Deconstructing the redox cascade: what role do microbial exudates (flavins) play?
Ekaterina Markelova A B E , Christopher T. Parsons A , Raoul-Marie Couture A C , Christina M. Smeaton A , Benoit Madé D , Laurent Charlet A B and Philippe Van Cappellen AA Ecohydrology Research Group, Department of Earth and Environmental Sciences and Water Institute, University of Waterloo, 200 University Avenue W, Waterloo, ON N2L 3G1, Canada.
B University Grenoble Alpes, University Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000 Grenoble, France.
C Norwegian Institute for Water Research-NIVA, Gaustadalléen 21, 0349 Oslo, Norway.
D Andra, National Radioactive Waste Management Agency, Research and Development Division, Transfer Migration Group, 1/7 Rue Jean Monnet, 92298 Chatenay Malabry Cedex, France.
E Corresponding author. Email: emarkelo@uwaterloo.ca
Environmental Chemistry 14(8) 515-524 https://doi.org/10.1071/EN17158
Submitted: 12 September 2017 Accepted: 8 November 2017 Published: 22 March 2018
Environmental context. Redox potential is a controlling variable in aquatic chemistry. Through time series data, we show that microbial exudates released by bacteria may control trends in redox potential observed in natural waters. In particular, electron transfer between these exudates and the electrode could explain the values measured in the presence of abundant oxidants such as oxygen and nitrate.
Abstract. Redox electrodes are commonly used to measure redox potentials (EH) of natural waters. The recorded EH values are usually interpreted in terms of the dominant inorganic redox couples. To further advance the interpretation of measured EH distributions along temporal and spatial redox gradients, we performed a series of reactor experiments in which oxidising and reducing conditions were alternated by switching between sparging with air and N2. Starting from a simple electrolyte solution and ending with a complex biogeochemical system, common groundwater solutes, metabolic substrates (NO3− and C3H5O3−), bacteria (Shewanella oneidensis MR-1) and goethite (α-FeOOH(s)) were tested by increasing the system complexity with each subsequent experiment. This systematic approach yielded a redox cascade ranging from +500 to −350 mV (pH ~7.4). The highest and lowest EH values registered by the platinum (Pt) electrode agreed with Nernstian redox potentials predicted for the O2/H2O2 and FeOOH/Fe2+(aq) couples respectively. Electrode poisoning by the organic pH buffer (MOPS) and addition of bacteria to the aerated solutions resulted in marked decreases in measured EH values. The latter effect is attributed to the release of flavins by Shewanella oneidensis MR-1 to the medium. As expected, equilibrium with the non-electroactive NO3−/NO2−/NH4+ redox couples could not account for the EH values recorded during dissimilatory nitrate reduction to ammonium (DNRA). However, the observed EH range for DNRA coincided with that bracketed by EH values measured in separate abiotic solutions containing either the oxidised (+324 ± 29 mV) or reduced (−229 ± 40 mV) forms of flavins. The results therefore suggest that the Pt electrode detected the presence of the electroactive flavins, even at submicromolar concentrations. In particular, flavins help explain the fairly low EH values measured in the presence of strong oxidants, such as O2 and NO3−.
References
[1] R.-M. Couture, L. Charlet, E. Markelova, B. Madé, C. T. Parsons, On–off mobilization of contaminants in soils during redox oscillations Environ. Sci. Technol. 2015, 49, 3015.| On–off mobilization of contaminants in soils during redox oscillationsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXhslags70%3D&md5=7da62c85baa8bc21dc7725ba014ebec5CAS |
[2] X. Liu, Y. Huang, W. Zhang, G. Fan, C. Fan, G. Li, Electrochemical investigation of redox thermodynamics of immobilized myoglobin: ionic and ligation effects Langmuir 2005, 21, 375.
| Electrochemical investigation of redox thermodynamics of immobilized myoglobin: ionic and ligation effectsCrossref | GoogleScholarGoogle Scholar |
[3] O. Husson, Redox potential (Eh) and pH as drivers of soil/plant/microorganism systems: a transdisciplinary overview pointing to integrative opportunities for agronomy Plant Soil 2013, 362, 389.
