Enhanced Removal of 2,4-Dichlorophenol From Wastewater Using Ternary Fe-Mn-Ce/γ-Al₂O₃ as Catalyst in Ozonation...

The toxic, persistent pollutant 2,4-dichlorophenol (2,4-DCP) is resistant to conventional treatment methods. Heterogeneous catalytic ozonation, driven by hydroxyl radicals (•OH), offers a powerful solution for its effective degradation. Ternary Fe-Mn-Ce/γ-Al₂O₃ catalyst (FMC, Fe-Mn-Ce = 1:2:4) prepared via the wet incipient impregnation method was investigated to degrade 2,4-DCP in wastewater. The integration of O₃ with the ternary FMC demonstrated a significant synergistic effect, achieving complete degradation and 88% chemical oxygen demand (COD) removal in 60 min at an initial pH of 7. COD removal was improved by 48% and 30% compared with single and binary catalysts, respectively. Scanning electron microscopy (SEM) analysis revealed a porous, textured surface with large crystalline particles, confirmed by a Brunauer-Emmett-Teller (BET) surface area of 184.05 m²/g. X-ray photoelectron spectroscopy (XPS) results confirmed a high density of Fe²⁺, Ce³⁺, Mn³⁺, and surface-active oxygen species, essential for promoting electron transfer. Surface hydroxyl groups (FMC-OH₂ ⁺) are essential for the adsorption and decomposition of O₃ into reactive oxygen species (ROS). Scavenging experiments revealed that •OH played a critical role in the degradation of 2,4-DCP. Seven days of continuous experiments maintained over 82% COD removal efficiency, exhibiting excellent stability. When utilized in real wastewater, the catalyst also maintained its efficiency, indicating significant potential for practical applications.