1
|
Chen MA, Mehta N, Kocar BD. Semiconducting hematite facilitates microbial and abiotic reduction of chromium. Sci Rep 2022; 12:9032. [PMID: 35641526 PMCID: PMC9156696 DOI: 10.1038/s41598-022-12824-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/11/2022] [Indexed: 11/21/2022] Open
Abstract
Semi-conducting Fe oxide minerals, such as hematite, are well known to influence the fate of contaminants and nutrients in many environmental settings through sorption and release of Fe(II) resulting from microbial or abiotic reduction. Studies of Fe oxide reduction by adsorbed Fe(II) have demonstrated that reduction of Fe(III) at one mineral surface can result in the release of Fe(II) on a different one. This process is termed “Fe(II) catalyzed recrystallization” and is believed to be the result of electron transfer through semi-conducting Fe (hydr)oxides. While it is well understood that Fe(II) plays a central role in redox cycling of elements, the environmental implications of Fe(II) catalyzed recrystallization require further exploration. Here, we demonstrate that hematite links physically separated redox reactions by conducting the electrons involved in those reactions. This is shown using an electrochemical setup where Cr reduction is coupled with a potentiostat or Shewanella putrefaciens, a metal reducing microbe, where electrons donated to hematite produce Fe(II) that ultimately reduces Cr. This work demonstrates that mineral semi-conductivity may provide an additional avenue for redox chemistry to occur in natural soils and sediments, because these minerals can link redox active reactants that could not otherwise react due to physical separation.
Collapse
Affiliation(s)
- Michael A Chen
- Parsons Laboratory, Department of Civil and Environmental Engineering, MIT, 15 Vassar St., Cambridge, MA, 02139, USA.,Department of Earth and Environmental Sciences, University of Minnesota, 116 Church St. SE, Minneapolis, MN, 55455, USA
| | - Neha Mehta
- Parsons Laboratory, Department of Civil and Environmental Engineering, MIT, 15 Vassar St., Cambridge, MA, 02139, USA.,Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, Sorbonne Universités, 75005, Paris, France
| | - Benjamin D Kocar
- Parsons Laboratory, Department of Civil and Environmental Engineering, MIT, 15 Vassar St., Cambridge, MA, 02139, USA. .,Environmental Laboratory, US Army Engineer Research & Development Center, 3909 Halls Ferry Road, Vicksburg, MS, 39180, USA.
| |
Collapse
|
2
|
Park S, Anggraini TM, Chung J, Kang PK, Lee S. Microfluidic pore model study of precipitates induced by the pore-scale mixing of an iron sulfate solution with simulated groundwater. CHEMOSPHERE 2021; 271:129857. [PMID: 33736220 DOI: 10.1016/j.chemosphere.2021.129857] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 01/27/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Precipitates induced by the pore-scale mixing of iron sulfate solutions with simulated groundwater were investigated using a microfluidic pore model to assess the environmental impacts of the infiltration of acid mine drainage into a shallow aquifer. This model was employed to visualize the formation of precipitates in a porous network and to evaluate their physicochemical influences on pore flow. Four types of groundwater (Na-HCO3, Na-SO4, Na-Cl, and Ca-Cl) were evaluated, and precipitation rates were calculated by processing images of precipitates in the pores captured via microscopy. The results showed that all groundwater types formed a yellow-brownish precipitate at the interface of the iron solution and simulated groundwater flow. Microscopic X-ray analyses demonstrated that precipitate morphology varied with groundwater type. Faster precipitation was observed in the following order by groundwater type: Na-HCO3 > Na-Cl > Na-SO4 > Ca-Cl, which was attributed to the different stability constants of the major anions in each simulated groundwater with Fe ions. Chemical equilibrium models suggested that precipitates were Fe minerals, with FeOOH as the predominant form consistent with the results of X-ray photoelectron spectrometry. The presence of FeOOH implies that precipitates may serve as an effective sorption barrier against some nutrients and heavy metals for the underlying groundwater. However, dye-flow experiments suggested that the precipitates may clog aquifer pores, thereby altering hydrogeological properties in the aquifer.
