Selective oxidation decontamination in cobalt molybdate activated Fenton-like oxidation via synergic effect of cobalt...

In this study, cobalt molybdate (CoMoO₄) activated peracetic acid (PAA) was developed for water purification. CoMoO₄/PAA system could remove 95% SMX with pseudo-first-order reaction rate constant of 0.15410 min^-1, which was much higher than CoFe₂O₄/PAA, FeMoO₄/PAA, and CoMoO₄/persulfate systems. CoMoO₄/PAA system follows a non-radical species pathway dominated by the high-valent cobalt (Co(IV)), and CH₃C(O)OO^• shows a minor contribution to decontamination. Density functional theory (DFT) calculation indicates that the generation of Co(IV) is thermodynamically more favorable than CH₃C(O)OO^• generation. The abundant Co(IV) generation was attributed to the special structure of CoMoO₄ and effect of molybdenum on redox cycle of Co(II)/Co(III). DFT calculation showed that the atoms of SMX with higher ƒ⁰ and ƒ^- values are the main attack sites, which are in accordance with the results of degradation byproducts. CoMoO₄/PAA system can effectively reduce biological toxicity after the reaction. Benefiting from the selective of Co(IV) and CH₃C(O)OO^•, the established CoMoO₄/PAA system exhibits excellent anti-interference capacity and satisfactory decontamination performance under actual water conditions. Furthermore, the system was capable of good potential practical application for efficient removal of various organics and favorable reuse. Overall, this study provides a new strategy by CoMoO₄ activated PAA for decontamination with high efficiency, high selectivity and favorable anti-interference.