swhitman
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Posts posted by swhitman
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Hello Jia,
Thanks for the clarification.
Some clarification of my own -- I did understand that the diagram itself used the dominant species, but I was hoping that it would be possible to smartly select corresponding data points from GSS to plot in the diagram.
For example, in the attached diagram, for pH < 6, pairs of pH and {Al3+} would plot, and for pH > 6 pairs of pH and {Al(OH)4-} would plot.
As I understand it, currently, only one variable can be plotted on the y-axis -- that is, the diagram species that is chosen in the basis pane.
As illustrated in the attached figure, there are cases where it would make sense to vary which species is plotted (as scatter points). In some cases, there are more than two predominant species to consider across a given pH range.
My current workaround for this is to make two separate diagrams: 1 for low pH conditions, and 1 for higher pH conditions. Another workaround might be to 'trick' the software by substituting values of {Al(OH)4-} into the {Al3+} row, in a separate GSS to avoid confusion.
Sound like the answer right now is 'that's not possible', but it would be a useful option!
Hopefully that all makes sense, please let me know if it is unclear.
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I'm wondering if it is possible to plot more than one species on the y-axis of an act2 diagram. In some cases, the most important species changes with the x-axis variable (e.g., pH). One example is attached as an image. For aluminum, Al3+ is most important for pH <6, while Al(OH)4- is most important for pH >6.
Can a plot like this be recreated in Act2, or another module in GWB?
More generally, would it be possible to create a mosaic diagram for pH activity plots, such that the concentration of the dominant species is used for scatter data, as well as the phase boundaries in these plots? It seems like this would be a very similar concept to the 'mosaic diagrams'.
Thanks,
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Hi Brian,
Thank you, this was very helpful!
A couple notes/questions:
Is there any way to change the visualization so that it is apparent which parameters are user defined in GSS? This would probably help me from making that mistake again if so.
When I set up the user defined eq. for carbonate alkalinity, it seems that it is adding the values to the total, even if they are preceded by a "<" character. Is there any way to change this behavior?
Thanks Again,
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I'm confused with how GWB is handling alkalinity, both in GSS and in calculations with SPECE8.
The data from my lab in mg/L CaCO3 eq. They report separately Carbonate, Bicarbonate, Hydroxide, and Total alkalinity. (results are <2, 100, <2, 100 respectively).
In their reporting system, it looks like Carbonate alkalinity refers only to alkalinity from CO32--, whereas it seems as though in GWB carbonate alkalinty refers to alkalinity from HCO3- AND CO3--. Is that correct.
Next, I am unsure if when I input data into GSS, for Bicarbonate Alkalinity, Carbonate Alkalinity, or Hydroxide Alkalinity if the implied units are as mg/L CaCO3.
Finally, when I use the GSS data to run a SPECE8 analysis, the basis field for HCO3- is already filled with a value not equal (<) to bicarbonate alkalinity. As a test, I set all alkalinity values equal to zero in the GSS file, and then re-ran SPECE8. The prepopulated HCO3- value was virtually unchaged!
Can you please explain 1) if GSS expects values as CaCO3 for alkalinity, 2) If carbonate alkalinity = bicarbonate alkalinity + carbonate alkalinity (as reported by lab), 3) what calculations SPECE8 is doing to arrive at a alkalinity numbers different from input values. ?
Thank You,
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I'm trying to make an log activity of Cu++ vs pH chart in act2, and then overlay a scatter plot of sample data onto it.
I'm having trouble because I can't calculate the log activity of Cu++ (only can do Cu+) in geochemists spreadsheet (see first image). I
I also tried just basis swapping Cu+ for Cu++ but that changes the minerals that appear on the activity vs pH diagram, and I want the divalent minerals to appear on the chart.
I am using the minteq database, but also tried some others and actually can't find any that have Cu++ as a species to calculate.
What's going on here?
Any help is appreciated.
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Quote
The bar chart expresses the bulk composition of the fluid in electrical equivalents and does not account for speciation.
Ah, OK. This is what I was looking for. I understand what it is doing now.
It is not really a visualization of charge balance showing the major species, just which basis cations and anions make up the solution.
