The formation of •OH with Fe-bearing smectite clays and low-molecular-weight thiols: Implication of As(III) removal

Sun, Zhaoyue; Huang, Meiying; Liu, Cun; Fang, Guodong; Chen, Ning; Zhou, Dongmei; Gao, Juan

doi:10.1016/j.watres.2020.115631

Cited by 29 publications

(5 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies regarding the influence of ligands on · OH production and contaminant degradation in Fe(II)–O 2 model systems partly support our hypothesis. − Ligands such as ethylene diamine tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and sodium tripolyphosphate (TPP) have been proven to increase the yield of · OH production upon oxygenation of dissolved Fe(II), − pyrite, − magnetite, , and Fe(II)-bearing clay minerals. − Particularly, for the oxygenation of reduced nontronite (a model Fe-rich clay mineral), Zeng et al found that ligands could dissolve a fraction of solid Fe(II) and then enhance the yield and rate of oxidant production through electron transfer from solid Fe(II) to dissolved Fe(III) . Because of the much more complicated composition of real sediments, it is still uncertain to what extent and how ligands influence · OH production and contaminant degradation during sediment oxygenation.…”

Section: Introductionsupporting

confidence: 65%

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ^·OH during Sediment Oxygenation

Xie

Zhang

Liao

et al. 2021

Environ. Sci. Technol.

View full text Add to dashboard Cite

The potential of oxygenating Fe(II)-bearing sediments for hydroxyl radical ( • OH) production and contaminant degradation has been proposed recently. Here, we further show that specific ligands can largely enhance contaminant degradation during sediment oxygenation due to increased utilization efficiency of sediment electrons. With the addition of 0− 2 mM sodium ethylene diamine tetraacetate (EDTA) or sodium tripolyphosphate (TPP) in sediment suspension (50 g/L, pH 7.0), trichloroethylene (TCE, 15 μM) degradation increased from 13% without ligand to a maximum of 80% with 2 mM TPP and was much higher with TPP than EDTA because EDTA competes for • OH. Electron utilization efficiency for • OH production increased with increased ligand concentration and was enhanced by up to 6−7 times with 2 mM EDTA or TPP. Electron transfer from sediment to dissolved Fe(III)-ligand is mainly accountable for the enhanced electron utilization efficiency by the ligands with low adsorption affinity (i.e., EDTA), and additional variation of sediment surface Fe(II) coordination is mainly responsible for the enhancement by the ligands with high adsorption affinity (i.e., TPP). Output of this study provides guidance and optional strategies for enhancing contaminant degradation during sediment oxygenation.

show abstract

Section: Introductionsupporting

confidence: 65%

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ^·OH during Sediment Oxygenation

Xie

Zhang

Liao

et al. 2021

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Low molecular weight organic acids, with oxalic acid (OA) being the most representative and active one, are frequently found in subsurface environments. − It is generally recognized that the presence of organic acids could impact the photolysis generation of ROS in iron-bearing mineral systems under light irradiation . Recently, several studies have demonstrated that organic acids can also alter the interfacial physicochemical properties of iron-bearing minerals, which ultimately affects the generation of ROS and the subsequent transformation of pollutants in darkness. − The dark environment is crucial for gaining insights into the role of organic acids and iron minerals in ROS production as well as the transformation of pollutants in light-deprived subsurface areas. There are two principal explanations associated with the ROS production in this scenario.…”

Section: Introductionmentioning

confidence: 99%

Unrecognized Role of Organic Acid in Natural Attenuation of Pollutants by Mackinawite (FeS): The Significance of Carbon-Center Free Radicals

Li,

Ma,

Zou

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

“…The observed Fe(II)-EPS complexes are likely important forms of bioavailable Fe(II) for micro-organisms, thereby in uencing Fe cycling and production of ROS (eg. •OH), and then affecting transfer and transformation of heavy metals, such as As or Sb(Sun et al, 2020).ConclusionsOur ndings clarify the mechanism of EPS-mediated •OH production by Fe(II) chemical oxidation in acidic conditions. Oxic experiments results substantiate that Fe( ) complexation by EPS increases the •OH yield from the in uence of carboxyl and hydroxyl groups in EPS.…”

mentioning

confidence: 62%

Production of Hydroxyl Radicals From Oxygenation of Simulated AMD In Presence of Extracellular Polymers Substances

Zhong

Liu

Fan

et al. 2021

Preprint

View full text Add to dashboard Cite

While the reaction mechanisms Fe(II) abiotic oxidation produce ·OH by CaCO3-induced in AMD are well-documented, little is known about the influence of extracellular polymeric substances (EPS) secreted by microorganisms on Fe(II) oxidation in AMD. Given the recent finding, this study experimently measured the cumulative concentrations of ·OH produced from oxygenation of simulated AMD in the presence of EPS. Results of this study show that the cumulative ·OH increased from 56.75 to 158.70 μM within 24 h at pH 3 with the increase in EPS concentration from 0 to 12 mg/L. An appropriate pH (about 6) and EPS (6 mg/L) concentration were required for the moderate rate of Fe(II) oxidation, corresponding to the maximum production of ·OH. The presence of EPS enhanced the ·OH production from Fe(II) oxidation in simulated AMD under acid conditions. In the presence of EPS, ·OH production is attributed mainly the complexation of Fe(II) with EPS, of which is rich of carboxyl and hydroxyl groups. Besides, the yield of ·OH increased remarkably with the addition of Fe3+. It is most likely that EPS can contribute to reduce Fe(Ⅲ) to Fe(II), which is beneficial to the production of ·OH. The findings reveal from this study supplement the fundamental of ·OH production from Fe(II) oxidation by microorganisms in natural AMD.

show abstract

The formation of •OH with Fe-bearing smectite clays and low-molecular-weight thiols: Implication of As(III) removal

Cited by 29 publications

References 50 publications

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ^·OH during Sediment Oxygenation

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ^·OH during Sediment Oxygenation

Unrecognized Role of Organic Acid in Natural Attenuation of Pollutants by Mackinawite (FeS): The Significance of Carbon-Center Free Radicals

Production of Hydroxyl Radicals From Oxygenation of Simulated AMD In Presence of Extracellular Polymers Substances

Contact Info

Product

Resources

About

The formation of •OH with Fe-bearing smectite clays and low-molecular-weight thiols: Implication of As(III) removal

Cited by 29 publications

References 50 publications

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ·OH during Sediment Oxygenation

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ·OH during Sediment Oxygenation

Unrecognized Role of Organic Acid in Natural Attenuation of Pollutants by Mackinawite (FeS): The Significance of Carbon-Center Free Radicals

Production of Hydroxyl Radicals From Oxygenation of Simulated AMD In Presence of Extracellular Polymers Substances

Contact Info

Product

Resources

About

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ^·OH during Sediment Oxygenation

Ligand-Enhanced Electron Utilization for Trichloroethylene Degradation by ^·OH during Sediment Oxygenation