| Redox potential (Eh) and pH as drivers of soil/plant/microorganism systems: a transdisciplinary overview pointing to integrative opportunities for agronomyCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhvV2ks7bM&md5=d46527016fd4436a8baf384ec715e094CAS |
[4] K. Rabaey, J. Rodríguez, L. L. Blackall, J. Keller, P. Gross, D. Batstone, W. Verstraete, K. H. Nealson, Microbial ecology meets electrochemistry: electricity-driven and driving communities ISME J. 2007, 1, 9.
| Microbial ecology meets electrochemistry: electricity-driven and driving communitiesCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXksFSgu70%3D&md5=f3e7453bfc567987534cb60ca1964b6aCAS |
[5] O. N. Oktyabrskii, G. V. Smirnova, Redox potential changes in bacterial cultures under stress conditions Microbiology 2012, 81, 131.
| Redox potential changes in bacterial cultures under stress conditionsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xlslagu7g%3D&md5=dc6c24fb728c5be1aef86848880a6a47CAS |
[6] L. F. Hewitt, Oxidation–Reduction Potentials in Bacteriology and Biochemistry 1950 (E. & S. Livingstone Ltd: Edinburg).
[7] L. Kjaergaard, The redox potential: Its use and control in biotechnology. In Advances in Biochemical Engineering, Vol. 7 1977, pp. 131–150 (Springer-Verlag: Berlin).
[8] M. Myers, L. Myers, R. Okey, The use of oxidation–reduction potential as a means of controlling effluent ammonia concentration in an extended aeration activated sludge system Proc. Water Environ. Fed. 2006, 2006, 5901.
| The use of oxidation–reduction potential as a means of controlling effluent ammonia concentration in an extended aeration activated sludge systemCrossref | GoogleScholarGoogle Scholar |
[9] J. Small, M. Nykyri, M. Helin, U. Hovi, T. Sarlin, M. Itävaara, Experimental and modelling investigations of the biogeochemistry of gas production from low- and intermediate-level radioactive waste Appl. Geochem. 2008, 23, 1383.
| Experimental and modelling investigations of the biogeochemistry of gas production from low- and intermediate-level radioactive wasteCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXmt1Ons7g%3D&md5=03a5e39043d3ba5d560a43c21e93dec8CAS |
[10] E. R. Hunting, A. A. Kampfraath, Contribution of bacteria to redox potential (Eh) measurements in sediments Int. J. Environ. Sci. Technol. 2013, 10, 55.
| Contribution of bacteria to redox potential (Eh) measurements in sedimentsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXjtVGhsw%3D%3D&md5=c2cf4bc5103b57c161d33ebf9a916707CAS |
[11] W. A. Gezahegne, B. Planer-Friedrich, B. J. Merkel, Obtaining stable redox potential readings in gneiss groundwater and mine water: difficulties, meaningfulness, and potential improvement Hydrogeol. J. 2007, 15, 1221.
| Obtaining stable redox potential readings in gneiss groundwater and mine water: difficulties, meaningfulness, and potential improvementCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtVSjs7rI&md5=24233a67e36196e3de17c0d7fc7cc790CAS |
[12] T. H. Christensen, P. L. Bjerg, S. A. Banwart, R. Jakobsen, G. Heron, H.-J. Albrechtsen, Characterization of redox conditions in groundwater contaminant plumes J. Contam. Hydrol. 2000, 45, 165.
| Characterization of redox conditions in groundwater contaminant plumesCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXmtlCntLo%3D&md5=0b48a3f3856541d301e3bfec0be0d2cdCAS |
[13] S. Peiffer, O. Klemm, K. Pecher, R. Hollerung, Redox measurements in aqueous solutions – A theoretical approach to data interpretation, based on electrode kinetics J. Contam. Hydrol. 1992, 10, 1.
| Redox measurements in aqueous solutions – A theoretical approach to data interpretation, based on electrode kineticsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XkslKjsbk%3D&md5=1b082ade10c07b6be8a4b41a5da821f3CAS |
[14] W. Stumm, J. Morgan, Aquatic Chemistry: Chemical Equilibria and Rates in Natural Waters 3rd Edn 1996 (Wiley: New York).