QuotePlease also note that the axis on the bar chart does not represent ionic strength of the fluid. If you want to check if mass balance is honored, you should use molality as the unit. If you add up the concentration of individual species, you will arrive at the bulk composition of that component.
That makes sense. I'm not sure what I was thinking with the ionic strength for these charts.
Thanks Again for your help.
Spencer
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Thanks.
If I do as you said for the example of sulfate, I get the following for by-component equivalents with the bar graph (169.7 meq/kg for SO4--):
Step Xi H2O Al+++ Ca++ Cd++ F- Fe++ H+ K+ Mg++ Mn++ O2(aq) SO4-- SiO2(aq) Zn++ meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg 0 0 0 12.01042 24.50093 0.012581 0.22226 23.2105 16.23034 0.163255 29.09023 67.92366 0 169.7019 0 5.106747 and the following for Total Sulfate Species (91.05 meq/kg) using the xy plot export procedures and selecting only SO4-- species (Total 91.05 meq/kg).
Sulfate Species: Rxn progress Al(SO4)2- AlSO4+ CaSO4 Cd(SO4)2-- CdSO4(aq) Fe(SO4)2- FeHSO4++ FeSO4 FeSO4+ H2S(aq) H2SO4 HS- HSO4- KSO4- MgSO4 MnSO4 S-- S2-- S3-- S4-- S5-- S6-- SO4-- ZnSO4 meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg meq/kg 0 1.42095 1.629153 0 0.002644 0 1.338236 0.035607 0 6.387276 0 0 8.57E-82 4.508028 0.01168 0 0 1.58E-92 9.45E-148 1.41E-203 7.52E-257 0 0 75.71746 0 So, it appears there is a mismatch, unless I'm still missing something about how these plots are representing the data?
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Thanks again, sorry to belabor this, but I just can't seem to make these plots in a way that actually reflect the data, as explained below.
I had gone over section 8.1 and de-selected "common ions".
Something still seems wrong, but I can't figure out what.
One thing I notice is that the bar chart (posted above) would seem to indicate about double the amount of ionic strength as what the results show (see text results below from SpecE8 for this water).
I ended up making the plot I wanted using a combination of PHREEQC and Python, included below. The ionic strength is pretty consistent with that reported by the SpecE8 results, and it shows the major species that make up the composition of the solution, not just the basis species.
I have tried to replicate this in GWB by doing as you suggest (adding or swapping basis species), but no luck so far.
Temperature = 25.0 C Pressure = 1.013 bars
pH = 2.510 log fO2 = -26.406
Eh = 0.6900 volts pe = 11.6642
Ionic strength = 0.187967 molal
Charge imbalance = 0.014914 eq/kg (7.833% error)
Activity of water = 1.000000
Solvent mass = 1.0000 kg
Solution mass = 1.0124 kg
Mineral mass = 0.00000 kg
Solution density = 1.019 g/cm3
Solution viscosity = 0.009 poise
Chlorinity = 0.000000 molal
Dissolved solids = 12210 mg/kg sol'n
Elect. conductivity = 8336.46 uS/cm (or umho/cm)
Hardness = 2681.46 mg/kg sol'n as CaCO3
Water type = Mn-SO4
Bulk volume = 994. cm3
Fluid volume = 994. cm3
Mineral volume = 0.000 cm3
Inert volume = 0.000 cm3
Porosity = 100. %
Permeability = 98.7 cm2Nernst redox couples Eh (volts) pe
----------------------------------------------------------------------------
e- + H+ + .25 O2(aq) = .5 H2O 0.6900 11.6642No minerals in system.
Aqueous species molality mg/kg sol'n act. coef. log act.
