Enhanced oxidation of arsenite to arsenate using tunable K+ concentration in the OMS-2 tunnel

Hou, Jingtao; Sha, Zhenjie; Hartley, William; Tan, Wenfeng; Wang, Mingxia; Xiong, Juan; Li, Yuanzhi; Long, Yi; Xue, Rui

doi:10.1016/j.envpol.2018.03.047

Cited by 12 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ferrihydrite and hematite, which showed opposite adsorption affinities to both As(III) and As(V), were used to perform the Donnan experiment. Considering that As(III) oxidation by dissolved oxygen is very slow, the dissolved oxygen in this study was not further removed by introducing an inert gas [4,41]. Arsenic concentration in the ferrihydrite chamber rapidly decreased after addition of As(III), whilst with Mn oxide there was a slight increase (Figure 4a), suggesting that most of the As(III) species may be rapidly adsorbed by ferrihydrite without further diffusion into the Mn oxide chamber.…”

Section: Aqueous Arsenic Dynamics Within Donnan Reactormentioning

confidence: 99%

As(III) adsorption on Fe-Mn binary oxides: Are Fe and Mn oxides synergistic or antagonistic for arsenic removal?

Zheng

Hou

Hartley

et al. 2020

Chemical Engineering Journal

Self Cite

113

View full text Add to dashboard Cite

Fe-Mn binary oxides are ubiquitous in the natural environment and have attracted increasing interest due to their high removal capacity for As(III), as well as their important role in the natural cycling of arsenic. Although numerous studies have characterized the respective roles of Fe and Mn oxides in As(III) removal, the relationship between different Fe-Mn binary oxides for As(III) removal has not been fully explored. In this study, three Fe-Mn binary oxides containing either ferrihydrite, hematite or goethite, were used to evaluate their adsorption capacities for As(III) in comparison with their corresponding single Fe and Mn oxide forms. We utilized spectroscopic techniques of in situ flow ATR-FTIR and XPS combined with a Donnan reactor, where Fe and Mn oxides were isolated by a semipermeable membrane through which arsenic could pass, to investigate the dynamics and speciation transformation of As(III) within mixed Fe and Mn oxides systems. The result showed that the synergistic effect, as well as antagonistic effects, between Fe and Mn oxides, was present in Fe-Mn binary oxides for As(III) removal. An obvious increase in As(III) removal with hematite, containing Fe-Mn binary oxides, and a decrease in ferrihydrite, containing Fe-Mn binary oxides, was attributed to As(III) oxidation mediated by Mn oxides as well as the difference in arsenic adsorption affinity in Fe oxides, evidenced by ATR-FTI R and XPS analyses. The findings of this work provide a new understanding of the fate of arsenic within mixed systems, which is very important for targeted application of Fe-Mn binary oxides in treating real arsenic contaminated groundwater.

show abstract

Section: Aqueous Arsenic Dynamics Within Donnan Reactormentioning

confidence: 99%

As(III) adsorption on Fe-Mn binary oxides: Are Fe and Mn oxides synergistic or antagonistic for arsenic removal?

Zheng

Hou

Hartley

et al. 2020

Chemical Engineering Journal

Self Cite

113

View full text Add to dashboard Cite

show abstract

“…18–20 Luo et al 21 found that K + concentration significantly affected the magnetism of OMS-2. Hou et al enhanced the oxidation of benzene 18 and arsenite 22 by tuning the K + concentration in the OMS-2 tunnel. Moreover, Hamaguchi et al 23 investigated the effect of K + content on the NO-adsorption properties and suggested that the adsorption sites of NO x were the K sites.…”

Section: Introductionmentioning

confidence: 99%

Promoting the mechanism of OMS-2 for gas adsorption in different K⁺ concentrations

et al. 2022

View full text Add to dashboard Cite

show abstract

“…This means that manganese oxide only acts as an oxidant for As(III) oxidation, rather than as a catalyst. In addition, a reduction in oxidation activity may occur in the presence of coexisting ions such as phosphate in arsenic‐containing wastewater . This is due to the favorable adsorption of coexisting ions onto manganese oxide surfaces, which then occupy and passivate its surface active sites .…”

Section: Introductionmentioning

confidence: 99%

Peroxymonosulfate Improves the Activity and Stability of Manganese Oxide for Oxidation of Arsenite to Arsenate

