The studies of the kinetic and
thermodynamic of the adsorption of malachite
green oxalate onto Periwinkle shell was carried
out. The Periwinkle shell was washed, dried and
carbonized at 400oC. It was ground, sieved and
activated at 800oC. 1000mg of the adsorbent was
mixed with 50ml of 50mg/l of malachite green
oxalate. Six samples were prepared and placed in
a temperature controlled water bath. It was
withdrawn at 30 minutes interval, filtered and the
concentration of the filtrate was determined with a
UV spectrophotometer at 618nm. The adsorption
followed a second order reaction with a
correlation coefficient of 0.999 and rate constant
of 0.1278, 0.1132 and 0.1081g/mg.min at 30, 40 and
50oC respectively. The activation energy, Ea = -
6.85KJ/mol, frequency factor, A = 0.0083(min-1).
The enthalpy change, ?Ho = 19.74KJ/mol, entropy
change, ?So, = 72.21J/mol.K and the change in
Gibbs free energy, ?Go= -1.53, -3.03, -3.13, -3.37, -
3.54 and -3.63KJ/mol. These results show that
activated carbon from Periwinkle shell will be a
good substitute to commercial activated carbon
for the removal of malachite green oxalate from
aqueous solution.