A portable system for extracting iodine from brine on-site is disclosed. The portable system includes a mobile platform containing a treatment unit for oxidizing iodine ions into elemental iodine, an adsorption unit capable of binding iodine, and may also have an electrolytic cell and/or a gas-liquid separator. The treatment unit and the adsorption unit may be located in the same or different portable operating devices. When transported to a field site containing natural gas wells, the natural gas wells provide a fluid stream containing natural gas and brine. The separators can separate the natural gas from the brine, and the brine is then run through the treatment unit and the adsorption unit to bind iodine present in the brine. The brine is then returned to the natural gas well. Upon saturation, the portable operating device is transported to a second location, where iodine is extracted from the adsorption unit.