Abstract

In the present investigation, the biosorption is carried out in a batch process to test the suitability of abundantly and freely available plant based material, Erythrina variegata orientalis (Indian coral tree) leaf powder, as an adsorbent for removal of Zn(II) from aqueous solution. The influence of various process parameters like agitation time, adsorbent size and dosage, pH of the aqueous solution and initial zinc concentration is studied. It is observed that there is a significant  increase  in  percentage  removal  of  Zn(II) as pH increases from 2 to 3 and attains maximum when pH is 7. The agitation time is to be 60 min. The Langmuir isotherm is more suited for biosorption followed by Freundlich isotherm. The biosorption of Zn(II) follows pseudo-second-order kinetics and is exothermic, irreversible and spontaneous.

Key words: Biosorption, zinc, leaf powder, kinetics.