A mechanistic approach of chromium (VI) adsorption onto manganese oxides and boehmite

Islam, Md. Aminul; Angove, Michael J.; Morton, David W.; Pramanik, Biplob Kumar; Awual, Md. Rabiul

doi:10.1016/j.jece.2019.103515

Cited by 134 publications

(34 citation statements)

References 99 publications

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“…The adsorption of phosphate on edges (Figure a) probably impairs the orderly distribution of Mn(III) and even Mn(III) incorporation into vacancies, and thus prevents the formation of T-bir (path b in Figure ), even if the total Mn(III) concentration in the layers is close to that in T-bir. Specifically, phosphate adsorption may concentrate Mn(III) around edges because oxyanions bind to Mn(III) much more strongly than Mn(IV), which can decrease the energy of the system. A similar mechanism was proposed by Wang et al, in which the presence of phosphate during acid birnessite synthesis (using HCl to reduce KMnO 4 ) increases the Mn(III) fraction up to 40% but without the formation of T-bir.…”

Section: Resultsmentioning

confidence: 99%

“…Due to their extraordinary adsorption and oxidation capacities, Mn oxides play an important role in metal ions dynamics, nutrient and carbon cycling, and the fate and transport of pollutants. − Among all Mn oxide phases, hexagonal birnessite (H-bir), a layered Mn(IV) oxide (LMO), is the most common one in the natural environment . Hexagonal birnessite is constructed by stacked sheets consisting of edge-sharing MnO 6 octahedra ,, and is the primary and initial product of biotic and abiotic Mn(II) oxidation in soils, sediments, oceanic nodules, and terrestrial Mn ore deposits. , Due to its high surface area, often poor crystallinity, and high abundance of structural defects (i.e., Mn(IV) vacancies), hexagonal birnessite is highly reactive − and subjected to topotactic or reductive transformation. Divalent Mn is a common reductant and closely associated with Mn(IV) oxides as a reductive dissolution product or a precursor for oxidative precipitation of Mn(IV) oxides.…”

Section: Introductionmentioning

confidence: 99%

“…The dispersed birnessite particles more effectively oxidize the pollutants, enhancing the overall oxidation treatment efficiency of permanganate . Moreover, oxyanions can strongly adsorb on LVMOs due to their high PZCs, which may affect LVMO formation and transformation during Mn(II)-reductive transformation of birnessite. Fulvic acid was recently shown to favor the formation of Mn 3 O 4 and γ-MnOOH more than that of β-MnOOH during mineral-surface catalyzed Mn(II) oxidation .…”

Section: Introductionmentioning

confidence: 99%

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Inhibition of Oxyanions on Redox-driven Transformation of Layered Manganese Oxides

Yang

Wen

Beyer

et al. 2021

Environ. Sci. Technol.

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Layered manganese (Mn) oxides, such as birnessite, can reductively transform into other phases and thereby affect the environmental behavior of Mn oxides. Solution chemistry strongly influences the transformation, but the effects of oxyanions remain unknown. We determined the products and rates of Mn(II)-driven reductive transformation of δ-MnO2, a nanoparticulate hexagonal birnessite, in the presence of phosphate or silicate at pH 6–8 and a wide range of Mn(II)/MnO2 molar ratios. Without the oxyanions, δ-MnO2 transforms into triclinic birnessite (T-bir) and 4 × 4 tunneled Mn oxide (TMO) at low Mn(II)/MnO2 ratios (0.09 and 0.13) and into δ-MnOOH and Mn3O4 with minor poorly crystallized α- and γ-MnOOH at high Mn(II)/MnO2 ratios (0.5 and 1). The presence of phosphate or silicate substantially decreases the rate and extent of the above transformation, probably due to adsorption of the oxyanions on layer edges or the formation of Mn(II,III)-oxyanion ternary complexes on vacancies of δ-MnO2, adversely interfering with electron transfer, Mn(III) distribution, and structural rearrangements. The oxyanions also reduce the crystallinity and particle sizes of the transformation products, ascribed to adsorption of the oxyanions on the products, preventing their further particle growth. This study enriches our understanding of the solution chemistry control on redox-driven transformation of Mn oxides.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Inhibition of Oxyanions on Redox-driven Transformation of Layered Manganese Oxides

Yang

Wen

Beyer

et al. 2021

Environ. Sci. Technol.

