[no subject]

["Bruno Haerens" <bruno.haerens@xxxxxxxxxxxxxxxxxx>]

Dear David,

I'm trying to execute a transport modelling of 1D-flowtube, containing an
ammonium contamination, that is flushed by pristine background water
(contains oxygen, but no ammonium).
Ammonium is retarded by cation exchange, which I can succesfully simulate.
But now I wanted to incorporate kinetic ammonium oxidation (inflowing
solution contains oxygen). I defined rates and kinetics in Phreeqc, but the
simulation allways ends after 7 transport steps.

Is it possible that this is due to the fact that the time to travel a 1m
cell (=1 shift)  is high (8.3333... days= 720 000s, because the effective
groundwater velocity = 0.11875m/d)?
I tried step_divide > 1 (till 1000), but this didn't seem to help.

Are these problems typically occurring when dealing with kinetics? have you
any suggestions to resolve this problem or did I make some error in my
kinetic formulation?

Thanks in advance and best regards,
bruno

Bruno Haerens
Hydrogeology & Engineering Geology
Dpt. Geography-Geology
Katholieke Universiteit Leuven
Redingenstraat 16
B-3000 Leuven (Belgium)
tel. +32-(0)16-326449
fax. +32-(0)16-326401
http://www.kuleuven.ac.be/geology/hsg/H&EG/H&EG.html


attached files:
input.pqi = input file for phreecI
phreeqc.dat = database file (ammonium considered as a seperate component
amm)
nitrification =  kinetic formulation of ammonium oxidation

Attachment: vgl_phreeqc_pht3d_interactive.pqi
Description: Binary data

Attachment: Phreeqc.dat
Description: Binary data

Attachment: Nitrification.doc
Description: MS-Word document