I'm sorry, but I still do not know what your problem is. "Unreasonable" pH
can be caused by the program not making the calculations correctly or the
problem specification generating reactions that you do not expect or
recognize. I do not see any reason to think that the program is making the
calculations incorrectly; until you show me otherwise, I am assuming it is
in your problem definition. If you can show me specific changes in surface
species that do not follow mass-action equations, or have mass-balance or
charge-balance errors, I will try to figure out the problem, but I need to
know what I am looking for. Please try to be as specific as possible and
simplify the input files as much as possible. If results are the same
without SURFACE, it seems that EQUILIBRIUM_PHASES must be dominating the
reactions. Perhaps you should run some batch reactions and look carfully at
what the initial solution, surface, equilibrium_phases compositions in the
column are and what happens when the minerals react with the infilling
solution.
Meanwhile, I have some comments on your input file as noted by "## dlp"
below.
David
TITLE with help of Example 11.--Transport and ion exchange.
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
##### Sandmodell ####
SURFACE_MASTER_SPECIES
Sand_w Sand_wOH
##dlp, you appear to be using PhreeqcI 1.03. A new version of PhreeqcI
version 2 has just been posted
##dlp, PhreeqcI version 1.03 uses PHREEQC version 1.6, which is no longer
supported.
SURFACE_SPECIES 1 # Do not change this number it is used by the program!
Sand_wOH = Sand_wOH
log_k 0.0
Sand_wOH + H+ = Sand_wOH2+
log_k 4.5 #log_k 7.29 # = pKa1,int
Sand_wOH = Sand_wO- + H+
log_k -7.2 #log_k -8.93 # = -pKa2,int
# Calcium
Sand_wOH + Ca+2 = Sand_wOHCa+2
log_k 7 #log_k -5.85
# Magnesium abgeschaltet
# Sand_wOH + Mg+2 = Sand_wOHMg+2
# log_k 7
# Eisen(2)
Sand_wOH + Fe+2 = Sand_wOHFe+2
log_k 7
# Natrium abgeschaltet
# Sand_wOH + Na+ = Sand_wONa + H+
# log_k -6.6
# Sulfate
Sand_wOH + SO4-2 + H+ = Sand_wSO4- + H2O
log_k 5 #7.78 mit Protonierung
Sand_wOH + SO4-2 = Sand_wOHSO4-2
log_k -2
PHASES 1 # Do not change this number it is used by the program!
JarositeH 337
(H3O)Fe3(SO4)2(OH)6 + 5H+ = 3Fe+3 + 2SO4-2 + 7H2O
log_k -5.390
delta_h -55.150 kcal
SOLUTION 0
units mg/l
temp 12.7
pH 6.14
pe 4.594
redox Fe(2)/Fe(3) #{Redoxsystem}
density 1.000
O(0) 0.11
Na 50.4
K 91.25
Mg 3.51
Ca 390.0
Alkalinity 101.0 as HCO3 #Ks,mess4,3*61=101
Cl 23.0
S(6) 1096.0 as SO4 charge
N(5) 0.022 #{Nitrat-Stickstoff:14/62*NO3}
# analyse <0.1
N(3) 0.03 #{Nitrit-Stickstoff14/46*NO2}
# analyse <0.1
N(-3) 1.03 #{Ammonium-Stickstoff:14/18*NH4}
# Amm 1.32 as AmmH+ #{Ammonium konservativ}
P 0.59
Si 7.38
Al 0.3 #analyse<0.3
Mn 0.74
Fe(2) 48.8 #Siderite 0.0
Fe(3) 3.5 #Fe(OH)3(a) 0.0
PRINT
-sa false
-sp false
END
SURFACE 0
-equil solution 0
Sand_wOH 0.01 0.05 1000
# sites Mol m2/g Masse/g
##dlp SAVE has no effect unless there is a batch-reaction calculation, in
this case there is only an initial surface calculation.
##dlp a batch-reaction calculation must have a solution (or mixture)
defined either by
##dlp SOLUTION, MIX, or USE, plus another reactant(s) EQUILIBRIUM_PHASES,
EXCHANGE, SURFACE, etc (or USE one of these)
##dlp neither SAVE surface or SAVE equilibrium phases have any effect here
SAVE SURFACE 0
SAVE EQUILIBRIUM_PHASES 0
KNOBS
-i 1000
PRINT
-sa false
-sp false
END
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TITLE 1964
USE SOLUTION 0
USE SURFACE 0
##dlp SAVE surface saves reults of SOLUTION 0 equilibrated with SURFACE 0,
however,
## dlp the previous simulation defined SURFACE 0 to be in equilibrium with
SOLUTION 0,
## dlp so the batch-reaction calculation puts SOLUTION 0 and SURFACE 0
together, but
## dlp calculates no change in composition of either the solution or the
surface.
SAVE SOLUTION 0
#dlp You did not specify EQUILIBRIUM_PHASES in this batch-reaction, so
there is no
#dlp EQUILIBRIUM_PHASES phase assemblage to save.
