01 - Fit Kinetics
This example corresponds to the an example from Phreeplot manual (Kinniburgh, D., & Cooper, D. (2011). PhreePlot: Creating graphical output with PHREEQC).
This example fits lab data by adjusting the logK on the Quartz rate sorption.
Studies
This project contains 2 Studies.
PhreeqcStudy: “study_01 - Fit Kinetics”
Db used: “wateq4f_dat” database
# Kinetics of quartz dissolution
# from Appelo 'Get-going sheet #11'
#TRANSPORT
# -initial_time 0
RATES
#1 dQu/dt = -k * (1 - SR(Quartz). k = 10^-13.7 mol/m2/s (25 C)
#2 parm(1) = A (m2), parm(2) = V (dm3) recalculate to mol/dm3/s
Quartz # rate name
-start
10 moles = parm(1) / parm(2) * (m/m0)^0.67 * 10^@{$log_k$}@ * (1 - SR("Quartz"))
20 save moles * time # integrate. save and time must be in rate definition
-end # moles count positive when added to solution
KINETICS # Sediment: 100% qu, grain size 0.1 mm, por 0.3, rho_qu 2.65 kg/dm3
Quartz # rate name
-formula SiO2
-m0 102.7 # initial moles of quartz
-parms 22.7 0.162 # parameters for rate eqn. Here:
# Quartz surface area (m2/kg sediment), water filled porosity (dm3/kg sediment)
-steps 1.5768e8 in 100 steps # 1.5768e8 seconds = 5 years
-tol 1e-8 # integration tolerance, default 1e-8 mol
INCREMENTAL_REACTIONS false # start integration from previous step
SOLUTION 1
END
/n
CeresStudy: “CeresStudy”
Plots
This project contains 1 Plots.
Plot 1: “Quartz dissolution”
