Equilibrium concentration Ce is the concentration of adsorbate that you measured   after shaking at  limiting time . When amount adsorbed equals Qe,you can find equilibrium concentration by measuring the solute concentration(Adsorbate) remaining in solution at equilibrium time.Firstly,you must to fix the reaction at a given time(equilibrium time).

     For determination of equilibrium time ,you have to prepare a set of suspensions . Also,you must to adjust temperature of shaker waterbath.Within shaking  , you have to remove adsorbent by either filtration or centrifugation and analyze the remaining adsorbate concentration in solution. In the same manner  remove another suspension at desired time intervals (usually 5-10 min intervals) and measure the remaining adsorbate concentration. Then  plot of Q vs  time (t). From graph find the time that Q value become constant. this time is the equilibrium time.

   Equilibrium concentration Ce is the concentration of adsorbate that you measured   after shaking at  limiting time . When amount adsorbed equals Qe,you can find equilibrium concentration by measuring the solute concentration(Adsorbate) remaining in solution at equilibrium time.Firstly,you must to fix the reaction at a given time(equilibrium time).

     For determination of equilibrium time ,you have to prepare a set of suspensions . Also,you must to adjust temperature of shaker waterbath.Within shaking  , you have to remove adsorbent by either filtration or centrifugation and analyze the remaining adsorbate concentration in solution. In the same manner  remove another suspension at desired time intervals (usually 5-10 min intervals) and measure the remaining adsorbate concentration. Then  plot of Q vs  time (t). From graph find the time that Q value become constant. this time is the equilibrium time.

Hello Fathima,

Please see these instructions which might help

https://chemistry.stackexchange.com/questions/14244/how-to-determine-langmuir-adsorption-isotherm-constants-and-use-the-models

http://www.chemistrylearning.com/langmuir-adsorption-isotherm/

Hi,

The perfect answer which introduced from prof. Hassan Alshamsi . Thus, check the file as practice for your to enhance your skills to complete all calculations.

Regards,

I AGREE WITH DR. Hassan Alshamsi 

REGARDS

The accuracy of determining qe depends on the time of the batch experiment. The longer it takes the better, but you can not overdo it. Having enough experimental points (at least 7), you can approximate them with exponential or hyperbolic function and set the upper limit of these functions. When determining the parameters of the Langmuir equation, avoid its linear forms. Regards,

@ Qhatan Adnan Yousif thanks for those pdfs. They were really helpful.