Catalytic ozonation by metal ions for municipal wastewater disinfection and simulataneous micropollutants removal

Abstract

This work evaluated the effects of Fe2+, Co2+ and Al3+ in municipal wastewater disinfection through E.coli and Pseudomonas spp inactivation along with cellular adenosine triphosphate (ATP) depletion. Simultaneously, the effect of catalytic ozonation of secondary effluent on the removal of selected micropollutants with different ozone kinetics (acetamiprid, dichlorvos and atrazine) was evaluated. E.coli and Pseudomonas spp inactivation increased almost 20% with 1 mgL-1 Fe2+, Co2+, Al3+ and 40% with 10 mgL-1 Fe2+ compared with single ozonation. The bacteria reactivation after the treatments showed that Fe2+ was the most effective metal ion on inhibiting regrowth. The cellular ATP followed the same trend as the indicators microorganisms inactivation, with significant reduction of ATP over the treatment compared to single ozonation. Finally, the HO¿ exposure per consumed ozone ratio was applied for single ozonation, Fe2+/O3, Co2+/O3 and Al3+/O3 processes to evaluate and compare the contribution of radical pathway on micropollutants abatement.