Collapse
Affiliation(s)
- Saerom Park
- Urban Water Circulation Research Center, Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT), Gyeonggi-do, 10223, Republic of Korea
| | - Theresia May Anggraini
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Energy and Environment Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Jaeshik Chung
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Peter K Kang
- Department of Earth and Environmental Sciences, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, United States
| | - Seunghak Lee
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Energy and Environment Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea.
| |
Collapse
|
3
|
Chen MA, Kocar BD. Development of a novel microfluidic device to study metal geochemistry in situ using X-ray fluorescence microprobe spectroscopy. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:461-471. [PMID: 33650558 DOI: 10.1107/s1600577520016239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
The study of in situ microscale biogeochemical processes represents a major challenge in the environmental sciences. The combination of microfluidic devices with X-ray fluorescence microprobe spectroscopy may address this need, but typical materials used in these devices attenuate the X-rays needed to analyze key elements of interest, such as Fe or As. In this work, a method is presented for fabricating an etched silicon microfluidic device that is sealed with a 30 µm thin glass window that is sufficiently transparent for X-ray fluorescence microprobe spectroscopy. The capabilities of these devices for X-ray microprobe spectroscopy are demonstrated using an Fe (hydr)oxide solid that is loaded with As and then infused with sulfide, on beamline 4-BM at NSLS-II, resulting in time-variant Fe precipitation reactions and As sorption. Key results include in situ X-ray fluorescence time-series maps of Fe, As and a Br flow tracer, as well as spot XANES at both the Fe K edge and As K edge. Additionally, multiple energy mapping is used to examine the spatial speciation of As over time. The results of this work clearly demonstrate the capabilities of this novel microfluidic system that can be analyzed using X-ray fluorescence microprobe spectroscopy and can be made to study a wide range of complex microscale geochemical systems.
Collapse
Affiliation(s)
- Michael A Chen
- Civil and Environmental Engineering, MIT, 15 Vassar Street, Cambridge, MA 02139, USA
| | - Benjamin D Kocar
- Civil and Environmental Engineering, MIT, 15 Vassar Street, Cambridge, MA 02139, USA
| |
Collapse
|
4
|
Majumder ELW, Wall JD. Uranium Bio-Transformations: Chemical or Biological Processes? ACTA ACUST UNITED AC 2017. [DOI: 10.4236/ojic.2017.72003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
5
|
Wu Y, Liu T, Li X, Li F. Exogenous electron shuttle-mediated extracellular electron transfer of Shewanella putrefaciens 200: electrochemical parameters and thermodynamics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:9306-9314. [PMID: 25058026 DOI: 10.1021/es5017312] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Despite the importance of exogenous electron shuttles (ESs) in extracellular electron transfer (EET), a lack of understanding of the key properties of ESs is a concern given their different influences on EET processes. Here, the ES-mediated EET capacity of Shewanella putrefaciens 200 (SP200) was evaluated by examining the electricity generated in a microbial fuel cell. The results indicated that all the ESs substantially accelerated the current generation compared to only SP200. The current and polarization parameters were linearly correlated with both the standard redox potential (E(ES)(0)) and the electron accepting capacity (EAC) of the ESs. A thermodynamic analysis of the electron transfer from the electron donor to the electrode suggested that the EET from c-type cytochromes (c-Cyts) to ESs is a crucial step causing the differences in EET capacities among various ESs. Based on the derived equations, both E(ES)(0) and EAC can quantitatively determine potential losses (ΔE) that reflect the potential loss of the ES-mediated EET. In situ spectral kinetic analysis of ES reduction by c-Cyts in a living SP200 suspension was first investigated with the E(ES), E(c-Cyt), and ΔE values being calculated. This study can provide a comprehensive understanding of the role of ESs in EET.
Collapse
Affiliation(s)
- Yundang Wu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences , Guangzhou, P. R. China
| | | | | | | |
Collapse
|
6
|
Kovarik ML, Ornoff DM, Melvin AT, Dobes NC, Wang Y, Dickinson AJ, Gach PC, Shah PK, Allbritton NL. Micro total analysis systems: fundamental advances and applications in the laboratory, clinic, and field. Anal Chem 2013; 85:451-72. [PMID: 23140554 PMCID: PMC3546124 DOI: 10.1021/ac3031543] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Michelle L. Kovarik
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Douglas M. Ornoff
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Adam T. Melvin
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Nicholas C. Dobes
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Alexandra J. Dickinson
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Philip C. Gach
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Pavak K. Shah
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599 and North Carolina State University, Raleigh, NC 27695
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599 and North Carolina State University, Raleigh, NC 27695
| |
Collapse
|