Electroassisted methods for waste destruction: Silver(II) and peroxydisulfate reagents in the electrochemically mediated oxidation of polyaromatic sulfonates

The electrochemical oxidation is a promising process for organic pollutants which are recalcitrant to biological degradation. The anodic oxidation of 1,5-naphthalenedisulfonic acid, hereafter NDS, was evaluated at a Pt anode using in situ generated Ag(II) cation or peroxydisulfate image anion as mediators. Kinetics of the direct chemical oxidation of NDS in the presence of Na2S2O8, and the identification of some oxidation intermediates are also reported. An analysis of the results shows that Ag(II) is characterized by a high-reaction rates, while image performs the oxidation of NDS in a complete way.