TITLE:
Biosorption Isotherms and Kinetics Studies for the Removal of 2,6-Dichlorophenolindophenol Using Palm Tree Trunk (Elaeis guineensis)
AUTHORS:
Marcel Cédric Deussi Ngaha, Lydiane Ghislaine Djemmoe, Evangéline Njanja, Ignas Tonle Kenfack
KEYWORDS:
Biosorption, Palm Tree Trunk, 2, 6-Dichlorophenolindophenol, Isotherms, Kinetics, Desorption
JOURNAL NAME:
Journal of Encapsulation and Adsorption Sciences,
Vol.8 No.3,
September
12,
2018
ABSTRACT: In this
work, the potential of natural and pretreated palm tree trunk (PTT) as agents
for adsorption of an organic dye, 2,6-dichlorophenolindophenol (2,6-DCPIP) from
aqueous solutions was probed. Natural and acetic acid treated PTT were
characterized by Fourier transform infrared (FT-IR) spectroscopy and by the
point of zero charge (pzc). The biosorption of 2,6-DCPIP was investigated in
batch mode using natural and treated PTT. This study was achieved by
highlighting several parameters such as the contact time, biosorbents dosage,
the initial concentration of 2,6-DCPIP, the pH of the solution, the ionic
strength and the interfering ions. The results showed that 2,6-DCPIP was
successfully adsorbed from aqueous solutions by natural and treated PTT. The
equilibrium was attained after 40 minutes for treated PTT and 20 minutes for
natural PTT. The maximum capacity of adsorption was obtained at pH = 2. The
adsorption isotherms were investigated and it was found that the experimental
data were best described by the Dubinin-Radushkevich isotherm for the natural
PTT (R2 = 0.979) and by the Temkin isotherm for the treated PTT (R2 = 0.976). The maximum adsorption capacities determined by Langmuir isotherm
were found as 108.932 and 157.233 μmol·g–1 for natural and treated
PTT, respectively. The adsorption kinetics was analyzed and was best described
by the pseudo-second order model (R2 ≥ 0.998). The diffusion
mechanism was studied and the result showed that external mass transfer is the
main rate controlling step. The desorption of 2,6-DCPIP is favorable in alkaline
medium.