Dear Dr. Farrel or others,
I am a new user of GWB. I will use React program of GWB 9.0 to simulate surface complexation of Fluoride (F) on different minerals. Before using my experimental results and surface data, I want to reproduce the modeling results of Dixit and Hering (2003) (Dixit and Hering, 2003, Env.Sci.Technol.,37,4182-4189). They modeled As (V) and As(III) sorption to HFO, Goethite and Magnetite, using MINEQL+.
Here I will show the simulation results that I got for As (V) sorption on to HFO (Fig. 1, Dixit and Hering, 2003) using both Visual MINTEQ and GWB 9.0 (react).
I attach the surface file, the figures from Visual MINTEQ, GWB and the GWB input file.
The results from Visual MINTEQ explains well the results of Dixit and Hering (2003), where as the results are not reproduced well using GWB (e.g., the maximum sorption is same to that of Dixit and Hering, 2003, where as the pH dependence is not correlated).
I used the Thermo_minteq.dat thermodynamic database. To get better result, I changed the log K values to match to that of thermo.dat file of Visual Minteq at 25 degree C. However, the results did not improve.
I would appreciate if you kindly help me to understand the problem.
Best regards,
Sakambari Padhi
input_results.pdf
modified_feoh_minteq.dat