Computational Geosciences

, Volume 19, Issue 3, pp 599–611

Benchmark problems for reactive transport modeling of the generation and attenuation of acid rock drainage

  • K. Ulrich Mayer
  • Peter Alt-Epping
  • Diederik Jacques
  • Bhavna Arora
  • Carl I. Steefel
ORIGINAL PAPER

DOI: 10.1007/s10596-015-9476-9

Cite this article as:
Mayer, K.U., Alt-Epping, P., Jacques, D. et al. Comput Geosci (2015) 19: 599. doi:10.1007/s10596-015-9476-9

Abstract

Acid rock drainage (ARD) is a problem of international relevance with substantial environmental and economic implications. Reactive transport modeling has proven a powerful tool for the process-based assessment of metal release and attenuation at ARD sites. Although a variety of models has been used to investigate ARD, a systematic model intercomparison has not been conducted to date. This contribution presents such a model intercomparison involving three synthetic benchmark problems designed to evaluate model results for the most relevant processes at ARD sites. The first benchmark (ARD-B1) focuses on the oxidation of sulfide minerals in an unsaturated tailing impoundment, affected by the ingress of atmospheric oxygen. ARD-B2 extends the first problem to include pH buffering by primary mineral dissolution and secondary mineral precipitation. The third problem (ARD-B3) in addition considers the kinetic and pH-dependent dissolution of silicate minerals under low pH conditions. The set of benchmarks was solved by four reactive transport codes, namely CrunchFlow, Flotran, HP1, and MIN3P. The results comparison focused on spatial profiles of dissolved concentrations, pH and pE, pore gas composition, and mineral assemblages. In addition, results of transient profiles for selected elements and cumulative mass loadings were considered in the intercomparison. Despite substantial differences in model formulations, very good agreement was obtained between the various codes. Residual deviations between the results are analyzed and discussed in terms of their implications for capturing system evolution and long-term mass loading predictions.

Keywords

Reactive transport modeling Model intercomparison Benchmark Acid rock drainage 

Supplementary material

10596_2015_9476_MOESM1_ESM.docx (74 kb)
ESM 1Model input parameters including boundary conditions, initial conditions, reactions stoichiometries, thermodynamic constants, rate coefficients, and parameters for activity corrections are provided in tabulated form. (DOCX 74 kb) In addition, input and database files, as well as selected output files for the four participating codes CrunchFlow, Flotran, HP1 and MIN3P are provided as either text files or Excel files.
10596_2015_9476_MOESM2_ESM.zip (73 kb)
ESM 2(ZIP 72.5 kb)
10596_2015_9476_MOESM3_ESM.zip (138 kb)
ESM 3(ZIP 137 kb)
10596_2015_9476_MOESM4_ESM.zip (3.4 mb)
ESM 4(ZIP 3.43 mb)
10596_2015_9476_MOESM5_ESM.zip (58 kb)
ESM 5(ZIP 58.2 kb)
10596_2015_9476_MOESM6_ESM.zip (1.3 mb)
ESM 6(ZIP 1.34 mb)

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • K. Ulrich Mayer
    • 1
  • Peter Alt-Epping
    • 2
  • Diederik Jacques
    • 3
  • Bhavna Arora
    • 4
  • Carl I. Steefel
    • 4
  1. 1.Department of Earth, Ocean and Atmospheric SciencesUniversity of British ColumbiaVancouverCanada
  2. 2.Rock-Water Interaction Group, Institute of Geological SciencesUniversity of BernBernSwitzerland
  3. 3.Belgian Nuclear Research Centre SCK.CENMolBelgium
  4. 4.Earth Sciences DivisionLawrence Berkeley National LaboratoryBerkeleyUSA