Transition Metal Ions as Ozonation Catalysts: An Alternative Process of Heterogeneous Catalytic Ozonation

The aim of this study is to elucidate the mechanism micropollutants’ removal in drinking water by application catalytic ozonation, using transition metals as appropriate catalysts. For that purpose, degradation 500 ?g/L p-chlorobenzoic acid (p-CBA) and benzotriazole with addition 2 mg/L ozone presence 1 Co(II) or Fe(II) at pH 7.8 were examined. It was found distilled experiments, both metal ions can be characterized catalysts, enhancing ozonation process; however, natural matrix, only iron presented higher rates examined organic pollutants, when compared single ozonation. present activity, they form precipitates, hence converting initially homogeneous process towards a heterogeneous one. However, applied Co(II)—unlike Fe(II)—could not oxidized into its trivalent form, it cannot precipitate Co(OH)3. Therefore, under these experimental conditions, any activity. Nevertheless, phosphates (PO43?) concentrations than 100 increase oxidation ability Co(II)/O3 system, due resulting sufficient formation Co3(PO4)2 precipitates. Although cobalt enhance •OH production (and therefore, procedure) relatively highly added concentration phosphate makes treated non-potable, further treatment remove excess phosphates. considered catalyst processes.