<abstract xmlns="http://www.w3.org/1999/xhtml"><p>HPx is a multicomponent reactive transport model which uses HYDRUS as the flow and transport solver and PHREEQC-3 as the biogeochemical solver. Some recent adaptations have significantly increased the flexibility of the software for different environmental and engineering applications. This paper gives an overview of the most significant changes of HPx, such as coupling transport properties to geochemical state variables, gas diffusion, and transport in two and three dimensions. OpenMP allows for parallel computing using shared memory. Enhancements for scripting may eventually simplify input definitions and create possibilities for defining templates for generic (sub)problems. We included a discussion of root solute uptake and colloid-affected solute transport to show that most or all of the comprehensive features of HYDRUS can be extended with geochemical information. Finally, an example is used to demonstrate how HPx, and similar reactive transport models, can be helpful in implementing different factors relevant for soil organic matter dynamics in soils. HPx offers a unique framework to couple spatial-temporal variations in water contents, temperatures, and water fluxes, with dissolved organic matter and CO<sub>2</sub> transport, as well as bioturbation processes.</p></abstract>

HPx is a multicomponent reactive transport model which uses HYDRUS as the flow and transport solver and PHREEQC-3 as the biogeochemical solver. Some recent adaptations have significantly increased the flexibility of the software for different environmental and engineering applications. This paper gives an overview of the most significant changes of HPx, such as coupling transport properties to geochemical state variables, gas diffusion, and transport in two and three dimensions. OpenMP allows for parallel computing using shared memory. Enhancements for scripting may eventually simplify input definitions and create possibilities for defining templates for generic (sub)problems. We included a discussion of root solute uptake and colloid-affected solute transport to show that most or all of the comprehensive features of HYDRUS can be extended with geochemical information. Finally, an example is used to demonstrate how HPx, and similar reactive transport models, can be helpful in implementing different factors relevant for soil organic matter dynamics in soils. HPx offers a unique framework to couple spatial-temporal variations in water contents, temperatures, and water fluxes, with dissolved organic matter and CO2 transport, as well as bioturbation processes.

The HPx software for multicomponent reactive transport during variably-saturated flow: Recent developments and applications

Engineered and Geosystems Analysis Unit, Belgian Nuclear Research Centre

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

HPx is a multicomponent reactive transport model which uses HYDRUS as the flow and transport solver and PHREEQC-3 as the biogeochemical solver. Some recent...

The HPx software for multicomponent reactive transport during variably-saturated flow: Recent developments and applications

Published Online: Feb 06, 2018

Page range: 211 - 226

Received: Jul 12, 2017

Accepted: Sep 21, 2017

DOI: https://doi.org/10.1515/johh-2017-0049

Keywords
HYDRUS, HPx, Numerical modeling, Reactive transport, Organic matter, Bioturbation

© 2018 Diederik Jacques et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The HPx software for multicomponent reactive transport during variably-saturated flow: Recent developments and applications

Published Online: Feb 06, 2018

Page range: 211 - 226

Received: Jul 12, 2017

Accepted: Sep 21, 2017

DOI: https://doi.org/10.1515/johh-2017-0049

KeywordsHYDRUS, HPx, Numerical modeling, Reactive transport, Organic matter, Bioturbation

© 2018 Diederik Jacques et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
HYDRUS, HPx, Numerical modeling, Reactive transport, Organic matter, Bioturbation