Beginners > SELECTED_OUTPUT
Fluoride Speciation, Controlling Factors & Exporting log K
i_azharkhan:
Hello everyone,
I?m working on modelling 35 water samples collected from an acid mine drainage site (same general location, but from different spots).
My main objectives are:
1. Calculate the distribution of fluoride species in each sample (F⁻, HF, Al?F complexes, etc.).
2. Identify key factors affecting fluoride speciation?such as pH, ionic strength, major cations/anions, and possible equilibrium with fluoride-bearing minerals.
I have a few specific questions:
Multiple samples: Can we run all 35 samples together in a single PHREEQC input file, or do they need to be run separately?
Output analysis: If we export results to a CSV file after running the model, will it directly identify the key factors controlling fluoride speciation, or will we need to process the output data further (e.g., statistical analysis or correlation) to find those relationships?
Equilibrium phases: Which equilibrium phases are most relevant for fluoride in acidic mine drainage (e.g., fluorite, cryolite, and aluminum fluoride minerals), and how should they be set up in the input?
Exporting log K: From the saturation indices section, how can we export the log K values (equilibrium constants) used for each mineral phase to a CSV or output file?
I have full chemical analyses for all samples (major cations/anions, pH, temperature, etc.) and can format them for PHREEQC?s SOLUTION blocks.
If anyone has example input files, guidance on structuring multiple-sample runs, or advice on interpreting the results to pinpoint fluoride controls, I?d greatly appreciate it.
Thank you!
dlparkhurst:
Look in the manual at the data block SOLUTION_SPREAD. It allows a tab-delimited table of data where each row is a solution definition. You can enter the data in Excel and then cut and paste into an input file if you want.
When you run the file with a SOLUTION_SPREAD data block, the output file will contain the saturation indices for every mineral of the database that is composed of the elements in the solution.
Data can be written to a tab-delimited output file using the data blocks SELECTED_OUTPUT and USER_PUNCH. USER_PUNCH allows calculation of output values using the Basic functions described in The Basic Interpreter in the manual. One of the functions is LK_PHASE, which give the log K for the phase at the temperature of the calculation.
You will have to study the literature to decide which minerals are relevant to your system.
i_azharkhan:
Thank you for your guidance.
I tried running my dataset using the SOLUTION_SPREAD block, but when I run the file, I get errors for all elements saying that the solution ?has not converged.?
Could this be due to certain combinations of concentrations in my samples causing unrealistic charge balance or extremely low/high pH values?
Or is there something in my formatting or units that might be leading to the convergence problem?
Any advice on how to troubleshoot and get the model to converge for all samples would be greatly appreciated.
dlparkhurst:
Perhaps you have not set the concentration units correctly. Default is mmol/kgw. Use -unots to define mg/L, for example.
i_azharkhan:
Respected sir, the unit is in mg/L, but I'm still facing the same problem. I will share the input. Please kindly have a look.
Thank you.
