Oxydation des isomères de dichlorobenzène à l'aide du persulfate de sodium soumis à une activation thermique

The chemical oxidation of a recalcitrant molecule, dichlorobenzene, with thermally activated persulfate was studied in an aqueous medium and in soil slurry (10% total solids). The use of persulfate was investigated to provide additional knowledge on its use in soil remediation. In an aqueous medium, a complete degradation of dichlorobenzene was observed at 50 and 60 ºC for a reaction time of 6 h. In soil slurry, a degradation of 90% and 100% was observed after 6 h at 50 and 60 ºC, respectively. At 40 ºC, the degradation was 64% in an aqueous medium and 26% in soil slurry. In both media, the activation energy of the reaction was 115 and 153 kJ/mol, respectively. It is more efficient to increase the activation temperature in soil slurry than in an aqueous medium. Key words: dichlorobenzene, persulfate, thermal activation, sulphate free radical, chemical oxidation, kinetics.