32-40Bagasse pith, a sugar industry waste, has
been converted into sulphurised activated carbon by carbonisation at 200°C under
N2 for 2h, followed by steam activation in presence of SO2
and H2S at 400°C for 2h. The adsorption characteristics of Pb(II) ions
on activated carbon have been examined from aqueous solutions using batch
technique. The effect of agitation
period, initial concentration of sorbate,
pH, ionic strength, temperature and particle size of the adsorbent has been
studied to optimise the conditions for maximum removal of Pb(II) ions. The maximum
removal takes place in the pH range of 4.0-8.0.With an initial concentration
of Pb(II) at 50 mg/L at 30°C and pH 6.0, its removal has been found to be
99.8%. The process of uptake is governed by a pseudo-second-order kinetics. Kinetic
parameters as a function of initial concentration and temperature have been calculated.
Decrease in ionic strength and increase in temperature of the solution has been
found to improve the uptake of Pb(II). Studies show that the adsorption decreases
with an increase in particle size of the adsorbent. Sorption data of Pb(II) in
the concentration range 50-1000 mg/L have been correlated with Langmuir isotherm
model. Sulphurised activated carbon had adsorption capacities for Pb(II) from
200.08 mg/g at 30°C to 243.93 mg/g at 60°C, which is much higher than the values
for the adsorbent materials reported in the literature. The adsorbent has been
satisfactorily used for the removal of Pb(II) from synthetic wastewaters. The adsorbed
Pb(II) ions are completely recovered with 0.2 M HCl