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git-subtree-dir: phreeqc3-examples git-subtree-mainline: 8de0e98ed90bb2b639659c820168ab18c1062992 git-subtree-split: e977363da4c1ae1708ebddca38d5312b6813a337
113 lines
3.5 KiB
Plaintext
113 lines
3.5 KiB
Plaintext
# check with analytical calc'n of the current:
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# sample with por = 0.1, diam 0.1 m, 30 mm long = 23.6 mL water
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# c = 0.3M NaCl, D = 1e-9 for all solutes, 3 V / 30 mm:
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# J_E(Na) = -(1e-9 * 0.1) * 0.3e3 * 96485 / (8.3145 * 298) * (3 - 0) / (30e-3 - 0) = -1.168e-4 * 7.85e-4 =
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# -9.175e-8 eq (Na+)/s * F = -8.85 mC/s = -8.85 mA due to Na
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# Total current : J_E(Na+) + -J_E(Cl-) = 2 * -8.85 = 17.7 mA
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# D_Cl- = 2e-9 ? Then D_NaCl = 1.33, and the current is 17.7 * 1.33 = 23.6 mA
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# With phreeqc.dat: Dw (25°C)): Na+ = 1.33e-9, Cl- 2.03e-9 : current = 1.61 * 17.7 = 28.5 mA
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DATABASE ../database/wateq4f.dat
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# SOLUTION_SPECIES
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# Cl- = Cl-; -Dw 2.0e-9
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EQUILIBRIUM_PHASES 0; H2(g) 0 0 # for bubbling out H2
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EQUILIBRIUM_PHASES 101; O2(g) 0 0 # ... and O2
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SOLUTION 0
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pH 7 charge; Cl 300; Na 300
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SOLUTION 1-100
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-water 23.56e-5 # kg water in a cell
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pH 7 charge; Cl 300; Na 300
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SOLUTION 101
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-water 1
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pH 7 charge; Cl 300; Na 300
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potential 3
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END
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PRINT; -reset false
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TRANSPORT
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-cells 100
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-lengths 30e-5
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-boundary_conditions 1 1
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-multi_d true 1e-9 0.1 0.0 1
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-flow_direction diffusion_only
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-time_step 1 sec 1
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-shifts 100
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-punch_frequency 5
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-punch_cells 0-101
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USER_GRAPH 1 current
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-headings t current_A from conc`s in cell 0
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-axis_titles "time / hour" "current / mA"
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-initial_solutions true
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-axis_scale x_axis 0 100
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1 if cell_no > 0 then end
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2 if step_no > 0 then 10
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3 put(mol("Na+") * tot("water"), 2) : put(mol("H+") * tot("water"), 3) : put(total_time , 1)
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4 put(mol("Cl-") * tot("water"), 4) : put(mol("OH-") * tot("water"), 5)
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5 end
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10 graph_x total_time / 3600
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20 graph_sy -1e3 * current_A
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30 c = (mol("Na+") * tot("water") - get(2)) : put(mol("Na+") * tot("water"), 2)
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# 32 c = c + (mol("H+") * tot("water") - get(3)) : put(mol("H+") * tot("water"), 3)
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40 c2 = (mol("Cl-") * tot("water") - get(4)) : put(mol("Cl-") * tot("water"), 4)
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# 42 c2 = c2 + (mol("OH-") * tot("water") - get(5)) : put(mol("OH-") * tot("water"), 5)
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50 graph_sy (c + -c2) / (total_time - get(1)) * 96485 * 1e3
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60 put(total_time , 1)
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USER_GRAPH 2 Na- and Cl-concentration
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-connect_simulations false
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-plot_concentration_vs dist
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-initial_solutions true
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-axis_scale x_axis 0 30
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-axis_titles "Distance in column / mm" "Na / (mol/kgw)" "Cl / (mol/kgw)"
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1 if (floor(step_no / 50) <> step_no / 50) then end
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2 if total_time < 100 then end
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10 graph_x dist * 1e3
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20 graph_y tot("Na")
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30 graph_sy tot("Cl")
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USER_GRAPH 3 potential
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-connect_simulations false
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-plot_concentration_vs dist
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-initial_solutions true
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-axis_scale x_axis 0 30
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-axis_titles "Distance in column / mm" "potential / Volt"
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1 if (floor(step_no / 50) <> step_no / 50) then end
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2 if total_time < 100 then end
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10 graph_x dist * 1e3
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20 graph_y pot_V
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USER_GRAPH 4 pH
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-initial_solutions true
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-connect_simulations false
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-plot_concentration_vs dist
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-axis_scale x_axis 0 30
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-axis_titles "Distance in column / mm" pH
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1 if (floor(step_no / 20) <> step_no / 20) then end
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2 if sim_no = 2 and step_no > 0 then end
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3 if sim_no = 3 and step_no = 0 then end
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10 graph_x dist * 1e3
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20 graph_y -LA("H+")
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USER_GRAPH 5 redox potential
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-initial_solutions true
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-connect_simulations false
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-plot_concentration_vs dist
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-axis_scale x_axis 0 30
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-axis_titles "Distance in column / mm" 'Eh / Volt'
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1 if (floor(step_no / 20) <> step_no / 20) then end
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2 if sim_no = 2 and step_no > 0 then end
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3 if sim_no = 3 and step_no = 0 then end
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10 graph_x dist * 1e3
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20 graph_y -LA("e-") * 0.059
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END
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TRANSPORT
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-time_step 1 hour 1
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END
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