71-Removal of toxic metals from water bodies using Saraca indica leaf powder : A novel and cost effective water treatment green technology

Abstract

Competitive biosorption of tri metallic combination [Cd (II), Cr (III) and Ni (II)] on unmodified Saraca indica leaf powder (SILP) was observed and compared with their single metal ion solutions. The adsorption capacities of the metal ions [Cd (II): 0.97 mgg-1, Cr (III): 0.89 mgg-1 and Ni (II): 0.65 mgg-1], when present in combination were tested on SILP. These were found to be lower (10-20%) as compared to single metal ion [Cd (II): 1.19 mgg-1, Cr (III): 1.14 mgg-1 and Ni (II): 0.82 mgg-1] solutions. SILP remove the target metal ions in the selectivity order of [Cd (II)>Cr (III)›Nli (II)]. Regeneration of metal treated biomass was attempted for several cycles with a view to restore the sorbent to its original state. The sorption capacity of the regenerated biomass remained constant after three cycles of sorption process, suggesting that the lifetime cycle was sufficient for continuous application. Kinetic studies revealed that adsorption equilibrium in each case follow first order equation. Experimental findings indicate that SILP has enough potential for the development of a simple, fast and ecofriendly method for decontamination of toxic metals from water bodies.