99/02219 Air toxics removal from coal-fired power plants: Tseng, S. et al. Proc., Annu. Meet. Air Waste Manage. Assoc., [computer optical disk], 1997, 90, WA72A01/1–WA72A01/6

Abstract

Fossil fuels contain trace amounts of heavy metals, which are the sources of air toxics when they are burned. If the combustion flue gas is not properly treated, the release of large amounts of these heavy metals can severely pollute the environment as experienced in some developing countries. Electrostatic precipitators (ESPs) are widely used to reduce the emissions of particulate matters (PMs) from flue gases at stationary sources such as coal-fired power plants. Properly designed and operated ESPs can remove more than ninety-nine percent of the incoming PMs. Wet scrubbers installed at the power plants were originally designed to reduce the emissions of sulfur dioxide. However, scrubbers are also known to be very effective to further reduce the emissions of PMs. Some of the heavy metals removed in the scrubbers are usually present in the form of dissolved cations in the scrubbing liquors. Uncontrolled release of such liquors may pollute the surface water. A simple and economical method to remove dissolved heavy metals from spent scrubbing liquors has been developed. Bench scale tests using simulated scrubber liquors were conducted. The liquors were doped with various amounts of lead, mercury, copper, iron, and zinc ions. The test data showed that majoritiesmore » of these cations were removed by this technique. Implications of this technique at full scale facilities will be discussed.« less