formula is ln (qe/(qmax-qe)=(1/n)lnCe +lnKs. I have only Lnce and q values so from where i find qmax in order to linear plot sips model ?
The function you presented is not a "Sips adsorption isotherm linear model" but a non-linear function, implicit with respect to qe and ce. You can get the linear function only after you enter new variables. However, both the error distribution and the statistical distribution of new variables will change. So it is better to use the explicit form of Sips isotherm: qe=f(Ce) and the non-linear method to determine the parameters. However, if you insist on the graphical method, because this is what you are aiming for, then you need to assume the value of qm (can be estimated from the graph qe vs Ce) and see if in the coordinate system ln(qe/(qm-qe)) vs lnCe the points lie along straight line. If not, the qm value must be changed. It's easy to make a mistake here.
Use this reference for help:
Benmessaoud A., Nibou D., Mekatel EH., Amokrane S., A comparative study of the linear and non-linear methods for determination of the optimum equilibrium isotherm for adsorption of Pb2+ ions onto Algerian treated clay, Iran. J. Chem. Chem. Eng., 39 (4) 153-171 (2020).
Perhaps you would share your equilibrium data. Then it's easier to advise something.
Hi, I would like a super help. I got this straight line equation by Sips regression, y = 0.9267x - 2.3143, I'm having difficulty finding the parameters of the equation like, ks and ns. My qmax was 99.35 mg g-1. can anybody help me?
Check this paper, "Characterization and adsorptive behaviour of snail shell-rice husk (SS-RH) calcined particles (CPs) towards cationic dye" doi: 10.1016/j.heliyon.2019.e01153
Alexis, thanks for your paper suggestion, was useful for me.
Dear Alex, thank you for your useful suggestion.
The explanation and interpretation are really useful.