[15] D. K. Nordstrom, E. A. Jenne, J. Ball, Redox equilibria of iron in acid mine waters. In Chemical Modeling in Aqueous Systems: Speciation, Sorption, Solubility and Kinetics 1979, pp. 51–80 (ACS Symposium Series No. 93, Washington, DC).
[16] M. Whitfield, Thermodynamic limitations on the use of the platinum electrode in Eh measurements Limnol. Oceanogr. 1974, 19, 857.
| Thermodynamic limitations on the use of the platinum electrode in Eh measurementsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2MXkvFWktQ%3D%3D&md5=21268ec8d0f05b917adf981f6b1082e4CAS |
[17] R. A. Berner, Electrode studies of hydrogen sulfide in marine sediments Geochim. Cosmochim. Acta 1963, 27, 563.
| Electrode studies of hydrogen sulfide in marine sedimentsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF3sXks1Sqtrc%3D&md5=a8d58f61fcf479bd47d140d21ea4f436CAS |
[18] O. Opel, T. Eggerichs, T. Otte, W. K. L. Ruck, Monitoring of microbially mediated corrosion and scaling processes using redox potential measurements Bioelectrochemistry 2014, 97, 137.
| Monitoring of microbially mediated corrosion and scaling processes using redox potential measurementsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXlt1Kitw%3D%3D&md5=6c1ef1d124139fa251fe9d186d42b78aCAS |
[19] A. M. L. Enright, F. G. Ferris, Bacterial Fe(II) oxidation distinguished by long-range correlation in redox potential J. Geophys. Res. Biogeosci. 2016, 121, 1249.
| Bacterial Fe(II) oxidation distinguished by long-range correlation in redox potentialCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28XpsFKhsrg%3D&md5=0cae40ef432b85730fc2cf506561ffb4CAS |
[20] L. G. M. B. Becking, I. R. Kaplan, D. Moore, Limits of the natural environment in terms of pH and oxidation–reduction potentials J. Geol. 1960, 68, 243.
| Limits of the natural environment in terms of pH and oxidation–reduction potentialsCrossref | GoogleScholarGoogle Scholar |
[21] D. G. Wareham, K. J. Hall, D. S. Mavinic, Real‐time control of aerobic‐anoxic sludge digestion using ORP J. Environ. Eng. 1993, 119, 120.
| Real‐time control of aerobic‐anoxic sludge digestion using ORPCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXis1Sntro%3D&md5=71cc840c9accb2f0c62d6f06774d5c76CAS |
[22] I. Al-Ghusain, O. J. Hao, Use of pH as control parameter for aerobic/anoxic sludge digestion J. Environ. Eng. 1995, 121, 225.
| Use of pH as control parameter for aerobic/anoxic sludge digestionCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXjvFentL4%3D&md5=fb9453bee81164310e886b22881e1493CAS |
[23] J. Guo, Q. Yang, Y. Peng, A. Yang, S. Wang, Biological nitrogen removal with real-time control using step-feed SBR technology Enzyme Microb. Technol. 2007, 40, 1564.
| Biological nitrogen removal with real-time control using step-feed SBR technologyCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXjsleitbw%3D&md5=2b9fc86c12cefc113d11c67a5c94f085CAS |
[24] C. T. Parsons, R.-M. Couture, E. O. Omoregie, F. Bardelli, J.-M. Greneche, G. Roman-Ross, L. Charlet, The impact of oscillating redox conditions: arsenic immobilisation in contaminated calcareous floodplain soils Environ. Pollut. 2013, 178, 254.
| The impact of oscillating redox conditions: arsenic immobilisation in contaminated calcareous floodplain soilsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXotlGltrY%3D&md5=818c604f43aa28e628ec9683b4e288f3CAS |
[25] S. Fiedler, M. Sommer, Water and redox conditions in wetland soils — their influence on pedogenic oxides and morphology Soil Sci. Soc. Am. J. 2004, 68, 326.
| Water and redox conditions in wetland soils — their influence on pedogenic oxides and morphologyCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXmsFartA%3D%3D&md5=4b00e1c4bfcd81db7e724157b2a2e1aaCAS |
[26] D. Coursolle, D. B. Baron, D. R. Bond, J. A. Gralnick, The Mtr respiratory pathway is essential for reducing flavins and electrodes in Shewanella oneidensis J. Bacteriol. 2010, 192, 467.
