Hello everyone,
I want to apply Temkin model in nonlinear form. I cannot found it in the built-in functions. So please help me how to create a new equation for Temkin model. The equation is
qe=BTln(KTCe)/b
Where:
BT = RT/b
R= universal gas constant (8.314J/mol/K)
T= Temperature at 298K.
Thank You
The correct form of the isotherm is: qe=BTln(KTCe)
The linear form of the isotherm is: qe=BT*ln(KT)+BT*ln(Ce)
or Y=BT*ln(KT)+BT*X
In an Excel data sheet put Ce data in column "A". In column "B" write =ln(A1)
Apply this for all of the cells in column "A".
In column"C" put the "qe" data.
Then plot column "B" vs. column "C"
Right click on the points of the plot and choose "Add Trendline", in the faced page on the bottom select "Display equation on the chart"
You'll see "y=...+...x" on the chart.
The Intercept of the line is BTln(KT), and the slop (coefficient of X) is the BT:
Slope: S=BT
Intercept: I=BT*ln(KT)=S*ln(KT)
or KT=e(I/S)
Thank you for your nice reply. but still, I am facing problem in calculating the values of parameters ( especially 'b'). So please help me in solving this problem. I have attached a copy of my data. and also I need help how to apply the nonlinear form of the model.
Best regards
Please fined the attachment.
The coefficient for non-linear form is quite close to the linear form.
To fit the non-linear form you need to use a software such as Matlab, TableCurve and so on.
qe=48.796*Ln(553.292Ce)
BTW, note that the value of "b" depends on the unit of "R" you use!
Salamolakum sir.
I need your help, once again. A number of authors have cited the following paper for Freundlich model, but I can't find it to download. [ H. Freundlich, Über die adsorption in lösungen (Adsorption in solution), Z. Phys. Chem. 57 (1906) 384–470]. if you found, please send to me on [email protected].
Salaam,
Unfortunately I don't have access to the paper. By the way, as you may aware it is in German.
Hello Sir
Can you please tell me how to do non-linear regression analysis in Langmuir isotherm in Origin? How can I determine the initial values for the parameters i.e lower bound? The equation is qe= qmKCe/(1+KCe) where the parameters are qm, K.
Kindly provide me the steps. I have tried but cannot. Kindly reply Sir
With best regards
Hi dear Shilpi Das,
click on 'Analysis'-->Fitting--->Nonlinear Curve Fit--->Open Dialog.....
then click the down drop in 'Category' and select 'Hyperbola'. then in 'Function' down drop choose RectHyperbola' and click Fit button. exactly the same function is used for Nonlinear pseudo-second-order kinetic model. I have attached my articles, the first one gives nonlinear isotherms and kinetic study while the second one gives linear regression analysis, please cite them. thank you.
the equation in origin is y=abx/1+bx, where y=qe, a=qm, b=K, and x=Ce.
Hope I have helped.
Dear Ayub Khan , can you please explain me how to fit Freundlich and Temkin models to my non-linear results?
Best regards!
Freundlich equation in Nonlinear form is easy to apply. follow these steps:
'Analysis'-->Fitting--->Nonlinear Curve Fit--->Open Dialog.....
then click the down drop in 'Category' and select 'Power'. then in 'Function' down drop choose 'Allometric1' and click Fit button. for Temkin fitting, please send me your data. i'll do for you.
Dear Ayub Khan,
It would be really helpful if you could please tell me how to plot the D-R isotherm and the Temkin Isotherm using the NL Fit in Origin software.
Regards
Please follow this paper
Reference
Laxmipriya Panda, Swagat S. Rath, Danda Srinivas Rao, Binod B. Nayak, Bisweswar Das, Pramila K. Misra, Thorough understanding of the kinetics and mechanism of heavy metal adsorption onto a pyrophyllite mine waste based geopolymer, Journal of Molecular Liquids, Volume 263, 2018, Pages 428-441,
https://doi.org/10.1016/j.molliq.2018.05.016.
- Badges
- Science topic