Powerspan Corp, is pursuing two approaches to reducing the mercury emissions of coal-fired power plants. One-called ECO (for Electro-Catalytic Oxidation)-incorporates mercury removal into a multi-pollutant control process. The other-called PCO (for Photochemical Oxidation)-can be used with existing air pollution control systems to control mercury alone at a low cost. Following are overviews of both approaches, including their development status.