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  1. Yesterday
  2. HI The default GWB DB only includes Au reactions involving Cl, however other ligands may form complexes with Au, including I and SO4. Does anyone know if Ks values for these reactions are available in anyother BD ? Best regards Silvain Rafini
  3. Dear GWB users, GWB14 is here! A new compute engine makes it a surface chemistry powerhouse. Plus, our latest release features user equations in GSS datasheets, high-temperature Pitzer coefficients, cluster computing, and flexible input for thermo data, just to start. Visit our GWB14 page to learn more. GWB subscribers upgrade automatically. Can’t wait another minute? Click “Check for updates” on your GWB dashboard. Not subscribing yet? Take advantage of one of our flexible plans—fixed or floating, 3 months to 3 years! Or, convert that old GWB license to a modern subscription and a free kick-off period is on us. Contact us today for a quote, or go shopping at our online store and you’ll be up and running in minutes. Sincerely, Brian Farrell Aqueous Solutions LLC
  4. Hi Sanjoy, I’m writing to let you know about a new feature in the GWB14 release. You can control species loading in a calculation by specifying a temperature range over which thermodynamic data should be available. In your case, many species have thermo data available at 25 C, but not other temperatures, so your calculations at 25 C and 26 C loaded a different set of species, which caused your results to differ more than expected. By specifying a temperature range, say 10-150 C, you can ensure that any calculations within that range load the same exact set of species. It’s basically like automatically suppressing a set of species with limited thermo data, simply by setting a temperature range. You can read about the span command in the GWB Command Reference. The new release has many more new features as well. Please let us know if you’re interested in trying GWB14. I’m happy to send you a demo. Cheers, Brian
  5. Hi Bill, I’m writing to let you know about a new feature available in GWB14. You can control species loading in a calculation by specifying a temperature range over which thermodynamic data should be available. You can additionally force the program to always get log K values by evaluating a polynomial, even when the calculation is isothermal at a principal temperature. In this case, the program would normally use the value directly from the thermo dataset. The difference is small, but it’s why the endpoint of your polythermal path and your isothermal calculation post-pickup were slightly different. You can read about the feature in section 6.92 span in the GWB Command Reference. The new release has many more new features as well. Please let us know if you’re interested in trying GWB14. I’m happy to send you a demo. Cheers, Brian
  6. Hi Mauricio, I’m writing to let you know that GWB 14 is now available. The new release includes support for several different polydentate surface complexation formalisms. You had to convert the log K for a bidentate reaction in your surface dataset to be consistent with the method in GWB9, but now you can choose one of four methods consistent with your log Ks and specify that in your surface dataset. React will read the dataset and evaluate mass action laws according to the convention you specified. In your case, you could set the stoichiometric approach in the dataset’s header and use the original literature reference’s log K value of 4.6. The calculation will reproduce figure 3A in your plot. However, this approach is not satisfactory, as described in the reference above, and it will be in error at other concentrations of the sorbing mineral. The better approach is to convert the log K, as you did before, to use the mole fraction approach, which is entitled Hiemstra-VanRiemsdjik in GWB14. This is the default approach in GWB14, so you can leave the method unspecified in your surface dataset, but to be clear it’s best to set the method in the header. With this approach, changing the amount of the sorbing mineral should still yield reasonable results. Please let us know if you’re interested in trying GWB14. I’m happy to send you a demo. You can read about the feature in section 2.5.8 Polydentate sorption in the GWB Essentials Guide. Regards, Brian
  7. Last week
  8. I understood what was happening - I did not have any log K's set. Honestly, I just calculated with the help of Rxn the value of log K for 25 degrees, based on the known values for H2O b SiO2. Apparently this is not possible?
  9. Thank you very much for your answers. I have one more question. I introduced a new component of an aqueous solution (H4SiO4) at TEdit. And I wanted to calculate Log K's for him in Rxn. However, in Rxn it is not in the "Balance reaction for" list. What am I doing wrong?
