TITLE:
Desorption of Methylene Blue Adsorbed on Activated Carbon from Cocoa Pod Shell
AUTHORS:
David Léonce Kouadio, Yapo Aristide Hermann Yapi, Djedjess Essoh Jules César Meledje, Kacou Alain Paterne Dalogo, Djamatché Paul Valery Akesse, Brou Dibi, Karim Sory Traore
KEYWORDS:
Desorption, Activated Carbon, Methylene Blue, Isotherm, Sodium Chloride
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.13 No.5,
May
11,
2023
ABSTRACT: Environmental protection has become a concern for the world. For this
reason, the objective of this work is to remove methylene blue adsorbed on activated carbon. The coal used comes from cocoa pod
shells. Before pyrolysis, the shells were ground, sieved and impregnated with
orthophosphoric acid. Before desorption, the activated carbons were initially
saturated with MB. These saturated
coals were brought into contact with a sodium chloride (NaCl) solution
and then stirred. The evolution of the resorbed MB concentration was monitored
by spectrophotometry. The desorption tests showed a remarkable elimination from
the first 10 minutes. The desorption kinetics comprises two phases: a rapid
kinetics between 0 and 30 minutes and a slow kinetics between 30 and 60
minutes. The desorption of the dye reaches a concentration aqual to 0.84 mg/l
at pH = 4 at temperature = 80°C. For modeling, the coefficient of the Langmuir
II model is greater than or equal to O.9893. The model of Langmuir III is less
than or equal to 0.9373. The Freundlich model coefficient is 0.9842 or less.
The desorption is thefore carried out on energy-homogeneous adsorption sites
and without any interaction between the adsorbed cations of the dye.
Experimental parameters such as pH, temperature and concentration of sodium
chloride (NaCl) solution influence the desorption of MB. And the model of Langmuir
II describes well the process of desorption of the MB.