| The Mtr respiratory pathway is essential for reducing flavins and electrodes in Shewanella oneidensisCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXptVahtA%3D%3D&md5=24a7661c2ffb97d9c004025d6dc37a11CAS |
[27] E. Marsili, D. B. Baron, I. D. Shikhare, D. Coursolle, J. A. Gralnick, D. R. Bond, Shewanella secretes flavins that mediate extracellular electron transfer Proc. Natl. Acad. Sci. USA 2008, 105, 3968.
| Shewanella secretes flavins that mediate extracellular electron transferCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXjs1Oms7g%3D&md5=b6f64cbaf74f334f7b86a88dc6980ea3CAS |
[28] H. von Canstein, J. Ogawa, S. Shimizu, J. R. Lloyd, Secretion of flavins by Shewanella species and their role in extracellular electron transfer Appl. Environ. Microbiol. 2008, 74, 615.
| Secretion of flavins by Shewanella species and their role in extracellular electron transferCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhvVSqurw%3D&md5=bc4f5031f45bb9e3c82b076e64368e7dCAS |
[29] E. D. Covington, C. B. Gelbmann, N. J. Kotloski, J. A. Gralnick, An essential role for UshA in processing of extracellular flavin electron shuttles by Shewanella oneidensis Mol. Microbiol. 2010, 78, 519.
| An essential role for UshA in processing of extracellular flavin electron shuttles by Shewanella oneidensisCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhsVWqu7%2FI&md5=c56553fa87dd7c8cd9f16f50e711c3d2CAS |
[30] C. T. Parsons, F. Rezanezhad, D. W. O’Connell, P. Van Cappellen, Sediment phosphorus speciation and mobility under dynamic redox conditions Biogeosciences 2017, 14, 3585.
| Sediment phosphorus speciation and mobility under dynamic redox conditionsCrossref | GoogleScholarGoogle Scholar |
[31] L. Aldous, R. G. Compton, The mechanism of hydrazine electro-oxidation revealed by platinum microelectrodes: role of residual oxides Phys. Chem. Chem. Phys. 2011, 13, 5279.
| The mechanism of hydrazine electro-oxidation revealed by platinum microelectrodes: role of residual oxidesCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXivFyrsrY%3D&md5=2ff9e3f848c1ba0ee3f3aefe11f690f3CAS |
[32] C. A. J. Appelo, D. Postma, Geochemistry, Groundwater and Pollution 2005 (A.A. Balkema Publishers: Leiden, The Netherlands).
[33] C. Cruz-Garcia, A. E. Murray, J. A. Klappenbach, V. Stewart, J. M. Tiedje, Respiratory nitrate ammonification by Shewanella oneidensis MR-1 J. Bacteriol. 2007, 189, 656.
| Respiratory nitrate ammonification by Shewanella oneidensis MR-1Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXpt1WqtQ%3D%3D&md5=d81a19c46b2d42ec49dc4dc4d513ab20CAS |
[34] T. J. DiChristina, Effects of nitrate and nitrite on dissimilatory iron reduction by Shewanella putrefaciens 200 J. Bacteriol. 1992, 174, 1891.
| Effects of nitrate and nitrite on dissimilatory iron reduction by Shewanella putrefaciens 200Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XhvFSrsrY%3D&md5=d0c5cf35daab1d6837834cc8d6a0d5b8CAS |
[35] R. S. Hartshorne, B. N. Jepson, T. A. Clarke, S. J. Field, J. Fredrickson, J. Zachara, L. Shi, J. N. Butt, D. J. Richardson, Characterization of Shewanella oneidensis MtrC: a cell-surface decaheme cytochrome involved in respiratory electron transport to extracellular electron acceptors J. Biol. Inorg. Chem. 2007, 12, 1083.
| Characterization of Shewanella oneidensis MtrC: a cell-surface decaheme cytochrome involved in respiratory electron transport to extracellular electron acceptorsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXpvVagtLg%3D&md5=81e8b38f75594eac6cfca3f136cf061eCAS |
[36] J. E. Hobbie, R. J. Daley, S. Jasper, Use of Nuclepore filters for counting bacteria by fluorescence microscopy Appl. Environ. Microbiol. 1977, 33, 1225.