  10. Dear Brian, Thanks for your kind response. I have already saved as a .tdat file in replace of .lnk file (a shortcut). Please refer to the attachment. Yes, I also ensured that the dataset and spreadsheet were using the same exact set of reactions and log K values. Can you explain why you’ve set your calculation up with trace quantities of all your basis entries, then titrated large amounts of all your minerals of interest? à The trace quantities of radionuclides need to be input in the dialog box as reminder before calculation. Actually, the concentrations of radionuclides within the spent nuclear fuels are quite low in case of copper canister corrosion resulted from the groundwater intrusion. The input values in the basis entries were just hypothetical and indicated very low concentrations of nuclides and “0 (zero)” value was not allowed for solubility calculation. Thanks for your further understanding. Best regards, Polly thermo_phreeqc_Polly.tdat
  11. Hello Mallen, Our records show that your student edition application was approved earlier this month and a new activation code was sent to you. Can you check if you are using the new activation code? If you are still have trouble activating your license, please send an e-mail including your activation code and screenshot of your activation utility to support@gwb.com. Best, Jia Wang
  12. Hello, Today (01/24/2020) I reactivated my account, however it states that the expiration date is Jan 30th 2020 which is a few days away. Can some please aid me with this issue? Best,
  13. Hello Anita, I took a quick look at your input file and here are a couple of suggestions to help you get started. It seems like you are trying to model a continuously leaking point source contamination for 1 year. However, I notice that in your Intervals pane, you are only setting a one day reaction interval for the 'contaminated' fluid to enter your system at the inlet and the remaining time flushing the system with dilute fluid. If the goal is to simulate a continuously leaking source of contamination at the inlet, then you should remove the second reaction interval from your simulation and allow for the contaminated fluid flow into the system for a full year. To quickly remove any reaction interval period in your Intervals pane, you can simply click to select it and then click the delete button. I deleted the reaction interval that set the inlet fluid as the dilute fluid (named 'fluid 2') and that allow the model to run to completion. For more information on setting boundary conditions and reaction intervals, please refer to section 2.10 and 2.9 in the Reactive Transport User's Guide. You might also be interested in looking at X1t examples listed in section 3.5. The input file corresponding to each example in section 3.5 is available in the GWB installation subdirectory 'Script'. Hope this helps, Jia Wang
  14. Hello Ulagai, On another thought, I think you will find Rxn useful. You can calculate the equilibrium equation for dolomite (CaMg(CO3)2) using Rxn and make the activity-activity plot manually. To do so, you would open up Rxn and balance the reaction for Dolomite. When you select dolomite, Rxn will automatically balance dolomite in terms of the original basis species, which is Ca++, Mg++, H+, and HCO3-. You can have Rxn write the equilibrium equation in terms of CO3-- by swapping it with HCO3-. If you wish, you can then enter the activity value for CO3-- and have the equation be simplified and solve for log[Mg++] + log[Ca++], which equivalent to the y-axis of the plot you attached. Please refer to section 4.2 Calculating equilibrium equations in the GWB Essential guide for more information and examples. Hope this helps, Jia
  15. Hi again Dave, Upon closer inspection, you can include a user-defined analyte in a radial plot as long as you put it in the "Components in fluid" category, since this is where the normal basis species plot in Gtplot. If you instead choose a category like "Chemical parameters" and pick Concentration for the dimension, it won't be recognized by the water chemistry plots. Still, if you want to do any thermodynamic calculations including Be, you'll need to use a dataset that includes the relevant reactions. Hope this helps, Brian
  16. Earlier
  17. Hi Dave, The radial diagram can plot uncharged species when you choose units like mg/l, as you've done. However, the special plots, including the radial plot, only diagram basis and redox species in your spreadsheet. They do not include user-defined analytes. User analytes can only be plotted in xy plots. You might try using a different thermo dataset, like thermo.com.V8.R6+.tdat. That has Be++ as a basis species. Or, you can modify the thermo dataset you're using by adding the element Be and any species that you need, then load that dataset into GSS. Hope this helps, Brian Farrell Aqueous Solutions LLC
  18. I am trying to plot an uncharged species using the Radial Plot. The uncharged (Be) species will not show up in my Available list. I am using GWB 11, I have the units changed to mg/L (since there is no charge). I even tried adding a new user defined species with units of concentration, this species also will not show up. See below and please advise
  19. Hi Reedhopk, I am glad to hear that it is working now. Best regards, Jia
  20. Hello Ulagai, You can set activity ratios (e.g. aK+/aH+) in the x and y axes but cannot simply raise the activity of species to a certain power. Please see section 5.1 Diagram calculation in the Essentials User Guide for examples. You can use the suppress function to suppress minerals that are unlikely to be forming in your system. To suppress minerals, go to 'Config' --> Suppress and select the minerals/species you wish to suppress. For more information regarding the the suppress feature, please refer to the GWB Command Reference guide. Hope this helps. Best regards, Jia Wang
  21. hi~ I'm just beginning to learn GWB. I am confused about the boundary condition setting of a single point source pollution for one-dimensional mass transport. Attached are the questions and the setting of X1t simulation parameters. Maybe I guess there are something wrong on the Intervals pane, so it can't be runing. But I don't know how to modify the setting. Could you please help me, thank you. Question of non-reactive one-dimensional solute transport.pptx 1D nonreact-2.x1t
  22. Thank you, the activation worked on my new computer.
  23. Hello Reedhopk, I am sorry to hear about your computer issues. I have reset your license and you can try activating on your new computer again. Best regards, Jia
  24. Thank you, Jia. This worked great. Looking forward to moving forward.
  25. My laptop with GWB student edition broke and no longer turns on. I now have a new laptop, and I need some way to activate GWB student on the new laptop. The old activation code no longer works, since it was used for the old laptop. Is there some way to cancel the activation on the old laptop or receive a new activation code?
  26. Hello. I want to build in Act2 a graph of this kind as in the attached image. The question is how do I set the values for the axes: Y - log [Ca2 +] * [Mg2 +], X - log [CO32 -] ^ 2? The second question is, as I understand it, the program itself selects mineral phases from the database depending on the set of components. Can I forcibly ban the display of certain minerals on the diagram, or is it necessary to remove them from the database?
  27. Hi Luis, Happy new year to you too! Unfortunately, there’s not a set equation to calculate the concentration of these species. If you would like more information on the calculations and the methods used, please refer to the Geochemical and Biogeochemical Reaction Modeling text. Best regards, Jia Wang
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