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Qin H, Sun Y, Rao D, Qiao J. Abiotic reductive removal of organic contaminants catalyzed by carbon materials: A short review. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:2374-2390. [PMID: 34250667 DOI: 10.1002/wer.1610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/19/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Since the observation that carbon materials can facilitate electron transfer between reactants, there is growing literature on the abiotic reductive removal of organic contaminants catalyzed by them. Most of the interest in these processes arises from the participation of carbon materials in the natural transformation of contaminants and the possibility of developing new strategies for environmental treatment and remediation. The combinations of various carbon materials and reductants have been investigated for the reduction of nitro-organic compounds, halogenated organics, and azo dyes. The reduction rates of a certain compound in carbon-reductant systems vary with the surface properties of carbon materials, although there are controversial conclusions on the properties governing the catalytic performance. This review scrutinizes the contributions of quinone moieties, electron conductivity, and other carbon properties to the activity of carbon materials. It also discusses the contaminant-dependent reduction pathways, that is, electron transfer through conductive carbon and intermediates formed during the reaction, along with possibly additional activation of contaminant molecules by carbon. Moreover, modification strategies to improve the catalytic activity for reduction are summarized. Future research needs are proposed to advance the understanding of reaction mechanisms and improve the practical utility of carbon material for water treatment. PRACTITIONER POINTS: Reduction rates of contaminants in carbon-reductant systems and modification strategies for carbon materials are summarized. Mechanisms for the catalytic activity of carbon materials are discussed. Research needs for new insights into carbon-catalyzed reduction are proposed.
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Affiliation(s)
- Hejie Qin
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China
| | - Yuankui Sun
- School of Ecological and Environmental Science, East China Normal University, Shanghai, China
| | - Dandan Rao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China
| | - Junlian Qiao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China
- International Joint Research Center for Sustainable Urban Water System, Tongji University, Shanghai, China
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Di Toro DM, Hickey KP, Allen HE, Carbonaro RF, Chiu PC. Hydrogen Atom Transfer Reaction Free Energy as a Predictor of Abiotic Nitroaromatic Reduction Rate Constants: A Comprehensive Analysis. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2020; 39:1678-1684. [PMID: 32593187 DOI: 10.1002/etc.4807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/28/2019] [Accepted: 06/21/2020] [Indexed: 06/11/2023]
Abstract
A linear free energy model is presented that predicts the second-order rate constant for the abiotic reduction of nitroaromatic compounds (NACs). Previously presented models use the one-electron reduction potential EH1(ArNO2) of the NAC reaction ArNO2+e-→ArNO2•- . If EH1(ArNO2) is not available, it has been proposed that EH1(ArNO2) be computed directly or estimated from the gas-phase electron affinity (EA). The model proposed uses the Gibbs free energy of the hydrogen atom transfer (HAT) reaction ArNO2+H•→ArNOOH• as the parameter in the linear free energy model. Both models employ quantum chemical computations for the required thermodynamic energies. The available and proposed models are compared using experimentally determined second-order rate constants from 5 investigations from the literature in which a variety of NACs were exposed to a variety of reductants. A comprehensive analysis utilizing all the NACs and reductants demonstrate that the HAT energy model and the experimental one-electron reduction potential model have similar root mean square errors and residual error probability distributions. In contrast, the model using the computed EA has a more variable residual error distribution with a significant number of outliers. The results suggest that a linear free energy model utilizing computed HAT reaction free energy produces a more reliable prediction of the NAC abiotic reduction second-order rate constant than previously available methods. The advantages of the proposed HAT energy model and its mechanistic implications are discussed as well. Environ Toxicol Chem 2020;39:1678-1684. © 2020 SETAC.
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Affiliation(s)
- Dominic M Di Toro
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
| | - Kevin P Hickey
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
| | - Herbert E Allen
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
| | - Richard F Carbonaro
- Department of Chemical Engineering, Manhattan College, Riverdale, New York, USA
| | - Pei C Chiu
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
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Stewart SM, Hofstetter TB, Joshi P, Gorski CA. Linking Thermodynamics to Pollutant Reduction Kinetics by Fe 2+ Bound to Iron Oxides. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:5600-5609. [PMID: 29595255 DOI: 10.1021/acs.est.8b00481] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Numerous studies have reported that pollutant reduction rates by ferrous iron (Fe2+) are substantially enhanced in the presence of an iron (oxyhydr)oxide mineral. Developing a thermodynamic framework to explain this phenomenon has been historically difficult due to challenges in quantifying reduction potential ( EH) values for oxide-bound Fe2+ species. Recently, our group demonstrated that EH values for hematite- and goethite-bound Fe2+ can be accurately calculated using Gibbs free energy of formation values. Here, we tested if calculated EH values for oxide-bound Fe2+ could be used to develop a free energy relationship capable of describing variations in reduction rate constants of substituted nitrobenzenes, a class of model pollutants that contain reducible aromatic nitro groups, using data collected here and compiled from the literature. All the data could be described by a single linear relationship between the logarithms of the surface-area-normalized rate constant ( kSA) values and EH and pH values [log( kSA) = - EH/0.059 V - pH + 3.42]. This framework provides mechanistic insights into how the thermodynamic favorability of electron transfer from oxide-bound Fe2+ relates to redox reaction kinetics.
