CHROMIUM (III) ADSORPTION FROM AQUEOUS SOLUTION BY Rhizophora apiculata TANNINS
ABSTRACT: Adsorption of Cr3+
from aqueous solution by Rhizophora
apiculata tannins was investigated in batch shaking experiments. Tannins
extracted from R. apiculata mangrove barks was chemically modified with
formaldehyde in the basic solution of sodium hydroxide. The performance of the
produced adsorbent on the adsorption of Cr3+ was evaluated based on the effect
of several parameters like initial pH, adsorbent dosage, initial Cr3+
concentration and contact time. Equilibrium adsorption data was analyzed by
Langmuir, Freundlich, Sips and Dubinin-Raduskhevich (D-R) isotherms. The
fitness of the isotherms to the
experimental data was determined by
non-linear regression analysis. Adsorption capacity calculated from Langmuir
isotherm was found to be 10.14 mg Cr3+/g of adsorbent at optimum adsorption pH
of 4.5. Mean energy of adsorption with the value of 10.35 kJ/mol indicated that
adsorption Cr3+ on Rhizophora apiculata tannins followed ion-exchange reaction. Kinetic study showed that the
adsorption process followed the pseudo second-order kinetic model.
Author: C.W. Oo and K. Jain
Journal Code: jpkimiagg070016
