TITLE:
Characterization of Cassava Root Husk Powder: Equilibrium, Kinetic and Modeling Studies as Bioadsorbent for Copper(II) and Lead(II)
AUTHORS:
Kaupa Philip, Rebecca Jacob, Janarthanan Gopalakrishnan
KEYWORDS:
Bioadsorption, Langmuir Isotherm, Freundlich Isotherm, Pseudo-First-Order Kinetics, Pseudo-Second-Order Kinetics, Cassava Root Husk, Molecular Modeling
JOURNAL NAME:
Journal of Encapsulation and Adsorption Sciences,
Vol.11 No.2,
June
8,
2021
ABSTRACT: This study was aimed to investigate Pb(II) and
Cu(II) ions removal ability from aqueous solution by cassava root husks (CRH)
as a cheap, sustainable and eco-friendly
bioadsorbent. The CRH was characterized by Fourier Transform Infrared (FTIR)
spectroscopy which indicated the availability of various functional groups for
metal coordination and the result was supported by elemental analysis studies.
UV-Visible spectral studies indicated the presence of oxalate () and it could possibly interact with metal ions to
give rise to a stable chelated coordination complex which affects metal ions
removal efficiency. Bioadsorption process was carried out as a function of
metal concentration, contact time, pH of the solution, particle size, and dosage of the
adsorbent. Experimental results indicated the optimal adsorption condition of
pH 4 for both Pb(II) and Cu(II) ions, dosage of 0.1 g/0.1L and 1 g/0.1L for Pb(II) and Cu(II) ions respectively,
adsorption equilibrium time of 2 and 25 minutes for Pb(II) and Cu(II)
respectively, and concentration of 0.5 mg/L for both metal ions. Kinetic data
best fitted
pseudo-second-order model and not the pseudo-first-order model. Equilibrium data best
fitted the Freundlich model than the Langmuir model. Specific surface area and pore volume studies indicated
that CRH is non-porous and hence rapid adsorption kinetics is expected.
Supporting the experimental results, molecular modeling studies performed using
Schrödinger software predicted several sites in the structure capable of
docking with metal ions.