Influence of Pyrophosphate on the Generation of Soluble Mn(III) from Reactions Involving Mn Oxides and Mn(VII)

Liu, Weifan; Sun, Bo; Qiao, Jinli; Guan, Xiaohong

doi:10.1021/acs.est.9b03456

Cited by 80 publications

(38 citation statements)

References 56 publications

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“…As demonstrated in Figure , no characteristic peaks of MnO 2 were observed after the addition of PP both in KMnO 4 /Na 2 S 2 O 3 and KMnO 4 /NH 2 OH·HCl systems. Instead, obvious peaks of Mn(III)‐PP were detected, indicating the presence of PP induced the generation of Mn(III)‐PP from reactions of KMnO 4 with Na 2 S 2 O 3 , and KMnO 4 with NH 2 OH·HCl, which is in agreement with literature (Liu, Sun, Qiao, & Guan, ). Many studies have shown that Mn(III)‐PP is less redox‐reactive (Nico & Zasoski, , ) and cannot oxidize contaminants effectively.…”

Section: Resultssupporting

confidence: 91%

Role of pyrophosphate on the degradation of sulfamethoxazole by permanganate combined with different reductants: Positive or negative

Liu

Yin

Guan

et al. 2019

Water Environment Research

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Activating permanganate with reductants has gained increasing attention recently for efficient organic contaminants abatement via reactive intermediate Mn species. However, few studies have been conducted to explore the role of pyrophosphate (PP), a typical complexing agent for intermediate Mn species, in activated permanganate systems. In this study, taking sulfamethoxazole (SMX) as a probe compound, the influences of PP on SMX degradation by permanganate/thiosulfate and permanganate/hydroxylamine were extensively studied. It was found that both thiosulfate and hydroxylamine were able to activate permanganate for oxidation of SMX in the absence of PP. However, upon the introduction of PP, opposite effects were observed in the two systems where PP further improved the activation of permanganate by thiosulfate but dampened the performance of permanganate/hydroxylamine markedly. For permanganate/hydroxylamine system, MnO2 was determined to be the only reactive oxidative species accounting for SMX degradation in the absence of PP, and its generation could be completely inhibited by PP. While in permanganate/thiosulfate system, both Mn(V) and MnO2 were responsible for SMX oxidation, and the introduction of PP could strengthen the oxidative ability of Mn(V). These results could shed some insights on the suitability of applying PP to explore the kinetics and mechanisms of manganese involved redox reactions. Practitioner points Both Na2S2O3 and NH2OH·HCl can activate KMnO4 for SMX removal without PP. MnO2 is the reactive oxidative species involved in KMnO4/NH2OH·HCl system. Mn(V) and MnO2 account for the SMX oxidation by KMnO4/Na2S2O3 system. PP could inhibit the formation of MnO2 but enhance the oxidative ability of Mn(V).

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Section: Resultssupporting

confidence: 91%

Role of pyrophosphate on the degradation of sulfamethoxazole by permanganate combined with different reductants: Positive or negative

Liu

Yin

Guan

et al. 2019

Water Environment Research

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“…More generally, the presence in the reactive medium of compounds chelating Mn, and more especially Mn(III), is expected to enhance the oxidative process (Ma et al, 2020). With this respect, pyrophosphate (PP) appears especially relevant owing to its strong affinity for Mn(III) (Liu et al, 2019;Marafatto et al, 2018;Parker et al, 2004;Soldatova et al, 2017). The relevance of PP is further increased by its common formation in natural environments, as the simplest polymer of orthophosphate resulting from the breakdown of ATP and ADP (Klewicki and Morgan, 1999b;Trouwborst et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Highly enhanced oxidation of arsenite at the surface of birnessite in the presence of pyrophosphate and the underlying reaction mechanisms

et al. 2020

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Manganese(IV) oxides, and more especially birnessite, rank among the most efficient metal oxides for As(III) oxidation and subsequent sorption, and thus for arsenic immobilization. Efficiency is limited however by the precipitation of low valence Mn (hydr)oxides at the birnessite surface that leads to its passivation. The present work investigates experimentally the influence of chelating agents on this oxidative process. Specifically, the influence of sodium pyrophosphate (PP), an efficient Mn(III) chelating agent, on As(III) oxidation by birnessite was investigated using batch experiments and different arsenic concentrations at circum-neutral pH. In the absence of PP, Mn(II/III) species are continuously generated during As(III) oxidation and adsorbed to the mineral surface. Field emission-scanning electron microscopy, synchrotron-based X-ray diffraction and Fourier transform infrared spectroscopy indicate that manganite is formed, passivating birnessite surface and thus hampering the oxidative process. In the presence of PP, generated Mn(II/III) species form soluble complexes, thus inhibiting surface passivation and promoting As(III) conversion to As(V) from 60% in the absence of PP to 100% with 3 mM PP (0.5 mM initial As(III)). Enhancement of As(III) oxidation by Mn oxides strongly depends on the affinity of the chelating agent for Mn(III) and from the induced stability of Mn(III) complexes. Compared to PP, the positive influence of oxalate, for example, on the oxidative process is more limited. The present study thus provides new insights into the possible optimization of arsenic removal from water using Mn oxides, and on the possible environmental control of arsenic contamination by these ubiquitous non-toxic mineral species.

