Currently, simultaneous removal of SO2 and NOx has gained significant attention in research field. It is desirable to remove SO2 and NOx simultaneously in a single unit, leading to lower capital cost for equipment and cutting operating costs. Besides activated carbon, various types of ash have been used for simultaneous removal of SO2 and NOx. However, activated carbon application is more favorable because of lower prices and better sorption ability. Researchers reported that impregnationof metal oxides into activated carbon is effective for simultaneously removing SO2 and NOx.