since beginning of 2023 muFlowRT a library that couples OpenFoam has been incrorporated in ORTI3D. It allows to compute flow, transport and chemistry in both structured and unstructured grid/mesh. It has more flexibility than the other models present in ORTI3D and provides a true dual phase code with chemistry (for solutes and gases).
To use it however it is required to install OpenFoam and PhreeqcRM on your computer whether directly on linux or using WSL (there is no exe version up to now). the library is at https://github.com/oatteia111/muFlowRTFoam.
OpenFoam is included in the help of ORTI3D so you can first dicsover it abilities there, details are given in github.