Abstract:
Coir pith was used as an alternative to commonly available adsorbents for heavy metal ion removal
from aqueous solutions. Batch and fixed bed column experiments were conducted to study adsorption
characteristics of Cd and Pb onto coir pith. Coir pith is an effective adsorbent for Pb and Cd removal.
The adsorbent dose, metal ion concentration and the solution pH affects the degree of adsorption. The
maximum adsorption was observed at solution pH values above 5. The equilibrium data was satisfactorily
fitted to Langmuir and Freundlich isotherms. Pb showed higher adsorption capacity compared to Cd
under the experimental conditions. Kinetic studies revealed that Pb and Cd uptake was fast within first
10 to 15 min of contact time and data fits to pseudo second-order model. Breakthrough curve data fits
to linear Bed Depth Service Time (BDST) model and bed capacities for Pb and Cd were 41 and 28 mg/
g of coir pith respectively.
