Dear all,
I am just starting to use the program. So, I am wondering some questions about it. I am grateful if anyone explain clealy my questions.
1.In CXTFIT, does it could estimate non-linear sorption isotherm, i.e. Freundlich or Lanmuir?
2.In non-equilibrium sorption, after I choose non-eqilibrium CDE, how should i do if i want to fit paremeters for physical non-eqilibrium or chemical non-eqilibrium?
3.Is it possible to compare the results from CXTFIT with hydrus 1d or hydrus 2d (in mode of non-equilibrium) ?
Thank you for your assistance
Best regards,
Srilert
CXTFIT and equilibrium sorption
Dear Srilert:
1.In CXTFIT, does it could estimate non-linear sorption isotherm, i.e.
Freundlich or Lanmuir?
No, CXTFIT is based on analytical solutions for the linear CDE in terms
of concentration. Analytical solutions can derived only for the linear
CDE. Hence, the solutions are only for the linear sorption.
2.In non-equilibrium sorption, after I choose non-eqilibrium CDE, how
should i do if i want to fit parameters for physical non-eqilibrium or
chemical non-eqilibrium?
As described in p.15-19 in the manual, chemical and physical
nonequilibrium models reduce to the same dimensionless form. Input
parameters are listed in Table 6.6 and nondimensional parameters are
described in Table 3.1.
3.Is it possible to compare the results from CXTFIT with hydrus 1d or
hydrus 2d (in mode of non-equilibrium) ?
Yes, it is possible for the steady-state flow with linear adoption.
Again, CXTFIT is based on analytical solutions for the equilibrium
and nonequilibrium CDE, while HYDRUS numerically evaluates CDE.
If any further questions, please do not hesitate to ask me.
Regards,
Nobuo
1.In CXTFIT, does it could estimate non-linear sorption isotherm, i.e.
Freundlich or Lanmuir?
No, CXTFIT is based on analytical solutions for the linear CDE in terms
of concentration. Analytical solutions can derived only for the linear
CDE. Hence, the solutions are only for the linear sorption.
2.In non-equilibrium sorption, after I choose non-eqilibrium CDE, how
should i do if i want to fit parameters for physical non-eqilibrium or
chemical non-eqilibrium?
As described in p.15-19 in the manual, chemical and physical
nonequilibrium models reduce to the same dimensionless form. Input
parameters are listed in Table 6.6 and nondimensional parameters are
described in Table 3.1.
3.Is it possible to compare the results from CXTFIT with hydrus 1d or
hydrus 2d (in mode of non-equilibrium) ?
Yes, it is possible for the steady-state flow with linear adoption.
Again, CXTFIT is based on analytical solutions for the equilibrium
and nonequilibrium CDE, while HYDRUS numerically evaluates CDE.
If any further questions, please do not hesitate to ask me.
Regards,
Nobuo
All HYDRUS models can handel both physical (mobile and immobile water content model) and chemical (two-site sorption model) nonequilibrium, as well as nonlinear sorption.
For mobile-immobile model you need to specify "ThetaIm" (immobile water content) and "Frac" (fraction of sorption sites in contact with mobile water).
For two-site sorption model, "ThetaIm" must be equal to zero and you need to specify "Frac" (fraction of equilibrium sorption sites).
Jirka
For mobile-immobile model you need to specify "ThetaIm" (immobile water content) and "Frac" (fraction of sorption sites in contact with mobile water).
For two-site sorption model, "ThetaIm" must be equal to zero and you need to specify "Frac" (fraction of equilibrium sorption sites).
Jirka