Transition metal catalyzed sulfite auto-oxidation systems for oxidative decontamination in waters: A state-of-the-art minireview

Electrolysis-Assisted Mn(II)/Sulfite Process for Organic Contaminant Degradation at Near-Neutral pH

“…As shown, the pseudo first-order reaction constant of BPA removal (k) by electro/Mn(II)/sulfite process at 0.5, 1, 2, 3, and 4 mM sulfite was 0.0081, 0.0179, 0.065, 0.0258, and 0.015 min −1 , respectively. The effect of sulfite concentration was consistent with previous reports [21][22][23][24].…”

“…As shown in Figure 2b, in conventional Mn(II)/sulfite process, the dissolved oxygen content rapidly decreased to 3.59 mg/L although this reaction is slow at pH 6. At pH 4, which is the optimum solution acidity for the Mn(II)/sulfite process, the complete depletion of dissolved oxygen can be achieved within a few seconds [24]. The consumption of dissolved oxygen is due to Equations (2) and (5), the latter of which plays an especially significant role.…”

“…•− production (Equations (1)-(7)), requiring minimal Mn(II) dose in solution as a catalyst [22,24]. Moreover, it should be noted that, besides SO 4…”

Interior engineering of seaweed-derived N-doped versatile carbonaceous beads with CoxOy for universal organic pollutant degradation

“…[1][2][3][4] Currently, advanced oxidation processes (AOPs) are considered effective remediation methods owing to their advantages of generating highly reactive oxygen species such as sulfate radicals (SO 4 c À ), hydroxyl radicals (cOH) and superoxide radicals (O 2 c À , HO 2 c, and 1 O 2 ) for the degradation of organic pollutants into harmless products. [5][6][7] Among various AOPs, considerable research efforts have been devoted to the typical Fenton reaction (Fe 2+ /H 2 O 2 ) in virtue of the strong oxidative potential (1.8-2.7 V vs. NHE) of the generated cOH. 8,9 However, its practical applications are prominently limited by the low operation pH (2-4) and a large amount of sludge production.…”

“…However, Liu et al 18 and Song et al 19 have already revealed that transition metals (Fe 2+ , Co 2+ ) can cause the adverse loss of dissolved metal ions, poor stability, and reusability. To alleviate these problems, various supported cobalt nanocomposites 12,20 and mixed transition-metal oxides 7,8 have been extensively investigated. Nevertheless, catalytic efficiency for PMS activation still needs to be further improved due to the slow conversion rate of Co 2+ /Co 3+ redox pairs.…”