SOLUTION_SPREAD
-units mg/l
Al Alkalinity Ba Ca Cd Cl Cu F K Mg Mn N(3) N(5) Na P Pb pH S(6) Sr Zn Br Fe
mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l
252 17.63 0.03 350 0.04783 8.66 4.558 228 8.45 487 17.267 0.08 24.6 60.8 0.1 0.0089 4.48 3362 1.88 9.392 0.02 0.09
5.43 35.26 0.16 487 0.04064 8.03 0.15 19.6 8.05 120 16.483 0.96 75.3 239 0.95 0.00018 6.33 2018 7.38 4.064 0.02 0.46
1397 0.0 0.08 320 1.35149 17.3 100.389 181 3.99 1240 36.954 0.08 14.3 9.25 0.1 0.01164 3.01 14854 0.42 197.612 0.02 212
0.12 155.8 0.02 860 0.00157 474 0.0809 0.21 8.10 12.4 0.44463 0.08 13.7 391 0.1 0.00002 7.09 2272 0.88 0.179 0.02 0.01
0.02 22.3 0.04 566 0.00133 419 0.02924 0.43 7.26 11 0.19318 0.08 63.6 384 0.1 0.00003 6.91 1711 0.93 0.109 0.02 0.01
0.05 164.8 0.05 714 0.00211 904 0.04083 0.24 5.63 59 1.24839 0.08 7.48 453 0.1 0.00001 6.36 1653 0.14 236.886 0.02 0.01
1030.3 0.0 0.0 254 0.223 14 0.0 149 1.73 898 243.4 0.08 15.1 7.1 0.0 1.652 7 9905 0.0 172.5 0.02 139
0.01 0.0 0.04 0.0 0.01 0.0 0.01 8.65 0.0 0.0 0.01 0.08 0.0 0.0 0.0 0.01 6.81 0.0 0.0 0.01 0.0 0.02
60.11 0.0 0.02 0.0 0.01 0.0 1.03 0.51 0.0 0.0 21.44 0.08 0.0 0.0 0.0 0.01 5.21 0.0 0.0 1.7 0.0 0.04
1539 0.0 0.01 0.0 3.74 0.0 183.8 0.04 0.0 0.0 532 0.08 0.0 0.0 0.0 0.49 3.33 0.0 0.0 354.5 0.0 197.8
0.1465 22.3 0.0 15.4 1.21 0.0 0.002393 0.39 0.96 2.12 0.01 0.08 18.5 2.32 0.0 0.0009 7.54 14.1 0.0 0.018425 0.0 0.0523
0.2758 24.1 0.0 16.5 1.23 0.0 0.003488 0.37 1.31 2.11 0.0067 0.08 18.4 2.59 0.0 0.000824 7.56 14.1 0.0 0.02 0.0 0.2237
3.894 103.3 0.0 474 48.8 0.0 0.01809 13.8 14.4 119 3.759 0.08 16.6 76.9 0.0 0.055257 7.18 1500 0.0 0.100898 0.0 14.86
0.324 190.2 0.0 68.5 4.8 0.0 0.003904 0.68 2.98 6.75 0.1125 0.08 11.4 61 0.0 0.542209 7.08 112 0.0 0.041691 0.0 0.6535
34.1 126.2 0.0 634 19 0.0 0.002482 1.43 15.5 222 1.702 0.08 3.71 154 0.0 0.000859 7.3 1470 0.0 0.0209 0.0 70.3
0.1806 91 0.0 165 16.8 0.0 0.00348 0.9 5.61 40 0.0295 0.08 22 40.2 0.0 0.000538 7.26 476 0.0 0.147055 0.0 0.0521
0.2568 81.6 0.0 83.1 7.35 0.0 0.003801 0.14 2.3 15.6 0.1349 18 87 8.56 0.0 0.023853 7.17 101 0.0 0.022088 0.0 0.0892
0.0832 29.6 0.0 100 11.5 0.0 0.002408 0.31 2.91 16.8 0.4923 21.8 209 12 0.0 0.000753 6.68 106 0.0 0.022807 0.0 0.0649
0.552 24.1 0.0 28.8 3.68 0.0 0.004957 0.36 1.82 3.93 0.0035 0.08 15.3 3.93 0.0 0.000956 7.35 4402 0.0 0.016474 0.0 0.0342
0.9926 53.7 0.0 28.7 2.35 0.0 0.011647 0.21 1.64 5.3 0.0446 0.08 8.2 6.96 0.0 0.028444 7.73 24.6 0.0 0.034792 0.0 1.08
1.458 59.3 0.0 237 11.4 0.0 0.011003 2.09 4.27 72.3 1.856 0.08 12.1 39 0.0 0.121578 7.2 830 0.0 0.063056 0.0 2.03
5.758 55.6 0.0 343 8.2 0.0 0.015322 21 10.9 58.7 8.451 0.08 32.8 226 0.0 0.054212 7.14 1380 0.0 0.302554 0.0 5.346
