Antimonite Complexation with Thiol and Carboxyl/Phenol Groups of Peat Organic Matter

Besold, Johannes; Kumar, Naresh; Scheinost, Andreas C.; Pacheco, Juan Lezama; Fendorf, Scott; Planer-Friedrich, Britta

doi:10.1021/acs.est.9b00495

Title: Antimonite Complexation with Thiol and Carboxyl/Phenol Groups of Peat Organic Matter

Full Record
Other Related Research

Abstract

Peatlands and other wetlands with abundant natural organic matter (NOM) are important sinks for antimony (Sb). While formation of Sb(III) sulfide phases or Sb(III) binding to NOM are discussed to decrease Sb mobility, the exact binding mechanisms remain elusive. Here, we reacted increasing sulfide concentrations with purified model peat at pH 6, forming reduced organic sulfur species, and subsequently equilibrated the reaction products with 50 μM of antimonite under anoxic conditions. Sulfur solid-phase speciation and the local binding environment of Sb were analyzed using X-ray absorption spectroscopy. We found that 85% of antimonite was sorbed by untreated peat. Sulfide-reacted peat increased sorption to 98%. Shell-by-shell fitting of Sb K-edge X-ray absorption fine structure spectra revealed Sb in untreated peat bound to carboxyl or phenol groups with average Sb–carbon distances of ~2.90 Å. With increasing content of reduced organic sulfur, Sb was progressively coordinated to S atoms at distances of ~2.45 Å and Sb–carbon distances of ~3.33 Å, suggesting increasing Sb–thiol binding. Iterative target factor analysis allowed exclusion of reduced inorganic Sb–sulfur phases with similar Sb–sulfur distances. In conclusion, even when free sulfide concentrations are too low for formation of Sb–sulfur precipitates, peat NOM can sequester Sb in anoxic, sulfur-enriched environments.

Authors:

Besold, Johannes ^[1]; Kumar, Naresh ^[2];

^[3]; Pacheco, Juan Lezama ^[4];

^[4];

^[1]

Bayreuth Univ., Bayreuth (Germany)
Stanford Univ., Stanford, CA (United States); Univ. of Vienna, Vienna (Austria)
Institute of Resource Ecology, Dresden (Germany)
Stanford Univ., Stanford, CA (United States)

Publication Date:: 2019-04-11

Research Org.:: SLAC National Accelerator Lab., Menlo Park, CA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1529259

Grant/Contract Number:: AC02-76SF00515; DAAD 57315737; DAAD 57314604; PL 302/20-1

Resource Type:: Accepted Manuscript

Journal Name:: Environmental Science and Technology

Additional Journal Information:: Journal Volume: 53; Journal Issue: 9; Journal ID: ISSN 0013-936X

Publisher:: American Chemical Society (ACS)

Country of Publication:: United States

Language:: English

Subject:: 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES

Citation Formats


                    Besold, Johannes, Kumar, Naresh, Scheinost, Andreas C., Pacheco, Juan Lezama, Fendorf, Scott, and Planer-Friedrich, Britta. Antimonite Complexation with Thiol and Carboxyl/Phenol Groups of Peat Organic Matter.  United States: N. p., 2019. 
Web.  doi:10.1021/acs.est.9b00495.

Copy to clipboard


                    Besold, Johannes, Kumar, Naresh, Scheinost, Andreas C., Pacheco, Juan Lezama, Fendorf, Scott, & Planer-Friedrich, Britta. Antimonite Complexation with Thiol and Carboxyl/Phenol Groups of Peat Organic Matter.  United States.  https://doi.org/10.1021/acs.est.9b00495

Copy to clipboard


                    Besold, Johannes, Kumar, Naresh, Scheinost, Andreas C., Pacheco, Juan Lezama, Fendorf, Scott, and Planer-Friedrich, Britta. Thu .  
"Antimonite Complexation with Thiol and Carboxyl/Phenol Groups of Peat Organic Matter".  United States.  https://doi.org/10.1021/acs.est.9b00495.  https://www.osti.gov/servlets/purl/1529259.

Copy to clipboard


                    
@article{osti_1529259,

  title        = {Antimonite Complexation with Thiol and Carboxyl/Phenol Groups of Peat Organic Matter},

  author       = {Besold, Johannes and Kumar, Naresh and Scheinost, Andreas C. and Pacheco, Juan Lezama and Fendorf, Scott and Planer-Friedrich, Britta},

  abstractNote = {Peatlands and other wetlands with abundant natural organic matter (NOM) are important sinks for antimony (Sb). While formation of Sb(III) sulfide phases or Sb(III) binding to NOM are discussed to decrease Sb mobility, the exact binding mechanisms remain elusive. Here, we reacted increasing sulfide concentrations with purified model peat at pH 6, forming reduced organic sulfur species, and subsequently equilibrated the reaction products with 50 μM of antimonite under anoxic conditions. Sulfur solid-phase speciation and the local binding environment of Sb were analyzed using X-ray absorption spectroscopy. We found that 85% of antimonite was sorbed by untreated peat. Sulfide-reacted peat increased sorption to 98%. Shell-by-shell fitting of Sb K-edge X-ray absorption fine structure spectra revealed Sb in untreated peat bound to carboxyl or phenol groups with average Sb–carbon distances of ~2.90 Å. With increasing content of reduced organic sulfur, Sb was progressively coordinated to S atoms at distances of ~2.45 Å and Sb–carbon distances of ~3.33 Å, suggesting increasing Sb–thiol binding. Iterative target factor analysis allowed exclusion of reduced inorganic Sb–sulfur phases with similar Sb–sulfur distances. In conclusion, even when free sulfide concentrations are too low for formation of Sb–sulfur precipitates, peat NOM can sequester Sb in anoxic, sulfur-enriched environments.},

  doi          = {10.1021/acs.est.9b00495},

  journal      = {Environmental Science and Technology},

  number       = 9,

  volume       = 53,

  place        = {United States},

  year         = {2019},

  month        = {4}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1021/acs.est.9b00495