| 1:STN:280:DyaE2s3itVertw%3D%3D&md5=286e7249d41dcbef12b34294250e7611CAS |
[37] L. C. Varanda, M. P. Morales, J. M. Jafelicci, C. J. Serna, Monodispersed spindle-type goethite nanoparticles from FeIII solutions J. Mater. Chem. 2002, 12, 3649.
| Monodispersed spindle-type goethite nanoparticles from FeIII solutionsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XptFSlsbg%3D&md5=51b9491f9d45b4b66aec6eff3083595dCAS |
[38] R. M. Cornell, U. Schwertmann, The Iron Oxides: Structure, Properties, Reactions, Occurrences and Uses 2003 (Wiley-VCH: Weinheim)
[39] T. E. Meyer, C. T. Przysiecki, J. A. Watkins, A. Bhattacharyya, R. P. Simondsen, M. A. Cusanovich, G. Tollin, Correlation between rate constant for reduction and redox potential as a basis for systematic investigation of reaction mechanisms of electron transfer proteins Proc. Natl. Acad. Sci. USA 1983, 80, 6740.
| Correlation between rate constant for reduction and redox potential as a basis for systematic investigation of reaction mechanisms of electron transfer proteinsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXhvFGjsg%3D%3D&md5=a20660c5627d4cf2d4d3383548e9ca0eCAS |
[40] F. Hammes, F. Goldschmidt, M. Vital, Y. Wang, T. Egli, Measurement and interpretation of microbial adenosine tri-phosphate (ATP) in aquatic environments Water Res. 2010, 44, 3915.
| Measurement and interpretation of microbial adenosine tri-phosphate (ATP) in aquatic environmentsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXnslamsbg%3D&md5=7bd239f78dccb110b000cd6912728fedCAS |
[41] W. T. Bolleter, C. J. Bushman, P. W. Tidwell, Spectrophotometric determination of ammonia as indophenol Anal. Chem. 1961, 33, 592.
| Spectrophotometric determination of ammonia as indophenolCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF3MXmtl2nug%3D%3D&md5=22a23f3805ae8b45363a2150fb03464fCAS |
[42] E. Viollier, P. W. Inglett, K. Hunter, A. N. Roychoudhury, P. Van Cappellen, The ferrozine method revisited: Fe(II)/Fe(III) determination in natural waters Appl. Geochem. 2000, 15, 785.
| The ferrozine method revisited: Fe(II)/Fe(III) determination in natural watersCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXhsVWhsLc%3D&md5=fc08a5cb098508f297b6243272db694aCAS |
[43] D. R. Lovley, E. J. P. Phillips, Organic matter mineralization with reduction of rerric iron in anaerobic sediments Appl. Environ. Microbiol. 1986, 51, 683.
| 1:CAS:528:DyaL28XhvVeis78%3D&md5=d7bfba000a00a63884a5a6e11f6fd4abCAS |
[44] L. L. Stookey, Ferrozine – A new spectrophotometric reagent for iron Anal. Chem. 1970, 42, 779.
| Ferrozine – A new spectrophotometric reagent for ironCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3cXkt1WjtL8%3D&md5=f28651781ed0742e62dc0c86e02933efCAS |
[45] D. M. Karl, Cellular nucleotide measurements and applications in microbial ecology Microbiol. Rev. 1980, 44, 739.
| Cellular nucleotide measurements and applications in microbial ecologyCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3MXmtFWkug%3D%3D&md5=6e78486507109ec9b90c78aba5d88f8cCAS |
[46] S. N. Yurgel, J. Rice, E. Domreis, J. Lynch, N. Sa, Z. Qamar, S. Rajamani, M. Gao, S. Roje, W. D. Bauer, Sinorhizobium meliloti flavin secretion and bacteria–host interaction: role of the bifunctional RibBA protein Mol. Plant Microbe Interact. 2014, 27, 437.
| Sinorhizobium meliloti flavin secretion and bacteria–host interaction: role of the bifunctional RibBA proteinCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXmslGmtbs%3D&md5=86062158cb7e6403e4d25d0f1111948fCAS |
[47] S. M. Ratusznei, J. A. D. Rodrigues, M. Zaiat, Operating feasibility of anaerobic whey treatment in a stirred sequencing batch reactor containing immobilized biomass Water Sci. Technol. 2003, 48, 179.
