High energy electron beam generation of oxidants for the treatment of benzene and toluene in the presence of radical scavengers

High energy electron beam irradiation of benzene and toluene in aqueous solution results in their destruction and the formation of highly oxidized reaction byproducts. The product distribution depends upon absorbed dose and pH and results from the reaction of benzene and toluene with the hydroxyl radical (OH .), followed by continued oxidation of intermediate by-products. The dose required to remove 99% ( D 0.99) of the benzene from solution, at an initial solute concentration of 17.0 μM (1.3 mg l −1), was 95 krad (0.95 kGy, [OH .] ≈ 2.7 × 10 −4 M). In the presence of a known radical scavenger, i.e. 3.3 mM methanol, a dose of 1510 krad ( 15.1 kGy, [OH .] ≈ 4.2 × 10 −3 M ) was required to achieve the same removal. Toluene showed greater removal, in the absence of methanol, than benzene under similar experimental conditions. The D 0.99 required to destroy an initial toluene concentration of 47.7 μM (4.4 mg l −1) was 165 krad (1.65 kGy, [OH .] ≈ 4.6 × 10 −4 M), whereas the D 0.99 for an initial toluene concentration of 16.4 μM (1.5 mg l −1), in the presence of 3.3 mM methanol, was 2074 krad (20.7 kGy, [OH .] ≈ 5.8 × 10 −3 M).