Sources of strong primary acidity in the atmosphere

The fly ashes produced by the burning of heavy oil have been identified in this study as carriers ofstrong primary acidity in the atmosphere in the form of sulphuric acidity and hydrolyzable metal ions. Thisis an acidity which is strong from the moment of its emission (strong primary acidity, SPA) and differentfrom common sources of weak acidity (SOz, NO) which give rise to strong acidity only after some time inthe atmosphere. The oil ash SPA is transmitted to water on impact resulting in highly acid pH values andhigh total acidity as well as significant concentrations of heavy metals. Here we present and discuss ourresults. 0 1997 Elsevier Science Ltd.