Au Recovery. Based on the findings of previous authors , , it can be expected that the application of the 12.9 V cell voltage during the laboratory experiment resulted in the transport of dissolved Au-iodide ions (primarily as AuI2 -) from the WPCB iodide leachate in the feed tank to the surface of the cathode in the catholyte tank where they underwent a reduction reaction (equation 2) which produced iodide ions and the solid Au deposit which was observed on the cathode surface as a brown powder. While iodide ions in the catholyte tank are believed to be transported (through the AEM) to the surface of the anode in the anolyte tank where they were oxidized to di-iodine (equation 3). This iodide oxidation reaction was presumed to be coupled by the simultaneous electrolysis of H2O at the anode surface to O2 and H + (equation 4).