Nonlocal Reactive Transport with Physical and Chemical Heterogeneity: Localization Errors

1995 ◽  
Vol 31 (9) ◽  
pp. 2219-2237 ◽  
Author(s):  
John H. Cushman ◽  
Bill X. Hu ◽  
Fei-Wen Deng
Keyword(s):  
Reactive Transport ◽  
Chemical Heterogeneity ◽  
Localization Errors ◽  
Physical And Chemical

scholarly journals Evolution of the Reaction and Alteration of Mudstone with Ordinary Portland Cement Leachates: Sequential Flow Experiments and Reactive-Transport Modelling

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1026
Author(s):  
Keith Bateman ◽  
Shota Murayama ◽  
Yuji Hanamachi ◽  
James Wilson ◽  
Takamasa Seta ◽  
...  
Keyword(s):  
Reactive Transport ◽  
Chemical Properties ◽  
Reactive Transport Modelling ◽  
Transport Modelling ◽  
General Sequence ◽  
Long Term Performance ◽  
Term Performance ◽  
Physical And Chemical ◽  
Flow Experiments

The construction of a repository for geological disposal of radioactive waste will include the use of cement-based materials. Following closure, groundwater will saturate the repository and the extensive use of cement will result in the development of a highly alkaline porewater, pH > 12.5; this fluid will migrate into and react with the host rock. The chemistry of the fluid will evolve over time, initially high [Na] and [K], evolving to a Ca-rich fluid, and finally returning to the groundwater composition. This evolving chemistry will affect the long-term performance of the repository, altering the physical and chemical properties, including radionuclide behaviour. Understanding these changes forms the basis for predicting the long-term evolution of the repository. This study focused on the determination of the nature and extent of the chemical reaction, as well as the formation and persistence of secondary mineral phases within a mudstone, comparing data from sequential flow experiments with the results of reactive transport modelling. The reaction of the mudstone with the cement leachates resulted in small changes in pH with the precipitation of calcium aluminium silicate hydrate (C-(A-)S-H) phases of varying compositions. As the system evolves, secondary C-(A-)S-H phases re-dissolve and are replaced by secondary carbonates. This general sequence was successfully simulated using reactive transport modelling.

Impact of Physico-Chemical Heterogeneity on Arsenic Sorption and Reactive Transport under Water Extraction

2020 ◽  
Vol 54 (23) ◽  
pp. 14974-14983
Author(s):  
Yanhua Duan ◽  
Rong Li ◽  
Yiqun Gan ◽  
Kai Yu ◽  
Jiarong Tong ◽  
...  
Keyword(s):  
Reactive Transport ◽  
Water Extraction ◽  
Chemical Heterogeneity ◽  
Physico Chemical

An analytical model for multispecies reactive transport through a heterogeneous formation consisting multiple layers of differing physical and chemical properties

2020 ◽  
Author(s):  
Jui-Sheng Chen ◽  
Ching-Ping Liang ◽  
Cheng-Hung Chang
Keyword(s):  
Analytical Model ◽  
Reactive Transport ◽  
Chlorinated Solvents ◽  
Chemical Properties ◽  
Transport Processes ◽  
Analytical Models ◽  
Physical And Chemical Properties ◽  
Heterogeneous Formation ◽  
Physical And Chemical ◽  
And Chemical Properties

<p>Transport behaviors of contaminants through a heterogeneous formation consisting multiple layers are complicated because of the different physical and chemical properties for each individual layer. Few analytical solutions for single-species contaminant transport in a multi-layer heterogeneous formation have been reported in the literature. Some contaminants of concern such as radionuclide, nitrogen and chlorinated solvents can decay or degrade to form new successor products during their transport processes, thus making migration of these contaminants much complicated. Clearly, analytical models for multispecies transport coupled by a series of decay reactions in a multi-layer formation are useful tools for synchronous determination of the fate and transport of the predecessor and successor species of decaying or degradable contaminants. This study attempts to develop an analytical model for the multispecies reactive transport of degradable or decaying contaminants through a multi-layer heterogeneous formation. The derived analytical model is shown to be correct and accurate as the consistent results of comparisons between the derived analytical model and the numerical model. The developed analytical model will provide a more reliable predicting tool for real world application.</p><p> </p>

Impacts of Physical and Chemical Heterogeneity on Cocontaminant Transport in a Sandy Porous Medium

1996 ◽  
Vol 32 (4) ◽  
pp. 801-818 ◽  
Author(s):  
Andrew F. B. Tompson ◽  
Annette L. Schafer ◽  
Robert W. Smith
Keyword(s):  
Porous Medium ◽  
Chemical Heterogeneity ◽  
Physical And Chemical
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