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 10 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Arsenic Fate in Peat Controlled by the pH-Dependent Role of Reduced Sulfur

Journal Article Eberle, Anne ; Besold, Johannes ; Kerl, Carolin F. ; ... - Environmental Science and Technology

Reduced sulfur (S) has a contrasting role in the fate of arsenic (As) in peatlands. Sulfur bridges provide efficient binding of As to organic carbon (C), but the formation of aqueous As–S species, so-called thioarsenates, leads to a low to no sorption tendency to organic C functional groups. Here, we studied how pH changes the role of reduced S in desorption and retention of presorbed As in model peat. Control desorption experiments without S addition revealed that As was mobilized, predominantly as arsenite, in all treatments with relative mobilization increasing with pH (4.5 < 7.0 < 8.5). Addition of sulfidemore »« less
https://doi.org/10.1021/acs.est.0c00457

Full Text Available
Iron speciation in peats: Chemical and spectroscopic evidence for the co-occurrence of ferric and ferrous iron in organic complexes and mineral precipitates

Journal Article Bhattacharyya, Amrita ; Schmidt, Michael P. ; Stavitski, Eli ; ... - Organic Geochemistry

The speciation of iron (Fe) in organic matter (OM)-rich environments under in situ variable redox conditions is largely unresolved. Peatlands provide a natural setting to study Fe–OM interactions. Utilizing chemical, spectroscopic and theoretical modeling approaches, we report the chemical forms, oxidation states and local coordination environment of naturally occurring Fe in the vertically redox-stratified Manning peatlands of western New York. In addition, we report dominant carbon, sulfur and nitrogen species that can potentially stabilize the various Fe species present in these peatlands. Our results provide clear direct and indirect evidence for the co-occurrence of ferrous (Fe²⁺) and ferric (Fe³⁺) ironmore »« less
Cited by 12
https://doi.org/10.1016/j.orggeochem.2017.10.012

Full Text Available
Peat Bogs as Hotspots for Organoarsenical Formation and Persistence

Journal Article Mikutta, Christian ; Rothwell, James J. - Environmental Science and Technology

Here, peatlands have received significant atmospheric inputs of As and S since the onset of the Industrial Revolution, but the effect of S deposition on the fate of As is largely unknown. It may encompass the formation of As sulfides and organosulfur-bound As, or the indirect stimulation of As biotransformation processes, which are presently not considered as important As immobilization pathways in wetlands. To investigate the immobilization mechanisms of anthropogenically derived As in peatlands subjected to long-term atmospheric pollution, we explored the solid-phase speciation of As, Fe, and S in English peat bogs by X-ray absorption spectroscopy. Additionally, we analyzedmore »« less
Cited by 4
https://doi.org/10.1021/acs.est.5b06182
Redox Heterogeneities Promote Thioarsenate Formation and Release into Groundwater from Low Arsenic Sediments

Journal Article Kumar, Naresh ; Noël, Vincent ; Planer-Friedrich, Britta ; ... - Environmental Science and Technology

Groundwater contamination by As from natural and anthropogenic sources is a worldwide concern. Redox heterogeneities over space and time are common and can influence the molecular-level speciation of As, and thus, As release/retention but are largely unexplored. Here, we present results from a dual-domain column experiment, with natural organic-rich, fine-grained, and sulfidic sediments embedded as lenses (referred to as “reducing lenses”) within natural aquifer sand. We show that redox interfaces in sulfur-rich, alkaline aquifers may release concerning levels of As, even when sediment As concentration is low (<2 mg/kg), due to the formation of mobile thioarsenates at aqueous sulfide/Fe molarmore »« less
Cited by 2
https://doi.org/10.1021/acs.est.9b06502

Full Text Available
Dual-domain column experiment data for aquifer sediments from Riverton, WY, 2018, examining groundwater mobility and speciation of arsenic

Dataset Kumar, Naresh ; Boye, Kristin ; Noel, Vincent

This dataset is a compilation of the data that supported the publication of Kumar et al. (2020) in ES&T, http://dx.doi.org/10.1021/acs.est.9b06502. The data is from a dual domain column experiment examining the impact of redox interfaces on arsenic speciation and mobility in natural groundwater sediments that were collected at the Riverton, WY, US Department of Energy Office of Legacy Management field site. The abstract for the associated publication reads:Groundwater contamination by As from natural and anthropogenic sources is a world-wide concern. Redox heterogeneities over space and time are common and can influence the molecular-level speciation of As, and thus As release/retention,more »« less
https://doi.org/10.15485/1609128

View Dataset

Similar Records