Electron Transfer between Iron Minerals and Quinones: Estimating the Reduction Potential of the Fe(II)-Goethite Surface from AQDS Speciation

被引:104
作者
Orsetti, Silvia [1 ]
Laskov, Christine [1 ]
Haderlein, Stefan B. [1 ]
机构
[1] Univ Tubingen, Ctr Appl Geosci ZAG, D-72074 Tubingen, Germany
关键词
NATURAL ORGANIC-MATTER; HUMIC SUBSTANCES; REDOX REACTIONS; FE(II); OXIDATION; HEMATITE; KINETICS; SORPTION; OXIDE;
D O I
10.1021/es403658g
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Redox reactions at iron mineral surfaces play an important role in controlling biogeochemical processes of natural porous media such as sediments, soils and aquifers, especially in the presence of recurrent variations in redox conditions. Ferrous iron associated with iron mineral phases forms highly reactive species and is regarded as a key factor in determining pathways, rates, and extent of chemically and microbially driven electron transfer processes across the iron mineral water interface. Due to their transient nature and heterogeneity a detailed characterization of such surface bound Fe(II) species in terms of redox potential is still missing. To this end, we used the nonsorbing anthraquinone-2,6-disulfonate (AQDS) as a redox probe and studied the thermodynamics of its redox reactions in heterogeneous iron systems, namely goethite-Fe(II). Our results provide a thermodynamic basis for and are consistent with earlier observations on the ability of AQDS to "shuttle" electrons between microbes and iron oxide minerals. On the basis of equilibrium AQDS speciation we reported for the first time robust reduction potential measurements of reactive iron species present at goethite in aqueous systems (E-H,E-Fe-GT approximate to -170 mV). Due to the high redox buffer intensity of heterogeneous mixed valent iron systems, this value might be characteristic for many iron-reducing environments in the subsurface at circumneutral pH. Our results corroborate the picture of a dynamic remodelling of Fe(II)/Fe(III) surface sites at goethite in response to oxidation/reduction events. As quinones play an essential role in the electron transport systems of microbes, the proposed method can be considered as a biomimetic approach to determine "effective" biogeochemical reduction potentials in heterogeneous iron systems.
引用
收藏
页码:14161 / 14168
页数:8
相关论文
共 38 条
[1]   Novel Electrochemical Approach to Assess the Redox Properties of Humic Substances [J].
Aeschbacher, Michael ;
Sander, Michael ;
Schwarzenbach, Rene P. .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2010, 44 (01) :87-93
[2]   Rates and Extent of Reduction of Fe(III) Compounds and O2 by Humic Substances [J].
Bauer, Iris ;
Kappler, Andreas .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2009, 43 (13) :4902-4908
[3]  
Brock TD, 2003, Brock Biology of microorganisms
[4]   Effects of Zwitterionic Buffers on Sorption of Ferrous Iron at Goethite and Its Oxidation by CCl4 [J].
Buchholz, Anke ;
Laskov, Christine ;
Haderlein, Stefan B. .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2011, 45 (08) :3355-3360
[5]   Natural attenuation of TCE, As, Hg linked to the heterogeneous oxidation of Fe(II): an AFM study [J].
Charlet, L ;
Bosbach, D ;
Peretyashko, T .
CHEMICAL GEOLOGY, 2002, 190 (1-4) :303-319
[6]   N-compound reduction and actinide immobilisation in surficial fluids by Fe(II):: the surface Fe(III)OFe(II)OH° species, as major reductant [J].
Charlet, L ;
Silvester, E ;
Liger, E .
CHEMICAL GEOLOGY, 1998, 151 (1-4) :85-93
[7]  
Clark W.M., 1960, OXIDATION REDUCTION
[8]   ULTRAVIOLET VISIBLE AND ELECTRON-PARAMAGNETIC RESONANCE SPECTROELECTROCHEMICAL STUDIES OF THE REDUCTION PRODUCTS OF SOME ANTHRAQUINONE SULFONATES IN AQUEOUS-SOLUTIONS [J].
GAMAGE, RSKA ;
MCQUILLAN, AJ ;
PEAKE, BM .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS, 1991, 87 (22) :3653-3660
[9]  
Gorski CA, 2011, ACS SYM SER, V1071, P315
[10]   Redox Behavior of Magnetite: Implications for Contaminant Reduction [J].
Gorski, Christopher A. ;
Nurmi, James T. ;
Tratnyek, Paul G. ;
Hofstetter, Thomas B. ;
Scherer, Michelle M. .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2010, 44 (01) :55-60