Modeling the Kinetics of Contaminants Oxidation and the Generation of Manganese(III) in the Permanganate/Bisulfite Process

Abstract

Permanganate can be activated by bisulfite to generate soluble Mn(III) (noncomplexed with ligands other than H2O and OH(-)) which oxidizes organic contaminants at extraordinarily high rates. However, the generation of Mn(III) in the permanganate/bisulfite (PM/BS) process and the reactivity of Mn(III) toward emerging contaminants have never been quantified. In this work, Mn(III) generated in the PM/BS process was shown to absorb at 230-290 nm for the first time and disproportionated more easily at higher pH, and thus, the utilization rate of Mn(III) for decomposing organic contaminant was low under alkaline conditions. A Mn(III) generation and utilization model was developed to get the second-order reaction rate parameters of benzene oxidation by soluble Mn(III), and then, benzene was chosen as the reference probe to build a competition kinetics method, which was employed to obtain the second-order rate constants of organic contaminants oxidation by soluble Mn(III). The results revealed that the second-order rate constants of aniline and bisphenol A oxidation by soluble Mn(III) were in the range of 10(5)-10(6) M(-1) s(-1). With the presence of soluble Mn(III) at micromolar concentration, contaminants could be oxidized with the observed rates several orders of magnitude higher than those by common oxidation processes, implying the great potential application of the PM/BS process in water and wastewater treatment.

The laccase-like reactivity of manganese oxide nanomaterials for pollutant conversion: rate analysis and cyclic voltammetry

“…The substrate oxidation can be represented in three steps, as it is a heterogeneous reaction. The substrate first adsorbs onto MnO 2 (equation 1 ), followed by oxidation by MnO 2 which was transformed to its reduced form MnOOH (equation 2 ), and then to aqueous Mn(II) (equation 3 ), and it is known that MnOOH is unstable and the reaction from MnOOH to Mn(II) is fast in the presence of substrate 27 , 28 . In the presence of oxygen, Mn(II) can be oxidized to MnOOH (equation 4 ) 19 , which appears to be rate limiting in the long run as discussed above.…”

Permanganate/bisulfite (PM/BS) conditioning–horizontal electro-dewatering (HED) of activated sludge: Effect of reactive Mn(III) species

“…Recently, Sun et al (2015Sun et al ( , 2016 reported a novel approach to yield the reactive Mn(III) species through the permanganate/ bisulfate (PM/BS) process. These reactive species could oxidize the organic contaminants at extraordinarily high rates.…”

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

“…). The presence of Mn(III) has been previously confirmed via pyrophosphate, and Mn(III) is able to rapidly remove organic compounds in tens of seconds[32][33][34]. The disproportion of Mn(III) could also generate Mn(IV) (Equation (11)).…”

“…•− could be generated and play a significant role in organic compound oxidation in manganese-catalyzed sulfite activation processes, such as permanganate/sulfite, MnO 2 /sulfite, and Mn(II)/sulfite reactions [32][33][34]40 (Figure 7a). It was shown that, as solution pH increased, the produced MnO 2 was improved for both Mn(II)/sulfite and electro/Mn(II)/sulfite processes.…”

“…•− , Mn(II)/sulfite reaction also generates Mn(III), a strongly oxidative species that has been recently reported to rapidly oxidize a variety of organic compounds [32][33][34].…”