The potential to remove Cr (VI) from aqueous solutions through
biosorption using the husk of Bengal gram ( Cicer arientinum ), was
investigated in batch experiments. The results showed removal of 99.9%
of chromium in the 10 mgl-1 chromium solution, the biomass required at
saturation was 1 g mg-1. Kinetic experiments revealed that the dilute
chromium solutions reached equilibrium within 180 min. The biosorptive
capacity of the (bgh) was dependent on the pH of the chromium solution,
with pH 2 being optimal. The adsorption data fit well with the Langmuir
and Freundlich isotherm models. The adsorption capacity calculated from
the Langmuir isotherm was 91.64 mg Cr (VI)/g at pH 2. The adsorption
capacity increased with increase in agitation speed and an optimum was
achieved at 120 rpm. The biosorption of Cr (VI) was studied by Fourier
transform infrared spectroscopy (FTIR), which suggested that the
presence of Cr (VI) ions in the biomass affects the bands corresponding
to hydroxyl and carboxyl groups. Comprehensive characterisation of
parameters indicates bgh to be an excellent material for biosorption of
Cr (VI) to treat wastewaters containing low concentration of the metal