A reactive transport benchmark on modeling biogenic uraninite re-oxidation by Fe(III)-(hydr)oxides

Date

2015-06-01

Author

Şengör, Sema Sevinç
Greskowiak, Janek
Wanner, Christoph
Su, Danyang
Prommer, Henning

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

112
views

0
downloads

A reactive transport benchmark on uranium (U) bioreduction and concomitant reoxidation has been developed based on the multicomponent biogeochemical reaction network presented by Spycher et al. (Geochim Cosmochim Acta 75:4426-4440, 2011). The benchmark problem consists of a model inter-comparison starting with the numerical simulations of the original batch experiments of Sani et al. (Geochim Cosmochim Acta 68:2639-2648, 2004). The batch model is then extended to 1D and 2D reactive transport models, designed to evaluate the model results for the key biogeochemical reaction processes and their coupling with physical transport. Simulations are performed with four different reactive transport simulators: PHREEQC, PHT3D, MIN3P, and TOUGHREACT. All of the simulators are able to capture the complex biogeochemical reaction kinetics and the coupling between transport and kinetic reaction network successfully in the same manner. For the dispersion-free variant of the problem, a 1D-reference solution was obtained by PHREEQC, which is not affected by numerical dispersion. PHT3D using the sequential non-iterative approach (SNIA) with an explicit TVD scheme and MIN3P using the global implicit method (GIM) with an implicit van Leer flux limiter provided the closest approximation to the PHREEQC results. Since the spatial weighting schemes for the advection term and numerical dispersion played an important role for the accuracy of the results, the simulators were further compared using different solution schemes. When all codes used the same spatial weighting scheme with finite-difference approximation, the simulation results agreed very well among all four codes. The model intercomparison for the 2D-case demonstrated a high level of sensitivity to the mixing of different waters at the dispersive front. Therefore this benchmark problem is well-suited to assess code performance for mixing-controlled reactive transport models in conjunction with complex reaction kinetics.

URI

https://hdl.handle.net/11511/93997

Journal

COMPUTATIONAL GEOSCIENCES

DOI

https://doi.org/10.1007/s10596-015-9480-0

Collections

Department of Environmental Engineering, Article

Suggestions

OpenMETU
Core

A quantum chemical study of nitric oxide reduction by ammonia (SCR reaction) on V2O5 catalyst surface

Soyer, Sezen; Uzun, Alper; Senkan, Selim; Önal, Işık (2006-12-15)

The reaction mechanism for the selective catalytic reduction (SCR) of nitric oxide by ammonia on (010) V2O5 surface represented by a V2O9H8 cluster was simulated by means of density functional theory (DFT) calculations performed at B3LYP/6-31G** level. The computations indicated that SCR reaction consisted of three main parts. For the first part, ammonia activation on V2O5 was investigated. Ammonia was adsorbed on Bronsted acidic V-OH site as NH4+ species by a non-activated process with an exothermic relati...
A Five Layer One-Dimensional PEMFC Model with Detailed Electrode Kinetics Ficicilar, B.; Eroğlu, İnci; Nguyen, T. V. (2010-10-01) In this study, a non-isothermal, two-phase, one-dimensional, and steady state proton exchange membrane (PEM) fuel cell model is developed to investigate the detailed electrode kinetics in the anode and cathode catalytic regions and the effects of these reaction mechanisms on the performance of a PEM fuel cell. Langmuir-Butler-Volmer (LBV) type reaction rate expressions are suggested for both anode and cathode electrochemical reactions. A two-phase energy balance approach is used to catch the thermal transpo...
A DFT Study of Direct Oxidation of Benzene to Phenol by N2O over [Fe(mu-O)Fe](2+) Complexes in ZSM-5 Zeolite Fellah, Mehmet Ferdi; Pidko, Evgeny A.; van Santen, Rutger A.; Önal, Işık (2011-05-19) Density functional theory (DFT) calculations were carried out in a study of the mechanism of benzene oxidation by N2O to phenol over an extra framework dimeric [FeOFe](2+) species in ZSM-5 zeolite represented by a [Si6Al2O9H14(Fe(mu-O)Fe)] cluster model. The catalytic reactivity of such a binuclear species is compared with that of mononuclear Fe2+ and (FeO)(+) sites in ZSM-5 investigated in our earlier works at the same level of theory (J. Phys. Chem. C 2009, 113, 15307; 2010, 114, 12580). The activation en...
AN INTERRUPTED IN-SITU METHOD FOR ELECTROCHEMICAL FORMATION OF Mg-Ni INTERMETALLICS Erden, Fuat; Karakaya, İshak; ERDOĞAN, METEHAN (2014-02-20) Mg-Ni system draws attention due to the promising hydrogen storage properties of Mg2Ni. The proposed method involves the use of NiO and MgCl2 in an electrochemical cell to from Mg-Ni intermetallics directly. The electrodeoxidation of NiO was followed by combination of Mg and Ni in molten salt electrolytes. The products were characterized by XRD analysis and SEM examinations. The quantitative results from Rigaku supported by Rietveld Refinement method conducted by Maud showed that more than 50 percent of the...
A novel phase-averaging method based on vortical structure correlation Vanierschot, Maarten; Perçin, Mustafa; Van Oudheusden, Bas W. (2016-10-25) In this paper we investigate a new method for phase averaging based on the correlation of vortical structures in a ow eld. The method requires the presence of a large scale precessing structure in the ow, such as for instance the precessing vortex core found in swirling ows. The transformation from time to phase is done by correlation of the instantaneous Q elds to determine the phase shift between two instants of the precession. Once the phase shift is determined, the dierent owelds are rotated bac...

Citation Formats

S. S. Şengör, J. Greskowiak, C. Wanner, D. Su, and H. Prommer, “A reactive transport benchmark on modeling biogenic uraninite re-oxidation by Fe(III)-(hydr)oxides,” COMPUTATIONAL GEOSCIENCES, vol. 19, no. 3, pp. 569–583, 2015, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/93997.