Reaction of sulphate radical anion (SO4·-) with cyanuric acid. A potential reaction for its degradation?

A novel reaction between sulfate radical anion (SO4·-) and cyanuric acid (CA), a non-degradable end product of the oxidative degradation of the triazine based herbicide, atrazine, is presented using laser flash photolysis and steady state radiolysis techniques at pH 5. A second order rate constant of 1.9x107 dm3 mol-1 s-1 has been determined and the transient intermediate (λmax=330 nm) is assigned to a radical cation of CA (CA·+). The degradation profile indicated that about 76% of CA have been decomposed after an absorbed γ-radiation dose of 18 kGy. It is therefore proposed that the reaction of SO4·- could be utilised for the degradation of CA in aqueous medium which is normally stable to any Advanced Oxidation Processes. (author)