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Journal of Applied Sciences and Environmental Management
World Bank assisted National Agricultural Research Project (NARP) - University of Port Harcourt
ISSN: 1119-8362
Vol. 12, No. 1, 2008, pp. 93-100
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Bioline Code: ja08014
Full paper language: English
Document type: Research Article
Document available free of charge
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Journal of Applied Sciences and Environmental Management, Vol. 12, No. 1, 2008, pp. 93-100
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Laterite-A Potential Alternative for Removal of Groundwater Arsenic
Rahman, I.M.M.; Iwakabe, K. & Kawasaki, J.
Abstract
Arsenic removal by heat treated laterite from contaminated water was investigated through
batch adsorption experiments. The removal rate was dependent on the initial arsenic concentrations and a high
initial rate of removal followed by a slower subsequent removal rate with a gradual approach to a steady-state
condition. Rate kinetics was studied using both first-order and pseudo-second order models, and intraparticle
diffusion from the solution to the adsorption sites was considered as major rate controlling step. Adsorption
equilibrium data pointed to favorable adsorption of arsenic onto laterite and fitted with both Langmuir and
Freundlich models. Thermodynamic data suggested chemical nature of the adsorption. Experimental data were
used to estimate the life-time of laterite as a column packing-adsorber with the simplest assumptions and for
typical initial concentration (∼0.30 mg L-1 arsenic) it was 74 days maximum while to achieve WHO safe limit
(0.01 mg L-1). Laterite is a natural substance and can be collected very cheaply, so its utilization for arsenic
removal is expected to be economical and feasible. It might be a promising alternative of other proposed arsenic
removal media for the arsenic-affected region of the world.
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© Copyright 2008 - Journal of Applied Sciences & Environmental Management
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