The importance of atmospheric ozone and hydrogen peroxide in oxidising sulphur dioxide in cloud and rainwater

摘要: The process by which sulphur dioxide is oxidised in atmospheric droplets has been studied laboratory experiments designed to collect a large amount of chemical data pertinent the situation. Thus oxidation sodium sulphite solutions oxygen, ozone and hydrogen peroxide at different pH's temperatures. In all cases reaction first order with respect ion but oxidant differs. For oxygen zero whereas for one. Varying concentration little effect on rate between pH 6 9; inversely proportional square root almost directly concentration. These last two observations are very important since case it indicates that proceeds via free radical mechanism involving hydroxyl radicals only so far investigated shows positive response presence ions. The experimental was used calculate sulphate formation water under conditions each three oxidants. If assumed gas phase concentrations initially 50 parts 109 1 part volume respectively, then rates equal cloud 5.8. Above this faster below due catalysis ions; unimportant comparison 7. such substantial amounts can still be formed rapidly values from 3 5, thus will creating acidity rainwater.