Determination of Hydroxyl Radical Production from Sulfide Oxidation Relevant to Sulfidic Porewaters

Samuel M. Lombardo; Amanda M. Vindedahl; William A. Arnold

doi:10.1021/acsearthspacechem.9b00297

Determination of Hydroxyl Radical Production from Sulfide Oxidation Relevant to Sulfidic Porewaters

Samuel M. Lombardo, Amanda M. Vindedahl, William A. Arnold

Civil, Environmental, and Geo- Engineering

Research output: Contribution to journal › Article › peer-review

14 Scopus citations

Abstract

Hydroxyl radical (·OH) production from the reaction between aqueous total sulfide ([H₂S]_T = [H₂S] + [HS^-] + [S^2-]) and dissolved oxygen is potentially an environmentally important reaction when anoxic, sulfidic water is exposed to oxygen. Using hydroxyterephthalate (hTPA) formation from the reaction of terephthalic acid (TPA) with ·OH as a probe for ·OH production, hydrogen peroxide was verified as an essential intermediate, and the production of free ·OH, versus lower energy hydroxylating agents, was established. The optimal conditions for the quantification of ·OH production kinetics and yield were determined by varying TPA and total sulfide concentrations. An initial total sulfide concentration of 10 μM and TPA concentration of 2 mM was used to find a yield of 15 mmol of ·OH per mole [H₂S]_T. Additionally, a pseudo-first-order model elucidated a maximum rate of production of 1.04 (±0.05) × 10^-4 moles of ·OH per hour per mole of [H₂S]_T. Experiments with sulfidic wetland porewaters containing up to 294 mg/L of dissolved organic carbon (DOC) revealed that [H₂S]_T, and not reduced DOC, was the dominant source of ·OH. A simple model considering a water containing [H₂S]_T, DOC, and methane exposed to a constant concentration of oxygen (∼ 50 μM) gave steady state values of [·OH] ranging from 5.7 × 10^-19 to 3.2 × 10^-18 M. The results indicate that [H₂S]_T should be considered a source of dark formation of ·OH in addition to ferrous iron and reduced DOC.

Original language	English (US)
Pages (from-to)	261-271
Number of pages	11
Journal	ACS Earth and Space Chemistry
Volume	4
Issue number	2
DOIs	https://doi.org/10.1021/acsearthspacechem.9b00297
State	Published - Feb 20 2020

Bibliographical note

Funding Information:
Thanks to Grant Wallace for performing sample collection and Zi-Yao Ngai for performing preliminary experiments. Dr. Dave N. Mushet and Matthew Solensky at the U.S. Geological Survey Northern Prairie Wildlife Research Center provided expertise, field support, and assistance with sample collection. This work was funded by the National Science Foundation (EAR-1245135 with ancillary support from CBET-1434148), the University of Minnesota Undergraduate Research Opportunities Program (SML), and the Joseph T. and Rose S. Ling Professorship. This NMR instrument was supported by Grant 1S10OD021536 (G. Veglia) from National Institute of General Medical Sciences. We also appreciate the helpful suggestions of Patrick Brezonik.

Funding Information:
Thanks to Grant Wallace for performing sample collection and Zi-Yao Ngai for performing preliminary experiments. Dr. Dave N. Mushet and Matthew Solensky at the U.S. Geological Survey Northern Prairie Wildlife Research Center provided expertise, field support and assistance with sample collection. This work was funded by the National Science Foundation (EAR-1245135 with ancillary support from CBET-1434148), the University of Minnesota Undergraduate Research Opportunities Program (SML), and the Joseph T. and Rose S. Ling Professorship. This NMR instrument was supported by Grant 1S10OD021536 (G. Veglia) from National Institute of General Medical Sciences. We also appreciate the helpful suggestions of Patrick Brezonik.

Publisher Copyright:
Copyright © 2020 American Chemical Society.