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Affiliation(s)
- Sydney M Stewart
- Department of Civil & Environmental Engineering , Pennsylvania State University , 212 Sackett Building , University Park , Pennsylvania 16802 , United States
| | - Thomas B Hofstetter
- Eawag , Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zurich , CH-8092 Zurich , Switzerland
| | - Prachi Joshi
- Department of Civil & Environmental Engineering , Pennsylvania State University , 212 Sackett Building , University Park , Pennsylvania 16802 , United States
| | - Christopher A Gorski
- Department of Civil & Environmental Engineering , Pennsylvania State University , 212 Sackett Building , University Park , Pennsylvania 16802 , United States
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Tratnyek PG, Bylaska EJ, Weber EJ. In silico environmental chemical science: properties and processes from statistical and computational modelling. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:188-202. [PMID: 28262894 DOI: 10.1039/c7em00053g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Quantitative structure-activity relationships (QSARs) have long been used in the environmental sciences. More recently, molecular modeling and chemoinformatic methods have become widespread. These methods have the potential to expand and accelerate advances in environmental chemistry because they complement observational and experimental data with "in silico" results and analysis. The opportunities and challenges that arise at the intersection between statistical and theoretical in silico methods are most apparent in the context of properties that determine the environmental fate and effects of chemical contaminants (degradation rate constants, partition coefficients, toxicities, etc.). The main example of this is the calibration of QSARs using descriptor variable data calculated from molecular modeling, which can make QSARs more useful for predicting property data that are unavailable, but also can make them more powerful tools for diagnosis of fate determining pathways and mechanisms. Emerging opportunities for "in silico environmental chemical science" are to move beyond the calculation of specific chemical properties using statistical models and toward more fully in silico models, prediction of transformation pathways and products, incorporation of environmental factors into model predictions, integration of databases and predictive models into more comprehensive and efficient tools for exposure assessment, and extending the applicability of all the above from chemicals to biologicals and materials.
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Affiliation(s)
- Paul G Tratnyek
- Institute of Environmental Health, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
| | - Eric J Bylaska
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, USA
| | - Eric J Weber
- National Exposure Assessment Laboratory, U.S. Environmental Protection Agency, 960 College Station Road, Athens, GA 30605, USA
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Sander M, Hofstetter TB, Gorski CA. Electrochemical analyses of redox-active iron minerals: a review of nonmediated and mediated approaches. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5862-78. [PMID: 25856208 DOI: 10.1021/acs.est.5b00006] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Redox-active minerals are ubiquitous in the environment and are involved in numerous electron transfer reactions that significantly affect biogeochemical processes and cycles as well as pollutant dynamics. As a consequence, research in different scientific disciplines is devoted to elucidating the redox properties and reactivities of minerals. This review focuses on the characterization of mineral redox properties using electrochemical approaches from an applied (bio)geochemical and environmental analytical chemistry perspective. Establishing redox equilibria between the minerals and working electrodes is a major challenge in electrochemical measurements, which we discuss in an overview of traditional electrochemical techniques. These issues can be overcome with mediated electrochemical analyses in which dissolved redox mediators are used to increase the rate of electron transfer and to facilitate redox equilibration between working electrodes and minerals in both amperometric and potentiometric measurements. Using experimental data on an iron-bearing clay mineral, we illustrate how mediated electrochemical analyses can be employed to derive important thermodynamic and kinetic data on electron transfer to and from structural iron. We summarize anticipated methodological advancements that will further contribute to advance an improved understanding of electron transfer to and from minerals in environmentally relevant redox processes.
