The MET-Team    

Mercury Emissions From Power Plants Targeted

Electric Power is a driver of our nation's economy and critical in maintaining our high quality of life. Coal-fired power plants, however have been targeted for additional emissions reductions including sulfur dioxide, nitrogen oxides, and mercury.

Coal-fired power plants are targeted for mercury reductions to help reduce the airborne levels of mercury that may eventually be deposited in water or on land. Mercury concentrations in the air are low and of little direct concern. However, once mercury enters water, biological processes transform it into methyl mercury that bioaccumulates in fish and other animals that eat fish. Human exposure to mercury occurs primarily through consumption of contaminated fish.

EPA Initiatives

For information on EPA initiatives, see www.epa.gov/mercury.

Test Method

For sorbent trap mercury monitoring, known volumes of flue gas are extracted from a stack or duct through paired spiked 3-section sorbent traps at an appropriate flow rate. The sampling period can vary from 30 minutes to several days in duration. After sampling, the sorbent can be acid leached and the resulting leachate is analyzed by cold vapor atomic fluorescence spectrometry (CVAFS) or cold vapor atomic absorption spectrometry (CVAAS). Other techniques for mercury analysis that use no solvent extraction include direction combustion and thermal decomposition with atomic absorption (AA) detection.

EPA Method 30B - For relative accuracy test audits (RATAs) of vapor phase Hg CEMS and sorbent trap monitoring systems, known volumes of flue gas are extracted from a stack or duct through paired spiked 2-section sorbent traps at an appropriate flow rate. A field recovery test that assesses recovery of an elemental Hg spike to determine measurement bias is also used to verify data acceptability. After sampling, sorbent traps are prepared for analysis and analyzed by any suitable determinative technique that can meet the performance criteria such as those outlined in the above paragraph.

Independent of the application, sorbent traps must be obtained from a reliable source such that high quality assurance and control ensure consistent reliability. Persons sampling should have a thorough working knowledge of other related sampling methods.

The Total Solution for Sorbent Trap Mercury Emissions Testing

Only the MET-Team offers an alliance of technical expertise from Clean Air Engineering, CONSOL Energy, and SKC Inc. to provide the sampling media, stack sampling systems, analysis, and services that make your sampling job easy and accurate.