---------------------------------------------------------------------------
SO4-- 0.04130 3919. 0.2786 -1.9390
Mn++ 0.01958 1062. 0.3399 -2.1769
MnSO4 0.01480 2207. 1.0000 -1.8297
Fe++ 0.01175 648.0 0.3399 -2.3987
Mg++ 0.008345 200.3 0.3934 -2.4838
FeSO4 0.007277 1092. 1.0000 -2.1380
Ca++ 0.006824 270.2 0.3399 -2.6346
MgSO4 0.006378 758.3 1.0000 -2.1953
CaSO4 0.005576 749.8 1.0000 -2.2537
HSO4- 0.004752 455.7 0.7363 -2.4560
H+ 0.003794 3.777 0.8146 -2.5100
AlSO4+ 0.001625 197.4 0.7363 -2.9222
Al(SO4)2- 0.001462 316.4 0.7363 -2.9680
Zn++ 0.001348 87.07 0.3399 -3.3388
ZnSO4 0.001236 197.1 1.0000 -2.9079
Al+++ 0.0007423 19.78 0.1370 -3.9928
AlF++ 0.0002196 9.973 0.3103 -4.1666
K+ 0.0001531 5.913 0.7129 -3.9620
SiO2(aq) 0.0001208 7.167 1.0491 -3.8972
KSO4- 1.214e-05 1.621 0.7363 -5.0486
Cd++ 3.421e-06 0.3799 0.1332 -6.3411
AlF2+ 2.469e-06 0.1585 0.7363 -5.7404
CdSO4(aq) 1.513e-06 0.3115 1.0000 -5.8202
Cd(SO4)2-- 1.433e-06 0.4309 0.1332 -6.7192
AlOH++ 1.233e-06 0.05357 0.3103 -6.4173
HF 3.064e-07 0.006055 1.0000 -6.5137
F- 9.258e-08 0.001737 0.7250 -7.1731
MgF+ 1.886e-08 0.0008068 0.7363 -7.8574
MnF+ 1.327e-08 0.0009691 0.7363 -8.0101
FeF+ 1.196e-08 0.0008841 0.7363 -8.0553
H2SO4 1.068e-08 0.001035 1.0000 -7.9712
CaF+ 2.664e-09 0.0001554 0.7363 -8.7075
AlF3 1.532e-09 0.0001271 1.0000 -8.8147
Al(OH)2+ 1.139e-09 6.865e-05 0.7363 -9.0763
ZnF+ 7.515e-10 6.263e-05 0.7363 -9.2571
Al2(OH)2++++ 5.360e-10 4.658e-05 0.0428 -10.6399
FeOH+ 1.162e-10 8.364e-06 0.7363 -10.0677
MnOH+ 7.540e-11 5.359e-06 0.7363 -10.2556
H3SiO4- 8.648e-12 8.124e-07 0.7363 -11.1960
OH- 4.601e-12 7.729e-08 0.7250 -11.4768
Mn2OH+++ 3.331e-12 4.175e-07 0.1199 -12.3988
MgOH+ 2.335e-12 9.531e-08 0.7363 -11.7646
MgH3SiO4+ 9.342e-13 1.102e-07 0.7363 -12.1625
CaH3SiO4+ 3.750e-13 5.008e-08 0.7363 -12.5589
H2F2 2.516e-13 9.943e-09 1.0000 -12.5993
Al(OH)3 2.347e-13 1.808e-08 1.0000 -12.6295
CaOH+ 2.088e-13 1.177e-08 0.7363 -12.8133
HF2- 8.831e-14 3.403e-09 0.7363 -13.1869
AlF4- 3.507e-14 3.567e-09 0.7363 -13.5881
Al3(OH)4(5+) 2.206e-14 3.247e-09 0.0072 -15.7998
CdOH+ 2.004e-14 2.562e-09 0.6123 -13.9111
Mg2OH+++ 1.255e-15 8.132e-11 0.1199 -15.8228
KOH 1.156e-16 6.404e-12 1.0000 -15.9372
Al(OH)4- 1.056e-16 9.906e-12 0.7363 -16.1095
AlF5-- 4.609e-19 5.553e-14 0.2786 -18.8914
MgH2SiO4 4.587e-19 5.365e-14 1.0000 -18.3384
Fe(OH)2 1.582e-19 1.404e-14 1.0000 -18.8009
Mn(OH)2 4.435e-20 3.897e-15 1.0000 -19.3531
CaH2SiO4 2.735e-20 3.625e-15 1.0000 -19.5630
Mg(H3SiO4)2 1.599e-20 3.387e-15 1.0000 -19.7963
Mn2(OH)3+ 2.594e-21 4.122e-16 0.7363 -20.7191
Ca(H3SiO4)2 1.336e-21 3.039e-16 1.0000 -20.8742
H2SiO4-- 5.896e-22 5.480e-17 0.2786 -21.7844
Cd(OH)2(aq) 2.132e-22 3.084e-17 1.0000 -21.6711
H6(H2SiO4)4-- 3.564e-24 1.346e-18 0.2786 -24.0031
AlF6--- 8.397e-26 1.169e-20 0.0552 -26.3342
SiF6-- 5.848e-27 8.207e-22 0.2786 -26.7880
Mn(OH)3- 1.870e-29 1.957e-24 0.7363 -28.8611
Fe(OH)3- 1.096e-29 1.157e-24 0.7363 -29.0932
O2(aq) 4.723e-30 1.493e-25 1.0491 -29.3050
