Hello,
I am wondering if anyone can help me successfully model the phosphate species present after Fe2+ addition. I am trying to model how much iron would need to be added to a lake system to precipitate the minerals vivanite and strengite.
I used values based off of measurements from the USGS on the specific lake system I am trying to model, and I seem to keep getting errors as my model is not showing all 100 steps for sliding the amount of Fe2+ in the system.
The errors I get when I run the model are: Newton-Raphson didn't converge after 999 iterations, max residual = 1, largest residuals: H+, H2O, SiO2(aq), HPO4, and the initial solution is too supersaturated.
I have attached my code. Any help would be greatly appreciated!
lake_mendota_waterchem.rea
