Sorption kinetics of arsenic on laterite soil in aqueous medium.

Sanjoy K Maji, Anjali Pal, Tarasankar Pal, Asok Adak

Index: J. Environ. Sci. Health. A. Tox. Hazard. Subst. Environ. Eng. 42(7) , 989-96, (2007)

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Abstract

The efficiency of a locally available laterite soil in removing both arsenite and arsenate from aqueous medium by adsorption was evaluated. It was observed that in batch experiment conducted at 0.5 mg/L initial concentration of arsenic, laterite soil could remove up to 98% of arsenite and 95% of arsenate under optimized conditions. The kinetic profiles under various conditions were developed. Both arsenite and arsenate removal followed pseudo--second order reaction kinetic model. Pore and film diffusion coefficients were determined from the half-time equation and film diffusion appeared to be the rate-limiting. This was further supported by multiple interruption tests.