Keyboard and Mouse


Computer codes developed by Dr. Oded Nir and collaborators for supporting the design of sustainable processes for water treatment and resource recovery. Codes are free to anyone, open sourced and represent our best efforts in integrating complex chemical equilibrium into mass-transport and kinetic models. However the code developers cannot guarantee for the accuracy of predictions made using the programs and has no legal responsibility on the outcome of using the programs.

WATRO - Weak Acid Transport in Reverse Osmosis

This Python-based simulation code accurately predict changes in acid-base properties in reverse-osmosis process streams.

Acid–base properties such as pH, Alkalinity and boron speciation are essential factors for the design and operation of reverse osmosis desalination, as they influence critical processes such as membrane scaling, biofouling and boron permeation. However, due to the high complexity of acid–base dynamics in both the retentate and permeate streams of reverse osmosis applications, acid–base behavior in these streams is not well implemented in today’s commercial software. This often leads to overly simplified models that make inaccurate predictions, which may impede optimal RO process design. Currently available RO design programs, distributed by e.g. membrane manufacturers and chemical suppliers, are unable to correctly predict pH to the extent that may even lead to an opposite trend of the predicted values compared to the empirical ones.

the WATRO code is Currently the only model that was tested and found to correctly predict pH values in both retentate and permeate RO streams. Developed recently by Nir and coworkers,4 WATRO is a unique simulation tool, dedicated to modeling acid–base dynamics within seawater reverse osmosis processes based on a reactive-transport algorithm that couples mass-transport and acid-base equilibria.

Relevant publication: Nir, O., Ophek, L. & Lahav, O. Acid-base dynamics in seawater reverse osmosis: Experimental evaluation of a reactive transport algorithm. Environ. Sci. Water Res. Technol. 2, 107–116 (2016).

Struvite Design

This program is an advanced tool for the design and cost estimation of struvite precipitation processes from wastewater streams

A friendly graphical user interface is included, as well as non-graphic interfaces for multiparameter testing:

Induced struvite (MgNH4PO4) precipitation from wastewater streams has been the topic of extensive research in the last two decades and is gathering worldwide momentum as a P-reuse technique.

This computer code support the design of struvite precipitation processes from wastewater streams with high loadings of ammoniacal nitrogen and phosphate species. A wide range of operational are available:

•Different wastewater compositions

•various Mg(II) sources, including dosing chemicals and mixing with Mg rich brines of any composition

•Vary reactor pH and Mg/P ratio

•Maintain a constant pH in the reactor by 3 ways – NaOH, Mg(OH)2, or CO2 Stripping by in-reactor diffusers

•Option to simulate precipitation of amorphous calcium phosphate following struvite precipitation (typical kinetic order)

•Optimize with respect to P removal efficiency, struvite purity, chemical consumption, energy consumption and overall cost

L. Birnhack, O. Nir, O. Lahav, A new algorithm for design, operation and cost assessment of struvite (MgNH4PO4) precipitation processes, 2015, Environmental Technology 36(15), 1892-1901.