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Heavy metal biosorption potential of a Malaysian Rhodophyte ( Eucheuma denticulatum ) from aqueous solutions
Rahman, Md. S. & Sathasivam, K. V.
Abstract
Biosorption is a promising technology for the
removal of heavy metals from industrial wastes and effluents. In the present study, biosorption of Pb2+, Cu2+, Fe2+
and Zn2+ onto the dried biomass of Eucheuma denticulatum (Rhodophyte) was investigated as a function of solution pH, contact time, temperature and initial metal ion
concentration. The experimental data were evaluated by
Langmuir, Freundlich, Temkin and Dubinin–Radushkevich
isotherm models. The sorption isotherm data followed
Langmuir and Freundlich models, and the maximum
Langmuir monolayer biosorption capacity was found as
81.97, 66.23, 51.02 and 43.48 mg g-1 for Pb2+, Cu2+,
Fe2+ and Zn2+, respectively. The sorption kinetic data
followed pseudo-second-order and intraparticle diffusion
models. Thermodynamic study revealed feasible, spontaneous and endothermic nature of the sorption process.
Fourier transform infrared analysis showed the presence of
amine, aliphatic, carboxylate, carboxyl, sulfonate and ether
groups in the cell wall matrix involved in metal biosorption
process. A total of nine error functions were applied in
order to evaluate the best-fitting models. We strongly
suggest the analysis of error functions for evaluating the
fitness of the isotherm and kinetic models. The present
work shows that E. denticulatum can be a promising low-cost biosorbent for removal of the experimental heavy
metals from aqueous solutions. Further study is warranted
to evaluate its potential for the removal of heavy metals
from the real environment.
Keywords
Eucheuma denticulatum; Biosorption; Heavy metals; Fourier transform infrared; Error functions; Malaysia
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