PhreeqcUsers Discussion Forum

Conceptual Models => Design of conceptual models => Topic started by: mcossio23 on November 27, 2017, 04:50:58 AM

Title: CO2 degassing
Post by: mcossio23 on November 27, 2017, 04:50:58 AM
Hi guys,

I am new to the forum and also relatively new to PHREEQC. I am in process of modelling Calcite precipitation in high salinity waters. These waters have been aerated to promote pH increase and calcite precipitation via CO2 degassing. So far, I have solution data and equlibrium_phases data. I am aware that you could gradually add O2(g) to your solution;however, I am not entirely sure how/if CO2(aq) to CO2(g) via aeration can be modeled. It would be greatly appreciated if any of you guys could provide me with some hints. Thank you so much

Regards,
Manny
Title: Re: CO2 degassing
Post by: dlparkhurst on November 27, 2017, 04:14:12 PM
You can either remove CO2 with REACTION (or KINETICS)

REACTION
CO2  -1
1 mmol in 2 steps

Or you can set the partial pressure of CO2, logically to atmospheric CO2 if you are using air to strip the CO2

EQUILIBRIUM_PHASES
CO2(g) -3.4 10