Role of Manganese in the Oxidation of Arsenite by Freshwater Lake Sediments1

Oscarson, D. W.; Huang, P. M.; Liaw, W. K.

doi:10.1346/ccmn.1981.0290308

Cited by 99 publications

(59 citation statements)

References 16 publications

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“…Oscarson et al (23) found that As(III) oxidation rate increased and reached a maximum as the amount of As(III) was increased at a fixed MnO2 suspension density. It was postulated that a barrier was formed at or near the surface of the oxide that prevented further reduction of the structural Mn(IV) in the interior of crystallites (23). This is consistent with our results, which suggest that a surface layer of covalently bound As(V) forms on the reacted MnO2 surface which would limit further reaction of MnO2 with As(III).…”

Section: Resultsmentioning

confidence: 99%

Arsenic(III) Oxidation and Arsenic(V) Adsorption Reactions on Synthetic Birnessite

Manning

Fendorf

Bostick

et al. 2002

Environ. Sci. Technol.

574

430

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., "Arsenic(III) Oxidation and Arsenic(V) Adsorption Reactions on Synthetic Birnessite" (2002). Publications from USDA-ARS / UNL Faculty. 503. http://digitalcommons.unl.edu/usdaarsfacpub/503 The oxidation of arsenite (As(III)) by manganese oxide is an important reaction in both the natural cycling of As and the development of remediation technology for lowering the concentration of dissolved As(III) in drinking water. This study used both a conventional stirred reaction apparatus and extended X-ray absorption fine structure (EXAFS) spectroscopy to investigate the reactions of As(III) and As(V) with synthetic birnessite (MnO 2 ). Stirred reactor experiments indicate that As(III) is oxidized by MnO 2 followed by the adsorption of the As(V) reaction product on the MnO 2 solid phase. The As(V)-Mn interatomic distance determined by EXAFS analysis for both As(III)-and As(V)-treated MnO 2 was 3.22 Å, giving evidence for the formation of As(V) adsorption complexes on MnO 2 crystallite surfaces. The most likely As(V)-MnO 2 complex is a bidentate binuclear corner sharing (bridged) complex occurring at MnO 2 crystallite edges and interlayer domains. In the As(III)-treated MnO 2 systems, reductive dissolution of the MnO 2 solid during the oxidation of As(III) caused an increase in the adsorption of As(V) when compared with As(V)-treated MnO 2 . This suggested that As(III) oxidation caused a surface alteration, creating fresh reaction sites for As(V) on MnO 2 surfaces. Arsenic(III) Oxidation and Arsenic(V) Adsorption Reactions on Synthetic Birnessite

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Section: Resultsmentioning

confidence: 99%

Arsenic(III) Oxidation and Arsenic(V) Adsorption Reactions on Synthetic Birnessite

Manning

Fendorf

Bostick

et al. 2002

Environ. Sci. Technol.

574

430

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“…As the reaction time increases, the oxidized fraction of As(III) in solution not removed by IMCS(7:3) is slightly increased, likely due to the presence of manganese oxide on the surface of IMCS(7:3). 38 Adsorption Isotherm of Phosphate and Arsenic. Adsorption isotherms of phosphate onto ICS, MCS, and IMCS(7:3) were obtained at pH 4.5 and 7 and at constant ionic strength (0.01 M NaNO 3 ) as shown in Figure 8a and b. MCS shows the least removal capacity for phosphate.…”

Section: Removal Of As(iii) By Ics Mcs and Imcs In A Batchmentioning

confidence: 99%

Removal of Arsenic and Phosphate from Aqueous Solution by Metal (Hydr-)oxide Coated Sand

Huang

Yang

Keller

2014

ACS Sustainable Chem. Eng.

