The sulphate radical is not involved in aqueous radiation oxidation processes

The H2O2/persulphate systems are of enormous environmental and commercial importance with the sulphate radical (SO4−) being assumed as the oxidizing/bleaching species. We show that under normal conditions (air-saturated) no SO4− is produced and, most likely, a much longer-lived species, the adduct of O2 and the persulphate radical, is formed.