Reactive Species from the Potassium Permanganate-Peracetic Acid System for Controlling Sulfide and Methane in Sewers

Developing environmentally friendly and effective strategies remains an urgent priority for controlling sulfide and methane emissions in sewer systems. In this study, the synergy between permanganate (Mn(VII)) and peracetic acid (PAA) enhanced the system oxidizing capacity and promoted reactive species production, leading to stronger microbial inactivation. A combined dosage of Mn(VII) and PAA at 3 mM in a 1:1 molar ratio effectively suppressed both the sulfide production rate (SPR) and methane production rate (MPR), and microbial activity required over 30 days for full recovery. Physicochemical characterization and metabolic analyses revealed that the combined Mn(VII)-PAA system induced more severe biofilm disruption and caused greater impairment to both the sulfidogenic and methanogenic metabolic pathways. Electrochemical and radical identification analyses revealed that Mn(VII)-PAA exhibited superior oxidative performance, attributed to the high-potential complex formation and the production of reactive species. In addition, the coexisting H2O2 in the PAA solution played a significant role by stabilizing Mn(III). This study proposes a promising strategy for mitigating sulfide and methane production, supported by a comprehensive elucidation of the underlying microbial and chemical inhibition mechanisms.