Reactive transport modeling of redox geochemistry: Approaches to chemical disequilibrium and reaction rate estimation at a site in northern Wisconsin

The purpose of this study is to investigate the hydrology and redox geochemistry of shallow groundwater discharging to a stream in northern Wisconsin. In this organic-rich aquifer, we observe both oxygen reducing zones and iron reducing zones whose boundaries are roughly constant over time. To investigate the apparent steady state between solute fluxes and redox reaction rates, we develop a reactive transport model of carbon oxidation. We use a “quasi-kinetic,” “partial-equilibrium” approach to modeling redox reactions, a hybrid approach between traditional equilibrium approaches and fully kinetic approaches that require large computer resources. Our model suggests that observed trends in redox sensitive elements can only be explained by oxidation rates that are both dependent on the predominant electron acceptor and are spatially variable. Our coupled models provide field-based estimates of redox kinetics, which are otherwise difficult to obtain in hydrologically complex systems.

[1]  C. Bowser,et al.  Groundwater chemical evolution in a sandy silicate aquifer in northern Wisconsin: 2. Reaction modeling , 1992 .

[2]  D. Lovley,et al.  Competitive Exclusion of Sulfate Reduction by Fe(lll)‐Reducing Bacteria: A Mechanism for Producing Discrete Zones of High‐Iron Ground Water , 1992 .

[3]  Barbara A. Bekins,et al.  Simulation of aerobic and anaerobic biodegradation processes at a crude oil spill site , 1995 .

[4]  M. Anderson,et al.  Groundwater's dynamic role in regulating acidity and chemistry in a precipitation-dominated lake , 1989 .

[5]  D. D. Runnells,et al.  Geochemical interactions between acidic tailings fluid and bedrock: use of the computer model MINTEQ , 1987 .

[6]  Gour-Tsyh Yeh,et al.  A Model for Simulating Transport of Reactive Multispecies Components: Model Development and Demonstration , 1991 .

[7]  D. Lovley,et al.  Measuring Rates of Biodegradation in a Contaminated Aquifer Using Field and Laboratory Methods , 1996 .

[8]  E. Keating,et al.  Using reactive solutes to constrain groundwater flow models at a site in northern Wisconsin , 1998 .

[9]  T. N. Narasimhan,et al.  Reactive Transport of Petroleum Hydrocarbon Constituents in a Shallow Aquifer: Modeling Geochemical Interactions Between Organic and Inorganic Species , 1995 .

[10]  A. Walter,et al.  Modeling of multicomponent reactive transport in groundwater: 1. Model development and evaluation , 1994 .

[11]  B. Herrling,et al.  Modeling of biologically mediated redox processes in the subsurface , 1994 .

[12]  Philippe Van Cappellen,et al.  A multicomponent reactive transport model of early diagenesis: Application to redox cycling in coastal marine sediments , 1996 .

[13]  P. Cappellen,et al.  Chapter 8. BIOGEOCHEMICAL DYNAMICS IN AQUATIC SEDIMENTS , 1996 .

[14]  Jean-François Gaillard,et al.  Biogeochemical dynamics in aquatic sediments , 1996 .

[15]  D. Postma,et al.  Nitrate Reduction in an Unconfined Sandy Aquifer: Water Chemistry, Reduction Processes, and Geochemical Modeling , 1991 .

[16]  Thomas D. Waite,et al.  Transport of chromium and selenium in the suboxic zone of a shallow aquifer: Influence of redox and adsorption reactions , 1994 .

[17]  T. Holm,et al.  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 , 1989 .

[18]  T. P. Clement,et al.  Modeling Multispecies Reactive Transport in Ground Water , 1998 .

[19]  René Therrien,et al.  Simulating transport and removal of xylene during remediation of a sandy aquifer , 1995 .

[20]  R. Berner.  A New Geochemical Classification of Sedimentary Environments , 1981 .

[21]  T. N. Narasimhan,et al.  Modeling reactive transport of organic compounds in groundwater using a partial redox disequilibrium approach , 1994 .

[22]  M. Anderson,et al.  Estimating groundwater exchange with lakes: 1. The stable isotope mass balance method , 1990 .

[23]  E. M. Thurman,et al.  Organic Geochemistry of Natural Waters , 1985, Developments in Biogeochemistry.

[24]  M. Anderson,et al.  Long- and short-term transience in a groundwater/lake system in Wisconsin, USA , 1993 .

[25]  E. Ledoux,et al.  Hydrogeochemical modelling of an active system of uranium fixation by organic soils and sediments (Needle's Eye, Scotland) , 1993 .

[26]  D. L. Peck,et al.  The concept of electron activity and its relation to redox potentials in aqueous geochemical systems , 1984 .

[27]  Robert P. Eganhouse,et al.  THE GEOCHEMICAL EVOLUTION OF LOW-MOLECULAR-WEIGHT ORGANIC ACIDS DERIVED FROM THE DEGRADATION OF PETROLEUM CONTAMINANTS IN GROUNDWATER , 1994 .

[28]  Jeanne M. VanBriesen,et al.  Chapter 7. MICROBIOLOGICAL PROCESSES IN REACTIVE MODELING , 1996 .

[29]  D. Lovley,et al.  Competitive Mechanisms for Inhibition of Sulfate Reduction and Methane Production in the Zone of Ferric Iron Reduction in Sediments , 1987, Applied and environmental microbiology.

[30]  Rasmus Jakobsen,et al.  Redox zonation: Equilibrium constraints on the Fe(III)/SO4-reduction interface , 1996 .

[31]  D. Krabbenhoft.  Hydrologic and geochemical controls of freshwater ferromanganese deposit formation at Trout Lake, Vilas County, Wisconsin , 1984 .

[32]  Thomas L. Theis,et al.  Complexation of iron(II) by organic matter and its effect on iron(II) oxygenation , 1974 .

[33]  E. Frind,et al.  Sulfide mineral oxidation and subsequent reactive transport of oxidation products in mine tailings impoundments: A numerical model , 1996 .

[34]  C. Bowser,et al.  Groundwater chemical evolution in a sandy silicate aquifer in northern Wisconsin: 1. Patterns and ra , 1992 .

[35]  W. Reeburgh,et al.  Anaerobic mineralization of marine sediment organic matter: Rates and the role of anaerobic processes in the oceanic carbon economy , 1987 .

[36]  R. Keil,et al.  Geochemical changes along a river-groundwater infiltration flow path: Glattfelden, Switzerland , 1988 .

[37]  J. Vanbriesen,et al.  Microbiological processes in reactive modeling , 1996 .