Equilibrium, Kinetic and Thermodynamic Studies Of Lead (II) Sorption on Hydrolyzed Starch Graft Copolymers

Hydrolyzed starch graft poly (acrylic acid) and

starch graft poly(acrylonitrile) copolymers were used as a

sorbents for the removal of Pb(II) from aqueous solution in

batch process. The sorbents were characterized by scanning

electron microscopy, Fourier transform infrared spectroscopy

and thermogravimetric analysis. The effect of contact

time, initial concentration and temperature were assessed to

optimize the conditions for maximum sorption of the metal

ions. The experimental data were analyzed by Langmuir,

Freundlich, Temkin, Dubinin Radushkevich and Sips isotherm

models. The Freundlich and the Sips isotherms confirmed

the applicability of the models. The sorption capacity

of the sorbent was found to be 118.61 mg/g for starch

graft poly (acrylic) acid and 115.83 mg/g for starch graft

poly (acrylonitrile). The Sorption kinetics was assessed by

Lagergren pseudo first order, pseudo second order, Elovich

equation, Intraparticle diffusion and the liquid film diffusion

models. The experimental data fitted very well with

the Elovich equation and the Intraparticle kinetic models.

The thermodynamic analysis showed that the sorption was

a spontaneous and endothermic process. The results indicated

that starch graft copolymers can be used as an effective

sorbents for Pb (II) removal from aqueous media.