Gas purification by removal of atomic mercury using electrochemical cells

Electrochemical cells are described, which allow the oxidative removal of gaseous atomic mercury from gas streams. The gas stream is fed into an electrochemical cell containing an electrolyte solution and a three-dimensional anode with a large surface. The results can be explained by assuming that the atomic mercury is first transferred from the gas to the electrolyte solution followed by oxidation to mercury(II) ions at the electrode surface. Once mercury(II) has reached a sufficient concentration, it reacts with the atomic mercury to form mercury(I). The dissolved mercury(I) is than oxidized to mercury(II) at the electrodes. Therefore the efficiency of mercury removal from the gas stream can be enhanced by adding mercury(II) to the electrolyte at the very beginning of the process.