The sulphate radical is not involved in aqueous radiation oxidation processes

The H 2 O 2 /persulphate systems are of enormous environmental and commercial importance with the sulphate radical (SO 4 − ) being assumed as the oxidizing/bleaching species. We show that under normal conditions (air-saturated) no SO 4 − is produced and, most likely, a much longer-lived species, the adduct of O 2 and the persulphate radical, is formed.