Research team identifies possible acid rain trigger
A research team at Academia Sinica, Taiwan’s leading academic research institution, has identified active molecules that may be critical to the formation of aerosols and acid rain.
The team found that the active molecules in the atmosphere, called Criegee intermediates, react with the pollutant sulfur dioxide (SO2) in the atmosphere at a fast speed in a process of oxidation.
The process produces sulfur ozone and subsequently sulfuric acid, an important constituent of aerosols and acid rain, according to a statement released by Academia Sinica on Friday.
The finding suggested that the molecules play a greater role in atmospheric chemistry than previously believed, the statement said.
Headed by Jim J. Lin, a research fellow at the Institute of Atomic and Molecular Sciences of Academia Sinica, the team studied the reactions of dimethyl substituted Criegee intermediate with water vapor and with SO2.
It found that when the dimethyl substituted Criegee intermediate reacted with water, the reaction was not fast enough to consume the Criegee intermediate, but its reaction with SO2 was swift.
The observation suggests that the substituted Criegee intermediate could survive under humid conditions long enough to react with SO2.
That was a clear departure from previous studies in which a simple form of the intermediate reacted with water so quickly that it could not survive long enough to react with SO2, the Academia Sinica statement said.