shensel

Ah of course, that solves my problem. Thank you!

Hi Jia, Thank you for the reply. I am trying to find a way to add molybdenum to the dataset so that I can add a surface species with my lab Kd data incorporated. I cannot find molybdenum in the Kd.sdat file, nor a way to add it (the add button is greyed out). Maybe I am going about this wrong? Thanks, Scott

Hello, I have laboratory Kd data for molybdenum that I would like to incorporate into a model, but don't see a way to add molybdenum to the Kd.sdat file. Is this possible to do with GWB? Thanks, Scott

Hello, just checking in on this. Thanks!

Ah yes that makes sense. Thank you!

Hi Jia, Thank you for the clarification, that is a much better description of the boundaries than what I described at first. However I am confused by your statement quoting my initial question that aqueous species never do not form at all. Could you please provide some further explanation there? I would expect certain aqueous species to not form at all under certain Eh pH conditions (example: the carbonate ion at pH of 1). Thanks, Scott

Hi Jia, I was referring to Act2, but I'm glad you mentioned Phase2. That is very useful information! I was able to create what I needed. Thanks, Scott

Hello, Given that boundaries drawn between species in Eh pH diagrams represent a 50/50 composition of the adjacent species, is it possible for GWB to create additional lines that show when a species is not favored to form at all, or some sort of other ratio of adjacent species such as 75/25? Thanks, Scott

Fantastic! Thanks to you both.

Hello, My question is regarding the quantification of sorption preferences of metals onto a given surface. If I have both arsenic and molybdenum in groundwater sorbing onto HFO, is there a way to tell which (As or Mo) is thermodynamically more stable after sorption? In other words, would some metals have the potential to 'kick off' others that have already sorbed (or out-compete other ions in the groundwater), and if so how can I tell what would remove what? I could probably test this qualitatively by adding and removing metals to see what happens, but am wondering if there is a way to calculate this a bit more quantitatively. I read the section in Bethke, perhaps comparing the products of the equilibrium constant and the boltzman factor of various surface complexes would tell me what I need? Thanks, Scott

Hello, Is there an available or recommended surface dataset for modeling sorption onto manganese oxides such as birnessite? Thanks, Scott

Hi Brian, I appreciate you keeping me informed. Thanks, Scott

Thanks Brian. A quick update: this doesn't always seem to be the case, though I'm not sure why. I've attached GSS examples of the unit change working correctly. I'll still proceed with the default units for now, but maybe this will help your troubleshooting. CB Test2_ug.L.gss CB Test2_mg.L.gss

Hello, When I calculate the CBE with a sample that has alkalinity as ug/L as CaCO3, it gives a different result compared to the same sample with alkalinity as mg/L as CaCO3 (same concentrations). Is this a bug or am I missing something? Example GSS files are attached. Thanks, Scott Hensel CB Test_ug.L.gss CB Test_mg.L.gss

Thanks so much! This really helped. I believe it was my misuse of iron that had me stuck.

Hi Jia, Thank you for the suggestions. I have now converted both fluids to a relative unit (mol/kg) and have attached an updated X1t file here. I still could not converge a reaction between my two fluids, so I tried them individually in React. I did get my Fluid 1 to converge when balancing on sulfate (among others), but could not get my Initial Fluid to converge. I'm not sure why it isn't working, maybe I'm not representing the system properly somehow? I've attached the React file with the fluid I can't converge. Thanks, Scott Initial Fluid_molkg.rea X1t for Quesiton3.x1t

Hi Jia, Thanks you for the reply and the help. I'm sorry I forgot to attach the thermo database, I've attached it here - it is a converted .geo EQ3/6 database that I believe is fairly similar to the thermo.V8.R6+ database. I've experimented with balancing on different ions and still can't seem to get my Fluid 1 to converge. Perhaps you'll have better luck? I did make a couple other changes to the fluids based on my data, so I've re-attached an updated X1t file here. Thanks, Scott X1t for Quesiton2.x1t data0.geo.tdat

Hello, I'm trying to run a flow path model using X1t and can't seem to get it to converge. I've attached my input files here. Any thoughts on how to fix this? I did get my Initial fluid to converge in React by reducing the alkalinity, but that doesn't seem to work for my Fluid 1 or for the Initial fluid in X1t. Any suggestions would be a great help! Thanks, Scott X1t for Quesiton.x1t

Superb! Thanks, Jia!

Hello, I'm running into an issue with piper plots not displaying properly for non-GWB users when copying as an enhanced meta file into PowerPoint for editing. I've attached a screenshot of this here. Is there a good workaround for this that isn't (for example) using the snipping tool post editing? Thanks, Scott

Hello, Without involving kinetics, what criteria does React use to know when to stop a reaction (i.e. xi=1)? I'm looking to make sure metastable conditions aren't misinterpreted as actual equilibrium. Can I manually react a system indefinitely, or at least until I know that no other reactions will occur? Thanks, Scott

Thanks Brian, that workaround will do just fine.

I see, that makes sense. Thank you!

Hi Jia, Thanks for the reply, that explanation helped quite a bit. So if I'm thinking about this right, H+ is swapped specifically for portlandite because of how H+ relates to OH-, and because OH is in the formula for portlandite? Also thanks for moving my question to the front page, I'll post any future questions there. Thanks, Scott

Hello, I have reacted some water with a mineral assemblage and get negative amounts of H+ and O2 in the "Original Basis" section post reaction. What does this mean? If I then pickup the entire system, it seems that portlandite and magnetite have replaced my H+ and O2 in the Basis tab. Why does this happen? I've attached the .rea and reaction output .txt files here. Thanks, Scott Hensel 01_Minteq_React_output.txt 01_Minteq.rea