Keywords

hydrogen peroxide
hydroxyl radical
oxidation
sulfide
wetlands

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10.1021/acsearthspacechem.9b00297

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@article{771d999434e44e49899461e1984d9caf,

title = "Determination of Hydroxyl Radical Production from Sulfide Oxidation Relevant to Sulfidic Porewaters",

abstract = "Hydroxyl radical (·OH) production from the reaction between aqueous total sulfide ([H2S]T = [H2S] + [HS-] + [S2-]) and dissolved oxygen is potentially an environmentally important reaction when anoxic, sulfidic water is exposed to oxygen. Using hydroxyterephthalate (hTPA) formation from the reaction of terephthalic acid (TPA) with ·OH as a probe for ·OH production, hydrogen peroxide was verified as an essential intermediate, and the production of free ·OH, versus lower energy hydroxylating agents, was established. The optimal conditions for the quantification of ·OH production kinetics and yield were determined by varying TPA and total sulfide concentrations. An initial total sulfide concentration of 10 μM and TPA concentration of 2 mM was used to find a yield of 15 mmol of ·OH per mole [H2S]T. Additionally, a pseudo-first-order model elucidated a maximum rate of production of 1.04 (±0.05) × 10-4 moles of ·OH per hour per mole of [H2S]T. Experiments with sulfidic wetland porewaters containing up to 294 mg/L of dissolved organic carbon (DOC) revealed that [H2S]T, and not reduced DOC, was the dominant source of ·OH. A simple model considering a water containing [H2S]T, DOC, and methane exposed to a constant concentration of oxygen (∼ 50 μM) gave steady state values of [·OH] ranging from 5.7 × 10-19 to 3.2 × 10-18 M. The results indicate that [H2S]T should be considered a source of dark formation of ·OH in addition to ferrous iron and reduced DOC.",

keywords = "hydrogen peroxide, hydroxyl radical, oxidation, sulfide, wetlands",

author = "Lombardo, {Samuel M.} and Vindedahl, {Amanda M.} and Arnold, {William A.}",

note = "Funding Information: Thanks to Grant Wallace for performing sample collection and Zi-Yao Ngai for performing preliminary experiments. Dr. Dave N. Mushet and Matthew Solensky at the U.S. Geological Survey Northern Prairie Wildlife Research Center provided expertise, field support, and assistance with sample collection. This work was funded by the National Science Foundation (EAR-1245135 with ancillary support from CBET-1434148), the University of Minnesota Undergraduate Research Opportunities Program (SML), and the Joseph T. and Rose S. Ling Professorship. This NMR instrument was supported by Grant 1S10OD021536 (G. Veglia) from National Institute of General Medical Sciences. We also appreciate the helpful suggestions of Patrick Brezonik. Funding Information: Thanks to Grant Wallace for performing sample collection and Zi-Yao Ngai for performing preliminary experiments. Dr. Dave N. Mushet and Matthew Solensky at the U.S. Geological Survey Northern Prairie Wildlife Research Center provided expertise, field support and assistance with sample collection. This work was funded by the National Science Foundation (EAR-1245135 with ancillary support from CBET-1434148), the University of Minnesota Undergraduate Research Opportunities Program (SML), and the Joseph T. and Rose S. Ling Professorship. This NMR instrument was supported by Grant 1S10OD021536 (G. Veglia) from National Institute of General Medical Sciences. We also appreciate the helpful suggestions of Patrick Brezonik. Publisher Copyright: Copyright {\textcopyright} 2020 American Chemical Society.",

year = "2020",

month = feb,

day = "20",

doi = "10.1021/acsearthspacechem.9b00297",

language = "English (US)",

volume = "4",

pages = "261--271",

journal = "ACS Earth and Space Chemistry",

issn = "2472-3452",

publisher = "American Chemical Society",

number = "2",

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TY - JOUR

T1 - Determination of Hydroxyl Radical Production from Sulfide Oxidation Relevant to Sulfidic Porewaters

AU - Lombardo, Samuel M.

AU - Vindedahl, Amanda M.

AU - Arnold, William A.

