Innovative Electrooxidation-Adsorption Technology for Efficient Iodine Recovery from Ultrahigh Cl/I Ratio Underground Brine

Abstract

Efficient and eco-friendly iodine recovery from underground brine with ultrahigh Cl/I ratios faces a great challenge to the traditional methods of iodine extraction from brine. In this work, we developed a novel electrooxidation-adsorption coupling technology for green and efficient iodine recovery from underground brine with an ultrahigh Cl/I ratio. Initially, the iodide ions (I-) were selectively oxidized to triiodide ions (I3-) with an excellent electrooxidation rate of 80.46% using an electrochemical apparatus. Subsequently, a novel porous Co-Vlm6 adsorbent synthesized via the hydrothermal method achieved a remarkable adsorption capacity of 1466.01 mg·g-1, with the adsorption equilibrium reached in just 3 min. Applying this electrooxidation-adsorption coupling process to underground brine resulted in 81.93% iodine recovery within 125 min. The outstanding electrooxidation-adsorption/desorption performance, cyclic stability, and cost-effectiveness make it a competitive candidate for the efficient recovery of iodine from underground brine and other liquid iodine resources.

Keywords: iodine, underground brine, electrooxidation, Adsorbent, Co-Vlm6