The biosorption of lead(II) and chromium(VI) on groundnut hull was
investigated. Batch biosorption experiments were conducted to find the
equilibrium time and biosorption capacity. Effect of parameters like
pH, temperature and initial metal concentration was studied. The
maximum biosorption capacity of lead(II) and chromium(VI) was found to
be 31.54 \ub1 0.63 and 30.21 \ub1 0.74 mg g-1, respectively. The
optimum pH for lead(II) and chromium(VI) removal was 5 \ub1 0.1 and 2
\ub1 0.1, respectively. The temperature change, in the range of 20 -
45\ubaC affected the biosorption capacity. The maximum removal of
lead(II) was achieved at 20 \ub1 2\ubaC, where as maximum uptake of
chromium(VI) was observed at 40 \ub1 2\ubaC. The biosorption data
was fitted to the Langmuir and the Freundlich isotherm models. The
Langmuir model showed better representation of data, with correlation
coefficient greater than 0.98. The kinetics of biosorption followed the
pseudo second order kinetics model. The thermodynamics parameters were
evaluated from the experimental data