| 1:CAS:528:DC%2BD3sXpvFemtrs%3D&md5=28c9893e17525717049cbff32aa486c9CAS |
[48] S. A. Cubas, E. Foresti, J. A. D. Rodrigues, S. M. Ratusznei, M. Zaiat, Effects of solid-phase mass transfer on the performance of a stirred anaerobic sequencing batch reactor containing immobilized biomass Bioresour. Technol. 2007, 98, 1411.
| Effects of solid-phase mass transfer on the performance of a stirred anaerobic sequencing batch reactor containing immobilized biomassCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXjtFak&md5=eb8b4460d74f94345750743e5ea31a55CAS |
[49] M. Altmaier, G. Xavier, F. David, B. Gunnar, Intercomparison of Redox Determination Methods on Designed and Near-Natural Aqueous Systems. Volume 7572 of KIT Scientific Reports 2010 (KIT Scientific Publishing: Karlsruhe).
[50] A. Thompson, O. A. Chadwick, D. G. Rancourt, J. Chorover, Iron-oxide crystallinity increases during soil redox oscillations Geochim. Cosmochim. Acta 2006, 70, 1710.
| Iron-oxide crystallinity increases during soil redox oscillationsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XisFChsrg%3D&md5=fc2bcb77252eab4e2b6f0053919aaf2eCAS |
[51] I. Helm, L. Jalukse, I. Leito, Measurement uncertainty estimation in amperometric sensors: a tutorial review Sensors 2010, 10, 4430.
| Measurement uncertainty estimation in amperometric sensors: a tutorial reviewCrossref | GoogleScholarGoogle Scholar |
[52] J. Schuring, H. D. Schulz, W. R. Fischer, Redox: Fundamentals, Processes and Applications 2000 (Springer-Verlag: Berlin).
[53] A. Hauch, A. Georg, Diffusion in the electrolyte and charge-transfer reaction at the platinum electrode in dye-sensitized solar cells Electrochim. Acta 2001, 46, 3457.
| Diffusion in the electrolyte and charge-transfer reaction at the platinum electrode in dye-sensitized solar cellsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXlvV2it7k%3D&md5=3aa0134281b99a00393c18de2c4f4f78CAS |
[54] M. I. Awad, M. M. Saleh, T. Ohsaka, Impact of SO2 poisoning of platinum nanoparticles modified glassy carbon electrode on oxygen reduction J. Power Sources 2011, 196, 3722.
| Impact of SO2 poisoning of platinum nanoparticles modified glassy carbon electrode on oxygen reductionCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhvVWitbw%3D&md5=bb3641109cdc9b9265fa3dd2b20bc3a9CAS |
[55] S. C. Perry, G. Denuault, Transient study of the oxygen reduction reaction on reduced Pt and Pt alloys microelectrodes: evidence for the reduction of pre-adsorbed oxygen species linked to dissolved oxygen Phys. Chem. Chem. Phys. 2015, 17, 30005.
| Transient study of the oxygen reduction reaction on reduced Pt and Pt alloys microelectrodes: evidence for the reduction of pre-adsorbed oxygen species linked to dissolved oxygenCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXhs1OmsrjM&md5=dc8e79c8fff44d02ad41b70fe96159f7CAS |
[56] T. J. Grundl, D. L. Macalady, Electrode measurement of redox potential in anaerobic ferric/ferrous chloride systems J. Contam. Hydrol. 1989, 5, 97.
| Electrode measurement of redox potential in anaerobic ferric/ferrous chloride systemsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXkvVCnurg%3D&md5=8adae730cb3326c215cfef488268b66fCAS |
[57] N. E. Good, G. D. Winget, W. Winter, T. N. Connolly, S. Izawa, R. M. M. Singh, Hydrogen ion buffers for biological research Biochemistry 1966, 5, 467.
| Hydrogen ion buffers for biological researchCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF28XltlKhuw%3D%3D&md5=793fb0c814cb23e3d7b4bc1aebdb0be2CAS |
[58] C. M. Smeaton, G. E. Walshe, A. M. L. Smith, K. A. Hudson-Edwards, W. E. Dubbin, K. Wright, A. M. Beale, B. J. Fryer, C. G. Weisener, Simultaneous release of Fe and As during the reductive dissolution of Pb–As jarosite by Shewanella putrefaciens CN32 Environ. Sci. Technol. 2012, 46, 12823.
