Removal of iodine from the salt water used for caustic soda production by ion-exchange resin adsorption

Abstract A lower concentration of iodine ( 2 is the optimal adsorbed species in salt water through the reaction between I 2 and Cl − in the resin to form (ClI 2 ) − . A simple pre-treatment method was developed to transform different iodine species in salt water into I 2 by adjusting the solution to pH 1.5–2.5 and redox potential (Eh) 530–560 mV. A novel purification system for the removal of iodine from salt water was subsequently developed and constructed based on the pre-treatment method and the adsorption thermokinetics of I 2 . The stability and reliability of this developed method and system were demonstrated by a scale-up experiment to remove iodine from the refined salt water used for caustic soda production, by which the concentration of iodine can be stably decreased to far