TITLE:
Removal of Cu(II), Pb(II) and Zn(II) Ions from Aqueous Solutions Using Selected Agricultural Wastes: Adsorption and Characterisation Studies
AUTHORS:
Siti Najiah Mohd Yusoff, Azlan Kamari, Wiwid Pranata Putra, Che Fauziah Ishak, Azmi Mohamed, Norhayati Hashim, Illyas Md Isa
KEYWORDS:
Adsorption; Characterisation; Metals; Durian Tree Sawdust; Coconut Coir; Oil Palm Empty Fruit Bunch
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.4,
March
25,
2014
ABSTRACT:
The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil
palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II),
Pb(II) and Zn(II) ions from aqueous solutions was investigated. The effects of
solution pH and initial metal concentration on adsorption capacity were
examined in batch experiments. The affinity and the adsorption capacity of DTS,
CC and EFB were evaluated. The adsorption behaviour of Cu(II), Pb(II) and
Zn(II) ions onto DTS, CC and EFB was described using Freundlich and Langmuir
isotherm models. The separation factor (RL)
analysis suggests that the removal of metal ions onto three agricultural wastes
studied was favourable. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II)
and Zn(II) were 18.42, 20.37 and 22.78 mg/g for DTS, 18.38, 37.04 and 24.39
mg/g for CC, and 26.95, 37.59 and 21.19 mg/g for EFB, respectively. The
characterisation studies were carried out using Scanning Electron Microscope
(SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform
Infrared Spectrometer (FTIR). The surface morphology of the biosorbents changed
significantly following interaction with metal ions. The primary adsorption
mechanism was complexation between metal ions and binding sites of biosorbents.
Both hydroxyl and amine groups are the main binding sites in DTS, CC and EFB.