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“…12,13 Mn(III) can be formed via the oxidation of Mn(II), 21 the one-electron reduction of Mn(IV), 22 and a conproportionation reaction between Mn(II) and Mn(IV). 23 Mn(III) is found in the minerals bixbyite (Mn 2 O 3 ), feitknechtite, groutite, and manganite (MnO[OH]), the mixed-charge phase hausmannite (Mn 3 O 4 ), and in minerals with more complex chemistries. Free aqueous Mn(III) is prone to disproportionation to yield dissolved Mn(II) and solid Mn(IV) and is assumed to be short-lived in solution, which has led to a general underappreciation of Mn(III) in the traditional paradigm of Mn redox cycling.…”

Section: ■ Introductionmentioning

confidence: 99%

“…39 A molar extinction coefficient of 6750 M −1 cm −1 was used to calculate Mn(III) concentrations. 23 The Mn content of MnO 2 stock solutions was quantified by monitoring the absorbance following the addition of LBB at 623 nm (see the Supporting Information for details). 40 Standard curves were prepared with LBB and KMnO 4 (Figure S2).…”

Section: ■ Introductionmentioning

confidence: 99%

“…Following iron and titanium, manganese (Mn) is the third most abundant transition metal in the earth’s crust and commonly occurs in three oxidation states, Mn(II), Mn(III), and Mn(IV), in the environment . Mn(IV) in the form of MnO 2 polymorphs is abundant in soils and sediments , and a strong oxidant ( E H ° (Mn(IV)/Mn(II)) = 1.23 V) capable of oxidizing a variety of organic compounds, , including BPA. , Mn(III) can be formed via the oxidation of Mn(II), the one-electron reduction of Mn(IV), and a conproportionation reaction between Mn(II) and Mn(IV) . Mn(III) is found in the minerals bixbyite (Mn 2 O 3 ), feitknechtite, groutite, and manganite (MnO[OH]), the mixed-charge phase hausmannite (Mn 3 O 4 ), and in minerals with more complex chemistries.…”

Section: Introductionmentioning

confidence: 99%

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Degradation of Adsorbed Bisphenol A by Soluble Mn(III)

Sun

Shobnam

et al. 2021

Environ. Sci. Technol.

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Bisphenol A (BPA), a high production volume chemical and potential endocrine disruptor, is found to be associated with sediments and soils due to its hydrophobicity (log K OW of 3.42). We used superfine powdered activated carbon (SPAC) with a particle size of 1.38 ± 0.03 μm as a BPA sorbent and assessed degradation of BPA by oxidized manganese (Mn) species. SPAC strongly sorbed BPA, and desorption required organic solvents. No degradation of adsorbed BPA (278.7 ± 0.6 mg BPA g −1 SPAC) was observed with synthetic, solid α-MnO 2 with a particle size of 15.41 ± 1.35 μm; however, 89% mass reduction occurred following the addition of 0.5 mM soluble Mn(III). Small-angle neutron scattering data suggested that both adsorption and degradation of BPA occurred in SPAC pores. The findings demonstrate that Mn(III) mediates oxidative transformation of dissolved and adsorbed BPA, the latter observation challenging the paradigm that contaminant desorption and diffusion out of pore structures are required steps for degradation. Soluble Mn(III) is abundant near oxic-anoxic interfaces, and the observation that adsorbed BPA is susceptible to degradation has implications for predicting, and possibly managing, the fate and longevity of BPA in environmental systems.

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Influence of Pyrophosphate on the Generation of Soluble Mn(III) from Reactions Involving Mn Oxides and Mn(VII)

Cited by 80 publications

References 56 publications

Role of pyrophosphate on the degradation of sulfamethoxazole by permanganate combined with different reductants: Positive or negative

Role of pyrophosphate on the degradation of sulfamethoxazole by permanganate combined with different reductants: Positive or negative

Highly enhanced oxidation of arsenite at the surface of birnessite in the presence of pyrophosphate and the underlying reaction mechanisms

Degradation of Adsorbed Bisphenol A by Soluble Mn(III)

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