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“…The sizes of particles formed in the liquid phase are 150-230 nm. The structural analysis of the synthesized samples showed that depending on the plasma parameters (discharge current, polarity of the electrode material), the 𝛾-AlOOH/Fe(OH) 3 13.1 [40] 𝛾-AlOOH hydrothermal method 64.7 [35] Mn-Al oxide binary system 178.85 [41] Ferrihydride 12.97 [42] Al substitute ferrihydride 39.79 [36] Fe-Al hydroxides 47.39 [37] Fe new method allows one to obtain binary oxyhydroxide systems. Surface morphology showed that the introduction of iron into the boehmite structure increases the specific surface area.…”

Section: Discussionmentioning

confidence: 99%

One‐Pot Underwater Plasma Synthesis and Characterization of Fe‐ and Ni‐Doped Boehmite

Khlyustova

Sirotkin

Титов

et al. 2021

Crystal Research and Technology

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This paper presents the one-pot method for the synthesis and doping of boehmite by a reagent-free method using the underwater plasma. Metal wires (Al, Fe, Ni) are used as sources of AlOOH and doping elements. The basic characterization tools have been used to determine the phase composition, particle size, morphology, and surface properties (X-ray diffractions (XRD), X-ray photoelectron spectroscopy (XPS) analysis, thermogravimetric analysis (TG), scanning electron microscopy (SEM), specific surface area). Varying the plasma parameters makes it possible to obtain either doped boehmite or systems of binary oxyhydroxides. The obtained materials are mesoporous, which are capable of removing the Cr(VI). The adsorption of chromium ions is studied as a function of concentration and reaction time. Fe-doped boehmite and Al-Fe oxyhydroxide system show high sorption activity concerning chromium ions (60-100 mg g −1 ). In contrast, materials based on Al-Ni have shown low efficiency as sorbents.

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“…Cr is also used as catalyst, oxidizing agent and cooling agent with water ( Saha et al, 2013 ). In another way, hastened dissolution of chromite and other minerals from natural reserves (i.e., serpentine soil and ultramafic rocks) as a natural event instigates the release of Cr into groundwaters upon suitable conditions ( Gonzalez et al, 2005 ; Islam et al, 2020 ). Moreover, volcanic eruptions and forest fires also account for some Cr contamination in the environment ( Viti et al, 2014 ).…”

Section: Introductionmentioning

confidence: 99%

Chemical-Assisted Microbially Mediated Chromium (Cr) (VI) Reduction Under the Influence of Various Electron Donors, Redox Mediators, and Other Additives: An Outlook on Enhanced Cr(VI) Removal

Rahman

Thomas

2021

Front. Microbiol.

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Chromium (Cr) (VI) is a well-known toxin to all types of biological organisms. Over the past few decades, many investigators have employed numerous bioprocesses to neutralize the toxic effects of Cr(VI). One of the main process for its treatment is bioreduction into Cr(III). Key to this process is the ability of microbial enzymes, which facilitate the transfer of electrons into the high valence state of the metal that acts as an electron acceptor. Many underlying previous efforts have stressed on the use of different external organic and inorganic substances as electron donors to promote Cr(VI) reduction process by different microorganisms. The use of various redox mediators enabled electron transport facility for extracellular Cr(VI) reduction and accelerated the reaction. Also, many chemicals have employed diverse roles to improve the Cr(VI) reduction process in different microorganisms. The application of aforementioned materials at the contaminated systems has offered a variety of influence on Cr(VI) bioremediation by altering microbial community structures and functions and redox environment. The collective insights suggest that the knowledge of appropriate implementation of suitable nutrients can strongly inspire the Cr(VI) reduction rate and efficiency. However, a comprehensive information on such substances and their roles and biochemical pathways in different microorganisms remains elusive. In this regard, our review sheds light on the contributions of various chemicals as electron donors, redox mediators, cofactors, etc., on microbial Cr(VI) reduction for enhanced treatment practices.

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A mechanistic approach of chromium (VI) adsorption onto manganese oxides and boehmite

Cited by 134 publications

References 99 publications

Inhibition of Oxyanions on Redox-driven Transformation of Layered Manganese Oxides

Inhibition of Oxyanions on Redox-driven Transformation of Layered Manganese Oxides

One‐Pot Underwater Plasma Synthesis and Characterization of Fe‐ and Ni‐Doped Boehmite

Chemical-Assisted Microbially Mediated Chromium (Cr) (VI) Reduction Under the Influence of Various Electron Donors, Redox Mediators, and Other Additives: An Outlook on Enhanced Cr(VI) Removal

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