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Affiliation(s)
- Michael Sander
- †Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Environmental Chemistry, Swiss Federal Institute of Technology (ETH), Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Thomas B Hofstetter
- ‡Environmental Chemistry, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Ueberlandstrasse 133,8600 Duebendorf, Switzerland
| | - Christopher A Gorski
- §Civil and Environmental Engineering, The Pennsylvania State University, 212 Sackett Building, University Park, Pennsylvania 16802-1408, United States
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Salter-Blanc AJ, Bylaska EJ, Johnston HJ, Tratnyek PG. Predicting reduction rates of energetic nitroaromatic compounds using calculated one-electron reduction potentials. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:3778-86. [PMID: 25671710 DOI: 10.1021/es505092s] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The evaluation of new energetic nitroaromatic compounds (NACs) for use in green munitions formulations requires models that can predict their environmental fate. Previously invoked linear free energy relationships (LFER) relating the log of the rate constant for this reaction (log(k)) and one-electron reduction potentials for the NAC (E1NAC) normalized to 0.059 V have been re-evaluated and compared to a new analysis using a (nonlinear) free-energy relationship (FER) based on the Marcus theory of outer-sphere electron transfer. For most reductants, the results are inconsistent with simple rate limitation by an initial, outer-sphere electron transfer, suggesting that the linear correlation between log(k) and E1NAC is best regarded as an empirical model. This correlation was used to calibrate a new quantitative structure-activity relationship (QSAR) using previously reported values of log(k) for nonenergetic NAC reduction by Fe(II) porphyrin and newly reported values of E1NAC determined using density functional theory at the M06-2X/6-311++G(2d,2p) level with the COSMO solvation model. The QSAR was then validated for energetic NACs using newly measured kinetic data for 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), and 2,4-dinitroanisole (DNAN). The data show close agreement with the QSAR, supporting its applicability to other energetic NACs.
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Affiliation(s)
| | - Eric J Bylaska
- ‡William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
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Luan F, Gorski CA, Burgos WD. Linear free energy relationships for the biotic and abiotic reduction of nitroaromatic compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:3557-3565. [PMID: 25723896 DOI: 10.1021/es5060918] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nitroaromatic compounds (NACs) are ubiquitous environmental contaminants that are susceptible to biological and abiotic reduction. Prior works have found that for the abiotic reduction of NACs, the logarithm of the NACs’ rate constants correlate with one-electron reduction potential values of the NACs (EH,NAC1) according to linear free energy relationships (LFERs). Here, we extend the application of LFERs to the bioreduction of NACs and to the abiotic reduction of NACs by bioreduced (and pasteurized) iron-bearing clay minerals. A linear correlation (R2=0.96) was found between the NACs’ bioreduction rate constants (kobs) and EH,NAC1 values. The LFER slope of log kobs versus EH,NAC1/(2.303RT/F) was close to one (0.97), which implied that the first electron transfer to the NAC was the rate-limiting step of bioreduction. LFERs were also established between NAC abiotic reduction rate constants by bioreduced iron-bearing clay minerals (montmorillonite SWy-2 and nontronite NAu-2). The second-order NAC reduction rate constants (k) by bioreduced SWy-2 and NAu-2 were well correlated to EH,NAC1 (R2=0.97 for both minerals), consistent with bioreduction results. However, the LFER slopes of log k versus EH,NAC1/(2.303RT/F) were significantly less than one (0.48–0.50) for both minerals, indicating that the first electron transfer to the NAC was not the rate-limiting step of abiotic reduction. Finally, we demonstrate that the rate of 4-acetylnitrobenzene reduction by bioreduced SWy-2 and NAu-2 correlated to the reduction potential of the clay (EH,clay, R2=0.95 for both minerals), indicating that the clay reduction potential also influences its reactivity.
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Affiliation(s)
- Fubo Luan
- †Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania 16801-1408, United States
| | - Christopher A Gorski
- †Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania 16801-1408, United States
| | - William D Burgos
- †Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania 16801-1408, United States
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The Use of Chemical Probes for the Characterization of the Predominant Abiotic Reductants in Anaerobic Sediments. ACTA ACUST UNITED AC 2011. [DOI: 10.1021/bk-2011-1071.ch024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Thermodynamic Redox Calculations for One and Two Electron Transfer Steps: Implications for Halide Oxidation and Halogen Environmental Cycling. ACTA ACUST UNITED AC 2011. [DOI: 10.1021/bk-2011-1071.ch002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Elsner M, Hofstetter TB. Current Perspectives on the Mechanisms of Chlorohydrocarbon Degradation in Subsurface Environments: Insight from Kinetics, Product Formation, Probe Molecules, and Isotope Fractionation. ACS SYMPOSIUM SERIES 2011. [DOI: 10.1021/bk-2011-1071.ch019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Martin Elsner
- Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1 85764 Neuherberg, Germany
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), Überlandstr. 133, 8600 Dübendorf, Switzerland
| | - Thomas B. Hofstetter
- Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1 85764 Neuherberg, Germany
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), Überlandstr. 133, 8600 Dübendorf, Switzerland
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