Direct chemical oxidation: applications to demilitarization and decontamination

The applicability of using aqueous solutions of sodium peroxydisulfate in the destruction of mustard gas surrogates has been demonstrated. This technique, known as Direct Chemical Oxidation (DCO), resulted in oxidative destruction of these surrogates, and a refinement was added to prevent the formation of slow-to-oxidize intermediates. Specifically, it was shown that `one-armed mustard` gas could be hydrolyzed to thiodiethanol and free chloride ion, and this species could then be partially oxidized to either the sulfoxide or sulfone depending on oxidant stoichiometry. Hydrolysis was accomplished on a mild basic solution at ambient temperature over a number of hours; oxidation was carried out at 90{degrees}C using peroxydisulfate solutions, Partial oxidation of thiodiethanol in the presence of chloride under basic conditions resulted in a a substantially pure mixture of the corresponding sulfone and sulfoxide, with no formation of chlorine gas. Analogous experiments in acid solutions produced a more complex mix of products and some oxidant was consumed in the evolution of chlorine. Complete destruction of the surrogates (to ppm level of detection) was achieved in either acid or base solution with less than a 7-fold excess of oxidant