| Simultaneous release of Fe and As during the reductive dissolution of Pb–As jarosite by Shewanella putrefaciens CN32Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhs1WgsbfE&md5=46c864a5d2647b961bbf3ee679527306CAS |
[59] J. O. Nriagu, Y. K. Soon, Distribution and isotopic composition of sulfur in lake sediments of northern Ontario Geochim. Cosmochim. Acta 1985, 49, 823.
| Distribution and isotopic composition of sulfur in lake sediments of northern OntarioCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2MXhslahurs%3D&md5=1a9a6e2e9d67a526529f53ff64f75675CAS |
[60] R.-M. Couture, D. Wallschläger, J. Rose, P. Van Cappellen, Arsenic binding to organic and inorganic sulfur species during microbial sulfate reduction: a sediment flow-through reactor experiment Environ. Chem. 2013, 10, 285.
| Arsenic binding to organic and inorganic sulfur species during microbial sulfate reduction: a sediment flow-through reactor experimentCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhtlakt7vP&md5=1763eec5ccb23dcebc617b61352b0d63CAS |
[61] M. E. Essington, Soil and Water Chemistry: An Integrative Approach 2004 (CRC Press: New York).
[62] A. Ishizaki, H. Shibai, Y. Hirose, Basic aspects of electrode potential change in submerged fermentation Agric. Biol. Chem. 1974, 38, 2399.
| Basic aspects of electrode potential change in submerged fermentationCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2MXps1Cnug%3D%3D&md5=5cf873b70d686d382adad4415cd3ca2eCAS |
[63] M. Sato, Oxidation of sulfide ore bodies – 1. Geochemical environments in terms of Eh and pH Econ. Geol. 1960, 55, 928.
| Oxidation of sulfide ore bodies – 1. Geochemical environments in terms of Eh and pHCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF3MXpt1CmsA%3D%3D&md5=8d91ea5fd38dea89ee1d57d5ef21f5dfCAS |
[64] T. R. Holm, G. K. George, M. J. Barcelona, Fluorometric determination of hydrogen peroxide in groundwater Anal. Chem. 1987, 59, 582.
| Fluorometric determination of hydrogen peroxide in groundwaterCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2sXlsFGisQ%3D%3D&md5=39f63290f9155ae74b5886b55d5f6ee2CAS |
[65] M. J. Barcelona, T. R. Holm, M. R. Schock, G. K. George, Spatial and temporal gradients in aquifer oxidation–reduction conditions Water Resour. Res. 1989, 25, 991.
| Spatial and temporal gradients in aquifer oxidation–reduction conditionsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXlsF2ks7w%3D&md5=115e6df95344e861e8221e7c23de8790CAS |
[66] T. Frevert, Can the redox conditions in natural waters be predicted by a single parameter? Schweiz. Z. Hydrol. 1984, 46, 269.
| Can the redox conditions in natural waters be predicted by a single parameter?Crossref | GoogleScholarGoogle Scholar |
[67] F. A. Koch, W. K. Oldham, Oxidation–reduction potential – a tool for monitoring, control and optimization of biological nutrient removal systems Water Sci. Technol. 1985, 17, 259.
| 1:CAS:528:DyaL28XhsFGit70%3D&md5=1a9622006fda365cf0908fc87d683debCAS |
[68] P. Tanwar, T. Nandy, P. Ukey, P. Manekar, Correlating on-line monitoring parameters, pH, DO and ORP with nutrient removal in an intermittent cyclic process bioreactor system Bioresour. Technol. 2008, 99, 7630.
| Correlating on-line monitoring parameters, pH, DO and ORP with nutrient removal in an intermittent cyclic process bioreactor systemCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXns1aksb0%3D&md5=c59f94e78e6858c3574fd38e4544610dCAS |
[69] A. Ramesh Kumar, P. Riyazuddin, Seasonal variation of redox species and redox potentials in shallow groundwater: a comparison of measured and calculated redox potentials J. Hydrol. 2012, 444–445, 187.
| Seasonal variation of redox species and redox potentials in shallow groundwater: a comparison of measured and calculated redox potentialsCrossref | GoogleScholarGoogle Scholar |
[70] T. Włodarczyk, P. Szarlip, M. Brzezińska, U. Kotowska, Redox potential, nitrate content and pH in flooded Eutric Cambisol during nitrate reduction Res. Agric. Eng. 2007, 53, 20.
