Surface precipitation model

[mmontecinos1]

Hello everyone,

I am trying to reproduce the surface precipitation model of Cu in HFO y HAO developed by Karthikeyan and Elliott (1999) (Surface Complexation Modeling of Copper Sorption by Hydrous Oxides of Iron and Aluminum, Journal of Colloid and Interface Science 220, 88–95 (1999). I would like to edit FeOH.dat sorption file to include equations [5] to [8] considered by the authors. However, I am not sure how due to these equations consider both sorbed and precipitated species

To include eqs. [5] and [6] I was thinking of include the following species:

 

>(s)FeOHCu(OH)2H+

     charge=  1.0       mole wt.=  171.4228

     4 species in reaction

       1.000 >(s)FeOH       -1.000 H+              1.000 Cu++

               2.000 H2O

     log K=  -0.7500    dlogK/dT=   0.0000

             

>(w)FeOHCu(OH)2H+

     charge=  1.0       mole wt.=  171.4228

     4 species in reaction

       1.000 >(w)FeOH       -1.000 H+              1.000 Cu++

               2.000 H2O

     log K=  -0.7500    dlogK/dT=   0.0000

 

but I am not sure if this is a proper way to represent this model of surface precipitation.

Regarding to eq. [7] and [8], I don’t know how to include it, due to these equations represent the change in Ksp precipitation due to HFO adsorption.

 

I would appreciate any recommendation

Best regards,

Mauricio Montecinos

[Brian Farrell]

Hi Mauricio,

The GWB does not currently support surface precipitation as developed in Dzombak and Morel’s generalized two-layer model.

Regards,

Brian Farrell
Aqueous Solutions LLC