A reactive transport benchmark on heavy metal cycling in lake sediments

Date

2015-06-01

Author

Arora, Bhavna
Şengör, Sema Sevinç
Spycher, Nicolas F.
Steefel, Carl I.

Metadata

Show full item record

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

Item Usage Stats

142
views

0
downloads

Sediments are active recipients of anthropogenic inputs, including heavy metals, but may be difficult to interpret without the use of numerical models that capture sediment-metal interactions and provide an accurate representation of the intricately coupled sedimentological, geochemical, and biological processes. The focus of this study is to present a benchmark problem on heavy metal cycling in lake sediments and to compare reactive transport models (RTMs) in their treatment of the local-scale physical and biogeochemical processes. This benchmark problem has been developed based on a previously published reactive-diffusive model of metal transport in the sediments of Lake Coeur d'Alene, Idaho. Key processes included in this model are microbial reductive dissolution of iron hydroxides (i.e., ferrihydrite), the release of sorbed metals into pore water, reaction of these metals with biogenic sulfide to form sulfide minerals, and sedimentation driving the burial of ferrihydrite and other minerals. This benchmark thus considers a multicomponent biotic reaction network with multiple terminal electron acceptors (TEAs), Fickian diffusive transport, kinetic and equilibrium mineral precipitation and dissolution, aqueous and surface complexation, as well as (optionally) sedimentation. To test the accuracy of the reactive transport problem solution, four RTMs-TOUGHREACT (TR), CrunchFlow (CF), PHREEQC, and PHT3D-have been used. Without sedimentation, all four models are able to predict similar trends of TEAs and dissolved metal concentrations, as well as mineral abundances. TR and CF are further used to compare sedimentation and compaction test cases. Results with different sedimentation rates are captured by both models, but since the codes do not use the same formulation for compaction, the results differ for this test case. Although, both TR and CF adequately capture the trends of aqueous concentrations and mineral abundances, the difference in results highlights the need to consider further the conceptual and numerical models that link transport, biogeochemical reactions, and sedimentation.

URI

https://hdl.handle.net/11511/93523

Journal

COMPUTATIONAL GEOSCIENCES

DOI

https://doi.org/10.1007/s10596-014-9445-8

Collections

Department of Environmental Engineering, Article

Suggestions

OpenMETU
Core

A Micromechanics Based Numerical Investigation of Dual Phase Steels Yalçınkaya, Tuncay; Çakmak, Serhat Onur (Elsevier BV; 2019-01-01) The aim of this paper is to investigate the effects of microstructural parameters such as the volume fraction, morphology and spatial distribution of the martensite phase and the grain size of the ferrite phase on the plasticity and localized deformation of dual-phase (DP) steels. For this purpose, Voronoi based representative volume elements (RVEs) are subjected to proportional loading with constant stress triaxility. Two alternative approaches are employed in a comparative way to model the plastic respons...
A coupled plankton-anchovy population dynamics model assessing nonlinear controls of anchovy and gelatinous biomass in the Black Sea OĞUZ, Temel; Salihoğlu, Barış; Fach Salihoğlu, Bettina Andrea (2008-01-01) A coupled model of lower trophic levels and anchovy Engraulis encrasicolus ponticus population dynamics was developed to analyze the mechanisms controlling sharp anchovy and gelatinous zooplankton biomass transitions from the 1960s to the 1980s in the Black Sea. An increase in anchovy stocks from estimated low (similar to 300 kt) to moderate (similar to 700 kt) in the late 1960s was related to weakening piscivore predation pressure, slight nutrient enrichment of the basin during an early eutrophication phas...
A DFT study on the [VO](1+)-ZSM-5 cluster: direct methanol oxidation to formaldehyde by N2O FELLAH, MEHMET FERDİ; Önal, Işık (2013-01-01) The mechanism of direct oxidation of methanol to formaldehyde by N2O has been theoretically investigated by means of density functional theory over an extra framework species in ZSM-5 zeolite represented by a [(SiH3)(4)AlO4](1) [V-O](1+) cluster model. The catalytic reactivity of these species is compared with that of mononuclear (Fe-O)(1+) sites in ZSM-5 investigated in our earlier work at the same level of theory (J. Catal. 2011, 282, 191). The [V-O](1+) site in ZSM-5 zeolite shows an enhanced catalytic a...
Simulation of eddy-driven phytoplankton production in the Black Sea Oguz, T; Salihoğlu, Barış (2000-07-15) A three dimensional, three-layer biological model is used to assess impact of eddy-dominated horizontal circulation on the spatial and temporal variations of plankton biomass in the Black Sea. Simulations are shown to exhibit patchy distributions of phytoplankton biomass as inferred from satellite images, and their intensities agree reasonably well with observations. Overall performance of the three layer model points to its potential capability as a practical alternative tool to more complex and computatio...
A novel approach to chemical resemblance of alternant hydrocarbons Türker, Burhan Lemi (2002-02-14) Within the constraints of the Huckel molecular orbital theory, a topological approach has been developed for the resemblance of alternant hydrocarbons. Four topological variables are considered which categorize alternant hydrocarbons having some resemblance of certain degree between them. Depending on variations of these topological variables, various groups of the compounds, including the identity case, various isomers and nonresembling systems have been investigated.

Citation Formats

B. Arora, S. S. Şengör, N. F. Spycher, and C. I. Steefel, “A reactive transport benchmark on heavy metal cycling in lake sediments,” COMPUTATIONAL GEOSCIENCES, vol. 19, no. 3, pp. 613–633, 2015, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/93523.