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 of strong primary acidity in the atmosphere in the form of sulphuric acidity and hydrolyzable metal ions. This is an acidity which is strong from the moment of its emission (strong primary acidity, SPA) and different from common sources of weak acidity (SO2, NO) which give rise to strong acidity only after some time in the atmosphere. The oil ash SPA is transmitted to water on impact resulting in highly acid pH values and high total acidity as well as significant concentrations of heavy metals. Here we present and discuss our results. (C) 1997 Elsevier Science Ltd.