nitrogen-dioxide and sulfur-trioxide

Mercury (Hg) is a toxic and bio-accumulating heavy metal that is predominantly released via the combustion of coal. Due to its toxicity, the Environmental Protection Agency (EPA) has introduced Mercury and Air Toxics Standards (MATS) Rule regarding allowable Hg emissions. In order to reduce emissions, power plants have widely adopted activated carbon (AC) injection. AC injection has proven to be an effective method to reduce Hg emissions, but the re-emission of previously adsorbed Hg during unit operation, likely due to changing temperature or flue gas composition, could be problematic. This study specifically examined the effects of temperature and sulfur trioxide (SO

Topics: Air Pollutants; Carbon; Coal; Mercury; Nitrogen Dioxide; Power Plants; Sulfur Dioxide; Sulfur Oxides; Temperature

Upon exposure to sunlight, or to artificial light at wavelengths longer than 290 nm, sulfur dioxide in air underwent oxidation to give sulfur trioxide in the presence of air pollutants such as biacetyl (2,3-butanedione), benzaldehyde and nitrogen dioxide, but not in their absence. Only nitrogen dioxide completely oxidized sulfur dioxide to sulfur trioxide.

Topics: Air Pollutants; Benzaldehydes; Diacetyl; Environmental Exposure; Environmental Monitoring; Nitrogen Dioxide; Oxidation-Reduction; Photochemistry; Sulfur Dioxide; Sulfur Oxides; Sunlight

Artifactual formation of N-nitrosodimethylamine during the extraction procedure from aminopyrine and nitrite was examined. The use of the basic pH condition was the most effective in preventing artifactual formation. Sulfamic acid or ascorbic acid was partially effective in preventing artifactual formation. Since significant losses of volatile N-nitrosodimethylamine occur during the extraction and concentration steps, we analyzed N-nitrosodimethylamine by combined gas chromatography mass spectrometry with 15N-nitrosodimethylamine as an internal standard. The use of a fused silica capillary column enabled us to obtain a fine separation of the chromatogram. This methodology was applied to our model experiment, which was performed to locate the formation of N-nitrosodimethylamine when a rabbit was exposed to NO2 after the administration of aminopyrine. SO3 inhaled together with NO2 was found to increase the nitrosation.

Topics: Aminopyrine; Animals; Dimethylnitrosamine; Gas Chromatography-Mass Spectrometry; Nitrogen Dioxide; Rabbits; Sulfur Oxides