Hello everyone.
In my research I'm using the CMAQ modeling system to estimate the impact of Ammonia on fine particle in China in January, May, August and November. From literature I generally found that ammonia is converted into ammonium ion which bonds either with nitrate or sulfate. In my simulation most of ammonium bonded with nitrate and only partially with sulfate (probably due to the fact that most PM2.5 was produced in low temperature weather condition, cold season). I got the confirm of this because I made a test, I lowered the ammonia emissions to zero, with the result that ammonium and nitrate dropped by 99%, but there is still a significant amount of sulfate in the atmosphere after the simulation.
So..my question is: since there is a fraction of sulfate that didn't bond with ammonium, what did sulfate POSSIBLY bond with?
thank all community for your support