Usefulness of a technique based on negative corona discharge for the degradation of selected, condensed PAHs: Application to the oxidation of anthracene and similar structures

The usefulness of negative corona discharge for oxidation of condensed poly cyclic aromatic hydrocarbons (PAHs). including anthracene, naphthalene and 2,3-benzanthracene, adsorbed on a solid substrate is evaluated. In the case of anthracene, the application of corona discharge under high voltage (10- 20 kV) for 10 to 180 min with a current intensity of 5-120 muA in a control led, humid atmosphere leads to the progressive formation of anthraquinone. A kinetic study of the anthracene oxidation shows that the apparent half-li ves range from 5 to 48 min, according to the initial anthracene amount (50- 5000 nmol). indicating a reaction order between 0 and 1. The effect of coro na discharge current intensity and the role of corona discharge-produced hi gh-speed electrical wind (approximate to 10 m/s) are discussed. The efficie ncy of the solid-phase corona discharge method is found to depend on the ad sorption strength of the PAH molecules on the solid substrate and/or their capacity to be sublimated under the influence of electrical wind.