Agricultural by-product biomass for removal of pollutants from aqueous solution by adsorption

Abstract

In this work author presented the up-to-date development on the various non-conventional low cost biomass adsorbent for the removal of inorganic/organic pollutants from aqueous solution. Author also presented the adsorptive properties of various agricultural by-products such as rambai tree leaves in the removal of Hg (II), castor hull in Zn (II) and Cd (II) removal, physic seed in heavy metal ion removal and finally pine cone biomass in the removal of dye and surfactants from their aqueous solution. This was studied by laboratory batch adsorption kinetic and equilibrium experiments. It was found that the implied mechanisms in this adsorption differ qualitatively and quantitatively according to the type of biomass, its origin and its processing. The results showed that the amount of adsorption of inorganic/organics depends on various physico-chemical factors such as inorganic/organic ion concentration, contact time, solution pH, temperature and the amount of adsorbent. Overall the kinetic studies showed that the adsorption process followed pseudo-second-order kinetics and it is a two steps process, a very rapid adsorption of ion to the external surface is followed by possible slow decreasing intraparticle diffusion in the interior of the adsorbent.