SAVE EQUILIBRIUM_PHASES 0
SAVE SURFACE 0
END
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#SOLUTION 1-20 Initial solution for column
TITLE Pore
SOLUTION 1-20
units mg/l
temp 13.0
pH 5.51
pe 5.278
redox Fe(2)/Fe(3) #{Redoxsystem}
density 1.000
O(0) 0.13
Na 36.88
K 6.35
Mg 43.4
Ca 429.0
Alkalinity 64.0 as HCO3 # 64.0=KS*61
Cl 9.35
S(6) 1329.0 as SO4 charge
N(5) 0.022 #{Nitrat-Stickstoff:14/62*NO3}
N(3) 0.03 #{Nitrit-Stickstoff14/46*NO2}
N(-3) 5.89 #{Ammonium-Stickstoff:14/18*NH4}
# Amm 7.57 as AmmH+ #{Ammonium konservativ}
P 0.09
Si 17.8
Al 0.3
Mn 2.69
Fe(2) 225.0 #Siderite 0.0
Fe(3) 34.0 #Fe(OH)3(a) 0.0
#EXCHANGE 1-20
# equilibrate 1
# X 0.0011
EQUILIBRIUM_PHASES 1-20
Pyrite 2.0 0.050 #FeS2
Calcite -2.1 0.0 #CaCO3
Siderite -0.13 0.0 #FeCO3
Gypsum -0.12 0.05 #CaSO4:2H2O
Fe(OH)3(a) 3.5 0.05
Gibbsite 1.26 0.05 #Al(OH)3
PRINT
-sa false
-sp false
##dlp This simulation defines a solution for cells 1-20 and equilibrium
phases for cells 1-20.
##dlp It also specifies a batch-reaction calculation putting SOLUTION 1 and
EQUILIBRIUM_PHASES 1
##dlp together and equilibrating. However, the result of this calculation
is not saved, so the equilibrated
##dlp solution is lost. I would use the following:
##dlp SOLUTION 1
##dlp EQUILIBRIUM_PHASES 1
##dlp SAVE solution 1-20
##dlp SAVE equilibrium_phases 1-20
END
##dlp Because the SAVE follows the END, it has no effect on the calculation
that precedes the END
##dlp As before, no solution or mixture is defined in this simulation, so
no batch-reaction calculation
##dlp is made, hence SAVE has no effect.
SAVE SOLUTION 1-20
SURFACE 1-20 ########### Oberflächendefinition #############
#dlp the following should be "-equil solution 1", not "1-20"
-equil solution 1-20
Sand_wOH 0.01 0.05 1000
SAVE SURFACE 1-20
USE SURFACE none
##dlp SAVE equilibrium_phases has no effect unless EQUILIBRIUM_PHASES is
defined in a batch-reaction
##dlp calculation.
SAVE EQUILIBRIUM_PHASES 1-20
END
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
##dlp USE is not used for transport calculation, only for batch-reaction
calculations
USE SOLUTION 0
TRANSPORT
-cells 20
-length 20*100.0
-shifts 20
-time_step 3.57e7 # dt=length/velocity,
vel=2.8*e-6
-flow_direction forward
-boundary_cond flux flux # erste und letzte Zelle RB 3.Art
-diffc 0.0e-9
-dispersivity 20*0.02 # in Meter
-correct_disp true
-punch 1-20
-punch_frequency 1
-print 20
-print_frequency 20
SELECTED_OUTPUT
-file 19646008trn.sel
-reset false
-soln
-distance
-time
-step
-pH
-pe
-alkalinity
##dlp Alkalinity is not defined for -totals
-totals O(0) Na K Mg Ca Alkalinity Cl S(6) N(5) N(3) N(-3)
P Si Al Mn Fe(2) Fe(3)
USER_PUNCH
-heading SO4 Cl Na Fe+2 Fe+3 K Mg Ca NH4 P Si Al Mn Alk
10 PUNCH TOT("S(6)")*81360 TOT("Cl")*35450 TOT("Na")*22989 TOT("Fe(2)")
*55850 TOT("Fe(3)")*55850 TOT("K")*39100 TOT("Mg")*24310 TOT("Ca")*40080
TOT("N(-3)")*14007 TOT("P")*30970 TOT("Si")*60080 TOT("Al")*26980 TOT("Mn")
*54940 TOT ("Alk")*61
##dlp In the previous statement, you should use ALK, not TOT("Alk")
END
##dlp extra END
END
David Parkhurst (dlpark@xxxxxxxx)
U.S. Geological Survey
Box 25046, MS 413
Denver Federal Center
Denver, CO 80225
Please note that some U.S. Geological Survey (USGS) information accessed through this page may be preliminary in nature and presented prior to final review and approval by the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the sole responsibility of the user.
Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.
The URL of this page is:
https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/mail/msg00273.html
Email:dlpark@usgs.gov
Last modified: $Date: 2005-09-13 21:04:21 -0600 (Tue, 13 Sep 2005) $
Visitor number 2635 since Jan 22, 1998.