102.1 11.1 0.0 514 13.2 0.0 1.109665 103 14.4 341 25.24 0.08 36.3 203 0.0 0.004472 4.77 3098 0.0 2.282672 0.0 0.3502
63.23 14.8 0.0 520 12.8 0.0 0.596851 67.4 14.2 262 13.8 0.08 38.9 200 0.0 0.000603 5.1 2651 0.0 1.50632 0.0 0.2658
0.7945 109.8 0.0 454 21 0.0 0.00845 14.6 11 340 0.0221 0.08 4 248 0.0 0.001147 8 2650 0.0 0.014109 0.0 0.5239
0.0 11.1 0.0 510 12 0.0 0.0 66.7 13.7 292 0.0 0.08 35.4 206 0.0 0.0 5.33 2774 0.0 0.0 0.0 0.0
0.0 7.4 0.0 520 11.5 0.0 0.0 53.1 13.7 289 0.0 0.08 36.7 200 0.0 0.0 4.99 2802 0.0 0.0 0.0 0.0
23.66 9.2 0.0 179 6.28 0.0 0.330346 32.4 5.81 80.3 10.07 0.08 35.1 20.9 0.0 0.004062 5.22 715 0.0 1.874565 0.0 0.8982
2.292 26.8 0.0 47.1 9.19 0.0 0.012326 1.85 3.67 9.69 1.599 0.83 15 10.3 0.0 0.005232 6.5 125 0.0 2.147558 0.0 13.64
0.6008 29.7 0.0 3.58 7.65 0.0 0.004652 0.93 0.28 0.6 0.0795 6.8 14.5 0.82 0.0 0.583197 6.72 60.2 0.0 0.0396 0.0 0.3729
0.5907 44.5 0.0 611 5.15 0.0 0.009522 3.56 26.3 78.7 0.0358 0.08 7.64 15.6 0.0 0.003815 7.37 16.98 0.0 0.047802 0.0 0.2901
2.274 192.7 0.0 517 25.4 0.0 0.009242 28.2 14.6 613 58.76 0.08 4.29 343 0.0 0.000735 3.75 4030 0.0 0.768787 0.0 0.4194
2.732 247.6 0.0 501 24.2 0.0 0.006868 25.3 11.2 500 48.42 0.08 3.84 366 0.0 0.000937 6.95 3560 0.0 0.335529 0.0 0.5686
1580 0.0 0.07 334 2.822 11.9 146.804 224 0.57 1775 93.847 0.08 25.5 7.21 0.04 0.00205 2.92 19256 0.27 350.565 0.02 43.5
0.82 19 0.06 565 0.0501 4.25 0.0637 2.89 12.5 152 6.593 0.08 6.52 9.69 0.04 0.00014 5.12 1990 0.41 1.309 0.02 0.06
SELECTED_OUTPUT 1
-file fluoride_speciation_sample1.csv
-reset false
-solution true
-pH true
-temperature true
-alkalinity true
-totals F Al Ca Mg Alkalinity Fe Cu
Cl Zn Sr N(5) N(3) Mn K
Cd Ba Br
-molalities F- AlF+2 AlF2+ AlF3
AlF4- CaF+ MgF+ CdF+
HF HF2- NaF ZnF+
-saturation_indices Fluorite Barite Calcite Basaluminite
Gypsum
END
REACTION 1
Ca(OH)2 1
0.02 moles in 40 steps
END
EQUILIBRIUM_PHASES 1
Barite 0 0
Fluorite 0 0
Gibbsite 0 0
SELECTED_OUTPUT 2
-file ca_precipitation_sample1.csv
-reset false
-solution true
-pH true
-totals F
-equilibrium_phases Fluorite Gibbsite Barite
-saturation_indices Fluorite Gibbsite Barite
USER_GRAPH 1
-headings pH F_total
-axis_titles "Ca(OH)2" "Fluoride Removal %" "pH"
-chart_title "Fluoride Removal with Ca(OH)2 Addition"
-axis_scale x_axis 0 10 1 1
-axis_scale y_axis 0 100 10 10
-axis_scale sy_axis 2 8 1 1
-initial_solutions false
-connect_simulations true
-plot_concentration_vs x
-start
10 GRAPH_X RXN
20 GRAPH_Y TOT("F") * 19000 (100*(1-TOT("F")/SYS("F")))
30 GRAPH_SY -LA("H+")
-end
-active true
END
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