Liu

Hou

Hartley

2020

CLEAN Soil Air Water

Self Cite

View full text Add to dashboard Cite

Manganese oxide has been widely investigated for oxidation of arsenite (As(III)) to arsenate (As(V)) due to its high redox potential; however, it becomes extremely unstable after reuse. Here, As(III) oxidation activity and stability of manganese oxide in the presence of peroxymonosulfate (PMS) is investigated. Batch experimental results reveal that manganese oxide/PMS exhibits high catalytic activity for As(III) oxidation compared to manganese oxide or PMS alone. Addition of PMS to manganese oxide not only reveals long-term stability for As(III) oxidation, but also shows high As(III) oxidation activity in the presence of coexisting ions such as As(V) and phosphate. Quenching tests reveal that As(III) oxidation in the manganese oxide/PMS system is attributed to activation of PMS by manganese oxide at different oxidation states (Mn(III) and Mn(IV)), and the generation of sulfate radicals that are responsible for As(III) oxidation. exist in polluted groundwater. Between them, As(III) is reportedly more harmful than As(V) due to its greater mobility and toxicity. [4] Therefore, oxidation of As(III) to As(V) is not only a possible approach to reducing arsenic impacts on human health, but also is a vital step for total arsenic immobilization prior to treatment by subsequent technologies such as sorption and coprecipitation. [5] Manganese oxide has been widely used for rapid oxidation of As(III) to As(V) due to its high redox potential of E 0 (MnO 2 / Mn 2+ ) = 1.22 V. [6][7][8][9][10][11][12][13][14][15] However, to our knowledge, manganese oxide is unstable after being reused for As(III) oxidation, which is attributed to the release of Mn 2+ during As(III) oxidation and a decrease in the Mn oxidation state. [8,9] This means that manganese oxide only acts as an oxidant for As(III) oxidation, rather than as a catalyst. In addition, a reduction in oxidation activity may occur in the presence of coexisting ions such as phosphate in arsenic-containing wastewater. [14][15][16][17] This is due to the favorable adsorption of coexisting ions onto manganese oxide surfaces, which then occupy and passivate its surface active sites. [16] Therefore, a strategy to improve As(III) oxidation rate and guarantee the recycling of manganese oxide activity is still required.Peroxymonosulfate (PMS, HSO 5 − ) is one form of peroxosulfate-based chemical that has been widely used as an oxidant in different advanced oxidation process (AOP) techniques for degradation of organic pollutants, which has been used to quickly oxidize As(III) to As(V) in recent works. [18,19] Due to the low As(III) oxidation rate of PMS at room temperature, there is still a need to activate PMS forming sulfate radicals (SO 4 −• ) with high redox potential (2.5-2.8 V). In peroxosulfate-based AOP systems, sulfate radicals (SO 4 −• ) can be formed through activation of PMS by UV, heat, and catalysts. [20][21][22] For example, peroxosulfate-based chemicals activated by UV and Fe 2+ rapidly oxidized As(III). [18,23] As a result of lower energy consumption and its recycling ...

show abstract

Enhanced oxidation of arsenite to arsenate using tunable K+ concentration in the OMS-2 tunnel

Cited by 12 publications

References 34 publications

As(III) adsorption on Fe-Mn binary oxides: Are Fe and Mn oxides synergistic or antagonistic for arsenic removal?

As(III) adsorption on Fe-Mn binary oxides: Are Fe and Mn oxides synergistic or antagonistic for arsenic removal?

Promoting the mechanism of OMS-2 for gas adsorption in different K⁺ concentrations

Peroxymonosulfate Improves the Activity and Stability of Manganese Oxide for Oxidation of Arsenite to Arsenate

Contact Info

Product

Resources

About

Enhanced oxidation of arsenite to arsenate using tunable K+ concentration in the OMS-2 tunnel

Cited by 12 publications

References 34 publications

As(III) adsorption on Fe-Mn binary oxides: Are Fe and Mn oxides synergistic or antagonistic for arsenic removal?

As(III) adsorption on Fe-Mn binary oxides: Are Fe and Mn oxides synergistic or antagonistic for arsenic removal?

Promoting the mechanism of OMS-2 for gas adsorption in different K+ concentrations

Peroxymonosulfate Improves the Activity and Stability of Manganese Oxide for Oxidation of Arsenite to Arsenate

Contact Info

Product

Resources

About

Promoting the mechanism of OMS-2 for gas adsorption in different K⁺ concentrations