N1 - Funding Information: Thanks to Grant Wallace for performing sample collection and Zi-Yao Ngai for performing preliminary experiments. Dr. Dave N. Mushet and Matthew Solensky at the U.S. Geological Survey Northern Prairie Wildlife Research Center provided expertise, field support, and assistance with sample collection. This work was funded by the National Science Foundation (EAR-1245135 with ancillary support from CBET-1434148), the University of Minnesota Undergraduate Research Opportunities Program (SML), and the Joseph T. and Rose S. Ling Professorship. This NMR instrument was supported by Grant 1S10OD021536 (G. Veglia) from National Institute of General Medical Sciences. We also appreciate the helpful suggestions of Patrick Brezonik. Funding Information: Thanks to Grant Wallace for performing sample collection and Zi-Yao Ngai for performing preliminary experiments. Dr. Dave N. Mushet and Matthew Solensky at the U.S. Geological Survey Northern Prairie Wildlife Research Center provided expertise, field support and assistance with sample collection. This work was funded by the National Science Foundation (EAR-1245135 with ancillary support from CBET-1434148), the University of Minnesota Undergraduate Research Opportunities Program (SML), and the Joseph T. and Rose S. Ling Professorship. This NMR instrument was supported by Grant 1S10OD021536 (G. Veglia) from National Institute of General Medical Sciences. We also appreciate the helpful suggestions of Patrick Brezonik. Publisher Copyright: Copyright © 2020 American Chemical Society.

PY - 2020/2/20

Y1 - 2020/2/20

N2 - Hydroxyl radical (·OH) production from the reaction between aqueous total sulfide ([H2S]T = [H2S] + [HS-] + [S2-]) and dissolved oxygen is potentially an environmentally important reaction when anoxic, sulfidic water is exposed to oxygen. Using hydroxyterephthalate (hTPA) formation from the reaction of terephthalic acid (TPA) with ·OH as a probe for ·OH production, hydrogen peroxide was verified as an essential intermediate, and the production of free ·OH, versus lower energy hydroxylating agents, was established. The optimal conditions for the quantification of ·OH production kinetics and yield were determined by varying TPA and total sulfide concentrations. An initial total sulfide concentration of 10 μM and TPA concentration of 2 mM was used to find a yield of 15 mmol of ·OH per mole [H2S]T. Additionally, a pseudo-first-order model elucidated a maximum rate of production of 1.04 (±0.05) × 10-4 moles of ·OH per hour per mole of [H2S]T. Experiments with sulfidic wetland porewaters containing up to 294 mg/L of dissolved organic carbon (DOC) revealed that [H2S]T, and not reduced DOC, was the dominant source of ·OH. A simple model considering a water containing [H2S]T, DOC, and methane exposed to a constant concentration of oxygen (∼ 50 μM) gave steady state values of [·OH] ranging from 5.7 × 10-19 to 3.2 × 10-18 M. The results indicate that [H2S]T should be considered a source of dark formation of ·OH in addition to ferrous iron and reduced DOC.

AB - Hydroxyl radical (·OH) production from the reaction between aqueous total sulfide ([H2S]T = [H2S] + [HS-] + [S2-]) and dissolved oxygen is potentially an environmentally important reaction when anoxic, sulfidic water is exposed to oxygen. Using hydroxyterephthalate (hTPA) formation from the reaction of terephthalic acid (TPA) with ·OH as a probe for ·OH production, hydrogen peroxide was verified as an essential intermediate, and the production of free ·OH, versus lower energy hydroxylating agents, was established. The optimal conditions for the quantification of ·OH production kinetics and yield were determined by varying TPA and total sulfide concentrations. An initial total sulfide concentration of 10 μM and TPA concentration of 2 mM was used to find a yield of 15 mmol of ·OH per mole [H2S]T. Additionally, a pseudo-first-order model elucidated a maximum rate of production of 1.04 (±0.05) × 10-4 moles of ·OH per hour per mole of [H2S]T. Experiments with sulfidic wetland porewaters containing up to 294 mg/L of dissolved organic carbon (DOC) revealed that [H2S]T, and not reduced DOC, was the dominant source of ·OH. A simple model considering a water containing [H2S]T, DOC, and methane exposed to a constant concentration of oxygen (∼ 50 μM) gave steady state values of [·OH] ranging from 5.7 × 10-19 to 3.2 × 10-18 M. The results indicate that [H2S]T should be considered a source of dark formation of ·OH in addition to ferrous iron and reduced DOC.

KW - hydrogen peroxide

KW - hydroxyl radical

KW - oxidation

KW - sulfide

KW - wetlands

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DO - 10.1021/acsearthspacechem.9b00297

M3 - Article

AN - SCOPUS:85080141291

SN - 2472-3452

VL - 4

SP - 261

EP - 271

JO - ACS Earth and Space Chemistry

JF - ACS Earth and Space Chemistry

IS - 2

ER -

Determination of Hydroxyl Radical Production from Sulfide Oxidation Relevant to Sulfidic Porewaters

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