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Re: Fw: Transport problem




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




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