H2(aq) 3.302e-32 6.575e-29 1.0491 -31.4604
Cd(OH)3- 1.265e-32 2.041e-27 0.6123 -32.1111
Mg4(OH)4++++ 6.666e-39 1.088e-33 0.0428 -39.5452
H4(H2SiO4)4---- 9.174e-40 3.448e-34 0.0057 -41.2805
Mn(OH)4-- 1.337e-40 1.624e-35 0.2786 -40.4289
Cd(OH)4-- 1.676e-43 2.987e-38 0.1332 -43.6511
MnO4- 3.648e-52 4.286e-47 0.7363 -51.5709
MnO4-- 5.045e-54 5.927e-49 0.2786 -53.8522
Al13O4(OH)24(7+) 8.224e-67 6.685e-61 0.0001 -70.2934
H2S(aq) 1.805e-80 6.077e-76 1.0000 -79.7434
HS- 9.042e-85 2.953e-80 0.7250 -84.1834
S-- 8.543e-96 2.705e-91 0.3103 -95.5766
S2-- 5.318e-151 3.368e-146 0.2786 -150.8292
S3-- 8.189e-207 7.780e-202 0.2786 -206.6417
S4-- 4.507e-260 5.709e-255 0.2786 -259.9011
S5-- 3.375e-316 5.345e-311 0.2786 -300.0000
S6-- 0.0000 0.0000 0.2786 -300.0000
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Thanks Jia, very helpful.
I think I am almost there. I can calculate the concentrations of the various species as you describe.
However, using the Graphs -> Pie Chart (or Bar Chart) option in GSS, all of the iron is still listed as Fe++, but from doing the calculations, I know that most of the iron is present as Fe(3) (mostly FeSO4+). Does the "Fe++" on the bar chart just mean that that portion of cations is from the BASIS species (Fe++), and not actually Iron in the Fe(2) state?
Also, I assume that "total component concentration" would be Fe in the original basis species (Fe++)?
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Hello Jia,
Thanks for the reply.
Good to know I can manually specify the redox distribution by decoupling.
What I was thinking I would like to do was to enter total iron, then enter either a redox couple (e.g. O(0)/O(-2) or my pe measurement, or specify redox equillibrium with a mineral phase (e.g. pyrite), and then speciate all redox species based on that.
Is that possible to do?
If so, can you help me with how to do it?
Thanks,
Spencer
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Hello,
I am interested in calculating the charge balance of some chemical analyses and representing them graphically (e.g. with a pie graph in units of meq).
The question I have is how to represent species that can be present in multiple valences (e.g. Fe). The default for Fe in GSS is as Fe+++, which is likely to be true for some of my samples, but not all. Do I need to do a SpecE8 run first and specify some kind of redox conditions in order to have Fe as both Fe++ and Fe+++? This question would apply to other elements with multiple charge states. When I calculate charge balance within the GSS program, is a speciation calculation run for the solution?
Thanks,
Spencer
Something wrong with my GSS
in The Geochemist's Workbench Community
Posted
Hello Jia,
You mention that hardness is based on a calculation, but I don't see it in the manuals.
There are a couple different ways you can calculate hardness, so I'm wondering which equations GWB uses.
Thanks!