[71] R. D. Lindberg, D. D. Runnells, Ground water redox reactions: an analysis of equilibrium state applied to eh measurements and geochemical modeling Science 1984, 225, 925.
| Ground water redox reactions: an analysis of equilibrium state applied to eh measurements and geochemical modelingCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXlsFOhsLs%3D&md5=fded8a672ea72998847b56523e7410d0CAS |
[72] D. Langmuir, Aqueous Environmental Geochemistry 1990 (American Chemical Society: Washington, DC).
[73] H. Senger (Ed.), The Blue Light Syndrome 1980 (Springer-Verlag: New York).
[74] E. Silvester, L. Charlet, C. Tournassat, A. Géhin, J.-M. Grenèche, E. Liger, Redox potential measurements and Mössbauer spectrometry of FeII adsorbed onto FeIII (oxyhydr)oxides Geochim. Cosmochim. Acta 2005, 69, 4801.
| Redox potential measurements and Mössbauer spectrometry of FeII adsorbed onto FeIII (oxyhydr)oxidesCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhtFOgs7zM&md5=c66aee6308c51ea37c9bfb91a53c340fCAS |
[75] D. K. Nordstrom, Hydrogeochemical processes governing the origin, transport and fate of major and trace elements from mine wastes and mineralized rock to surface waters Appl. Geochem. 2011, 26, 1777.
| Hydrogeochemical processes governing the origin, transport and fate of major and trace elements from mine wastes and mineralized rock to surface watersCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsVamu7nF&md5=5756e58a5ed81ece55e0706452300fe9CAS |
[76] T. R. Holm, C. D. Curtiss, A comparison of oxidation–reduction potentials calculated from the As(V)/As(III) and Fe(III)/Fe(II) couples with measured platinum-electrode potentials in groundwater J. Contam. Hydrol. 1989, 5, 67.
| A comparison of oxidation–reduction potentials calculated from the As(V)/As(III) and Fe(III)/Fe(II) couples with measured platinum-electrode potentials in groundwaterCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXkvVCnurs%3D&md5=c59d06757228854a5be7ac4ae1369be5CAS |
[77] D. L. Macalady, D. Langmuir, T. Grundl, A. Elzerman, Use of model-generate Fe3+ ion activities to compute Eh and ferric oxyhydroxide solubilities in anaerobic systems. In Chemical Modeling of Aqueous Systems II (Eds D. C. Melchior, R. L. Bassett) 1990, pp. 350–367 (American Chemical Society: Washington, DC).
[78] L. Matia, G. Rauret, R. Rubio, Redox potential measurement in natural waters Fresenius J. Anal. Chem. 1991, 339, 455.
| Redox potential measurement in natural watersCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3MXitFCjsbg%3D&md5=aaa95cba2bf3da3951bcbd1802c02d07CAS |
[79] I. Grenthe, W. Stumm, M. Laaksuharju, A. C. Nilsson, P. Wikberg, Redox potentials and redox reactions in deep groundwater systems Chem. Geol. 1992, 98, 131.
| Redox potentials and redox reactions in deep groundwater systemsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XlvFGnt7o%3D&md5=2f2135ec035def3c1f2c1893d0620f2bCAS |
[80] Y. Wang, P. Van Cappellen, A multicomponent reactive transport model of early diagenesis: application to redox cycling in coastal marine sediments Geochim. Cosmochim. Acta 1996, 60, 2993.
| A multicomponent reactive transport model of early diagenesis: application to redox cycling in coastal marine sedimentsCrossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XlvVSksb8%3D&md5=8f052715bb8a792047dd36ea2b288dc6CAS |
[81] D. L. Macalady, K. Walton-Day, Redox chemistry and natural organic matter (NOM): Geochemists’ dream, analytical chemists’ nightmare. In Aquatic Redox Chemistry 2011, pp. 85–111 (American Chemical Society: Washington, DC).