Selenium Speciation and Control Technologies for Sulfate-Rich Wet FGD Systems

Coal is used to generate more than half of the electricity in the United States. Historically, coal has been an abundant and low-cost source of energy for electricity generation. However, coal has a range of environmental disadvantages, which include emissions of selenium via the flue gas and via environmental releases during subsequent processing. Development of selenium control technologies is complicated by a limited understanding of selenium chemistry in pollution control systems and by challenges in measuring the amount and form of selenium in these systems. This project will develop technology to reduce selenium discharges from coal-fired power plants equipped with flue gas desulfurization (FGD) units. The technology will use a combination of scrubber operating conditions, scrubber additives, and wastewater treatment additives to manage selenium speciation and precipitation in FGD units and wastewater treatment plants. Commercial Applications and other Benefits as described by the awardee: The technology should have extensive commercial applications in the electric utility industry for both new and existing coal-fired power plants equipped with wet FGD scrubbing systems. The public would benefit from reduced exposure to selenium and reduced environmental discharges of selenium.