maki

Dear Brian, Thank you for your advice. I'll try to do that. Best regards, Maki

Hi, I apologize for my poor English in advance. I have some questions about χ and m values in the kinetic of microbial reaction of React software. I am referring to the two articles to understand the logic of the input values, which are Jin and Bethke, 2005 and Bethke et al, 2011. Article1. Jin and Bethke (2005) Geochimica et Cosmochimica Acta Vol. 69(5) pp. 1133-1143. Article2. Bethke et al. (2011) American Journal of Science Vol. 311 pp.183-210. Q.1 In the case of SO4 reduction consuming H2, the article1 used (m, χ) = (1/3, 2), and the article2 used (1, 6), respectively. If the article2 considered four H2 (p. 188 and p. 192), I thought that (m, χ) = (4/3, 8) should be adopted based on the values of the article2 which considered one H2 (p. 1136). Could you help me understand the logic of that? Instead of four times, why does it three times? Q.2 I could not lead same values as Table 3 of the article2 using Table 1 and the information written in the section of 3.2. Thermodynamic Parameters of the article1 in each of microbial reactions. Why was the m value in methanogenesis 1/4 not 2/9? How about other reactions? I’m looking forward to hearing from you. Best regards, Maki

Hello. I am conducting basic practice for GWB. Now I want to calculate the pH of the solution comprised of some aqueous species using SpecE8. Composition: Na+: 1000 mg/L K+: 30 mg/L Mg++: 300 mg/L Ca++: 2000 mg/L Cl-: 500 mg/L SO4--: 500 mg/L HCO3-: 3000 mg/L Although I gained the result of calculation regarding almost all of the System parameters, the value of pH wasn't be shown. How can I gain the value of pH in this case? Many thanks, maki

Hi, Brian. Thank you for your advice. According to your suggestion, I have conducted many trials while varying the concentrations of Cl- and Na+ and swapping Fe++ to Pyrite or Fe++ to Hematite with SO4-- to Pyrite, and so on. However, the program has not worked yet. Although I didn't understand the reason and the process, the error messages depended on the combination of the Cl- and Na+. If you have any other idea to run the calculation, could you give me that? Thank you for your time. Best regards, Maki

Thank you for the response. I posted my scripts (v01, with minimum conditions provided by the paper; v02, with additional parameters demanded by the program). Note: In the paper, specific surface area used is 58.7 m2 m-3. On the other hand, in the X1t, I input the value as 0.587 cm2 g-1 without considering the density of pyrite. Best regards, maki 1-D_pyrite_oxidation_v01.x1t 1-D_pyrite_oxidation_v02.x1t

Hi. I am trying to reproduce the simulation of pyrite oxidation in 1-D porous media flow system by Xu et al (2000) for the training of GWB. Given conditions for the simulation are as below, only. [Domain] length (x), 2m; height (z), 1cm; width (y), 1.0 cm; nodes, 40; discharge, 0.02m/day [Medium] porosity, 40% [Reactants] Kinetic; Pyrite, 9 volume% surface area, 0.587 cm2/g rate constant, 4e-15 mol/cm2 sec, or (range from 2e-17 to 2e-14 mol/cm2 sec) [initial] O2(aq), 1.0e-70 mol/L time, 3 days [inlet] O2(aq), 2.53e-4 mol/L Although I conducted the X1t simulation, I cannot acquired the result; even if I tried the simulation with the addition of the values of Fe++ and SO-- (demanded by the program), H+(initially pH 7, maybe), Na+ and Cl- (demanded by the program for charge balance) and so on, according to error messages. Final error message is about large residual, and of course no plot data. The result of the paper shows that the pH value of the water changed from nutrality to around 3.8. I hope to acquire the result of the variation of pH derived from pyrite oxidation with time. How should I deal with this case? Reference Xu et al (2000) Transport in Porous Media 39: 25-56.