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Arsenic contamination is a major concern in many drinking water supplies around the world. One low-cost approach for removing arsenic and other oxyanions such as phosphate is to use metal (hydro-)oxide coated sands. In this study, solution pH, sand grain size, coating efficiency, and mineral type for iron-coated sand (ICS), manganese-coated sand (MCS), and iron-and manganese-coated sand (IMCS) were evaluated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were used to investigate the surface properties of the coated layer. The mineral type of ICS prepared at different solution pH was identified as a mixture of FeOOH and Fe 2 O 3 . The mineral type of MCS prepared at pH 4 and 7 was identified as MnO 2 and changed to ramsdellite (γ-MnO 2 , a mixture of α-MnO 2 and β-MnO 2 ) at pH 10. ICS exhibited a greater phosphate removal capacity, and phosphate removal increased with increasing iron oxide on the sand. ICS was also shown to have a greater removal capacity for phosphate than chemical precipitation methods by FeCl 3 , especially below neutral pH. In contrast, IMCS(Fe:Mn = 7:3) was better for removing As(III), which occurs through oxidation to As(V) and adsorption of As(III) and As(V) and can reach >98% removal rate (residual concentration <0.02 mg/L) at neutral pH. IMCS(7:3) is an efficient adsorbent for arsenic, as >50% can be removed within 60 min; 66% adsorption was reached after 24 h. Removal of arsenic and phosphate by these metal (hydro-)oxide coated sand adsorbents followed a pseudo-second-order rate and Langmuir as well as Freundlich adsorption isotherms. Removal under different conditions (e.g., pH, ionic strength) was also evaluated to provide information to optimize the process.

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“…Mn oxides are common soil minerals with a high capacity to oxidize heavy metals and metalloids including As(III) (Post 1999). The effective oxidation of As (III) by synthetic Mn oxides such as birnessite (δ-MnO 2 ) has been reported (Oscarson et al 1981(Oscarson et al , 1983. However, 4…”

Section: Solid Phase Analysismentioning

confidence: 99%

Effect of soil microorganisms on arsenite oxidation in paddy soils under oxic conditions

Dong

Yamaguchi

Makino

et al. 2014

Soil Science and Plant Nutrition

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The contribution of abiotic and biotic processes to the oxidation of arsenite [As(III)] when anaerobic paddy soils were shifted to oxic conditions was investigated. Soil slurries were first incubated under reducing conditions to allow indigenous arsenic (As) to be dissolved into the liquid phase as As(III), and were then switched to oxic incubation conditions with shaking. One day after switching to oxic incubation, As(III) almost disappeared from the liquid phase without any increase of arsenate [As(V)], suggesting that dissolved As(III) was coprecipitated or adsorbed on the soil solid phase. X-ray adsorption near-edge structure (XANES) analysis revealed that the predominant species of As in the solid phase before the oxic incubation was As(III), ranging from 74 to 85% of total As. After 1 d of the oxic incubation, the proportion of As(III) decreased to 46-47%. This oxidation step was an abiotic process and 28-38% of As(III) was oxidized per day on average. However, the abiotic oxidation ceased within 24 h probably due to passivation of reactive sites on the mineral surface. Afterward, a second slow oxidation step (2.5-2.8% per day on average) became predominant. Interestingly, this step was microbiologically mediated, since it did not occur in sterilized soil slurries. Determination of putative arsenite oxidase gene (aioA) sequences suggested that arsenite-oxidizing bacteria are actually present in our soil slurries. Our results suggest that microbial As(III) oxidation accounts for more than 30% of total As(III) oxidation, and thus it is an important process especially after abiotic oxidation ceases.

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Role of Manganese in the Oxidation of Arsenite by Freshwater Lake Sediments1

Cited by 99 publications

References 16 publications

Arsenic(III) Oxidation and Arsenic(V) Adsorption Reactions on Synthetic Birnessite

Arsenic(III) Oxidation and Arsenic(V) Adsorption Reactions on Synthetic Birnessite

Removal of Arsenic and Phosphate from Aqueous Solution by Metal (Hydr-)oxide Coated Sand

Effect of soil microorganisms on arsenite oxidation in paddy soils under oxic conditions

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