Simulate Scale Formation and Brine Concentration during Reverse Osmosis Desalination

PyPI version DOI link Actions Status Downloads License

Desalinating ocean water is crucial for meeting the 6th UN Sustainable Development Goal of univeralizing potable water. Reverse Osmosis (RO) is the leading desalination technology, although, it remains hindered by membrane scaling, which lessens its energy efficiency and economic practicality. The geochemistry of mineral scaling evades experimental methods, and existing software programs to simulate scaling geochemistry – e.g. French Creek – are insufficient to explore all relevant variables and are furthermore inaccessible to many researchers.

Reverse Osmosis Scaling Software in Python (ROSSpy) satisfies this niche in RO research by implementating a one-dimesnional RO model through PHREEQpy, which is the Python version of PHREEQC. The examples/scaling/scaling_validation directory of the ROSSpy GitHub details validation studies and sensitivity analyses of ROSSPy via Notebook examples. We encourage users and developers to critique and improve the open-source (MIT License) ROSSpy package by creating new GitHub issues or emailing afreiburger@uvic.ca.

Theory

The ROSSpy framework represents RO desalination as a 1D reactive transport model of the membrane-solution interface in the RO feed channel. The feed solution is represented as a single, homogeneous, solution. The inlet boundary is defined by the Dirichlet condition, where the inlet concentrations are assumed to be independent of desalination, with the feed as an infinite reservoir. The outlet boundary is defined by the Cachy condition, where the effluent concentration is assumed to be dependent upon the reactive transport processes within the RO module.

Note

This project is under active development.

Installation

ROSSpy is installed in a command prompt, Powershell, Terminal, or Anaconda Command Prompt via pip:

pip install rosspy

The IPHREEQC module must then be installed, since this is the source of geochemical calculations and data for ROSSpy. The appropriate version of IPHREEQC can be installed from the USGS .

Installation in Linux distributions, Ubuntu >=20 or an equivalent, requires addition steps (Ubuntu < 20 is currently unsupported):

wget https://water.usgs.gov/water-resources/software/PHREEQC/iphreeqc-3.7.3-15968.tar.gz
tar -xzvf iphreeqc-3.7.3-15968.tar.gz
cd iphreeqc-3.7.3-15968
./configure
make
make check
sudo make install
pip show phreeqpy
mkdir -p /path/to/site-packages/phreeqpy/iphreeqc
sudo cp /usr/local/lib/libiphreeqc.so  /path/to/site-packages/phreeqpy/iphreeqc/libiphreeqc.so.0.0.0

Citation

Please cite this work:

Freiburger, Andrew P. and Molins, Sergi and Buckley, Heather L., A One-Dimensional Reactive Transport Model of Geochemical Scaling in Reverse Osmosis Desalination. http://dx.doi.org/10.2139/ssrn.4124149

Contents