Status of Condensable Particulate Matter Testing and Implications for the Cement Industry

摘要

There is a well recognized bias in EPA Method 202 condensable particulate matter test results due to the absorption and subsequent oxidation of sulfur dioxide and other soluble gases in the water-filled impingers. Significant sulfate artifact formation can occur at all sources of sulfur dioxide. The presence of ammonia in the gas stream increases the bias in the method. The problem associated with Method 202 introduces significant error in the development of particulate matter air quality control strategies. The Method 202 bias also creates enforcement liabilities for sources in states that have changed their particulate matter emission regulations to include condensable particulate matter.EPA has recognized the problem associated with Method 202 and has sponsored developmental work on EPA Conditional Method 039, a dilution-based test method. Unfortunately, Conditional Method 039 requires extremely bulky sampling equipment and is impractical to use for tests outside of the laboratory. It is unlikely that Conditional Method 039 or any other dilution-based technique will be available for routine emission testing in the near future.Air Control Techniques, P.C. has developed a Dry Impinger Method 202 that eliminates 85% to 90% of the bias in Method 202 due to the absorption and oxidation of soluble gases. This method is both economical and practical. Tests conducted by EPA have confirmed the effective minimization of artifact sulfate formation. Enhancements to the Dry Impinger Method based on the EPA tests have further reduced the method bias. Both EPA and Environment Canada are moving toward the adoption of the Dry Impinger Method 202 as a supplement or replacement to conventional Method 202. This paper summarizes the status of the Dry Impinger Method 202 and provides recommendations for its use as regulatory agencies complete work on the adoption of this method.