cesium could be desorbed through nitric acid, and solid cesium nitrate would be obtained by drying the desorbed solutions. In the end, the Dowex G26 system would be compared with the t-BAMBP/kerosene system and t-BAMBP/C₂ mimNTf₂ system to demonstrate its advantages and drawbacks.